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ANSC 1000 Final Exam Study Guide

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ANSC 1000 Final Exam Study Guide ANSC 1000

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Good luck everyone!
Introduction to Animal Sciences
Dr. Carolyn Huntington
Study Guide
auburn, Auburn University, au, ANSC, ansc1000, animal, Animal Science, Science, 1000, Huntington, final
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This 24 page Study Guide was uploaded by Hannah B. on Wednesday May 4, 2016. The Study Guide belongs to ANSC 1000 at Auburn University taught by Dr. Carolyn Huntington in Spring 2016. Since its upload, it has received 28 views. For similar materials see Introduction to Animal Sciences in Animal Science at Auburn University.

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Date Created: 05/04/16
ANSC 1000 FINAL EXAM STUDY GUIDE PPT. 1: ANIMAL TERMINOLOGY AND ENTERPRISES -animal: a living organism having sensation and the power of voluntary movement and requiring for its existence oxygen and organic food -science: the systematic observation of natural phenomena for the purpose of discovering laws governing those phenomena -animal science: the systematic observation of domesticated creatures used as food by humans for the purpose of discovering laws governing their existence -bullock: male bovine less than 20 months -heiferette: calved, didn't nurse, feedlot -stag: male castrated after sexual maturity -stud: synonymous with stallion; also a place where males are kept -jack: male donkey -jennet: female donkey -mule: jack x mare -hinny: stallion x jennet -kinds of livestock production -purebred or seedstock producers: use intense selection and sell animals or semen -purebred: animals eligible for registry -seedstock: breeding animals -commercial producers: livestock raised primarily for slaughter Page 1 of 24 -types of beef cattle producers -commercial: operation where animals are bred and raised for slaughter -cow-calf: operator raises calf from birth to wean -stocker-yearling: wean to 600-850 lbs. -feedlot: high energy feed to finish to desirable slaughter weight and degree of finish -purebred or seedstock -similar to cow-calf; primarily sell bulls to commercial or other purebred producers -also sell heifers to other purebred producers -may sell semen -beef industry -countries with the most cattle: Brazil, India, United States -states with the most cattle: Texas, Missouri, Oklahoma -types of swine operations -feeder-pig production: producer maintains a breeding herd and produces pigs for sale at an average of 40 lbs. -feeder-pig finishing: feeder pigs are purchased and then fed to slaughter weight -farrow-to-finish: producers maintains a breeding herd; pigs are produces and fed to market weight on the same farm -purebred (or seedstock) operation: similar to farrow-to-finish expect sale is for breeding -swine production -importance of 21-day litter weight -intestines not fully developed to sustain pig with a dry diet -immunity against disease is lowest at 3 weeks of age -last 25 years, number of hogs decreased while pork production has increased -number of hog farms has also declined -countries with the most swine: China, United States, Brazil -states with the most swine: Iowa, North Carolina, Minnesota -sheep production -sheep and goats are closely related -sheep tails go down, goats go up -both provide fiber, milk, hides, and meat -countries with most sheep: China, India, Australia -states with most sheep: Texas, California, Wyoming -types of sheep operations -farm flock: purebred and commercial; primarily in the midwest and west coast; most have <50 head; generally raise more lambs/ewe than range flocks -range flock: most in the west; account for 80% of sheep in US; many have >1000 head -feedlot (not a large industry): many have >1000 head many lambs ready for slaughter at weaning -horse production -two million horse owners, five million people involved in the industry -3.5% of consumer expenditure for recreation spent -no slaughter industry in US -countries with most horses: United States, China, Brazil -states with most horses: Texas, California, Florida -countries with most donkeys and mules: China, Ethiopia, Mexico -dairy production -highly specialized (requires more technical skill than other livestock enterprises) Page 2 of 24 -number of dairy herds decreasing, average herd size increasing, number of dairy cows decreasing, milk production per cow increasing -total US milk production increasing -standard for reporting milk production (305-day 2X ME) -2X = twice daily -ME = mature equivalent adjustment -family dairy produces 16,000-18,000 lbs -corporate dairy produces 27,000-29,000 lbs -countries with most cattle: India, Brazil, China -states with most cattle: California, Wisconsin, New York -countries with most milk production: United States, India, China -evolution of the meat processing industry -1600s: local meat markets in Colonial America -1800s: salting and “packing” of pork for Europe -1865: stockyard opened in Chicago -1870: plants opened in Chicago (Armour & Swift) -1900-1950: little change -1950: processing in cities began to decline -importance of meat -amino acids: animal protein more closely match needs of human body than from plant protein -vitamin b12: required in human nutrition; cannot be adequately obtained from plants -why do we produce livestock? -besides nutritional value… -usually profitable (animal products, food, fiber, by-products) -offers a way to market grain products (we produce more grain than humans can eat) -utilizes land unsuitable for cultivation -provide year-round productive employment -food sources and economics -most human populations consume both plant and animal products -chronic persistent hunger (CPH): long-term issue related to poverty, climate change, political instability, water shortage, soil fertility issues, lack of infrastructure, and illiteracy -famine: limited time issue normally related to infrastructure or production breakdown due to natural disaster, war, drought, etc. -15% of US household are “food insecure” -6% “with hunger” -only 1% of the United States population is active in agriculture -food is becoming more affordable over time in the US -eating less red meat, more poultry and fish -red meat declined due to price, health issues, and acceptance of product -the land-grant system -1862: lincoln created US Department of Agriculture -1862: Morrill Land-Grant College Act -at least one agriculture and mechanics college in each state -1887: Hatch Experiment Station Act -federal grants to states to set up experimental stations for agriculture research -1914: Smith-Lever Act -created federal/state extension service -modern Land-Grant Missions: teaching, research, extension Page 3 of 24 PPT. 2: ANIMAL USE WELFARE -animal exploitation: human use (abuse); dog and cock fights; pain/death for entertainment -animal use: primarily for human use; have guidelines; producers, zoos, hunting, rodeo -animal control: enforce laws, use for research, advocate spay and neuter -animal welfare: humane treatment, try to chance laws, no research, may kill surplus -animal rights: rights like humans; no killing, eating, research, abuse; require spay/neuter -animal liberation: not forced to work or produce for human benefit -welfare concerns -production diseases: liver abscesses in cattle due to high concentration, low roughage -roughages are lower in energy than concentrates -scale effects from large animal units: less individual attention -physical and psychological deprivation from prolonged confinement -cruelty: showing indifference or pleasure in another’s pain or suffering -neglect: failing to provide an animal with vital requirements such as food or shelter -abuse: willfully striking or harming an animal -deprivation: limiting an animals freedom or other like restriction -ethology: the study of behavior of animals in the wild, or laboratory -speciesism: a prejudice or bias toward the interests of members of ones own species -vivisection: act of operating or experimenting on live animals -a society’s interactions and growth is related to the way it treats its’ animals -anthropomorphic: having human characteristics -animal health is non-negotiable in production -animal welfare legislations -1966: Animal Welfare Act (set control of the sale of dogs and cats for research) -1985: amendment to the Animal Welfare Act (minimize pain and discomfort) -1985: mandate to the National Institute of Health (same as above) -1988: Swedish animal rights law that agriculture should be suited to animals nature PPT. 3: ANIMAL BEHAVIOR -psychology: studying learning in humans and applying insights gained from nonhuman animal studies to understanding human behavior -ethology: study of animal behavior in the animals natural environment -instinct: reflexes and behavioral patterns inherently present at birth -habituation: lack of response to a repeated stimulus -conditioning: association between a previously neutral stimulus or behavioral response to a previously significant stimulus -types of conditioning -classical: a formed association btw an unconditioned stimulus and a neutral stimulus -Pavlov’s dog salivating at the sound of a bell -operant: learning to respond to a stimulus as a result of reinforcement when the proper response is made -reasoning: ability to respond correctly to a stimulus the first time a new situation is presented Page 4 of 24 -intelligence: ability to learn to adjust successfully to certain conditions; involve long-term and short-term memory -imprinting: young bond to their caretaker, usually dam -trial and error: trying different responses to a stimulus until the correct response is achieved, gets reward -sexual behavior -cows in heat allow themselves to be mounted -pheromones: chemical substances that attract the opposite sex -flehmen: male animal lifts head and curls upper lip -females receptive for different lengths of time -cows in heat ~12 hours, mares 5-7 days (ovulate during last 24 hrs) -bulls may breed more than one cow or become attached to one -in poultry there must be mutual courtship -extreme sex drive has shown reduced fertility -profound behavioral changes associated with castration -caregiving behavior -females become aggressive in protecting their young shortly after parturition -caregiving declines when young has a reduction in milk consumption -most effective way a dam recognizes her offspring is by smell -agonistic behavior -fight or flight and those of aggressive and passive behavior in physical contact -interaction with other animals -males fight when meet unfamiliar males to point of exhaustion -resident fights more intensely to protect their territory -four stages to establish social dominance: offense, defense, escape, passivity -unfamiliar males “defeated” after they escape and become passive -females have pecking order but fight less often -young animals raised with own species learn social behavior -almost all animals withdraw when sick -animals fed together consumer more than if fed individually -interactions with humans -evaluating posture can help interpret the mood and intent -animals remember positive and negative experiences -most animals have a flight zone -ingestive behavior -exhibited when animals eat or drink -ruminants swallow as soon as food is lubricated with saliva -do not graze far from water -eliminative behavior -cattle, sheep, goats, and chicken void indiscriminately -swine defecate in specific areas -horses void on scent piles of other horses -shelter-seeking behavior -if weather is hot: cattle and sheep seek shady areas, pigs seek wet areas -if weather is cold: pigs crowd against one another -investigative behavior -pigs, horses, and goats are very curious (sheep are more timid) -allelomimetic behavior -“monkey see, monkey do” Page 5 of 24 PPT. 4: GENETICS -zygote is a fertilized egg -starting point of most life cycles -zygote divides many times to produce an adult organism -adult produces gametes that combine to start the process over again -cells: outer membrane, cytoplasm, and nucleus -two processes of nuclear division -mitosis: simple division of one cell into two; the two daughter cells receive an exact copy of genetic material of parent cell -meiosis: genetic material halved so that diploid complement is reformed by fertilization gamete formation in animals -chromosomes separated in both processes -background -nucleus contains rod-like chromosomes -“colored body” with staining -constrictions where point of attachment lie = centromere -chromosomes are in pairs, and each has genes (inheritance) -when cells divide, chromosomes do as well -species and chromosomes -each species has a characteristic number of pairs of chromosomes (total = 46) -poultry = most swine = fewest humans = 23 -mitosis -continuous process with prophase, metaphase, anaphase, and telophase -prophase: centrioles separate and move to opposite poles of cell -metaphase: chromosomes line up at center of cell and become connected -anaphase: sister chromatids separate and are pulled apart -telophase: two new nuclear membranes form -meiosis: -pmat1 and pmat2 -gametogenesis -production of sex cells occurs in the testicle (spermatogenesis) or ovary (oogenesis) -spermatogenesis -process in males where each meiosis produces four equally sized sperm sells -spermatid: lose cytoplasm and develop tail mature into sperm by spermatogenesis -oogenesis -process in females that produces ova Page 6 of 24 -fertilization -when a sperm and ovum unite, each contributes one chromosome to the resulting pair -ovum fertilized —> zygote -zygote is termed diploid (2n), gametes are haploid (n) -gametogenesis reduces the number of chromosomes in a cell to half the diploid number -fertilization reestablishes the normal diploid number (diplo means double) -DNA and RNA -chromosomes consist of deoxyribonucleic acid -segments of DNA are genes -locus: location of gene on chromosome -what is a gene -basic unit of inheritance; short section of a chromosome; segments of DNA -genes and chromosomes -chromosomes in pairs —> genes in pairs -transmission of genes to offspring depends on transmission of chromosomes -DNA -contains deoxyribose sugar, phosphate, and one of four bases -Adenine (A) pairs with Thymine (T) and Guanine (G) pairs with Cytosine (C) -coding -genes code for proteins (made up of 20 amino acids) -amino acids are coded by DNA triplet sequence -protein synthesis -transcription is first step (synthesis of RNA from DNA in the nucleus) -second step (tRNA is coded and moves to cytoplasm —> unites with amino acid) -sex chromosomes -y chromosome is shorter than the x -in chickens and turkeys, the female determines the sex (female has Y chromosome) -homozygous and heterozygous -genes at corresponding loci may correspond two each other in a way that they control a trait (homozygous), or they may contrast (heterozygous) -alleles: occupy corresponding loci, but affect the same character in different ways -genotype is genetic makeup (BB, Bb, bb); phenotype is physical appearance (black or red) -linear interaction: with another gene in the same chromosome -allelic interaction: with its corresponding gene in a homologous chromosome -epistatic interaction: with genes in non-homologous chromosomes -when a gene or gene pair alters or masks the expression of genes on another chromosome -internal factors: hormones; external factors: nutrition, temperature, amount of light -overdominance: a condition where the heterozygous animals are superior to either of the homozygous conditions -heterosis: heterozygotes of breed crosses are more vigorous than straight-bred parents -hybrid vigor: greater vigor of productivity of crossbreds -lack of dominance: heterozygous animal shows different phenotype than either homologous -also known as additive genetic effects -partial dominance: heterozygote expressed phenotype intermediate to either homozygote -easy keepers can survive when feed is in short supply for long periods of time -biotechnology -use of living organisms to improve, modify, or produce industrially important products -superovulation: produce greater than normal number of eggs Page 7 of 24 -genetic engineering: alters hereditary traits -nuclear fusion: union of nuclei from two sex cells; two eggs or sperm can occur -gene therapy: insert genes into cell to treat or cure disease; alter WBC for immunity -somatotropin: protein hormone produced in anterior pituitary to stimulate growth PPT. 5: BREEDING -quantitative: measure with numbers; qualitative: descriptively measure -pleiotropy: some genes may have an effect on more than one trait -P = G + E -p = phenotype (what we see or measure) -g = genotype (true breeding value) -e = environment (smoke screen) -contemporary group: a group of animals with the same herd, sex, breed, birth season, etc. -weaning weight adjustment -205-d WW = (((actual WW - birth wt) x 205)/weaning age (days)) + birth wt + adjustment age of dam male female 2 60 54 3 40 36 4 20 18 5-10 0 0 >10 20 18 -expected progeny difference (EPD): a prediction of future progeny performance relative to some standard designed to compare animals -cannot be compared across breeds; reliability scaled from 0.00 – 1.00 -heritability (h ): the portion of phenotypic (observed) variation in a trait which can be attributed to transmissible genetic effects (i.e. additive genetic effects) trait heritability range level reproductive < 0.20 low growth 0.20 — 0.40 moderate carcass > 0.40 high -correlated responses: genetic change seen in traits not directly selected for (can be + or —) -direct and maternal EPDs -calf’s own genes: inherent ability to grow = EPD weaning weight -genes of calfs dam: nutritional environment (EDPmilk) -production EPDs (direct) -birth weight, calving ease, weaning weight, yearling weight, scrotal circumference -production EPDs (maternal) -milk (ww), scrotal circumference, stayability, calving ease, heifer pregnancy -carcass EPDs -carcass weight, marbling, ribeye area, backfat -ultrasound EPDs -percent intramuscular fat, ribeye area, fat Page 8 of 24 -what makes animals different -cannot select for environmental differences and carry it into the next generation -selection: preventing some animals from reproducing, allowing others to have many offspring -to change gene frequency (how rare or abundant a particular gene is in a population) -four factors affecting rate of genetic improvement: -maximum genetic variation -accuracy (heritability) -intensity of selection (selection differential) -generation interval -genetic variation: processors like groups that are uniform in size, conformation, and finish -genetic differences must exist for progress to be made -accuracy: how well we can predict the genotype from the phenotype -reproductive traits are lowly heritable -intensity of selection refers to the proportion needed for herd replacements -the smaller fraction saved, the greater the intensity, the more genetic progress made -selection differential (SD): the superiority or inferiority of the individuals to be mated as compared to the herd average -generation interval: average age of the parents when the offspring are born -predicting genetic change through phenotypic selection -genetic change per generation = h x SD -annual progress = (h x SD)/GI -evidence of genetic change -marked increase in meat-to-bone ratio of modern turkeys compared to wild turkeys -genetic change 0.5% per year -identification of superior breeding stock -appearance (eyeball evaluation): important for inherited anatomical abnormalities, little value for performance traits -pedigree (record of the animals ancestry) -most useful before animals have their own performance data -half of animals gene comes from each parent, fourth from grandparent -performance test: evaluation of an animal on the basis of its own record -heritability must be high enough to select for a trait -progeny test: evaluation of an animal on the performance of its offspring -extremely accurate, but takes a lot of time -systems of multiple trait selection -tandem method: select for only one trait at a time in sequence (inefficient) -independent culling levels: establish minimum cull standards and select simultaneously, but independently, for each character -most prevalent method of selection -weakness: individual culled for lacking one trait, but excellent in others -selection index: formula is set up that assigns a weighting factor for each trait being considered in a selection program (average is 100); ranked in order of their net genetic worth for traits considered -weakness: index is difficult to come up with -inbreeding: mating of animals more closely related than the average of the breed or population from which they came -increases homozygous genes, may uncover undesirable recessive genes -linebreeding: form of inbreeding in which an attempt is made to concentrate the inheritance of one or more outstanding ancestors in a pedigree Page 9 of 24 -outbreeding: mating of individuals not related; increases heterozygosity (resulting herd productivity being at a high level) -species cross: horse to donkey -outcrossing: mating unrelated individuals of the same breed, not widely used, safe -grading up: continuous use of purebred sires of the same breed in a trade herd or flock -crossbreeding: mating individuals of different breeds -reasons are breed complementation and heterosis -traits with high heritability have low heterosis -rotational cross: crossbred female bred to a male of third breed or bred back to the breed of sire that is present in her genetic make-up in the lowest percentage -terminal cross: all offspring are sold; none are kept for breeding purposes PPT. 6: REPRODUCTION -what is reproduction? -a goal-directed process; for repro to be successful, many biological events must occur in a specific and orderly manner; low heritability -status of reproduction -current: artificial insemination (AI), embryo transfer (ET), transgenic animals, cloning -future: technology: sequencing of animal genome -conception: mating or union of the male and female gametes -anatomy of the male reproductive system -testis (gonad): primary sex organ; produce sperm and male sex hormones -monorchid: failure of one to descend or cryptorchid: failure of both to descend -castrate: remove testicles before animal reaches puberty -stag: castrated after puberty -ram and bull are vertical, stallion is horizontal, boar is posterior to hams -scrotum (sac contains the testes): regulates temperature of testes -tunica dartos muscle: pushes the testes upward toward the body for warmth or relaxes to cool the testes -cremaster muscle: located in the body cavity; also helps regulate the temp. -seminiferous tubules: sperm producing units of testes; make up ~90% of tests mass; where spermatogenesis occurs -epididymis: duct located on the outside of the testes -vas deferens: duct that connects epididymis to urethra; transports sperm at ejaculation -accessory sex glands: 50-90% of ejaculate -seminal vesicles: supply nutrients for the sperm following ejaculation -prostate gland: clean and lubricate urethra ahead of the sperm -bulbourethral or cowpers gland: clean and lubricate the urethra -ram semen has highest concentration but smallest volume; boar semen has most volume; man semen has smallest concentration -penis proper: organ of copulation; provides passageway for semen and urine -urethra: duct through penis that carries sperm and urine -sigmoid flexure: extension of penis in species with fibro-elastic penis (ruminants, boar) -retractor penis muscle: attached to the sacral vertebra; relaxes during arousal -glans penis: terminal portion of penis -bull —> tapers at the end -ram —> filiform (tubular) appendage -boar —> deposits semen in the cervix -stallion —> butts up agains cervix Page 1 0 of 4 -sertoli cells: provide nourishment for the developing sperm; located within semi tubules -leydig or interstitial cells: produce testosterone; located between semi tubules -sperm cell -sperm found in seminiferous tubules -head contains genetic material (chromatin) -tail propels sperm (motility), mid piece produces energy needed to be motile -repro in poultry males -no penis, have rudimentary organ of copulation, testes inside body cavity -endocrinology: study of hormones, their effects, and glands that secrete them -hormones: chemical substances produced by endocrine glands located in different regions of the body and released into the blood circulation -3 classes: amines (single amino acids), peptide and protein hormones (several amino acids), and steroid hormones (converted from parent compound) -hypothalamus: located within the brain; produces releasing hormones (RH) which travel to pituitary gland and cause the release of several hormones -pituitary gland: located in bony depression at base of brain; the hormones it releases control many functions of the body — including: -basal metabolism (thyrotropes), lactation (mammotropes), growth of bone and other tissues (somatotropes), secretion of steroid hormones by the adrenal glands (corticotropes), many functions of testes and ovaries (gonadotropes) -hormonal interrelationships in the male -hypothalamus: produces a peptide called gonadotropic releasing hormone (GnRH) -which controls the release of two hormones from anterior pituitary gland call gonadotropic hormones (FSH and LH) -which go to the gonads where they stimulate specific functions -function of repro hormones -LH stimulates the Leydig cells to produce testosterone -FSH stimulates the sertoli cells to produce nutrients for the sperm -breeding soundness examination -visual evaluation: feet, legs, masculine traits (crest and muscling) -scrotal circumference: indicator of sperm production -scrotal palpation: prominence of epididymis indicates presence of sperm -penis and prepuce observation: infection, split, rupture -rectal palpation: examine accessory glands -libido test: able and willing -semen evaluation: microscopic (tailless/bent tails/no head, % live sperm, motility) -anatomy of the female reproductive system -external genitalia: vulva and clitoris (homologous to male penis) -vagina: between external genitalia and cervix -site of semen deposition during natural service for bulls and rams -passageway for fetus at birth -cervix: lies between vagina and uterus -site of semen deposition during natural service by boars and stallion -composed primarily of connective tissue -uterus: site of placental attachment, nourishes growing fetus, expels fetus -oviduct: long convoluted tube connecting uterine horns to infundibulum -site of fertilization, transports sperm to site of fertilization (muscle contractions) -ovaries: paired; shape varies with species; produce ovum and female sex hormones (estrogen and progesterone) Page 1 1 of 4 -repro in poultry females -egg laid daily outside the body -no well-defined estrous cycle (sex mature at 20 wks) -follicular growth and development -oogonia: primitive gamete of the female -by birth, have max number will ever have (~2mil at birth, ~40k at puberty) -hormone stimulus initiates growth and development of a new follicle —> layers of cells -primary follicle: surrounded by a single layer of cells -secondary follicle: surrounded by a double layer of cells -tertiary follicle: cells begin migration to one side leaving a cavity (antrum) -estrogen is produced by cells lining the antrum -mature or graafian follicle: ready to ovulate —> ovulation: follicle ruptures and ovum released -ovum caught by infundibulum (oozes out) -development of the corpus luteum -after the ovum escapes the mature follicle, cells of the follicle are structurally and biochemically transformed into a “yellow body” called a corpus luteum -produces hormone that maintains pregnancy (progesterone) -if no pregnancy, CL regresses and new follicle begins to develop; corpus luteum destroyed by a process of luteolysis -resulting structure is a corpus albicans (remnant of a previous cl) -female reproductive physiology (identical to the male system) -GnRH: gonadotrophic releasing hormone -FSH: follicle stimulating hormone -LH: luteinizing hormone -FSH + LH = gonadotrophic hormones -stimulate follicular growth -antrum of growing follicle develops and produces estrogen -functions of estrogen -excitatory hormone in female (induces heat) -stimulates growth of cells of uterus and oviduct in preparation for conception/pregnancy -coordinates events associated with sperm and egg transport -initiates duct growth and development in the mammory tissue -lactation follows reproduction, mammory system has two types of tissue: -secretory tissue and ducts and cisterns -secondary sex characteristics of female (characteristic of species, site of fat deposition) -when the follicle is mature -a surge of LH is released, causing: rupture follicle, develop CL, produce progesterone -functions of progesterone -completes uterine growth initiated by estrogen and thus prepares uterus for nourishment of developing embryo if pregnancy occurs -supports pregnancy by maintaining quiescent state of reproductive tract and suppresses mating behavior -prevents ovulation -stimulates growth and development of the secretory tissue in the mammary system -estrous cycle -series of events occurring from one heat period to the next, beginning at puberty -estrous = adjective -estrus = noun: refers to heat or period of time when the female is receptive to the male Page 1 2 of 4 -types of estrous cycles: -monoestrous: one estrous period per year; fox -diestrous: heat twice per year; dog -polyestrous: many estrous periods per year; cow and sow -seasonally polyestrous: many estrous periods during certain periods of the year -mare: increasing daylight hours; begin irregular in January and regular in March -ewe: decreasing daylight hours; begin cycling in August in northern US -estrous cycle lengths: -ovine = about 17 days -porcine = about 21 days -bovine = about 21 days -equine = about 21 days -estrous length: -ovine = about 24 to 36 hours -porcine = about 48 to 72 -bovine = about 12 hours -equine = about 5 to 7 days -behavioral signs of estrus -standing to be mounted, mounting others, restless, gregarious activity, vocalizing, frequent urination, mucous discharge -fertilization and attachment -fertilization: union of male and female gametes -2cell—>4cell—>8cell—>morula—>blastocyst—>embryo—>fetus -developing embryo reaches uterus in 3-5 days, and continues to develop -chorionic, allantoic and amniotic membranes develop around the new embryo, and the chorion attaches to the uterus -embryo (fetus) obtains nutrients/discharges wastes through these membranes -unless the environment is favorable, the embryo dies -classifying placental shape -attachment begins at (22 days in cows), (15-d in ewes), (13-d in sows), (37-d in mares) -diffuse placenta: sow and mare -cotyledonary placenta: cow and ewe -caruncles (maternal side) on uterus; cotyledons (fetal side) on chorion -parturition — termination of gestation -controlled by hormones produced by fetus and dam -initiated by fetus, cervix dilates, pelvis relaxes, uterine contracts, pressure -normal presentation -fetus of cow, mare, and ewe assume positions in which the front feet are extended with the head between them -fetal pigs do not orient themselves in any way -dystocia: abnormal or difficult labor -heavy birthweight of calf is major cause in cattle -age of cow (heifer vs mature) -presentation: rump first, head or leg folded back -“red bag” delivery in horses -aka chorioallantois; exchange of nutrients/waste -white bag (or amnion) surrounds fetus for lubrication and protection -fescue toxicosis (KY 31) -endophyte fungus produces ergot alkaloid toxins Page 1 3 of 4 -fungus passed in the seed heads -broodmares -dystocia, prolonged gestation, enlarged foals, thickened placenta, agalactia -excess dopamine?? suppresses prolactin which signals body to foal -cattle “summer slump” -agalactia, thickened placenta, aborted fetuses, poor appetite -exacerbated by fertilizing with high N; fate necrosis causes problems with digestion and calving -fescue toxicosis prevention -fungicides do not work -pasture management is only option -factors affecting reproductive performance -nutrition -environment: embryonic mortality (temperature, humidity, seasonality) -anatomical defects in reproductive tract -endocrine system imbalance -diseases: brucellosis, metritis, vibriosis, leptospirosis, trichomoniasis, IBR -terminology -over-condition (fat): rarely observed -increased dystocia due to fat around tract -not a big problem -flushing: increase the level of nutrition ~30 days before breeding -increases rate of ovulation in herd -effective for heifers, ewes, and gilts -undercondition (thin) -female must have certain amount of body fat to reproduce -recommended feeding program -cattle can lose weight between weaning and calving, but you must go into calving season in gaining condition -“120 critical days” don't feed to fatten, just gain weight -first-calf heifers -have three critical needs for extra nutrients -will be lactating for the first time -still growing -uterine involution: preparation for another pregnancy -keep them separated from main cow herd -energy: the dietary component that is usually limiting -artificial insemination -history (AI is not new) -14 century legend —> 1780 documentation (a dog) —> 1900 cattle and sheep —> 1941 yolk-citrate extender —> 1949 glycerol as cyro-protectant for freezing -percent AI matings -95% turkey industry, 80-90% dairy cattle, 8-10% beef cattle, 40-50% horses, 80-85% in swine, < 5% in sheep -advantages of AI -maximum use of genetically superior sires, greater selection of sires, deceased sires, dangerous sires, aid in reduction of diseases, improve management -disadvantages of AI -increased labor, mngmt, facilities; accentuate poor genetics using inferior sire Page 1 4 of 4 -semen collection -artificial vagina: for bulls, stallions, rams; not for boar -electroejaculator: probe into rectum —> electrical stimulation —> ejaculation -if collected too frequently, number of semen per ejaculate decreases -semen processing -semen evaluated for volume, concentration, motility, abnormalities -semen mixes with an extender that dilutes to a greater volume -fresh semen (1-2 days); frozen lasts indefinitely -when to inseminate -fertile life of ovum: capable of being fertilized 12 to 24 hours -fertile life of sperm: 12 hour window; 5 minutes for transfer -site of semen deposition -in uterus of cows and mares: deposition in uterine horn has lower conception due to uterine trauma and possible infection -in cervix of sows: locking of AI rod -superovulation -hormone treatment of the female to induce multiple ovulations -uses: multiple births and embryo transfer -multiple births: not a practical procedure at this time, the increased number of offspring does not warrant the cost and problems -embryo transfer -advantages: increased reproduction of valuable dams, decreased time for proof of dam through a greater number of progeny, extended reproductive life of injured or older dams, transport of exotic breeds or proven stock to restricted or underdeveloped areas -disadvantages: costly, ET offspring are not necessarily genetically superior, success rate is variable and not guaranteed -injection programs -FSH is commonly used to induce superovulations in cattle -gonadotropins (FSH/LH combo) have been used since 1940 -PMSG (eCG): this product contains mostly FSH activity, but has LH; obtain from pregnant mare serum -hCG: this product contains mostly LH, with some FSH; used in combination with FSH or PMSG; obtain from pregnant women -prostaglandins are used to synchronize the estrous cycle of the donor cow and recipient cows -not hormones, produced by many tissues -for repro, we will be concerned with just one —> PGF(2a) -regression of the CL -procedures -selection: donors must be healthy, cyclic animals of superior genetic make-up -synchronization: donor/recipient animals must be in same stage of estrous cycle -within +/— 12 hours for best results (use prostaglandin) -superovulation (donors) -FSH is injected twice daily during days 9-14 after estrus -PGF(2a) is given on day 3 or 4 of FSH injection to regress existing CL, bringing animals into estrus 2-3 days later -future -freezing embryos: currently being done but the technology is not completely worked out; cloning and micromanipulation of embryos; sexing embryos Page 1 5 of 4 PPT. 7: LACTATION -lactation is a distinguishing feature of mammals -mammory gland serves two functions: -provide nutrition to offspring and source of passive immunity to offspring -what makes a mammal? -most have hair -all have mammary glands -modified sweat glands regulated by hormone control used to nurture offspring -lactation: critical part of reproduction strategy in mammals -structure of the udder -cow: 4 glands, 4 teats -mare: 4 glands, 2 teats -sheep and goat: 2 glands, 2 teats -multiparous animals (sow): 6 to 20 glands in two rows -major characteristic of mammals is an adaption of skin glands (hair and mammory glands) -gland: a secreting organ -a secretion may be: -poured out (secreted) onto the surface -poured into a cavity -taken into blood -mammory gland -the secretion is milk -synthesized and secreted from epithelial cells in a tissue consisting of alveoli, which are connected to a duct system —> follows to exterior of animal -exocrine gland: gland that secreted fluid into a duct -endocrine gland: ductless, secrete hormones into bloodstream -protective factors in milk -antimicrobial proteins -Lactoferrin: binds iron (Fe) required for bacterial growth -Lysozyme: enzyme that hydrolyzes bacterial cell walls -Immunoglobulins (Ig) -proper intestinal flora: factors in milk contribute to their establishment -milk composition can vary -time of sampling: first-drawn milk is lower in fat and increases as milk is removed -fat % varies by season: higher in fall and winter, lower in spring and summer -temperatures > 85 F: accentuated with high humidity Page 1 6 of 4 -factors affecting milk production -inheritance determines potential (low producers vs. high producers) -feed and management determine whether potential is reached -mastitis can decrease production by > 30% -consumption of the calf -reduced production causes some regression -inbreds grow more slowly, less vigorous -crossbreds usually larger and more vigorous -male offspring cause greater milk production (they are heavier and grow more quickly) -multiple births produce more milk than females with single births -age of animal (maximum production at six years) -younger and older females produce less vs. females have had several lactations -nutritional needs greater during lactation than gestation -mastitis: inflammation of the udder -most costly disease of dairy cattle -usually caused by chronic infection of streptococcus & staphylococcus bacteria -three main causes: -dirty or poorly adjusted milking equipment -poor milking practices (dirty animals) -injuries to cows because of their surroundings -symptoms of mastitis -clots or flakes in milk, udder is sensitive, swollen or hot to touch -tested for via California mastitis test -treatment for mastitis -identify organisms by milk cultures -treated by intramammary injection of antibiotics -antibiotics in milk are illegal —> cannot use that milk -importance of mothers milk -prior to birth, fetus is in a sterile, protected, moist, warm environment with nutrients/O2 -at birth, exposed to cold, dry environment —> exposed to harmful organisms/predators -colostrum (first milk): transfers immunoglobulins that lasts 24 hours; passive immunity -cows milk not salable until after the 11th milking -mammogenesis: structural development of growth of mammary gland -lactogenesis: associated with end of pregnancy; tissues change from non-lactating to lactating -milk secretion: synthesis of milk by epithelial cells -milk removal: passive removal from cisterns and ejection of milk from alveolar lumen -lactation: milk secretion + milk removal -galactopoesis: maintenance of lactation -structure of the cow udder -suspension: maintain attachment to body -median suspensory ligament (separates left and right halves) -lateral suspensory ligament (outer wall of udder) -four glands or quarters separate from each other -rear quarters are 60% of the milk -alveolus: sac-like structure with a hollow center; basic milk producing structure in udder -lumen lined with single layer of epithelial cells -remove nutrients from the blood, transform nutrients into milk, discharge milk into the center of the alveolus Page 1 7 of 4 -epithelial cells are surrounded by contractile myoepithelial cells involved in milk ejection -milk collects in alveolus lumen until forced out by hormone action of oxytocin on small muscle tissue around the alveoli at time of milking -neural system: innervation inside udder is sparse, sensory nerves found in teats&skin -circulatory system: extremely important for mammory function, all milk precursors come from blood (~500 gal blood pass through udder to supply nutrients needed for 1 gal milk) -milk secretion and removal -in general… -each alveolus can independently synthesize new milk; not dependent on the help of specialized cells; very efficient -synthesis is a continuous process -80% of milk present is in ducts -15% to 20% of total milk in udder at the start of milking is not removed when milking is completed -growth hormone, adrenal corticosteroids, and prolactin are responsible for the initiation of lactation -prior to milking, milk is stored in milk cavity of the alveoli (lumen) -milk letdown occurs after around 45 seconds -oxytocin, hormone produced by posterior pituitary, causes contractions of myoepithelial cells surrounding each alveolus -forces milk into duct system and cisterns -streak canal must be opened to remove milk -negative pressure (milking machine), positive pressure (hand milking), positive and negative pressure (suckling) -milk “hold-up”: if cow is upset, letdown may not occur -epinephrine (adrenalin) is released into blood and can override action of oxytocin -reduce blood to alveoli and redirect it to muscles for flight response -mammary gland development -starts early in growth of fetus -at birth: teats, cisterns, and glands already exist -birth to puberty -isometric growth for first 2-3 months after birth (grows at same rate as general body growth) -at 2-3 months until about one year of age, allometric growth begins (faster than the rest of the body) -puberty (7 to 9 months): some allometric growth occurs -greatest degree of structural development occurs during pregnancy -stimulation of FSH and LH from anterior pituitary -ovary > estrogen and progesterone -estrogen stimulates growth of mammory duct system -progesterone stimulates growth of alveoli -anterior pituitary also produces: -growth hormone (aka somatotropin) -prolactin: helps initiate milk secretion -involution: young no longer needs milk; cycle restarts with new pregnancy -maintenance of lactation -milk removal is required, when stopped alveoli are distended -dry period: 2 months is ideal Page 1 8 of 4 PPT. 8: GROWTH -true growth: increase in body weight until mature size is reached -does not include excess fat -don’t know: why it starts, how its regulated, why it stops -hyperplasia: increase in cell number -hypertrophy: increase in cell size -muscle cells, nerve cells, adipose cells -prenatal growth -endoderm: GI tract, lungs, bladder -mesoderm: skeleton, skeletal muscle, CT -ectoderm: skin, hair, brain, spinal cord -tissues —> organs —> systems -muscular -skeletal: largest component of red meat products -smooth: digestive, repro, urinary -cardiac: heart -circulatory -arteries: transport blood away from the heart -veins: vessels that carry blood to heart -lymph: transport lymph (intercellular fluid) -break joint: lamb -spool joint: mutton -osteoblasts: bone matrix production; bone cell precursors -osteocytes: maintenance of bone matrix; mature osteoblasts -osteogenesis: formation of bone -bone growth -periosteum: outer epithelial layer of bone -diaphysis: shaft of long bone lengthens because cartilage growth is faster than osteoblasts (bone cell precursor) -osteoclasts: involved in bone resorption -amount of cartilage (or lack) is used to estimate maturity in beef carcasses -muscle weighs more than fat weighs more than bone -subcutaneous fat (under skin) -largest quantity of fat in the body of hogs -muscle structure -muscles are made up of bundles of muscles -muscle bundles are made up of individual muscle cells -myofibrils are the basic functional unit of the muscle fiber contractile system -actin: thin microfilament -myosin: thick microfilament PPT. 9: NUTRITION -carnivores -consume animal tissues as their source of nutrients -length of the digestive tract is relatively short -examples: cats and dogs -herbivores -primarily consume plant tissues -longest of the digestive systems with modified gastric and or cecal-colon areas Page 1 9 of 4 -examples: goats and horses -omnivores -each both plant and animal products -intermediate length systems -examples: swine and humans -monogastrics (also called non-ruminants, simple stomach) -digestion begins in stomach -most digestion and absorption occurs in SI -carnivores and omnivores -examples: pigs, dogs, cats, humans -ruminants -stomachs are complex in structure -have one stomach with four compartments -rumen, reticulum, omasum, abomasum -feed can go between reticulum and rumen -microorganisms in the reticulum and rumen account for much of the breakdown of feeds -examples: cattle, sheep, goats, deer, elk, moose -non-ruminant herbivores (aka hindgut fermenters) -have a simple or monogastric stomach -cecum is critical; cecum is enlarged pouch located at the anterior end of the large intestine; very important in digestion of fibrous feeds -examples: horses, guinea pigs, rabbit -anatomy of the digestive system -a tube from the lips to the anus -regions divided into: mouth, esophagus, stomach, small intestine, cecum, large intestine, rectum, and anus -attached to the tube are the liver and pancreas -other than lips, tongue, and muscles for swallowing on one end, and sphincter muscle on the other end, the system is a smooth muscle -digestive tract of monogastrics -varies between species -basic parts include: -mouth (saliva), esophagus (cardiac valve), stomach (pyloric sphincter), small intestine (ileocecal v.), large intestine (aka colon), rectum and anus (sphincter) -the function of parts preceding the intestines is to reduce particle size -small intestine (duedenum, jejunum, ileum): splits food molecules; finger-like projections (villi) absorb nutrients -large intestine: absorbs water; forms indigestible waste (feces); mucous -species variation: equine -large cecum where feed is fermented -do not obtain all nutrients made by mo because cecum is posterior to site of absorption -species variation: poultry -no teeth: peck with beak or scratch with feet to break food particles -crop: enlargement of esophagus where food stored -proventriculus: glandular stomach; secretes juices, HCl -gizzard: ground finer -cloaca: droppings and urine -stomach parts of ruminant Page 2 0 of 4 -rumen: large fermentation vat where bacteria and protozoa work -lined with numerous papillae -mo can digest cellulose and synthesize amino acids from NPN and B-complex vit -mo are later digested in small intestine to provide nutrients for the animal -reticulum (honeycomb): interacts with rumen in initiating the mixing; provides additional area for fermentation -omasum: many folds; no major digestive function -abomasum (true stomach) -regurgitate each bolus of food (cud) -chewed more thoroughly and swallowed -another bolus is regurgitated and chewed -this process is call rumination -as feeds ferment by mo in rumen, large amounts of methane and CO2 produced -eliminate by belching and called eructation -nutrients: six basic classes -water, carbohydrates, fats, proteins, minerals, vitamins -water (used interchangeably with moisture) -water refers to drinking -moisture refers to amount of water in a given food or ration -dry matter: remainder of feed after accounting for moisture -two to four times as much water consumed as feed -important functions: metabolic reaction, transports, nutrients, maintain body temp, cell shape -carbohydrates (CHO) -simple carbs: glucose, fructose, galactose -complex carbs: cellulose (cell walls of plants which require microbial interaction) -glucose and glycogen are CHO stored in tissue to provide sources of energy -fats -fats: solid at room temperature -oils: liquid at room temperature -fats have 2.25x more energy per pound than carbohydrates -composed of three fatty acids and glycerol -fatty acids are saturated or unsaturated -saturated (single bonds) -unsaturated ( >1 double bond) -fat (lipid, triglyceride) -most diets less than 5% -functions: essential fatty acids, insulation, cushion organs and joints, protect nerve fibers, storage of energy -proteins -always contain C, H, O, N (only class that contains nitrogen) -only class that contains nitrogen -simple protein: contains one amino acid -complex protein: contains additional non-amino acid substances like CHO, or lipids -proteins in feed contain about 16% N -100% divided by 16% = 6.25 factor -made up of combos of amino acids (building blocks of the body) -amino acids come from protein in feed -used for growth (muscle, bone, CT), milk production, tissue repair, etc. Page 2 1 of 4 -required for all enzyme (protein) production -dipeptide: bonding of two amino acids -amino acids can connect end to end into long chains with an assortment -when digestion occurs, amino acids are freed from one another at the peptide bond -amino acids can be classified as essential or nonessential -essential amino acids (EAA) -remember PVT TIM HALL -minerals -chemical elements other than C, H, O, N -macrominerals: required by body in large amounts -2:1 Ca/P ratio in bone -sodium&chlorine: osmotic balance; lost by sweat; salt blocks -potassium: osmotic balance in cells -magnesium: required for bone and activation of several enzymes -sulfur: required for some amino acids and vitamins -microminerals: required by the body in trace amounts -chromium, cobalt (vitamin b12), iodine (thyroid), iron (blood), etc. -can be bound to other things like amino acids, proteins, polysaccharides -called organic materials, do contain carbon -inorganic minerals do not contain carbon -nutritional problems -white muscle disease: deficiency of Se and/or Vitamin E; associated with Se deficient soils and inadequate plant uptake; stiffness or inability to stand; alert but grow weak -grass tetany (or staggers): deficiency of magnesium; nervous, tense head, staring into space; occurs in spring when lactating animals on pasture; treat with Mg and/or Ca injection (often too late) -rickets (or osteomalacia): deficiency of Ca and P or Vitamin D; bones become soft and deformed; fail to calcify; observe pica = eating non-food items; wood -parakeratosis: excess Ca in diet causes deficiency of Zn; unthrifty appearance; skin conditions resemble mange -vitamins (fat soluble): A, D, E, K -vitamin a: vision, maintain and repair body linings -vitamin d: required for proper use of Ca/P for bone growth; required for absorption of Ca/P from intestine -produced by the sun, deficiency leads to rickets -vitamin e: excellent antioxidant -vitamin k: blood clotting -if deficient, can hemorrhage -absorbed with lipids (fats); can be stored by body -vitamins (water soluble) -vitamin c (ascorbic acid): scurvy -thiamin (B1): beri beri -riboflavin (B2) -niacin (B3): pellagra -pantothenic acid (B5) -pyridoxine (B6) -biotin (B7) -folic acid (B9) -cobalamin (B12) Page 2 2 of 4 -choline -water soluble (except C and choline) are made by rumen microbes of ruminants -also available to horses via cecum -most water soluble can’t be synthesized by monogastric animals —> must be fed in diet -fat-soluble must be fed to both ruminants and monogastrics -except vitamin k which is produced in rumen -what are nutrients used for? -maintenance, production (growth, repro, lactation, fattening, work, eggs, wool, meat) -nutrient: any feed constituent that functions in support of life -diet: feed mixture consumed by animals -ration: amount of the diet supplied for a specific time period (24 hours) -ingredient: constituent in the diet or feed material -concentrates -high in energy, low in fiber -usually highly digestible by all classes -high concentrate diets are often called “high-energy” or “high-grain” -produce most rapid gains -examples: cereal grains, oil meals -roughages -high in fiber (cellulose), low in energy -less digestible -do not gain as fast -examples: legumes, hays -natural energy balance: energy intake = energy expenditure -positive energy balance: energy intake < energy expenditure -negative energy balance: energy intake > energy expenditure -dietary management -evaluate livestock, evaluate feed/pasture, determine requirements, adjust feed accordingly, adjust management accordingly, keep accurate records -proximate analysis -separates feed components into groups accordingly to their feeding value -based on a feed sample and the analysis performed therefore it is critical to obtain a representative feed sample -caution needed in interpreting results -digestibility of feeds -digestibility: refers to the amount of various nutrients in a feed that is absorbed from the digestive tract -feeds and nutrients vary in their digestibility -subject to digestion trials, feeds of known composition are fed, feces analyzed -energy evaluation of feeds -nutrients that contain carbon provide energy to animals -carbs, fats, and protein all provide energy -carbs supply most of energy -energy is used to power movement of animal, but most is used to drive chemical reactions to convert feed into products o -calorie(cal): amount of energy or heat required to raise the temp of 1g of water 1 C -kilocalorie(kcal): to raise temp of 1kg of water 1 C -megacalorie(mcal): equal to 1000 kcal or 1 million calories -digestion Page 2 3 of 4 -must occur before the body can absorb and use the feeds eaten -reduces feed particles to molecules that can be absorbed into the blood -mechanical, chemical, and enzymatic -enzymatic breakdown -amylase: in saliva breaks down starches (only in primates and pigs) -enzymes: an organic catalyst that speeds a reaction without being altered by the rxn -feed is mixed well and some digestion occurs resulting in chyme (the liquid food mixture that proceeds to the duodenum of the SI) -at the small intestine -duodenal cells release hormones which stimulate enzyme release from pancreas and bile stored in gallbladder -bile emulsifies fat; strong alkaline to neutralize acidic chyme -young ruminants -essentially monogastric: only abomasum -3 weeks: rumen begins to become functional -fully functional at 3 to 4 months -esophageal groove: muscle -regurgitate: to cast up digested feed to the mouth -ruminate: regurgitation, chewing, reswallowing -eructate: elimination of gas via belching -bloat: inability to expel gas Page 2 4 of 4


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