Which of the following lines the body cavities exposed to the external environment? a

Feedstuffs - Go into 2 categories - 1. Concentrates o highly digestible, do not contain a lot of cellulose o less than 18% crude fiber o divided into 2 parts o 1. Carbonaceous concentrates (less than 20% crude protein)  energy source  grains, corn, wheat, oat, barley, molasses  corn is the main carbonaceous concentrates in the US bc we can produce it so cheaply o 2. Proteinaceous concentrates (greater than 20% protein)  soy beans (have anti trypsin factor which blocks the protein enzyme)  NPN nonprotein nitrogen for ruminants but not monogastrics o no feed is balanced in all the amino acids… there will always be a lack of something - 2. Forages or roughages o greater than 18% crude fiber o 2 types  1. Legumes  high in protein 15-25% usually  will always be greater than 10% protein  alphalpha, clover, peanut, soy bean  symbiotic relationship with protein at the root of their plants  2. Grasses  can be pretty good in protein if you cut them early, before they become fibrous  we can grow grasses year round  fescue- winter o can be a problem for animals