Protein and energy value of dehydrated poultry excreta in diets for feedlot cattle.
Four Holstein steers (222 kg) with cannulas in the rumen and proximal duodenum were used in a crossover design experiment to evaluate the energy and protein value of dehydrated poultry excreta (DPE). Dietary treatments contained (DM basis) 4% alfalfa hay, 8% sudangrass hay, 49% flaked barley, 8% cane molasses, 3% yellow grease, .8% urea, 1.4% limestone, .3% mineral salt, and .4% chromic oxide, plus 25% of either tapioca pellets or DPE. The DPE contained 42% ash and 27% CP (6% true protein). Substituting DPE for tapioca decreased the DE value of the diet (P < .01). The estimated DE value of the DPE was 1.36 Mcal/kg (.34 Mcal NEm/ kg). There were no treatment effects (P > .10) on microbial N flow to the small intestine or ruminal microbial efficiency (grams of microbial N/kilogram of OM fermented). The addition of DPE increased (P < .05) the flow of non-ammonia and feed N to the small intestine. The estimated ruminal escape N value of DPE was 22%, although very little of this was true protein. Dehydrated poultry excreta did not increase (P > .10) flow of alpha-amino N to the small intestine. Ruminal degradability of uric acid was 96%. Total tract true digestibility of N in DPE was 84%. It is concluded that the NE value of DPE is markedly overestimated in current tables of feeding standards. Less than 10% of the N in DPE escapes the rumen as true protein N.
Zinn
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RA
Imperial Valley Agricultural Center, University of California, El Centro 92243, USA.
Barajas
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R
Montaño
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Shen
Y
Y
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D002417:Cattle / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology; D018592:Cross-Over Studies; D004032:Diet / Q000592:standards / Q000662:veterinary*; D004044:Dietary Proteins / Q000032:analysis / Q000592:standards*; D004063:Digestion / Q000502:physiology; D002149:Energy Intake / Q000502:physiology*; D005243:Feces / Q000737:chemistry*; D007421:Intestine, Small / Q000378:metabolism / Q000382:microbiology; D008297:Male; D002365:Manihot / Q000592:standards; D011897:Random Allocation; D012417:Rumen / Q000378:metabolism / Q000382:microbiology; D014527:Uric Acid / Q000378:metabolism
D000596:Amino Acids; D004044:Dietary Proteins; D014527:Uric Acid