title: Duodenal flow of microbial and feed nitrogen in sheep fed normal soybean meal or soybean meal treated with modified zein.
abstract: The effect of protecting soybean meal from microbial degradation in the rumen on duodenal flow of microbial N and feed N was studied with sheep. The soybean meal was protected with chemically modified zein. Two groups of four wethers, each equipped with a ruminal cannula and a duodenal reentrant cannula, were fed a diet based on corn silage (1 kg of DM/d) that contained either a normal or protected soybean meal supplement. The results showed no appreciable differences between the two supplements in ruminal fluid pH, total N, and NAN concentrations; however, the concentration of total VFA was lower for protected soybean meal than for normal soybean meal. Although the flow of NAN into the duodenum was not affected, bacterial N flow was 18% lower, and feed N flow was 195% higher, for protected soybean meal than for normal soybean meal. The digestibilities of OM, ADF, and N in the digestive tract were not affected by the type of supplement. The treatment of soybean meal decreased the degradability of total feed N in the stomach by 22 percentage points, but the increased supply of feed N into the small intestine because of the treatment was at the expense of decreased bacterial synthesis of protein in the rumen, probably because of a shortage of RDP in the diet.
authors.affiliation: Centre for Food and Animal Research, Agriculture and Agri-Food Canada, Ottawa, ON, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Ivan
authors.forename: S
authors.initials: S
authors.lastname: Mahadevan
authors.forename: M S
authors.initials: MS
authors.lastname: Dayrell
mesh_terms: D000821:Animal Feed; D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D004063:Digestion; D004386:Duodenum / Q000378:metabolism* / Q000382:microbiology; D005232:Fatty Acids, Volatile / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008297:Male; D009584:Nitrogen / Q000378:metabolism*; D012417:Rumen / Q000378:metabolism; D012756:Sheep / Q000378:metabolism*; D013025:Glycine max; D015028:Zein / Q000008:administration & dosage
chemical_list: D005232:Fatty Acids, Volatile; D015028:Zein; D009584:Nitrogen