RESUMO
Soybean meals (SBM) from different locations differ in their protein content, subsequently influencing their amino acid (AA) profile. In this study, standardized ileal digestibility (SID) of AA and growth or production performance were evaluated in pullets and hens fed SBM derived from soybean grown in Western Canada, primarily Manitoba (MB) labelled as A-, B- and C-SBM compared with that from Eastern Canada (Ontario, ON-SBM) and contained 38.3 ± 0.44, 38.6 ± 0.61, 39.4 ± 0.49, or 44.0 ± 0.87% CP, respectively. A N-free diet was used to determine basal ileal endogenous losses of AA. The study included the grower, developer, and layer phases (9-12, 13-16, and 44/59-64-wk old birds, respectively). Although a lower (P = 0.029) SID for cysteine was noted in the grower phase for the C-SBM compared with other SBM, the developer phase had higher (P < 0.05) SID for methionine, phenylalanine, cysteine (more by 4.4, 2.4 and 7.2% units, respectively) on average for SBM samples from MB compared with the ON-SBM. Regardless the source of the SBM, no difference in SID of AA was noted in the layer phase. Overall, in all phases the SID values of most AA in the SBM from MB were comparable with the ON-SBM, which may be linked to higher values of these AA per unit of protein content in the former source. In addition, the growth performance including feed intake, BW gain and feed conversion ratio in pullets, and egg production/quality in layers were similar between treatments. These findings show that the MB-SBM have a comparable feeding value with the ON-SBM, hence represent a suitable alternative protein source for poultry.
RESUMO
BACKGROUND: There is a lack of nutrition guidelines for the feeding of omega-3 polyunsaturated fatty acids (PUFA) to laying hens. Knowledge as to whether the type and concentrations of α-linolenic acid (ALA) and/or docosahexaenoic acid (DHA) in the diet can make a difference to the birds' immune responses when subjected to a lipopolysaccharide (LPS) challenge is limited. OBJECTIVES: The study was designed to determine the potential nutritional and health benefits to laying hens when receiving dietary omega-3 PUFA from either ALA or DHA. METHODS: A total of 80 Lohmann LSL-Classic (white egg layer, 20 wk old) were randomly assigned to 1 of 8 treatment diets (10 hens/treatment), provided 0.2%, 0.4%, 0.6%, or 0.8% of total dietary omega-3 PUFA, provided as either ALA-rich flaxseed oil or DHA-enriched algal biomass. After an 8-wk feeding period, the birds were challenged with Escherichia coli-derived LPS (8 mg/kg; i.v. injection), with terminal sample collection 4 h after challenge. Egg yolk, plasma, liver, and spleen samples were collected for subsequent analyses. RESULTS: Increasing dietary omega-3 supplementation yielded predictable responses in egg yolk, plasma, and liver fatty acid concentrations. Dietary intake of ALA contributed mainly to ALA-derived oxylipins. Meanwhile, eicosapentaenoic acid- and DHA-derived oxylipins were primarily influenced by DHA dietary intake. LPS increased the concentrations of almost all the omega-6 PUFA-, ALA-, and DHA-derived oxylipins in plasma and decreased hepatic mRNA expression of COX-2 and 5-LOX (P < 0.001) involved in the biosynthesis of oxylipins. LPS also increased mRNA expression of proinflammatory cytokine IFN-γ and receptor TLR-4 (P < 0.001) in the spleen. CONCLUSIONS: These results revealed that dietary intake of ALA and DHA had unique impacts on fatty acid deposition and their derived oxylipins and inflammatory responses under the administration of LPS in laying hens.
