Partial replacement of soybean meal with pea grains and sunflower cake in ewe diets: milk quality and blood biochemical parameters

ABSTRACT The objective of this research was to evaluate the effect of pea and sunflower cake as partial replacement for soybean meal in diet, as well as to assess their effect on milk quality during lactation and on blood parameters of ewes kept in organic farming. The research was carried out with 30 ewes of Merinolandschaf breed during 75 days. Ewes were given mixtures based on soybean meal as a protein source in control group (SBM), while in experimental groups, soybean meal was partially replaced with pea grain (P) and sunflower cake (SFC). Biochemical parameters (urea, glucose, total protein, albumin, globulins, cholesterol, HDL, LDL, triglyceride, β-hydroxybutyrate, and non-esterified fatty acids), as well as enzyme activity (ALT, AST, ALP, GGT, and CK) were determined in blood of ewes. Milk composition and concentration of fatty acids in milk fat were also determined. In comparison with control, sunflower cake as a protein source affected the increase of fat content in milk. When compared with pea grain and SBM, it decreased the urea concentration in milk. Oleic acid, total monounsaturated fatty acids, and n-6 increased, while saturated fatty acids, atherogenic, and thrombogenic indices decreased in SFC. Feeding ewes with peas increased the content of n-3 fatty acids in their milk. If compared to SFC, it also improved the n-6:n-3 ratio. Partial replacement of soybean meal with SFC reduced the blood concentration of total protein, globulin, and AST, and GGT enzyme activities and increased the β-hydroxybutyrate. Inclusion of pea grain and SFC can be adequately used as partial replacement of soybean meal in feeding of ewes kept in organic farming.

摘要
本研究旨在评估豌豆与葵花饼部分替代日粮豆粕的应用效果，同时考察其对有机养殖母羊泌乳期乳品质及血液生理生化参数的影响。试验选取30只Merinolandschaf品种母羊，试验周期为75天。对照组（SBM组）以豆粕（soybean meal，SBM）作为蛋白质来源配制混合日粮，试验组则分别采用豌豆粒（P）与葵花饼（SFC）部分替代豆粕。
本研究测定了母羊血液中的生化指标：尿素、葡萄糖、总蛋白、白蛋白、球蛋白、胆固醇、高密度脂蛋白（HDL）、低密度脂蛋白（LDL）、甘油三酯、β-羟丁酸（β-hydroxybutyrate）以及非酯化脂肪酸；同时测定了相关酶活性：丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、碱性磷酸酶（ALP）、γ-谷氨酰转移酶（GGT）与肌酸激酶（CK）。此外还检测了乳成分及乳脂中脂肪酸的浓度。
与对照组相比，以葵花饼作为蛋白质来源可提升乳脂含量；相较于豌豆粒组与SBM组，葵花饼组可降低羊乳中尿素浓度。在SFC组中，油酸、总单不饱和脂肪酸及n-6多不饱和脂肪酸水平升高，而饱和脂肪酸、致动脉粥样硬化指数与致血栓形成指数则有所降低。饲喂豌豆粒的母羊其羊乳中n-3多不饱和脂肪酸含量升高，且相较于SFC组，其n-6:n-3比值得到改善。采用葵花饼部分替代豆粕，可降低母羊血液中总蛋白、球蛋白浓度以及AST与GGT的酶活性，同时升高β-羟丁酸水平。
综上，在有机养殖母羊的日粮中，豌豆粒与葵花饼可有效作为豆粕的部分替代原料。