Naves A B, Freitas Júnior J E, Barletta R V, Gandra J R, Calomeni G D, Gardinal R, Takiya C S, Vendramini T H A, Mingoti R D, Rennó F P
Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Sciences, University of Sao Paulo, Pirassununga, Brazil.
J Anim Physiol Anim Nutr (Berl). 2016 Aug;100(4):778-88. doi: 10.1111/jpn.12413. Epub 2015 Oct 9.
Differing soya bean particle sizes may affect productive performance and ruminal fermentation due to the level of fatty acid (FA) exposure of the cotyledon in soya bean grain and because the protein in small particles is more rapidly degraded than the protein in large particles, which influence ruminal fibre digestion and the amounts of ruminally undegradable nutrients. The objective of this experiment was to investigate the effects of raw soya bean particle size on productive performance, digestion and milk FA profile of dairy cows. Twelve Holstein cows were assigned to three 4 × 4 Latin squares with 21-day periods. At the start of the experiment, cows were 121 days in milk (DIM) and yielded 30.2 kg/day of milk. Cows were fed 4 diets: (i) control diet (CO), without raw soya bean; (ii) whole raw soya bean (WRS); (iii) cracked raw soya bean in Wiley mill 4-mm screen (CS4); and (iv) cracked raw soya bean in Wiley mill 2-mm screen (CS2). The inclusion of soya beans (whole or cracked) was 200 g/kg on dry matter (DM) basis and partially replaced ground corn and soya bean meal. Uncorrected milk yield and composition were not influenced by experimental diets; however, fat-corrected milk (FCM) decreased when cows were fed soya bean treatments. Soya bean diets increased the intake of ether extract (EE) and net energy of lactation (NEL ), and decreased the intake of DM and non-fibre carbohydrate (NFC). Ruminal propionate concentration was lower in cows fed WRS than cows fed CS2 or CS4. Cows fed cracked raw soya bean presented lower nitrogen in faeces than cows fed WRS. The milk of cows fed WRS, CS2 and CS4 presented higher unsaturated FA than cows fed CO. The addition of raw soya bean in cow diets, regardless of the particle size, did not impair uncorrected milk yield and nutrient digestion, and increased the concentration of unsaturated FA in milk. Cows fed cracked raw soya bean presented similar productive performance to cows fed whole raw soya bean.
不同大小的大豆颗粒可能会影响生产性能和瘤胃发酵，这是因为大豆籽粒中子叶的脂肪酸（FA）暴露水平不同，而且小颗粒中的蛋白质比大颗粒中的蛋白质降解得更快，这会影响瘤胃纤维消化和瘤胃不可降解养分的含量。本实验的目的是研究生大豆颗粒大小对奶牛生产性能、消化和乳脂肪酸谱的影响。12头荷斯坦奶牛被分配到三个4×4拉丁方中，每期21天。实验开始时，奶牛处于泌乳121天（DIM），日产奶量为30.2千克。给奶牛饲喂4种日粮：（i）对照日粮（CO），不含有生大豆；（ii）全生大豆（WRS）；（iii）通过威利磨4毫米筛网破碎的生大豆（CS4）；（iv）通过威利磨2毫米筛网破碎的生大豆（CS2）。以干物质（DM）为基础，大豆（全粒或破碎）的添加量为200克/千克，部分替代了玉米粉和豆粕。未校正的产奶量和乳成分不受实验日粮的影响；然而，当给奶牛饲喂大豆处理日粮时，校正乳脂后的产奶量（FCM）下降。大豆日粮增加了奶牛的乙醚提取物（EE）摄入量和泌乳净能（NEL），并降低了干物质和非纤维碳水化合物（NFC）的摄入量。饲喂WRS的奶牛瘤胃丙酸浓度低于饲喂CS2或CS4的奶牛。饲喂破碎生大豆的奶牛粪便中的氮含量低于饲喂WRS的奶牛。饲喂WRS、CS2和CS4的奶牛所产牛奶中的不饱和脂肪酸含量高于饲喂CO的奶牛。在奶牛日粮中添加生大豆，无论颗粒大小，都不会损害未校正的产奶量和养分消化，并增加了牛奶中不饱和脂肪酸的浓度。饲喂破碎生大豆的奶牛与饲喂全生大豆的奶牛具有相似的生产性能。
