Venturelli B C, de Freitas Júnior J E, Takiya C S, de Araújo A P C, Santos M C B, Calomeni G D, Gardinal R, Vendramini T H A, Rennó F P
Department of Animal Nutrition and Production, Faculty of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, Brazil.
Department of Animal Science, Federal University of Bahia, Ondina, Brazil.
J Anim Physiol Anim Nutr (Berl). 2015 Dec;99(6):1149-60. doi: 10.1111/jpn.12297. Epub 2015 Apr 3.
Whole oilseeds such as soya beans have been utilized in dairy rations to supply additional fat and protein. However, antinutritional components contained in soya beans, such as trypsin inhibitors and haemagglutinins (lectins) may alter digestibility of nutrients and consequently affect animal performance. The objective of the present experiment was to quantify the effect of different levels of whole raw soya beans in diets of dairy cows on nutrient intake, total tract digestion, nutrient balances and milk yield and composition. Sixteen mid to late-lactation cows (228 ± 20 days in milk; mean ± SD) were used in four replicated 4 × 4 Latin square design experiment with 21-d periods. Cows were assigned to each square according to milk yield and DIM. The animals were randomly allocated to treatments: control (without soya beans addition; CO), WS9, WS18 and WS27, with addition of 9%, 18% and 27% of whole raw soya bean in diet on a dry matter (DM) basis respectively. All diets contained identical forage and concentrate components and consisted of maize silage and concentrate based on ground corn and soya beans at a ratio of 60:40. There were no differences in OM, CP, NDF and NEL intakes (kg/day and MJ/day) among the treatments (p > 0.05). However, DM and NFC intakes were negatively affected (p = 0.04 and p < 0.01, respectively) and ether extract (EE) intake was positively affected (p < 0.01). Total tract digestion increased linearly with whole raw soya beans for EE (p < 0.01) and NDF (p = 0.01). The excretion (kg/day) of digested soya beans grains increased linearly according to addition of whole raw soya beans. However, the nutritive characteristics of excreted grains were not altered. Milk (kg), milk lactose (kg) and protein (kg) yield decreased linearly (p < 0.01, p < 0.01 and p = 0.04, respectively) milk fat content (%) increased linearly (p < 0.01) with whole raw soya beans inclusion. Increasing addition of whole raw soya beans affected milk fatty acid profile with a linear decrease of cis-9-trans 11CLA and total saturated FA; and linear increase of total unsaturated and C18:3 FA. Energy balance was positively affected (p = 0.03) by whole raw soya beans as well as efficiency of NEL milk/DE intake (p = 0.02). Nitrogen balance and microbial protein synthesis were not affected by whole raw soya beans. Increasing doses of whole raw soya beans decreased dry matter intake and milk yield, however, led to an increase of unsaturated acids in milk and higher milk fat concentration.
全脂大豆等完整油籽已被用于奶牛日粮中，以提供额外的脂肪和蛋白质。然而，大豆中含有的抗营养成分，如胰蛋白酶抑制剂和血凝素（凝集素），可能会改变养分的消化率，从而影响动物的生产性能。本实验的目的是量化奶牛日粮中不同水平的全脂生大豆对养分摄入量、全消化道消化率、养分平衡以及产奶量和奶成分的影响。16头处于泌乳中期至后期的奶牛（平均泌乳天数为228±20天；均值±标准差）被用于进行一项4×4拉丁方设计实验，共4个重复，每期21天。根据产奶量和泌乳天数将奶牛分配到每个方格中。动物被随机分配到各处理组：对照组（不添加大豆；CO）、WS9、WS18和WS27，日粮中分别按干物质（DM）基础添加9%、18%和27%的全脂生大豆。所有日粮的粗饲料和精饲料成分相同，由玉米青贮和以玉米粉和大豆为基础的精饲料组成，比例为60:40。各处理组之间的有机物、粗蛋白、中性洗涤纤维和净能摄入量（千克/天和兆焦/天）没有差异（p>0.05）。然而，干物质和非纤维性碳水化合物摄入量受到负面影响（分别为p = 0.04和p < 0.01），而乙醚提取物（EE）摄入量受到正面影响（p < 0.01）。全消化道对EE（p < 0.01）和NDF（p = 0.01）的消化率随全脂生大豆的添加量呈线性增加。消化后的大豆籽粒排泄量（千克/天）随全脂生大豆添加量的增加呈线性增加。然而，排泄籽粒的营养特性没有改变。牛奶产量（千克）、乳糖产量（千克）和蛋白质产量（千克）呈线性下降（分别为p < 0.01、p < 0.01和p = 0.04），牛奶脂肪含量（%）随全脂生大豆的添加呈线性增加（p < 0.01）。全脂生大豆添加量的增加影响了牛奶脂肪酸谱，顺-9-反-11共轭亚油酸和总饱和脂肪酸呈线性下降；总不饱和脂肪酸和C18:3脂肪酸呈线性增加。全脂生大豆对能量平衡有正面影响（p = 0.03），对净能转化为牛奶能量的效率也有正面影响（p = 0.02）。全脂生大豆对氮平衡和微生物蛋白质合成没有影响。全脂生大豆添加量的增加降低了干物质摄入量和牛奶产量，但导致牛奶中不饱和脂肪酸增加和牛奶脂肪浓度升高。
