Feeding dairy cows with soybean by-products: effects on metabolic profile

Ciência Rural

Wald, Vera³  González, Félix³  Alves, Marilia¹  Lima, Verônica²  Mühlbach, Paulo²  Carvalho, Nelcy⁴  Conceição, Tiago Reis¹ 

[1] Universidade Universidade Federal do Rio Grande do Sul;Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil;Universidade Universidade Federal de Santa Maria

关键词: metabolic profile;    roasted soybean;    dairy cows;    milk;    protein;    urea;   

DOI  :  10.1590/S0103-84782004000100037

学科分类：农业科学（综合）

来源: Universidade Federal de Santa Maria * Centro de Ciencias Rurais

【 摘 要 】

Soybean by-products are currently used in Rio Grande do Sul, Brazil, as a source of protein in dairy cows. However, the high protein breakdown of this feed source in the rumen causes loss of the intrinsic quality of the protein and increases plasma urea with deleterious consequences to animal metabolism. Thermal treatment of soybean can overcome this limitation. The aim of this study was to evaluate the metabolism of dairy cows fed with thermally treated soybean and raw soybean, through the analyses of the metabolic profile of plasma and milk. Twelve Holstein cows in mid-lactation period were studied using four treatments: commercial concentrated of protein, soybean meal, raw soybean and roasted soybean. Protein and urea levels in milk were measured in morning and afternoon samples. Data were arranged in a Latin square design (4 treatments and 3 animals in each square). There were no significant differences in glucose, beta-hydroxybutyrate, calcium, phosphorus and magnesium concentrations among treatments. Cows consuming raw and thermally treated soybean had higher levels of plasma cholesterol. Cows consuming roasted soybean had lower level of plasma and milk urea in the morning. Afternoon milk samples had higher levels of urea than morning samples. It is suggested that thermally treated soybean was effective in diminishing the breakdown of protein in the rumen. It is better to employ morning milk samples to evaluate metabolic profile than afternoon samples.

【 授权许可】

CC BY-NC