Levels of multiple supplements or nitrogen salt for beef heifers in pasture during the dry season

Revista Brasileira de Zootecnia

Valente, Ériton Egidio Lisboa²  Acedo, Tiago Sabella¹  Lopes, Sidnei Antonio²  Campos Valadares Filho, Sebastião de²  Barros, Lívia Vieira de²  Couto, Victor Rezende Moreira²  Detmann, Edenio²  Paulino, Mário Fonseca² 

[1] Universidade Federal de Viçosa

关键词: digestibility;    intake;    performance;    self-control;   

DOI  :  10.1590/S1516-35982011000900024

学科分类：兽医学

来源: Universidade Federal de Vicosa

【 摘 要 】

The study assessed performance, microbial protein synthesis, intake and digestibility of nutrients by beef heifers receiving levels of multiple supplements or nitrogen salt, in a self-controlled intake, on pasture, during the dry season. Thirty-five beef heifers, from 6 to 9 months of age and average initial body weight of 203.4 + 4.5 kg, were used. Study factors were: control – mineral mixture; nitrogen salt – 50% of urea + mineral mixture, at proportion of 1:1, and 50% of corn (75% of crude protein); levels of multiple supplementation – multiple supplements with different percentages of intake controller mixture (urea + mineral mixture, at the proportion of 1:1), corn and soybean meal (45% of crude protein). Supplement consumptions observed were: 115, 173, 572 and 1214 g/animal/day for animals fed on nitrogen salt, low, medium and high levels of multiple supplement, respectively. Supplemented animals had greater average daily gain, evidencing the positive linear effect of the levels of multiple supplementation on average daily gain. Overall, there were no significant differences between average daily gain of animals fed on multiple supplements or nitrogen salt. Supplementation increased the intake and digestibility of nutrients, except for digestibility of neutral detergent fiber, although the intake of digested neutral detergent fiber increased. Supplementation increased the production of microbial nitrogen as well as nitrogen losses in urine, although the quantity of nitrogen assimilated by bacteria, proportionally to intake, was higher. Supplementation improves nutritional parameters and weight gain.

【 授权许可】

CC BY-NC