Grant R J, Albright J L
Department of Animal Science, University of Nebraska, Lincoln 68583-0908, USA.
J Anim Sci. 1995 Sep;73(9):2791-803. doi: 10.2527/1995.7392791x.
Little research has focused specifically on the relationships among feeding behavior, management strategy, and optimal intake by the transition cow. Most information must be extrapolated from studies of cattle at other stages of lactation. The transition period can be divided into two distinct phases: 5 to 7 d prepartum, characterized by a 30% reduction in DMI, and 0 to 21 d postpartum, during which time intake should increase rapidly. Feed restriction can reduce number of daily meals by 50%, but when feed is offered for ad libitum consumption, with consistent time of feeding, access can be limited to 8 h daily with no adverse effects on performance of midlactation cows. Sequence of offering feeds may affect intake, but relative degradabilities of dietary protein and starch need to be considered. During early lactation, increased feeding frequency of a total mixed diet may most improve intake when dietary fermentability is moderate to high and management quality is poor. High-producing dairy cows achieve greater intake by increasing meal size and spending less time eating and ruminating per unit of intake. Control of feed intake and meal patterns may differ by parity and should be considered when grouping cattle. Daily exercise of tied dairy cows may not affect intake. Grouping strategy and group feeding behavior influence cow productivity and profitability. Competition for feed and space can be reduced by fenceline feeding vs bunks. Optimum intake during the transition period will occur only if feeding management accommodates normal feeding behavior of dairy cows.
很少有研究专门关注围产母牛的采食行为、管理策略和最佳采食量之间的关系。大多数信息必须从泌乳其他阶段的牛的研究中推断得出。围产期可分为两个不同阶段:产前5至7天,其特征是干物质采食量(DMI)降低30%;产后0至21天,在此期间采食量应迅速增加。限饲可使每日采食次数减少50%,但当提供饲料任其自由采食时,若喂食时间一致,每天的采食时间可限制在8小时,而对泌乳中期奶牛的生产性能无不利影响。饲料的投喂顺序可能会影响采食量,但需要考虑日粮蛋白质和淀粉的相对降解率。在泌乳早期,当日粮发酵性为中度至高且管理水平较差时,增加全混合日粮的投喂频率可能最有助于提高采食量。高产奶牛通过增加采食餐量并减少单位采食量的采食和反刍时间来实现更高的采食量。采食量和采食模式的控制可能因胎次而异,在对牛进行分组时应予以考虑。拴系奶牛的日常运动可能不会影响采食量。分组策略和群体采食行为会影响奶牛的生产效率和盈利能力。与围栏饲喂相比,围栏线饲喂可减少饲料和空间竞争。只有当饲养管理适应奶牛的正常采食行为时,围产期才会出现最佳采食量。