Cattle diets under continuous and four-pasture, one-herd grazing systems in southcentral New Mexico.
Cattle diets under continuous and four-pasture, one-herd grazing systems in southcentral New Mexico.
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新墨西哥州中南部连续四牧场、一群放牧系统下的牛饮食。
DOI：
10.2307/3898823
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
E. E. Parker
中科院分区：
文献类型：
--
作者：
J. Pfister;G. B. Donart;R. Pieper;J. D. Wallace;E. E. Parker
从放牧四个牧场，一个牛群轮换系统和一年的牧场的奶牛中收集饲料样品。两个系统之间的饮食植物含量的差异是不一致的两年。在第一年的饮食奶牛放牧的旋转牧场更高的浏览和更低的草含量相比，放牧的全年牧场。然而，在第二年，浏览内容的饮食是几乎相同的两个系统。显然，较高的断奶重量的小牛从全年系统相关的更大的牧草的可用性和消化率相比，轮换制度。放牧制度往往被视为一种改善牧场条件的手段，同时仍然允许放牧。近年来，随着对我们牧场的压力增加，人们对放牧系统的兴趣有所增加。环境影响报告往往建议实施放牧制度。然而，最近对专门放牧系统的审查显示了不同的和经常令人困惑的结果（Shiflet和Heady 1971，Herbel 1974，McDaniel和Allison 1980）。传统上，对轮作和连续放牧制度进行比较的研究是测量植被覆盖和牲畜产量。牲畜的反应是有据可查的，并已根据牛的体重变化、平均日增重和小牛断奶体重进行了测量。将牲畜限制在相对较小的牧场上的密集放牧系统通常会降低个体动物的性能（Pieper 1980）。然而，由于影响反应的因素很多，根本原因往往不清楚（Heady 1961）。在专门的放牧系统中，评估牛的饮食选择性的变化可能有助于量化和解释牲畜和植被的反应。本研究的目的是比较植物组成，并确定之间的四个牧场，一个牛群和一年的放牧系统牛饲料的消化率。
Diet samples were collected from cows grazing a four-pasture, one-herd rotation system and a yearlong pasture. Differences in botanical content of the diet between the two systems was not consistent for the two years. During the first year diet of cows grazing the rotation pastures were higher in browse and lower in grass content compared to those grazing the yearlong pasture. However, during the second year, browse content of the diets was nearly identical for the two systems. Apparently higher weaning weights of calves from the yearlong system are related to greater herbage availability and digestibility compared to the rotation system. Grazing systems have often been looked upon as a means of improving range conditions while still allowing grazing. In recent years, the interest in grazing systems has increased as additional pressures are brought to bear on our rangelands. Environmental impact statements often recommend implementation of grazing systems. However, recent reviews of specialized grazing systems have shown diverse and often confusing results (Shiflet and Heady 1971, Herbel 1974, McDaniel and Allison 1980). Research comparing rotation and continuous grazing systems has traditionally measured vegetational cover and livestock production. Livestock responses are well-documented and have been measured in terms of cattle weight flux, average daily gain and calf weaning weights. Intensive grazing systems in which livestock are confined to relatively small pastures often decrease individual animal performance (Pieper 1980). However, underlying causes have often not been clear because of the large number of factors influencing responses (Heady 1961). Evaluating changes in selectivity of diet by cattle in specialized grazing systems may aid in quantifying and interpreting livestock and vegetational responses. The objectives of this study were to compare botanical composition and determine digestibility of cattle diets between a fourpasture, one-herd and a year-long grazing system.