Teagasc, Moorepark Dairy Production Research Centre, Fermoy, Co. Cork, Ireland.
J Dairy Sci. 2010 Feb;93(2):764-74. doi: 10.3168/jds.2009-2659.
The objectives of this study were to investigate differences in grazing behavior among Holstein-Friesian (HF), Jersey (JE), and Jersey x Holstein-Friesian (F(1)) cows under an intensive, seasonal, grass-based environment and to determine whether associations exist among grazing behavior, intake capacity, and production efficiency. Data from a total of 108 animals (37 HF, 34 JE, and 37F(1)) were available for analysis. Measurements included milk production, body weight (BW), intake, and grazing behavior. Breed group had a significant effect on all of the production, grass dry matter intake, and efficiency parameters investigated. No differences were observed among the breeds for grazing time, number of grazing bouts, grazing bout duration, and total number of bites. Grazing mastications were higher for the JE cows compared with the HF cows. Grass dry matter intake per bite and rate of intake per minute were higher for the HF cows compared with the JE cows. Large differences between the breeds were apparent when grazing behavior measurements were expressed per unit of BW and per unit of intake. In absolute terms, the HF cows spent more time ruminating and had more mastications during rumination than the JE cows. However, when expressed per unit of BW, ruminating time was greater for the JE cows and they tended to have more ruminating mastications compared with the HF cows. Despite these differences, ruminating time and ruminating mastications per unit of intake were similar for the 2 breeds. For the most part, the F(1) cows tended to be similar to the mid-parent mean, but results showed an increase in biting rate, lower grazing duration per bout, and a tendency to achieve a high intake per bite compared with the average of the parent breeds. The results obtained also indicate that inherent grazing and ruminating differences exist between cows varying in intake capacity and production efficiency. Cows with higher intake capacities have increased grazing time and rate of intake per unit of BW. Increased production efficiency, on the other hand, appears to be aided, in particular by improvements in mastication behavior during grazing.
本研究的目的是在密集、季节性、以草为主的环境下，研究荷斯坦-弗里生牛（HF）、泽西牛（JE）和泽西牛与荷斯坦-弗里生牛杂交后代（F(1)）的放牧行为差异，并确定放牧行为、采食能力和生产效率之间是否存在关联。共有 108 头动物（37 头 HF、34 头 JE 和 37 头 F(1)）的数据可用于分析。测量指标包括产奶量、体重（BW）、采食量和放牧行为。品种组对所有调查的生产、牧草干物质采食量和效率参数均有显著影响。三种品种之间的放牧时间、放牧次数、单次放牧持续时间和总咀嚼次数均无差异。JE 牛的咀嚼次数高于 HF 牛。HF 牛的每口牧草干物质采食量和每分钟采食量均高于 JE 牛。当以 BW 和采食量为单位表示放牧行为测量值时，品种间差异明显。就绝对值而言，HF 牛反刍时间长，反刍时咀嚼次数多于 JE 牛。然而，当以 BW 为单位表示时，JE 牛的反刍时间较长，反刍时的咀嚼次数也比 HF 牛多。尽管存在这些差异，但两种品种的单位采食量的反刍时间和反刍咀嚼次数相似。在大多数情况下，F(1)牛的表现与中间亲代均值相似，但结果显示，与亲本品种相比，F(1)牛的采食率增加，单次放牧持续时间减少，且每口采食的牧草量增加。研究结果还表明，在采食能力和生产效率不同的奶牛之间存在固有的放牧和反刍差异。采食能力较高的奶牛增加了放牧时间和单位 BW 的采食量。另一方面，提高生产效率，特别是通过提高放牧时的咀嚼行为，似乎有所帮助。
