Department of Field Crops, Faculty of Agriculture, Canakkale Onsekiz Mart University, Canakkale, Turkey.
Anim Sci J. 2009 Feb;80(1):34-40. doi: 10.1111/j.1740-0929.2008.00592.x.
This study aimed at identifying changes in natural pastures during the grazing season and investigating the effects of these changes on pasture feeding potential for high yielding dairy goats. During the study, 12 dairy goats were grazed on a 1.5 ha natural pasture for three months from April to June in 2003, 2004 and 2005. The goats were fed 0.5 kg/day of concentrate as a supplement during the grazing season. Botanical composition, herbage production and intake, crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of the pasture were determined. Live weight, milk yield, milk dry matter (DM) and fat content of the goats were monitored. The data were analyzed using a linear model, which evaluated the effects of grazing seasons in each year. Based on the three-year average, 87% of pasture was herbaceous plants and the remaining was shrubs in DM basis with Cistus creticus, Quercus ithaburensis, Pistacia atlantica and Asparagus acutifolius being the major shrub species. The herbage yield in June was significantly lower than in other months in all years (P = 0.001). In all experimental years, the CP content of the pasture decreased but the structural carbohydrates increased as the grazing season proceeded. While live weight was not affected by grazing periods except for 2004 (P = 0.001), milk yield significantly decreased with advancing grazing period (P = 0.001). The results of the present study indicate that natural pasture has a supportive effect in April and May on the milk yield of lactating goats which are in mid-lactation, and suggested that supplementary feeding is required in consecutive grazing periods.
本研究旨在鉴定放牧季节中天然草地的变化，并研究这些变化对高产奶山羊牧场采食潜力的影响。在研究期间，2003 年、2004 年和 2005 年 4 月至 6 月，12 只奶山羊在 1.5 公顷的天然牧场上放牧了三个月。放牧期间，羊每天补饲 0.5 公斤浓缩饲料。测定了草地的植物组成、牧草产量和采食量、粗蛋白（CP）、中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）含量。监测了羊的活重、产奶量、奶干物质（DM）和脂肪含量。数据采用线性模型进行分析，评估了每年放牧季节的影响。基于三年的平均值，牧草地上 87%为草本植物，以灌木为主的有 Cistus creticus、Quercus ithaburensis、Pistacia atlantica 和 Asparagus acutifolius，DM 基础上占 13%。所有年份的 6 月牧草产量均明显低于其他月份（P = 0.001）。在所有实验年份中，随着放牧季节的进行，草地 CP 含量降低，但结构性碳水化合物增加。除 2004 年外（P = 0.001），活重不受放牧期的影响，但随着放牧期的延长，产奶量显著下降（P = 0.001）。本研究结果表明，天然草地对处于泌乳中期的泌乳山羊在 4 月和 5 月的产奶量有一定的支持作用，并表明在连续放牧期间需要补充饲料。
