Ingestive behavior of dairy goats fed diets containing increasing levels of neutral detergent fiber and particle size using multivariate analysis

ABSTRACT. The purpose of this study was to evaluate the effect of interaction between increasing neutral detergent fiber content and particle sizes on ingestive behavior of dairy goats. Forty-eight lactating, multiparous Saanen and Alpine goats, with average milk production of 1.4 ±0.57 kg d-1, around 60th ±12 day of lactation were distributed in a 3 x 4 factorial completely randomized design. The diets consisted: three particles sizes (02, 05 or 15 cm) and four levels of neutral detergent fiber (34, 41, 49 or 57% NDFf) from forage (Tifton 85 hay). The ingestive behavior was monitored during 24 hours. A regression and a multivariate time series cluster analysis were performed. No interaction was found (p > 0.05) between treatments. Feeding time was different according to the particle size, having an increasing linear effect. Rumination and idle times were not affected (p > 0.05). The temporal feeding behavior was clustered into two groups according to the profile of particle size of the diet. Rumination peaks were randomly distributed with more intense activity before morning and afternoon meals. The increase in NDFf content in the diet did not change the ingestive behavior. The multivariate cluster analysis in a time series data is useful to interpret animal feeding behavior.

摘要。本研究旨在评估中性洗涤纤维（neutral detergent fiber, NDF）含量提升与饲草粒径大小的交互作用对奶山羊采食行为的影响。试验选取48头泌乳中期、经产的萨能奶山羊与阿尔卑斯奶山羊，其日均产奶量为1.4±0.57千克/日，泌乳天数处于60±12天区间，采用3×4析因完全随机试验设计进行分组。日粮设置包含3个饲草粒径水平（0.2、0.5或1.5厘米）与4个中性洗涤纤维（NDFf）水平（34%、41%、49%或57%），粗饲料为蒂夫顿85干草。研究对山羊的采食行为开展了24小时连续监测，并进行回归分析与多变量时间序列聚类分析。结果显示，各处理组间未检测到显著交互作用（p>0.05）。采食时间随饲草粒径增大呈现显著线性递增趋势；反刍时间与空闲时间不受处理因素影响（p>0.05）。根据日粮粒径特征，采食时间序列可被划分为2个聚类组别。反刍活动峰值呈随机分布，且在晨间与午后采食前的活动强度更高。日粮中NDFf含量提升并未改变奶山羊的采食行为。多变量时间序列聚类分析可有效用于阐释动物采食行为的规律。