Byskov M V, Nadeau E, Johansson B E O, Nørgaard P
Knowledge Centre for Agriculture-Cattle, 8200 Aarhus N, Denmark; Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark.
Department of Animal Environment and Health, Swedish University of Agricultural Sciences, 532 23 Skara, Sweden.
J Dairy Sci. 2015 Jun;98(6):3926-37. doi: 10.3168/jds.2014-8012. Epub 2015 Mar 18.
Individual recording of rumination time (RT) is now possible in commercial dairy herds, through development of a microphone-based sensor, which is able to record RT by the sound of rumination activity. The objectives of this study were to examine the relationship between daily RT and intakes of different dietary fractions, the relationship between RT in minutes per kilogram of dry matter intake (DMI) and milk production, and to examine the variation in RT within and between mid-lactating dairy cows. Data from 3 production trials were used in which a total of 27 different diets were fed. The data contained 761, 290, and 203 daily recordings of RT, milk yield, milk components, DMI, and intake of dietary fractions recorded on 29, 26, and 24 Holstein and Swedish Red cows from trials 1, 2, and 3, respectively. The dietary fractions included forage neutral detergent fiber (NDF), concentrate NDF, crude protein, sugar, starch, and the remaining fraction represented by organic matter--(forage NDF+concentrate NDF+crude protein+sugar+starch). The relationship between the dietary fractions and RT was analyzed in 2 steps. In step 1, the dietary fractions, which were significantly related to RT, were selected and simultaneously checked for multicollinearity between the dietary components; in step 2, a multivariate model, including the effect of repeated measurements, the main effect of the selected dietary fractions from step 1, random effects of cow(trial) and trial, and information on breed, days in milk, and parity was used to analyze the relationship between RT and the selected dietary fractions. Relationships between RT in minutes per kilogram of DMI and milk yield and milk components were analyzed, using the same multivariate model as in step 2. Approximately 32% of the variation in daily RT could be explained by variations in intakes of the dietary fractions, whereas 48% of the total variation in RT was accounted for by individual variations between cows. Intakes of forage NDF and starch were positively related to daily RT, whereas intakes of sugar and the remaining fraction were negatively related to daily RT. Rumination time in minutes per kilogram of DMI was negatively related to milk yield and protein percentage, but positively related to milk fat percentage.
通过开发基于麦克风的传感器，现在可以在商业化奶牛场中对反刍时间（RT）进行个体记录，该传感器能够通过反刍活动的声音记录反刍时间。本研究的目的是研究每日反刍时间与不同日粮成分摄入量之间的关系、每千克干物质摄入量（DMI）的反刍时间与产奶量之间的关系，并研究泌乳中期奶牛个体内和个体间反刍时间的变化。使用了来自3个生产试验的数据，其中共投喂了27种不同的日粮。数据包含分别来自试验1、2和3的29头、26头和24头荷斯坦奶牛和瑞典红牛的761次、290次和203次每日反刍时间、产奶量、乳成分、干物质摄入量以及日粮成分摄入量的记录。日粮成分包括饲草中性洗涤纤维（NDF）、精料NDF、粗蛋白、糖、淀粉，其余部分由有机物表示（饲草NDF + 精料NDF + 粗蛋白 + 糖 + 淀粉）。日粮成分与反刍时间之间的关系分两步进行分析。第一步，选择与反刍时间显著相关的日粮成分，并同时检查日粮成分之间的多重共线性；第二步，使用一个多变量模型，包括重复测量的效应、第一步中选择的日粮成分的主效应、奶牛（试验）和试验的随机效应，以及品种、泌乳天数和胎次信息，来分析反刍时间与所选日粮成分之间的关系。使用与第二步相同的多变量模型分析每千克DMI的反刍时间与产奶量和乳成分之间的关系。日粮成分摄入量的变化可以解释约32%的每日反刍时间变化，而奶牛个体间的差异占反刍时间总变化的48%。饲草NDF和淀粉的摄入量与每日反刍时间呈正相关，而糖和其余部分的摄入量与每日反刍时间呈负相关。每千克DMI的反刍时间与产奶量和蛋白质百分比呈负相关，但与乳脂百分比呈正相关。
