McGee M, Ramirez J A, Carstens G E, Price W J, Hall J B, Hill R A
Department of Animal and Veterinary Science, University of Idaho, Moscow 83844.
Department of Animal Science, Texas A&M University, College Station 77843.
J Anim Sci. 2014 Aug;92(8):3580-90. doi: 10.2527/jas.2013-7360. Epub 2014 Jun 19.
New approaches to limit expenses associated with input, without compromising profit, are needed in the beef industry. Residual feed intake (RFI) is an efficiency trait that measures variation in feed intake beyond maintenance, growth, and body composition. The addition of feeding behavior analysis to standard RFI tests may provide an approach to more readily identify feed-efficient cattle. The current study analyzes 7 feeding behaviors (BVFREQ: bunk visit frequency, BVDUR: bunk visit duration, FBFREQ: feed bout frequency, FBDUR: feed bout duration, MFREQ: meal frequency, MDUR: meal duration, and AMINT: average meal intake) and their relationships with RFI, ADG, and DMI in Japanese Black (Wagyu) cattle. Three cohorts of yearling Wagyu animals were studied using a standard 70-d RFI test, and data from divergent ( ± 0.5 SD from population RFI mean) subsets of animals were analyzed for feeding behaviors [n = 58, bulls on high-concentrate diet (C1); n = 36, bulls on a lower-concentrate diet (C2); n = 34, heifers on a lower-concentrate diet (C3)]. The following behaviors were correlated with ADG: BVFREQ (r = 0.32, P = 0.01; C1 bulls), BVDUR (r = 0.42, P = 0.01, C2 bulls), FBFREQ (r = 0.37, P < 0.01; C1 bulls), FBDUR (r = 0.46, P < 0.01, C1 bulls), and MFREQ (r = 0.42, P < 0.01, C2 bulls). Behaviors were trending or significantly correlated with DMI for all cases except for MFREQ for C3 and AMINT for C2. Residual feed intake was positively correlated with MDUR across all cohorts (r = 0.31, P = 0.02; r = 0.38, P = 0.02; r = 0.54, P ≥ 0.01, respectively). For C2 bulls and C3 heifers, RFI was positively correlated with behavior frequency categories (BVFREQ; r = 0.44, P = 0.01; r = 0.60, P ≤ 0.01, respectively, and FBFREQ r = 0.46, P ≤ 0.01; r = 0.60, P ≤ 0.01, respectively). Bunk visit frequency and FBFREQ were highly correlated with RFI status (high or low) in C2 bulls and C3 heifers. Behavior duration categories (BVDUR, FBDUR, and MDUR) were most correlated with efficiency status in C1 bulls. However, behavior frequency categories (BVFREQ and FBFREQ), as well as MDUR, were most correlated with efficiency status in C2 bulls and C3 heifers. Inclusion of meal duration measurements when evaluating RFI provides an additional tool in understanding the drivers of variation in this important trait in Wagyu cattle. The present study provides new insights into feed intake patterns of a beef breed for which there are few reports of feeding behavior.
肉牛行业需要新的方法来控制与投入相关的成本，同时又不影响利润。剩余采食量（RFI）是一种效率性状，用于衡量维持、生长和身体组成之外的采食量变化。在标准RFI测试中增加采食行为分析，可能提供一种更容易识别饲料效率高的牛的方法。本研究分析了日本黑毛（和牛）的7种采食行为（BVFREQ：采食槽访问频率、BVDUR：采食槽访问持续时间、FBFREQ：采食回合频率、FBDUR：采食回合持续时间、MFREQ：进餐频率、MDUR：进餐持续时间和AMINT：平均进餐摄入量）及其与RFI、平均日增重（ADG）和干物质采食量（DMI）的关系。使用标准的70天RFI测试对三组一岁和牛动物进行了研究，并对来自不同（相对于群体RFI平均值±0.5标准差）动物子集的数据进行采食行为分析[n = 58，高浓缩日粮公牛（C1）；n = 36，低浓缩日粮公牛（C2）；n = 34，低浓缩日粮小母牛（C3）]。以下行为与ADG相关：BVFREQ（r = 0.32，P = 0.01；C1公牛）、BVDUR（r = 0.42，P = 0.01，C2公牛）、FBFREQ（r = 0.37，P < 0.01；C1公牛）、FBDUR（r = 0.46，P < 0.01，C1公牛）和MFREQ（r = 0.42，P < 0.01，C2公牛）。除C3的MFREQ和C2的AMINT外，所有情况下行为与DMI呈趋势相关或显著相关。在所有组中，剩余采食量与MDUR呈正相关（分别为r = 0.31，P = 0.02；r = 0.38，P = 0.02；r = 0.54，P≥0.01）。对于C2公牛和C3小母牛，RFI与行为频率类别呈正相关（BVFREQ；分别为r = 0.44，P = 0.01；r = 0.60，P≤0.01，以及FBFREQ，r = 0.46，P≤0.01；r = 0.60，P≤0.01）。在C2公牛和C3小母牛中，采食槽访问频率和FBFREQ与RFI状态（高或低）高度相关。行为持续时间类别（BVDUR、FBDUR和MDUR）在C1公牛中与效率状态相关性最高。然而，行为频率类别（BVFREQ和FBFREQ）以及MDUR在C2公牛和C3小母牛中与效率状态相关性最高。在评估RFI时纳入进餐持续时间测量，为理解和牛这一重要性状变异的驱动因素提供了一个额外工具。本研究为一种鲜有采食行为报道的肉牛品种的采食量模式提供了新见解。
