Miller-Cushon E K, Bergeron R, Leslie K E, Mason G J, DeVries T J
Department of Animal and Poultry Science, University of Guelph, Kemptville Campus, 830 Prescott Street, Kemptville, ON, K0G 1J0, Canada.
Department of Animal and Poultry Science, University of Guelph, Campus d'Alfred, Alfred, ON, K0B 1A0, Canada.
J Dairy Sci. 2013;96(11):7260-7268. doi: 10.3168/jds.2013-7013. Epub 2013 Sep 12.
The objectives of this study were to determine the effect of feed presentation on meal frequency and duration, as well as diurnal feeding patterns of dairy calves, and to assess any longer-term differences in feeding patterns resulting from previous experience. Twenty Holstein bull calves were exposed from wk 1 to 8 of life to 1 of 2 feed presentation treatments: concentrate and chopped grass hay (<2.5 cm) offered at a ratio of 7:3 as a mixture (MIX), or as separate components (COM). Feed was provided ad libitum. Calves received 8L/d of milk replacer (1.2 kg of dry matter), with the amount progressively reduced after 5 wk to facilitate weaning by the end of wk 7. At the beginning of wk 9, all calves received the MIX diet and remained on trial for an additional 3 wk. Feeding behavior was recorded from video for 4d during wk 6, 8, 9, and 11. In wk 6, calves fed MIX spent more time feeding than calves fed COM (56.7 vs. 46.8 min/d). In wk 8, calves fed MIX spent more time feeding (174.0 vs. 139.1 min/d) and had a lower rate of intake (11.5 vs. 14.7 g/min) compared with calves fed COM. Meal frequency was similar between treatments (12.2 meals/d). Diurnal feeding patterns in wk 8 were also affected by feed presentation, with calves fed MIX spending less time feeding at time of feed delivery and more time feeding throughout the rest of the daylight hours than calves fed COM. Diurnal feeding patterns of hay and concentrate in wk 8 differed for calves fed COM, with more time spent consuming hay at time of feed delivery and less time spent consuming hay throughout the rest of the day. Once calves previously fed COM were transitioned to the MIX diet in wk 9, meal frequency, meal duration, and diurnal feeding patterns were similar between treatments: both treatments spent similar amounts of time feeding (173.9 min/d) and had similar peaks in feeding activity at time of feed delivery, sunrise, and sunset. Provision of hay and concentrate to young calves as a mixed ration, compared with separate components, increases time spent feeding and results in more evenly distributed diurnal feeding patterns. However, differences in feeding patterns resulting from feed presentation did not persist after 8 wk of age, when all calves were fed a mixed ration.
本研究的目的是确定饲料呈现方式对犊牛采食频率、采食持续时间以及昼夜采食模式的影响，并评估先前经历导致的采食模式的任何长期差异。20头荷斯坦公牛犊在出生后第1至8周接受两种饲料呈现处理中的一种：以7:3的比例混合提供精料和切碎的禾本科干草（<2.5厘米）（混合组），或以单独成分提供（分开组）。自由采食。犊牛每天摄入8升代乳粉（1.2千克干物质），5周后逐渐减少摄入量，以便在第7周结束时顺利断奶。在第9周开始时，所有犊牛都改为混合组日粮，并继续试验3周。在第6、8、9和11周期间，通过视频记录4天的采食行为。在第6周，混合组犊牛的采食时间比分开组犊牛长（56.7分钟/天对46.8分钟/天）。在第8周，与分开组犊牛相比，混合组犊牛的采食时间更长（174.0分钟/天对139.1分钟/天），采食速度更低（11.5克/分钟对14.7克/分钟）。两组的采食频率相似（12.2次/天）。第8周的昼夜采食模式也受饲料呈现方式的影响，与分开组犊牛相比，混合组犊牛在饲料投喂时的采食时间较少，而在其余白天时间的采食时间较多。对于分开组犊牛，第8周干草和精料的昼夜采食模式不同，在饲料投喂时消耗干草的时间较多，而在一天中的其余时间消耗干草的时间较少。一旦先前饲喂分开组日粮的犊牛在第9周过渡到混合组日粮，两组的采食频率、采食持续时间和昼夜采食模式相似：两组的采食时间相似（173.9分钟/天），在饲料投喂、日出和日落时的采食活动峰值相似。与单独提供成分相比，给幼龄犊牛提供混合日粮会增加采食时间，并导致昼夜采食模式分布更均匀。然而，在8周龄后，当所有犊牛都饲喂混合日粮时，由饲料呈现方式导致的采食模式差异不再持续。
