Department of Animal and Food Sciences, Pork Industry Institute, Texas Tech University, Lubbock, TX, 79409-2141, USA.
Animal. 2008 Apr;2(4):600-5. doi: 10.1017/S1751731108001766.
This study was initiated to understand whether feeding behaviour and physiology may contribute to the rate of fatigued pigs at processing plants. Specifically, this study sought to determine: (1) how often pigs eat during the day, (2) the times of the day they eat and (3) a first approximation of the time from feed consumption to excretion (rate of passage) when housed in a group in conventional finishing facilities. Finally, models were constructed to try to predict the percentage of pigs with empty/diminished gastrointestinal (GI) tracts depending on the time of day of truck loading and transport durations. Pigs were randomly selected, weighed and selected for behavioural observations. From video records and live observations, the number of meals (feeding bouts) per day and the time of the day meals took place were recorded. Feed containing chromic oxide was fed to determine when a given meal was excreted. With the feeding times of day determined, models were constructed of the percentage of pigs that would have empty stomachs depending on the time of day pigs were removed from the barn and the length of transport/lairage. Finishing pigs housed in groups ate 5.6 ± 0.6 meals per day with an average feeding bout (meal) length of 11.3 ± 1.1 min. Many pigs fed ad libitum ate most of their meals during the afternoon and evening. The rate of passage of feed was 20.5 h (range = 18 to 24 h). Because fewer pigs ate in the late evening through morning, if pigs were shipped at these times they would have an increased risk of arriving at the stun at a plant with an empty GI tract. Some of the variation in rates of fatigued pigs and pork quality may be explained by times of day taken off feed and transport duration. Shipping in the afternoon or early evening may result in fewer pigs with empty/diminished GI tracts at processing which may influence the rate of fatigued pigs and pork quality.
这项研究旨在了解采食行为和生理机能是否会影响屠宰加工厂疲劳猪的比例。具体而言，本研究旨在确定：（1）猪在白天的进食频率；（2）一天中的进食时间；（3）在传统育肥设施中群体饲养时，从采食到排泄（通过时间）的初步估计。最后，构建模型来尝试预测根据装猪时间和运输时间的不同，空肠/空胃猪的比例。随机选择猪进行称重和行为观察。从视频记录和现场观察中，记录每天的进食次数（采食回合）和一天中进食的时间。给猪喂食含铬氧化物的饲料，以确定每次进食的排泄时间。根据每天的进食时间，构建了模型，根据猪从谷仓中取出的时间和运输/休息时间的长短，预测空胃猪的比例。群体饲养的育肥猪每天进食 5.6±0.6 餐，平均每次采食（餐）时长 11.3±1.1 分钟。许多自由采食的猪在下午和晚上大部分时间进食。饲料通过时间为 20.5 小时（范围为 18 至 24 小时）。由于傍晚到清晨进食的猪较少，如果此时将猪运走，它们在到达屠宰厂时排空胃肠道的风险会增加。疲劳猪和猪肉质量的一些变化可能是由于停食和运输时间的不同造成的。在下午或傍晚装猪可能会导致在加工过程中排空/减少胃肠道的猪较少，从而影响疲劳猪和猪肉质量的比例。
