MEASURING HUNGER IN THE PIG USING OPERANT-CONDITIONING - THE EFFECT OF FOOD RESTRICTION
MEASURING HUNGER IN THE PIG USING OPERANT-CONDITIONING - THE EFFECT OF FOOD RESTRICTION
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DOI：
10.1017/s0003356100037132
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发表时间：
1988-08-01
影响因子：
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通讯作者：
MACLEOD, HA
中科院分区：
文献类型：
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作者：
LAWRENCE, AB;APPLEBY, MC;MACLEOD, HA
操作式条件反射技术被用来测量在特定商业条件下限制在低食物水平下的猪的喂养动机(饥饿)。六个大白牌。时代。长白公猪被饲养在单独的围栏里，在那里它们得到了每天的食物津贴。起初，公猪可以随意获得食物；随后，按照拉丁方设计，公猪被按比例限制在随意摄入量的0.8、0.6和0.4。最后，再次向公猪提供其先前测量的随意摄入量(处理1.0)。饥饿是通过让公猪按压面板10次来获得7克食物奖励来衡量的。在每次治疗期间和一天中的三个时间段(喂养前、喂养后立即和喂养后5小时)测量操作应答率。手术应答率受限制食物津贴的影响很大(手段：治疗1.0，42组压力机；0.8,212；0.6,266；0.4,320)。食物配给量和一天中的时间之间存在显著的交互作用(P<；0.001)。在喂养前，处理组的应答率没有变化。处理1.0和处理0.8降低了饲喂后的反应率(P<；0.001)，处理1.0也降低了饲喂后5h的反应率(P<；0.001)。0.6和0.4处理的应答率彼此之间或一天中的不同时间没有显著差异。将猪限制在低食物水平会导致一整天的高度饥饿。即使是达到当前建议的喂养水平，足以维持和低体重增加的食物津贴也是如此(处理0.6相当于维持1.3倍)。在满足生产需要的同时，养猪种群的商业饲喂水平不能满足饲养动机。在某些饲养条件下，低食物水平引起的饥饿可能会成为压力的主要来源，例如干母猪的系绳和畜栏系统，在那里母猪受到身体和食物的限制。
Operant conditioning techniques were used to measure the feeding motivation (hunger) of pigs restricted to the low food levels used under certain commercial conditions. Six Large White .times. Landrace boars were maintained in individual pens where they received their daily food allowance. Initially food was available ad libitum; subsequently boars were restricted proportionately to 0.8, 0.6 and 0.4 of their ad libitum intake in a Latin-square design. Finally boars were again offered their previously measured ad libitum intake (treatment 1.0). Hunger was meaured by conditioning boars to press a panel 10 times to receive a 7-g reward of food. Operant response rates were measured over 20-min sessions during each of the treatments and at three times of day (pre-feeding, immediately post feeding and 5 h post feeding). Operant response rate was strongly affected by restricting food allowance (means: treatment 1.0, 42 panel presses; 0.8, 212; 0.6, 266; 0.4, 320). There was a significant interaction between food allowance and time of day (P < 0.001). Treatments did not vary in response rate before feeding. Treatments 1.0 and 0.8 depressed response rate post feeding (P < 0.001) and treatment 1.0 also 5 h post feeding (P < 0.001). Response rates on treatments 0.6 and 0.4 did not vary significantly from one another or with time of day. Restricting pigs to low food levels resulted in a high level of hunger throughout the day. This was so even for food allowances that met current recommended feeding levels sufficient for maintenance and low weight gain (treatment 0.6 equivalent to 1.3 times maintenance). Commercial levels of feeding for the pig breeding population whilst meeting production needs do not satisfy feeding motivation. The hunger resulting from low food levels may act as a major source of stress under certain husbandry conditions such as tether and stall systems for dry sows, where sows are subject to both physical and food restriction.