ABSTRACT
1. The effects of beak trimming on 16-week-old Brown Leghorn hens, housed individually in battery cages, was assessed by comparing their behaviour after trimming with their behaviour before trimming and with the behaviour of a sham-operated control group. 2. In the short-term, times spent feeding, drinking and preening decreased. 3. In the long-term, times spent preening and pecking at the cage decreased and times spent standing inactive increased, with no signs of returning to pretreatment values after 5 weeks. 4. During the first three weeks, times spent feeding and drinking decreased and during the first two weeks, times spent sitting dozing increased, but after 5 weeks these had returned to near pre-treatment values. 5. It is argued that pain is the most probable cause of these behavioural changes. 6. The decrease in welfare to the individual bird caused by this pain will conflict with any increase in welfare to the flock brought about by beak trimming; this should be considered before any decision to beak trim is taken.
Subject(s)
Animal Welfare , Beak/surgery , Behavior, Animal , Chickens/physiology , Amputation, Surgical/veterinary , Animals , Chickens/surgery , Drinking , Eating , Feeding Behavior , Female , GroomingABSTRACT
The procedures of manual and machine catching acted as short-term stressors, and induced a state of fear in 8-week-old broiler chickens. The heart rate of birds caught by both methods rose to similar high values but that of birds caught by machine returned to near normal rates more quickly, suggesting that they were less stressed. The duration of tonic immobility, a response which increases with fearfulness, was much longer in manually-caught birds. These results suggest that stress could be reduced and welfare improved by catching and picking up broiler chickens by a carefully designed machine, rather than by hand.
Subject(s)
Chickens/physiology , Heart Rate , Stress, Physiological/veterinary , Animals , Electrocardiography , Fear/physiology , Stress, Physiological/physiopathologyABSTRACT
The heart rates of caged hens, from two strains of domestic chicken (Gallus gallus domesticus), during the 20 min before and after oviposition were studied. Heart rates were measured using subcutaneously implanted radiotelemetry devices. In one strain, heart rate was low and relatively constant before laying, increased sharply at the moment of laying, and then decreased gradually during the post-laying period. Hens from this strain exhibited sitting behavior before laying. In contrast, in the other strain, heart rates increased steadily during the pre-laying period, peaked sharply at the moment of laying, and then declined during the post-laying period. Hens from this strain exhibited restless pacing behavior before laying.
