In a Canadian study on the effect of dietary alterations during rearing on feather condition in broiler breeder females, feather condition was better with the alternative diets tested.

This, the researchers suggested, may indicate a reduction in stereotyped feather pecking with these diets. The alternative diets appeared to increase satiety compared with the control diets.

In commercial production, broiler breeders are severely feed restricted to maintain healthy bodyweight, according to the paper in Poultry Science. This restriction can induce stereotypic behaviour, including feather pecking, which has negative welfare implications for both the victim and performer. It has been suggested that the problem may be symptomatic of chronic hunger or the frustration of feeding motivation.

In this study, K.L.H. Morrissey of the University of Guelph and co-authors in Canada and Scotland determined whether feather condition, as an indirect measure of feather pecking, could be improved via dietary manipulation.

Six dietary treatments were tested, each with five replicate pens of nine to 12 birds. Control diets (C) were fed on a daily or skip-a-day (SAD) basis. Alternative diets included soybean hulls as a bulking ingredient and calcium propionate (CaP) as an appetite suppressant of either a feed grade (F) or purified (P) quality. Both alternative diets were fed on either a daily or SAD basis.

Five or 6 birds were randomly chosen from each pen and feather scored at 10, 14, 20, 26 and 36 weeks of age. Six body parts (neck, back, wings, legs, vent area, tail) were given a score from 0 to 5 (0 = no feather damage, and 5 ≥50 per cent feather loss with tissue damage). Scores were summed for each bird and averaged for each pen.

Data were analysed with room and feeding frequency as main factors and diet as the sub-factor with repeated measures.

The researchers found an interaction between diet and time (P<0.01) with the feather condition of the C birds worsening more quickly than the F and P birds.

There was an interaction between feeding frequency and time (P=0.015), with SAD-fed birds scoring better than daily-fed birds at 20, 26 and 36 weeks.

Morrissey and co-authors concluded this interaction could indicate that SAD feeding increased satiety after the birds became accustomed to the schedule. Because feather condition was better with the alternative diets, this may indicate a reduction in stereotyped feather pecking with these diets. This suggests that the alternative diets increase satiety compared with the control diets.

Reference

Morrissey K.L.H., T. Widowski, S. Leeson, V. Sandilands, A. Arnone and S. Torrey. 2014. The effect of dietary alterations during rearing on feather condition in broiler breeder females. Poultry Science. 93(7):1636-1643. doi: 10.3382/ps.2013-03822