Stocking Density Effects on Male Broilers Grown to 1.8 Kilograms of Body Weight

Abstract

This study examined the effects of stocking density on live performance, physiological stress level indicators, and processing yields of male broilers grown to 1.8 kg. A total of 3,120 Ross x Ross 708 male chicks was placed into 32 floor pens (5.57 m2/pen). Stocking density treatments were 25, (75 birds/pen), 30 (90 birds/ pen), 35 (105 birds/pen), and 40 (120 birds/pen) kg of BW/m2. The BW gain, feed consumption, and feed conversion were adversely affected with increasing stocking densities by 35 d. Physiological stress indicators (plasma corticosterone, glucose, cholesterol, total nitrites, and heterophil:lymphocyte) were not affected. Litter moisture was higher as stocking density increased, which led to higher footpad lesion scores. In parallel to growth responses, carcass weight was depressed by increasing stocking density, but carcass yield, absolute and relative amounts of abdominal fat, and carcass skin defects were not affected. Increasing stocking density decreased breast fillet weight and its relative yield and breast tender weight, but not breast tender yield. As calculated stocking density increased 5 kg of BW/m2 beyond 25 kg of BW/ m2, final BW and breast fillet weight decreased by 41 and 12 g, respectively. We conclude that increasing stocking density beyond 30 kg of BW/m2 adversely affects growth responses and meat yield of broilers grown to 1.8 kg but does not alter physiological stress indicators.

Impact of stocking density and feeding regimen on broilers: performance, carcass traits and bone mineralisation

“…When examined carcass characteristics (Table 2), stocking density did not affect the carcass yield and other carcass features as also reported by previous studies (Feddes et al 2002;Dozier et al 2006). However, ad libitum feeding program increased breast meat ratio parallel to increasing BW and reduced wings, neck and back ratios.…”

“…Any deviation from optimal conditions may impair performance (Imaeda 2000;Dozier et al 2006). High stocking density can reduce performance because of several factors such as high environmental temperature in the microclimate of the bird, inadequate air exchange, increasing ammonia level and impeded access to feed and water (Thomas et al 2004;Muniz et al 2006;Onbasilar et al 2008).…”

Live Performance, Carcass Yield, and Welfare of Broilers of Different Genetic Strains Reared at Different Housing Densities

“…Similar results were reported by Dozier et al (2005a) and Onbasilar (2008), who observed FCR improvement as housing density increased in young broilers. It should be noted that, despite of the lack of statistical significance (p≥0.05), the best FCR and the lowest FI at the lowest density were obtained only during the period of 21-28 days of age.…”

“…Rearing density had no effect on weight gain. Moreira et al (2004) obtained higher DWG in broilers housed at higher densities, but other studies reported no effect (Ravindran et al, 2006) or negative effects (Dozier et al, 2005a) on increasing rearing densities.…”

“…On the other hand, Moreira et al (2004), evaluating three housing densities (10, 13, or 16 broilers/m 2 ), observed significant reduction in weight gain in birds housed at 10 and 16 birds/ m 2 . Mortari et al (2002) also reported reduced body weight as rearing density increased, and Thomas et al (2004), Dozier et al (2005a) *significant at 5%; **significant at 1%; means followed by different lowercase letters within a column are statistically different; means followed by different uppercase letters within a row are statistically different.…”