Strain and sex effects on growth performance and carcass traits of contemporary commercial broiler crosses

Abstract

In total, 3,840 sexed birds from 6 commercial cross broiler strains (4 male and 3 female) were raised and processed to analyze the effect of strain and sex on growth performance and carcass traits. Chicks from M1 × F1, M2 × F1, M3 × F1, M4 × F1, M3 × F2, and M4 × F3 crosses were sexed. Fifty female and 40 male chicks were randomly allocated to 24 floor pens (119 × 300 cm) covered with pine shavings in each of 4 rooms. The FCR was adjusted for the weight of dead birds (AFCR). Four birds/pen were processed at 7 wk of age. Carcasses were deboned after 2 h of chilling (n = 32 birds per treatment). There were significant strain by sex interactions for BW gain from 0 to 21 and 0 to 48 d. Strain differences in growth rate and mortality increased with age. The cross with the fastest growth rate also had the highest mortality. Because of differences in mortality and carcass yields, birds with the fastest growth (0-48 d) did not produce the most salable meat. Both the heaviest live BW per bird at 48 d (3.45 kg) and highest mortality (13.40%) were observed with the M4 × F3 cross. However, the heaviest live BW per 1,000 chicks placed was from the M3 × F2 cross (3,107 kg). The highest chilled carcass yield was from the M3 × F2 cross (76.05% of live BW) as was the highest meat yield (2,364 kg per 1,000 chicks placed) and highest pectoralis meat yield (805 kg per 1,000 chicks placed). The M3 × F2 cross produced the most total white meat (1,058 kg per 1,000 chicks placed), but interestingly the slowest-growing strain (M1 × F1) produced more white meat (breast + tenders + wings) than did the fastest-growing M4 × F3 strain (980 kg vs. 1,002 kg per 1,000 chicks placed). These results demonstrate the complexity of choosing between commercial strain crosses. The most profitable choice will be dependent on whether whole birds or parts are marketed and the relative values of the parts.

Gender‐specific effects of a phytogenic feed additive on performance, intestinal physiology and morphology in broiler chickens

“…Differences in zootechnical performance and carcass traits regarding sex are well documented in broiler chickens. Thus, the improved ADG and FCR as well as higher carcass yield and organ weights in male broilers correspond to data from previous studies (Kidd et al., ; Lopez et al., ; Shim et al., ).…”

Straight-run vs. sex separate rearing for 2 broiler genetic lines Part 1: Live production parameters, carcass yield, and feeding behavior

“…Estimated parameters for body weight (BW), feed intake (FI), feed conversion ratio (FCR), and body weight coefficient of variation (CV) predictive models of female, male, and straight-run birds, Ross 308 and Ross 708. estimate growth curves for birds raised sex separate. Not surprisingly, in the data presented here, males were heavier followed by straight-run birds and then females, which is consistent with most of the data present in the literature (Smith et al, 1954;Hess et al, 1960;Brake et al, 1993;Gous et al, 1999;May and Lott, 2001;Aggrey, 2002;de Albuquerque et al, 2006;Aggrey, 2009;Shim et al, 2012;Api, 2014;Zuidhof et al, 2014). The growth curve analysis revealed a higher maturity rate and an earlier in life inflection point for the females in comparison with males.…”

Impact of broiler processing scalding and chilling profiles on carcass and breast meat yield

“…Carcasses that were hard-scalded (60°C for 1.5 min) lost the vast majority of the surface cuticle during defeathering, whereas softscalded (52.8°C for 3 min) carcasses retained the yellow cuticle. Shim et al (2012) recently reported similar hot carcass yield values from 73.5 to 74.5% for 49 d broiler strain crosses for carcasses that were scalded at an intermediate temperature of 54°C and for 120 s. Their broilers had live weighs ranging from 3.08 to 3.39 kg and were the same age and approximate weight (3.12 kg) as our broilers from trial 4 (3.26 kg; Table 1).…”