The effect of sex and rearing system on carcass composition and cut yields of broiler chickens

Abstract

As generally known, broiler meat quality is a very complex issue that can be looked at from several aspects. In terms of the meat processing industry and consumers' interests, fattened chicks should be characterised by good dressing percentage, desired conformation, as much meat on the carcass as possible, optimal distribution of fat tissues, appropriate skin colour and least damage possible occurring during fattening, loading and unloading. With respect to that, the proportions of major basic carcass parts (breast, drumstick and thigh) as well as the presence of certain tissues in them are regarded as vital parameters determining broiler meat quality (Lewis et al., 1997;Sütö et al., 1998;Holcman et al., 2003;Ristic, 2003). The above-mentioned quality traits depend on a number of factors. Of the biological ones, the greatest impact is produced by genotype, sex and age (Lewis et al., 1997;Bokkers and Koene, 2003;Hellmeister et al., 2003).Among numerous non-genetic factors that may have a considerable effect on meat quality, a broiler rearing system has been recognised over the past years by a large number of authors as being particularly important (Lewis et al., 1997;Bokkers and Koene, 2003;Hellmeister et al., 2003;Ristic, 2003). ABSTRACT:The objective of this study is an analysis of meat quality in broilers of standard fast-growing hybrid Hybro G, reared in two different non-industrial systems (extensive rearing in a poultry house or "extensive indoor" system and rearing in a poultry house using a free range or "free-range" system). Quality parameters, i.e. proportions of basic carcass parts (breasts, drumsticks and thighs), abdominal fat, and proportions of basic tissues (muscles, bones and skin) in more valuable carcass parts, were investigated. The aim of the investigation was to analyse the effect of the two non-industrial rearing systems and broiler sex on the above-mentioned traits of broiler meat quality. The used rearing systems (free-range and extensive indoor ones) did not have a statistically significant effect on the proportions of major basic carcass parts and of abdominal fat in broiler chickens (P > 0.05). Heavier carcasses at slaughter (on the 56 th day of fattening) were recorded in the male broilers compared to the female ones, the differences being statistically significant (P < 0.01). The drumstick proportion in the male broiler carcasses was statistically significantly higher (P < 0.05) than the proportion in the female broilers. The interaction between the investigated effects (of sex and rearing system) did not exert a statistically significant effect on the proportions of major basic carcass parts and abdominal fat in broiler chickens (P > 0.05). The rearing system (free-range and extensive indoor) and the interaction between the investigated effects (of sex and rearing system) did not affect statistically significantly the differences expressed in the meat, skin and bone proportions in breasts, drumsticks and thighs of the broilers (P > 0.05). The sex effect on the skin proportions in b...

Results of Rearing Broiler Chickens Under Various Systems

“…Lower content of abdominal fat deposition was potentially caused by an increased motor activity in chickens (Lewis et al, 1997;Castelini et al, 2002;Dou et al, 2009). This is confirmed by the research carried out by Bogosavljević-Bošković et al (2006) on broilers Hybro G, in which proportion of abdominal fat deposition was respectively: 1.88% in free-range chickens and 1.98% in those under an intensive indoor system. Dou et al (2009) noted 3.0% abdominal fat deposition in free-range broilers and up to 6.5% in those housed indoors.…”

Free Range Poultry Husbandry and Physiochemical Quality of Meat: A Review

“…Free range birds have lower proportion of abdominal fat content due to higher activity of these birds 6,40 . Likewise, (Hybro G) birds in another experiment under free range and intensive condition showed increase abdominal fat of 1.98% in intensive husbandry than free range (1.88%) 46 , while similar result was found in an experiment on Gushi birds which showed increase abdominal fat percentage (6.5%) in intensive husbandry as compared to 3% in free range 40 .…”

“…Comparative study on free range and indoor system showed increase in the yield of Gushi broilers thigh (27. 46 . Free range birds have lower proportion of abdominal fat content due to higher activity of these birds 6,40 .…”

Physiological Responses of Slow-Growing Chickens under Diurnally Cycling Temperature in a Hot Environment

“…In their study, OV chickens were significantly heavier than PK, which, like in the current study, were heavier than NN at 26 weeks of age. Sexual dimorphism in BW is common in various chicken genotypes (Bogosavljevic-Boskovic et al, 2006), including in slow-growing strains, and therefore, this was expected in the current study.…”