Growth and Carcass Characteristics of Early- and Late-Feathering Broilers Reared Under Different Feeding Regimens

Abstract

Growth, immunological characteristics, and carcass traits were measured in early-and latefeathering chickens maintained under three feeding regimens. The regimens were 1) AL, ad libitum, 2) RL, alternate day feed restriction from 6 to 27 days of age and then released to ad libitum, 3) SOD, alternate day feeding restriction from 6 days of age to the end of the experiment Sexual dimorphism was observed for accelerated growth with convergence in BW of RL with AL chickens occurring at a younger age in males than females. Absolute BW, feather weight, and gastrointestinal tract (GIT) weights were lower for SOD, after 45 days of age, than for AL and RL chickens. Relative to BW, however, GIT and liver weights, at 45 days of age but not 64 days of age, were heavier for SOD than for AL and RL chickens. Percentage of carcass lipid was lower for SOD than for AL and RL chickens. Generally, carcass traits and components of the GIT were similar for Regimens AL and RL at 45 and 64 days of age. Exceptions were lower percentages for carcass lipid and liver lipid for RL than AL chickens at 64 days of age. There was a significant feeding regimen by age interaction for heterophil to lymphocyte ratios caused by a greater increase in ratios with age for AL than for RL and SOD chickens. At 37 days of age, AL chickens had lower antibody titers to SRBC than SOD or RL chickens that did not differ. The AL chickens had reduced bursa of Fabricius and thymus weights relative to BW, indicative of immunological involution, along with reduced livability, compared with RL and SOD chickens, which did not differ in livability. Early-and late-feathering chickens were similar for most of the traits measured. One exception was higher antibody titers to SRBC in early-than late-feathering chickens. (

Feather growth, bodyweight and body temperature in broiler lines with different feathering rates

“…Similar findings were observed by other researchers (Katanbaf et al, 1989). Therefore, the early feathering birds had better insulation against heat loss during the first weeks of life (O'Sullivan et al, 1991). The later feathering chicks were heavier than the early feathering ones from hatch to 21 days old, which might contribute to their higher internal temperature.…”

Feeding Regimen by Sire Family Interactions on Growth, Immunocompetence, and Disease Resistance in Chickens

“…Greater relative weights of empty esophagus plus crop and of crop contents of AD chicks than AL chicks is consistent with a functional adaptation by the former to AD feeding (Nir et al, 1987;Katanbaf et al, 1988a;O'Sullivan et al, 1991b;Zulkifli et al, 1993). Although there were no differences between feeding regimens for empty esophagus plus crop weight, differences in crop storage capacity among sire families (as evidenced from the differences in crop content weights) demonstrate variability in ability to increase intake capacity.…”

Comparison of Production Performances between Early- and Late-feathering Chickens in Parent Stocks of Korean Native Chicken

“…지금까지 닭의 조 만성과 생산능력 간의 관계에 대해 다양한 연구들이 수행되 었으나, 조만성에 따른 생산능력의 양부에 대해서는 연구자 들 간에 많은 이견이 있다. 브로일러에 있어 조우성 개체들 이 만우성 개체에 비해 성장능력 및 생존율이 우수하다고 보고하고 있으나 (Saeki and Katsuragi, 1961;Somes, 1970;Dunnington and Siegel, 1986;Khosravinia, 2008), 성장율과 조만성 간에 거의 관련이 없거나 (Godfrey and Farnsworth, 1952;Lowe and Garwood, 1981;O'Sullivan et al, 1991;Fotsa et al, 2001), 오히려 만우성이 조우성에 비해 성장능력이 우 수하다는 보고도 있다 (Lowe and Merkley, 1986;Merkley and Lowe, 1988;Nahashon et al, 2004). 산란계에 있어서는 조우 성 개체들이 만우성 개체에 비해 산란능력이 우수하고, 초산 일령도 빠르다고 하였으나 (Harris et al, 1984;Havenstein et al, 1989;Durmus et al, 2010;Goger et al, 2017), 깃털 조만 성과 산란능력 간에 거의 관련성이 없다는 보고도 있다 (Lowe and Garwood, 1981;Ledvinka et al, 2011;Mincheva et al, 2012).…”

“…그러나 한편으로 조우성과 만우성 개체간 마렉병 감염율을 비교 분석하여 깃 털 조만성에 따른 감염율이나 페사율의 차이는 없었으며, 브로일러에서도 조우성 개체와 만우성 개체간 생존율의 차 이는 없다고 하였다(Some and Jakowski, 1974; Lowe and Merkley, 1986). 한편, Sohn et al(2013) (Dunnington and Siegel, 1986;Khosravinia, 2008)와 만우성이 조우성에 비해 성장능력이 우 수하다는 보고 (Lowe and Merkley, 1986;Merkley and Lowe, 1988;Nahashon et al, 2004)들과는 상이한 결과이나, 성장 율과 깃털 조만성 간에 관련이 없다는 보고들과는 일치된 양상이다 (Lowe and Garwood, 1981;O'Sullivan et al, 1991;Fotsa et al, 2001). 한편, Sohn et al(2013) (Havenstein et al, 1989;Durmus et al, 2010;Goger et al, 2017), 겸용종 또는 육용종계의 경 우는 깃털 조만성에 따른 산란능력의 차이는 없다고 하였다 (Ledvinka et al, 2011(Ledvinka et al, , 2014Mincheva et al, 2012).…”