Selection index alternatives for increased marketing body weight with minimum concomitant reduction in body bone percentagerecourse to tissue dissection on Japanese quail

Abstract

SummaryLive body weight, shank length, keel length and carcass dissection data taken at 6 weeks of age were available on 103 quails from 33 sires. In a principal factor analysis, the first varimax rotated factor explaining 46.1% of the total Variation, revealed that body weight had negative loading and all bone percentages positive. The implied contrast was confirmed by the finding that body weight (h 2 = 0.61) was genetically correlated negatively with weight of total bone relative to body weight (-0.23) and to carcass weight (-0.58). Noticeably, shank length (SL) had large positive genetic correlation with body weight (0.90) and practically independent relationship with body bone percentage (-0.04). Selection indexes for meat production capacity were construeted. The breeding goal was defined as body weight (BW) and body bone percentage (BBP). The descending order ofthe unrestricted indexes with respect to the correlation between the index and genetic worth was: the füll index utilising body weight, shank length and keel length (0.95), indexes based on body weight and one length measurement (0.86), body weight alone (0.78). The accuracy was reduced by 17-35% upon restraining changes in BBP to zero. This study indicated that an index of considerable accuracy and remarkable usefulness would be I 3 = 4.56 BW + 244.87 SL. Use of this index should result in developing birds with higher body weight and more advantageous carcass attributes than selecting for body weight alone (L) or on the restricted füll index (II(BBP)). Such three indexes were most efficient in limiting reduction in BBP.

Effects of breed, sex and diet and their interactions on carcass composition and tissue weight distribution of broiler chickens

“…In the present study breast muscle accounted for 40% of the total carcass muscle weight and the thigh muscle accounted for 24% of the total carcass muscle weight. Corresponding values for in Pekin ducklings were 28 and 20%, respectively (SHAHIN et al, 2000a) and for Japanese quail were 47 and 23% (SHAHIN et al, 2000b). Fat tended to accumulate differentially in different carcass parts and the patterns of accumulation varies with species.…”

“…Muscle, bone and fat relative to live body weight were estimated at 40.4%, 11.4% and 15.5% for broiler chickens, 27.9%, 11.8% and 15.9% for Pekin ducklings (SHAHIN et al, 2000a) and 39.7%, 9.6% and 5.6% for the Japanese quail (SHAHIN et al, 2000b). The carcass muscle: bone ratio in the present study ranged from 2.77 to 4.85 with a mean of 3.57, corresponding value in Pekin ducklings was 2.4 (SHAHIN et al, 2000a) and in Japanese quail was 4.23 (SHAHIN et al, 2000b). In the present study breast muscle accounted for 40% of the total carcass muscle weight and the thigh muscle accounted for 24% of the total carcass muscle weight.…”

Effect of separate and mixed rearing according to sex on fattening performance and carcass characteristics in Japanese quails (<i>Coturnix coturnix Japonica</i>)

“…Some researchers reported that body weight and hatching egg weight are correlated (ADEDOKIN and SONAIYA, 2002;OZCELIK and OZBEY, 2004) and by selection the body weight could be increasing (MIELENZ et al, 2000;SHAHIN et al, 2000;BRAH et al, 2001). In addition, gender of quails also play a role on fattening performance and body weight of quail.…”

Effects of storage period and egg weight of Japanese quail eggs on hatching results (short communication)

“…al., 1988;BRAH et al, 2001;ALTAN et al, 2002). Some researchers reported that body weight and egg weight are correlated (OZCELIK and OZBEY, 1993;ADEDOKIN and SONAIYA, 2002) and by selection the body weight could be increasing (MIELENZ et al, 2000;SHAHIN et al, 2000;BRAH et al, 2001). Optimization of storage period and conditions of hatching eggs are essential for hatching industry.…”