Response to selection for feed conversion ratio in Japanese quail

Abstract

We investigated the effect of selection for 4-wk feed conversion ratio (FCR) on genetic improvement of FCR, BW, weight gain (WG), feed intake (FI), and residual FI (RFI) in Japanese quail. The F line was selected for reduced FCR and the C line was maintained as a randombred control. In each generation, 35 sires and 70 dams were used as parents for the next generation. Three generations of selection were performed. Realized heritability for FCR was calculated as the ratio of cumulative selection response to the cumulative selection differential, and additionally, genetic response was quantified as the difference between the means of selection and control lines. The results showed that realized heritability for FCR after 3 generations of selection was 0.67. The mean FCR in F line and C line in the last generation was 2.13 and 2.61, respectively. This is 18.4% cumulative genetic improvement, or 6.1% improvement per generation. In the last generation, the means of F and C lines were 193 and 166 g for BW at age 28 d (16.4% total increase, or 5.5% per generation), 184 and 158 g for WG (17.2% total higher gain and 5.7% per generation), 393 and 413 g for FI (4.9% total higher consumption and 1.6% per generation), and -24.5 and 10.2 for RFI (-34.7 g of cumulative gain; -11.6 g per generation), respectively. These results show that selection to decrease FCR increases BW and WG and decreases FI and RFI as a correlated response.

Effects of Multi-Trait Selection on Phenotypic and Genetic Changes in Japanese Quail (<i>Coturnix coturnix japonica</i>)

“…It was stated that progress in FCR also increased body weight. Next, 16.4% increase in body weight at 4 weeks of age reported by researchers (Varkoohi et al, 2010). Similar results were also stated for relative growth rate by Hyánková et al (2001) and those findings are in agreement with our study.…”

“…Varkoohi et al (2010) performed selection in order to amend FCR character and reported selection differential in the first generation 10.22%, selection response 8.21%, heritability as a 0.80. Varkoohi et al (2010) have reported that as a result of selection through the 4 generations, FCR value (2.68) was improved to 2.13. However, selection response and cumulative heritability for mentioned trait decreased.…”

Genotype and protein level interaction in growth traits of meat-type quail through reaction norm models

“…These estimates were partially higher than previous estimates reported in Japanese quail (Varkoohi et al, 2010); and partially similar to the results obtained by Silva et al (2013) in meat-type quail. However, in the latter, different PL had not been considered for the genetic parameter estimation.…”

Effect of selection for body weight in Japanese quails(Coturnix coturnix Japonica) on some production traits

“…Quails in the high group of second generation had the highest feed intake (39.2g) and the lowest in low group of first generation (33.1g). Improvement in FCR is due to the population's genetic structure, and to a certain extent, diet and environmental conditions (Varkoohi et al, 2010). Improved FCR for a certain body weight could be partially due to lower maintenance costs and lower fat deposition of birds with higher growth rate (Pym, 1979).…”