Evaluation of two Indian native chicken breeds for reproduction traits and heritability of juvenile growth traits

Characterization of Mewari, an indigenous chicken breed, from hot tropical climate of India

Mewari, an indigenous chicken breed, was characterized for phenotypic parameters, growth, reproduction and production traits under the hot tropical climate of India. The data collected on 690 chicks were analyzed for effect of sex, hatch and their interaction on body weight and body measurements. The body weights of males were significantly higher at different weeks except at day old. Significantly higher shank and keel length was found in males as compared to females. The effect of hatch was significant on mean body weights at all ages, on shank length and breast angles at 8 weeks of age. The fertility and hatchability on fertile eggs set (FES) was 74.15±4.29% and 71.37±8.15%, respectively. The age at first egg (AFE) in the flock was 142 days and the age at sexual maturity (ASM) was 181.2±3.85 days. The average egg weights at 28 and 40 weks of age were 36.61±0.29 and 42.59±0.37 g, respectively. The hen day egg production (HDEP) up to 40 and 52 weeks of age was 28.93±0.13 and 59.87±0.14 eggs, respectively. The annual HDEP up to 72 weeks of age was 86.37± 0.13 eggs. The growth and egg production of Mewari chicken is comparable with other indigenous breeds. Mewari, a newly registered indigenous breed, needs to be further studied for various parameters to conserve and improve the breed for higher productivity.

Effect of Betaine and Raffinose in Cryopreservation Medium on Fertility in Kadaknath Chicken

BACKGROUND: Kadaknath is an important indigenous chicken with black pigmentation and cryopreserved semen reputably had low fertility. OBJECTIVE: The aim of this study was to evaluate the effects of betaine and raffinose in semen extenders on post thaw semen parameters and fertility. MATERIALS AND METHODS: Semen was cryopreserved in 4% dimethyl sulfoxide (DMSO) with betaine supplemented at 0.1, 0.2 and 0.4 M or raffinose supplemented at 1, 5 and 10 mM. Post thaw semen parameters and fertility were evaluated. RESULTS: Betaine at higher concentrations significantly (p < 0.05) inhibited the post thaw sperm motility, live sperm and MTT dye reduction and a declining trend in the fertility with increasing betaine. Inclusion of raffinose had no effect on the post thaw in vitro semen parameters, however, the fertility was significantly (p < 0.05) higher in the 10 mM raffinose supplemented group. CONCLUSION: Betaine has negative effect on post thaw semen parameters and raffinose at 10 mM concentration improves the fertility from cryopreserved semen.

Genetic parameters of growth traits, trend of production and reproduction traits, and meat quality status of Ghagus, an indigenous chicken of India

Indigenous chickens play a vital role in providing nutritional security and economic support for the rural and tribal people in tropical countries like India. Ghagus, an indigenous chicken breed of India, was characterized for growth, production, and reproduction (fertility and hatchability) traits over different generations and for carcass and meat quality traits. Heritability, and genetic and phenotypic correlations among growth traits were estimated using mixed model least squares and maximum likelihood methods. Estimates of heritability of growth traits such as bodyweights at different age and 8-week shank length were high (0.32 to 0.39) in initial generation and moderate to high during latest generation (0.20 to 0.42). The correlations of growth traits with 40-week egg production were positive and significant (P < 0.001). There was improvement in 8-week bodyweight (559.3 ± 4.40 g) by 177 g over the generations. The average egg production up to 40 weeks over the generations was 35.66 eggs. There was also a significant (P < 0.001) increase in egg weights over the generations. The fertility (mean 89.3%) ranged from 85.2 to 92.3%. The hatchability on fertile egg set (mean 90.8%) ranged from 86.5 to 94.1% and it was improved by 3.9% over the generations. The carcass and meat quality study revealed that this breed has the lean meat, high protein, and attractive meat color with desirable meat quality characteristics. The study concluded that the Ghagus breed with self-propagation capacity has the potential to be improved as an indigenous meat-type breed to meet the ever-increasing demand for indigenous chickens' meat in the country.

Genetic parameters for production traits in F1 reciprocal crossbred Chee Fah and Fah Luang chickens

ContextRecently, Chee Fah and Fah Luang chickens have been registered as a black-bone native chicken in Thailand. Only a few studies revealed genetic information about them. No publication has reported any data related to their cross-mating, particularly, genetic parameters.AimsThis study aimed to estimate genetic parameters for production traits of F1 generation of reciprocal crossbred Chee Fah and Fah Luang chickens.MethodsA dataset of production traits of two crossbred groups was used in the present study. Effects of breed, month-day of incubation and sex were tested at P&lt;0.05. Genetic parameters were estimated using the restricted maximum likelihood method with multi-trait animal model.Key resultsThe crossbred Chee Fah×Fah Luang was significantly heavier and consumed more feed than Fah Luang×Chee Fah (P&lt;0.05). Male chickens had significantly better 20-week-old bodyweight, feed conversion ratio and average daily gain compared with females for both crossbred groups (P&lt;0.05). The effect of month-day of incubation had a significant influence on production traits (P&lt;0.05), except for day-old bodyweight. Heritabilities for production traits of crossbred chickens were low to high. The highest estimate was observed for day-old bodyweight (0.97), followed by feed intake (0.40), 20-week-old bodyweight (0.06), average daily gain (0.05) and feed conversion ratio (0.03), respectively. Both positive and negative genetic correlations were found among their production traits. Favourable relationships were found between average daily gain versus bodyweight and versus feed conversion ratio (rgg=0.99 and −0.90, respectively). Similarly, production traits showed phenotypic correlations in both directions, which ranged from −0.95 to 0.99.ConclusionsHeritability estimations for production traits were found in low to high magnitude. The desirable genetic relationships were found between feed conversion ratio and day-old bodyweight, 20-week-old bodyweight and average daily gain, and between 20-week-old bodyweight and average daily gain.ImplicationsThese findings could be considered as a source of genetic data for enhancing production traits of crossbred black-bone native chickens.

Analysis of (co) variance components and estimation of breeding value of growth and production traits in Dahlem Red chicken using pedigree relationship in an animal model

Variance and covariance components of growth and production traits were analyzed employing REML animal model to assess the Dahlem Red (PD-3) chicken population for direct additive genetic, maternal effects and to estimate the estimated breeding value (EBV), genetic parameters, genetic trends and rate of inbreeding (ΔF) utilizing seven generation’s data. The generation and hatch had significant (P≤0.01) effect on the body weight at 0 day (BW0), 2 (BW2), 4 (BW4) and 6 weeks (BW6) and shank length at six weeks of age (SL6). The average least squares means (LSM) for BW6 and SL6 were 273.93±0.62 g and 53.97±0.05 mm, respectively. All the production traits were significantly (P≤0.01) influenced by generation and hatch. The average LSM for age at sexual maturity (ASM), egg production up to 40 weeks (EP40) and egg mass up to 40 weeks (EM40) were 168.82±0.25 d, 72.60±0.41 eggs and 4.21±0.07 kg, respectively. Model 5 with additive direct, maternal genetic, maternal permanent environmental and residual variance components was the best for BW0, BW2 and BW4 based on the AIC values obtained in WOMBAT. Model 4 was the best model for BW6, SL6, ASM, EP40 and EM40 with additive direct, maternal permanent environmental and residual variance components. Maternal effects were higher during early age, decreased with age, and remained present until 20 weeks of age. The heritability (h²) estimates were low to moderate in magnitude for all the growth traits and ranged from 0.02±0.03 to 0.19±0.03. The maternal heritability was high at hatch (0.35±0.06), decreased gradually until 4^th week (0.02±0.01) and ceased afterwards. The heritabilities of EP40 (0.11±0.03) and EM40 (0.12±0.04) were low. The direct additive genetic correlations (r_a) between BW2, BW4, BW6 and SL6 were high and positive (P≤ 0.05). The additive genetic and maternal permanent environmental correlation between EP40 and EM40 were high and positive (P≤ 0.05). The EBV of EM40 was significant (P≤ 0.05) with 0.48 kg/generation in PD-3 chicken at the end of the seventh generation. The EBV of EP40 showed an increasing trend with a genetic gain of 1.87 eggs per generation. The average inbreeding coefficient of the population was 0.019 and average ΔF was 0.007 over the last seven generations of selection. The EBV trends for primary and associated traits showed linear trends in the desired direction and negligible inbreeding.

The Effects of Weather on Avian Growth and Implications for Adaptation to Climate Change

Climate change is forecasted to generate a range of evolutionary changes and plastic responses. One important aspect of avian responses to climate change is how weather conditions may change nestling growth and development. Early life growth is sensitive to environmental effects and can potentially have long-lasting effects on adult phenotypes and fitness. A detailed understanding of both how and when weather conditions affect the entire growth trajectory of a nestling may help predict population changes in phenotypes and demography under climate change. This review covers three main topics on the impacts of weather variation (air temperature, rainfall, wind speed, solar radiation) on nestling growth. Firstly, we highlight why understanding the effects of weather on nestling growth might be important in understanding adaptation to, and population persistence in, environments altered by climate change. Secondly, we review the documented effects of weather variation on nestling growth curves. We investigate both altricial and precocial species, but we find a limited number of studies on precocial species in the wild. Increasing temperatures and rainfall have mixed effects on nestling growth, while increasing windspeeds tend to have negative impacts on the growth rate of open cup nesting species. Thirdly, we discuss how weather variation might affect the evolution of nestling growth traits and suggest that more estimates of the inheritance of and selection acting on growth traits in natural settings are needed to make evolutionary predictions. We suggest that predictions will be improved by considering concurrently changing selection pressures like urbanization. The importance of adaptive plastic or evolutionary changes in growth may depend on where a species or population is located geographically and the species’ life-history. Detailed characterization of the effects of weather on growth patterns will help answer whether variation in avian growth frequently plays a role in adaption to climate change.

Inheritance of growth traits and impact of selection on carcass and egg quality traits in Vanashree, an improved indigenous chicken

The present study was carried out to assess the inheritance of growth traits and to study the effect of selection on carcass characteristics and egg quality traits in Vanashree, an improved indigenous chicken. Estimates of heritability were high for body weights recorded at 4, 5 and 6 weeks of age and 8th week shank length, while it was moderate for 8th week body weight. Estimates of heritability on sire component of variance declined as age increased from 4 to 8 weeks of age. The genetic and phenotypic correlations among various growth traits were positive and high in magnitude. The body weight continued to increase up to 40 weeks of age particularly in male birds, while there was little increase in shank length from 20 to 40 weeks of age particularly in hens. There was no significant change in carcass characteristics and egg quality traits except that there was some improvement in dressing percentage over the generations. Sex effect was significant on relative weights of the breast, legs, gizzard, liver and heart and abdominal fat percentage. There was increase in Haugh unit and albumen index, yolk percentage, yolk to albumen ratio and yolk colour in the present generation. The results suggest that there is adequate additive genetic variation for growth traits in the population and that Vanashree chicken could continue to be improved so as to make it a promising dual purpose purebred indigenous chicken for increasing the productivity of free range or semi-intensive systems of production.

Estimation of breeding value, genetic parameters and maternal effects of economic traits in rural male parent line chicken using pedigree relationships in an animal model

Breeding value (BV), genetic parameters and additive genetic, and maternal effects were evaluated on growth and production traits utilizing data from eight generations employing animal model in a rural male parent line (PD-6) chicken at ICAR-Directorate of Poultry Research, Hyderabad, India. The least squares means (LSM) for body weight (BW) and shank length (SL) up to 6 weeks of age varied significantly (p ≤ .01) among the generations and hatches. BW increased significantly (p ≤ .01) over the generations and decreased with the hatches. Sex also had a significant effect on BW and shank length except for BW at 0 day (BW0). LSM for BW (BW6) and Shank length (SL6) at 6 weeks of age were 598.84 ± 0.79 g and 74.57 ± 0.04 mm, respectively. Males recorded significantly (p ≤ .01) higher BWs and shank length. All the production traits were significantly (p ≤ .01) influenced by the generation effect. The overall LSM for age at sexual maturity (ASM), egg production at 40 weeks (EP40) and egg weight at 40 weeks (EW40) were 164.93 ± 0.23 days, 74.66 ± 0.40 eggs and 54.79 ± 0.08 g, respectively. Model 3 with additive, maternal permanent environmental and residual effects was the appropriate model for BW2, BW4, BW6, SL4 and SL6, whereas Model 4 with maternal effects was the best for BW0. The heritability estimates for BW6 and SL6 were 0.22 ± 0.02 and 0.18 ± 0.02, respectively. Model 1 with additive direct and residual effects was the best appropriate model for all the production traits. The heritability estimates of EP40 and EW40 were 0.16 ± 0.04 and 0.34 ± 0.05, respectively. BW and shank length were highly correlated with significant (p ≤ .05) positive association from different components. The correlation coefficient from direct additive component between egg production and BW40 was negative, while it was positive with less magnitude between egg production and BW20. The egg production and egg weights had a negative association at different ages. BV of SL6, the primary trait of selection, was significant (p ≤ .05) across the generations and increased linearly with an average genetic gain of 1.05 mm per generation. BV of BW6 was also significant (p ≤ .05) and increased linearly as correlated response with an average genetic response of 22.34 g per generation. BV of EP40 showed an increasing trend with a genetic gain of 0.02 eggs per generation. The EW 40 also increased linearly with an average genetic gain of 0.06 g. The average inbreeding coefficient of the population was 0.015. The study concluded that the population was in ideal status with a linearly increasing trend of average BV with negligible inbreeding over the eight generations of selection.

Evaluation of Vanaraja female line chicken for growth, production, carcass and egg quality traits

Vanaraja female line (PD-2) chicken was evaluated for growth, production, carcass and egg quality traits utilizing the data generated from 3,737 chicks and 599 hens produced in pedigreed mating with 50 sires and 250 dams at ICAR-Directorate of Poultry Research, Hyderabad, Telangana. Fertility was 86.63% and the hatchability was 86.72% on fertile egg set and 72.53% on total egg set basis in PD-2 line. The least squares means (LSM) for six week body weight and shank length were 662.38±2.54 g and 71.48±0.12 mm, respectively. Sex had significant influence on live weight, thigh and wing proportions wherein cocks had heavier and stronger legs and wings. Abdominal fat was significantly higher in females. The egg production up to 40 and 52 weeks of age was 80.29±0.03 and 133.16±0.05 eggs, respectively. The egg mass up to 52 weeks of age was 7447.41±2.98 g in PD-2 line. The heritability was low up to 15% for egg production and 17% for egg mass, the primary trait of selection in PD-2 line. Egg mass and egg weights at different ages had positive association as larger and high number of eggs contributed more to the egg mass. The egg mass and egg production had a significant positive association in PD-2 line. The egg quality was reasonably fair with average shape index of 75.22 and Haugh unit of 79.0±0.62. The albumen, yolk and shell weights were 30.20±0.14, 15.8±0.09, 0.40±0.02 g, respectively. The proportion of heritability and the magnitude of association between the important traits provide requisite information for implementing the breeding program for improvement of egg production in PD-2 line.

Genetic evaluation of growth and production performance and short term selection response for egg mass in Gramapriya female line chicken

A comprehensive study was carried out in Gramapriya female line (PD-3) with respect to growth, production, selection response and population structure utilizing the data generated for the last 7 generations at ICAR-Directorate of Poultry Research, Hyderabad, Telangana. The average fertility was 71.89% and hatchability was 80.52% on fertile egg set and 57.08% on total egg set. The least squares means (LSMs) for body weight at 4 and 6 weeks of age were 168.06±0.01 and 320.10±0.02 g, respectively. The heritability estimates from sire and dam components of variance were moderate to high for both body weight and shank length (0.27 to 0.35). The correlation coefficients (genetic and phenotypic) between body weights and shank length were positive and high in magnitude except with day old body weight. Age at sexual maturity (ASM) was 171.47±0.01 days in PD-3 population. The part period egg production (EP 40) at 40 weeks of age was 75.60±0.01 eggs with an egg mass (EM 40) of 4,157.19±0.99 g. The h2 estimates for ASM, EW 40, EP 40 and EM 40 were 0.16±0.07, 0.42±0.11, 0.18±0.07 and 0.15±0.06, respectively, which were moderate to high in magnitude. The egg production at 40 weeks of age was negatively associated with ASM, body weight and egg weight at different ages. Egg mass had significant positive association with egg production and egg weight at 40 weeks of age. The selection intensity (i) ranged from 0.32 to 0.85 while, rate of inbreeding ranged between 0.0031 and 0.0033 in PD-3 line. The direct selection response was 151.54 g on genetic scale and 79.75 on phenotypic scale for primary trait of selection, EM 40 over the last 7 generations. Realized and estimated heritability estimates were 0.29 and 0.15, respectively for EM 40. The study concluded that, PD-3 population was in ideal condition with respect to growth and production performance. Positive selection response for primary trait EM 40 was observed in the population maintaining both egg production and egg weight, the important traits for sustainable rural poultry farming.

Genetic analysis of growth and egg production traits in synthetic colored broiler female line using animal model

Variance and genetic parameters were estimated for growth and production traits of synthetic broiler female line (PB-2) using REML animal model to delineate the population status, direct additive, maternal genetic, permanent environmental effects, besides genetic trends and performance of economic traits. The overall least squares mean (LSM) for body weights at 0 day (BW0), at 2 weeks (BW2), at 4 weeks (BW4), at 5 weeks (BW5), shank length at 5 weeks (SL5), and breast angle at 5 weeks (BA5) of age were 40.03 g, 207.40 g, 589.58 g, 828.51 g, 76.89 cm, and 80.78°, respectively. The overall LSM for egg production up to 40 weeks of age (EP40) and egg weight at 40 weeks (EW40) were 66.02 eggs and 58.23 g, respectively. The heritability estimates using the best model for BW0, BW2, BW4, BW5, SL5, and BA5 were 0.06 ± 0.03, 0.19 ± 0.03, 0.15 ± 0.03, 0.14 ± 0.02, 0.08 ± 0.02, and 0.02 ± 0.01, respectively. The heritability estimates were low to moderate in the magnitude for all early growth traits. The heritability estimate for egg production up to 40 weeks (EP40) was 0.30 ± 0.05. The heritability estimates for adult body weights at 20 and 40 weeks of age (BW 20 and BW 40), age at sexual maturity (ASM), and egg weight at 40 weeks (EW40) were 0.21 ± 0.04, 0.19 ± 0.04, 0.16 ± 0.03, and 0.33 ± 0.05, respectively, and the estimates were moderate to high in magnitude. Model 4 with additive, maternal permanent environmental, residual, and phenotypic effects was the best model for growth traits except for BW0 and BA5. The average genetic gain observed in primary trait (BW5) over the five generations was 13.62 g per each generation indicating effective selection. The animal model minimized the overestimation of genetic parameters and improved the accuracy of the BV, thus enabling the breeder to select the suitable breeding strategy for genetic improvement.

Variance component analysis of growth and production traits in Vanaraja male line chickens using animal model

Objective

A comprehensive study was conducted to study the effects of partition of variance on accuracy of genetic parameters and genetic trends of economic traits in Vanaraja male line/project directorate-1 (PD-1) chicken.

Methods

Variance component analysis utilizing restricted maximum likelihood animal model was carried out with five generations data to delineate the population status, direct additive, maternal genetic, permanent environmental effects, besides genetic trends and performance of economic traits in PD-1 chickens. Genetic trend was estimated by regression of the estimated average breeding values (BV) on generations.

Results

The body weight (BW) and shank length (SL) varied significantly (p≤0.01) among the generations, hatches and sexes. The least squares mean of SL at six weeks, the primary trait was 77.44±0.05 mm. All the production traits, viz., BWs, age at sexual maturity, egg production (EP) and egg weight were significantly influenced by generation. Model four with additive, maternal permanent environmental and residual effects was the best model for juvenile growth traits, except for zero-day BW. The heritability estimates for BW and SL at six weeks (SL6) were 0.20±0.03 and 0.17±0.03, respectively. The BV of SL6 in the population increased linearly from 0.03 to 3.62 mm due to selection. Genetic trend was significant (p≤0.05) for SL6, BW6, and production traits. The average genetic gain of EP40 for each generation was significant (p≤0.05) with an average increase of 0.38 eggs per generation. The average inbreeding coefficient was 0.02 in PD-1 line.

Conclusion

The population was in ideal condition with negligible inbreeding and the selection was quite effective with significant genetic gains in each generation for primary trait of selection. The animal model minimized the over-estimation of genetic parameters and improved the accuracy of the BV, thus enabling the breeder to select the suitable breeding strategy for genetic improvement.

Importance of Indigenous Breeds of Chicken for Rural Economy and Their Improvements for Higher Production Performance

Indigenous/native breeds of chickens are playing an important role in rural economies in most of the developing and underdeveloped countries. They play a major role for the rural poor and marginalised section of the people with respect to their subsidiary income and also provide them with nutritious chicken egg and meat for their own consumption. Performance of native fowl can be improved by change in husbandry, feeding, and better health cover. However, genetic improvement may be made either through selection and crossbreeding or by utilisation of both selection and crossbreeding. Improvement through selection may be time consuming but the improvement will be permanent. Through crossbreeding improvement may be faster but research has to aim for the production of native-type birds with higher production potential. In the present review efforts have been made to present the importance of native fowl to rural economy and their improvement for higher production performance.

Evaluation of breeding objectives for purebred and crossbred selection schemes for adoption in indigenous chicken breeding programmes

1. The aim of the study was to evaluate the genetic and economic breeding objectives for an indigenous chicken (IC) breeding programme in Kenya. 2. A closed three-tier nucleus breeding programme with three breeding objectives and two selection schemes was simulated. The breeding objectives included IC dual-purpose (ICD) for both eggs and meat, IC layer (ICL) for eggs and IC broiler (ICB) for meat production. 3. Pure line selection scheme (PLS) for development of IC pure breeds and crossbreeding scheme (CBS) for the production of hybrids were considered. Two-and three-way crossbreeding strategies were evaluated under CBS and the impact of nucleus size on genetic gains and profitability of the breeding programme were investigated. 4. Males were the main contributors to genetic gains. The highest genetic gains for egg number (2·71 eggs) and growth traits (1·74 g average daily gain and 57·96 g live weight at 16 weeks) were realised under PLS in ICL and ICB, respectively. 5. The genetic response for age at first egg was desirable in all the breeding objectives, while that for fertility and hatchability were only favourable under ICL and PLS in ICD. Faecal egg count and immune antibody response had low, but positive gains except under PLS where the later was unfavourable. ICB was the most profitable breeding objective, followed by ICD and ICL under all the selection schemes. 6. Although PLS was superior in genetic gains and profitability and recommended in breeding programmes targeting ICL and ICB, a three line CBS should be considered in development of a dual-purpose breed. 7. Increasing the nucleus size beyond 5% of the IC population was not attractive as it resulted in declining profitability of the breeding programme.