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Rural poultry farming with improved high producing chicken varieties is transforming the rural livelihoods. The present study was aimed at developing a high egg producing variety suitable for backyard poultry farming. A total of 602 female birds representing five crossbreds, i.e. Kadaknath × IWH (KH), PD-3 × IWH (DH), PD-2 × IWH (VH), PD-1 × IWH (CH) and PD-3 × KH (DKH) were evaluated for their performance up to 72 weeks under farm conditions. The traits evaluated were body weights at 8, 16, 20, 40, 52, 64 and 72 weeks age at sexual maturity (ASM), egg production and egg weight at 40, 52, 64 and 72 weeks and egg quality traits. Analysis of variance was used to assess the effect of genotypes on different traits and heterosis was estimated to check the superiority of the crosses over the parent lines. Genotype had significant influence on all the traits. Morphologically, only DKH crossbred had multi-coloured plumage, while all other crosses had white plumage with brown patches. DKH cross produced about 239.2±2.96 eggs annually and also witnessed the highest heterotic gains for all the body weight traits. Also, heterosis for ASM was very low for DKH cross and hence, in desired direction. Based on present findings, the three-way DKH cross owing to its multi-coloured plumage and good performance can be further studied for its potential as a high-producing layer variety in rural backyards.

Selection index (SI) is one of the best methods for estimating the breeding value of an animal combining all sources of information on the animal and its relatives. In the present study, the SI was constructed utilizing the five generations data of Vanaraja male line (PD-1) for body weight (BW-6) and shank length (SL-6) at 6 weeks of age with variance, covariance estimates and heritability of both the traits. The SI was employed on three generations data on simulation basis and the selection parameters were estimated and compared with the mass selection (MS) actually practiced in the population. The least squares mean of SL-6, the primary trait of selection increased from 76.63±0.002 (G-I) to 82.85 ±0.002 mm (G-II), and subsequently reduced to 80.17±001 mm (G-III). The BW-6 also followed similar trend. Generation had significant effect on both SL-6 and BW-6. The heritability estimates for SL-6 and BW-6 were moderate with 0.21 to 0.28 for SL-6 and 0.22 to 0.27 for BW-6. The two traits exhibited high degree of positive association with 0.87 to 0.92 correlation coefficient. The economic value estimated for weight and shank length was 1:8.95. Thus, the selection index constructed was I= 0.2260*BW6, g + 0.7717*SL6, mm. Selection differential was higher in SI method on pooled basis compared to MS in all three generations for the primary trait, SL-6. The response to selection and selection intensity was also higher in SI method compared to MS. A similar trend was observed for BW-6 with respect to selection differential and response to selection. The study concluded that SI was superior to mass selection based on the results in Vanaraja male line chicken.

Short term selection response for egg mass at 52 weeks of age (EM52), the primary trait of selection and the correlated response of other production traits was evaluated utilizing the last five generations data of Vanaraja female line (PD-2) at ICAR-Directorate of Poultry Research, Hyderabad. The phenotypic and genetic response for EM52 was significant with a magnitude of 341.9 and 237.4 g per generation, respectively. The correlated response of egg production at 52 weeks was also significant with 5.68 and 4.37 eggs per generation on genetic and phenotypic scale, respectively. The age at sexual maturity reduced over the generation in a desired direction. The least square means (LSMs) for production traits (EM52, EP52, EW52, EP 40 and ASM) varied significantly across the generations. The LSMs of EM52 (7898±2.01 g) and EP52 (138.60±0.03 eggs) were significantly higher in S-5 generation. Selection intensity (i) ranged from 0.44 to 1.10 and the rate of inbreeding was 0.003. Realized and estimated heritabilities of EM52 were 0.04 and 0.11, respectively. The significant improvement in primary trait and other important correlated traits indicated the effectiveness of Osborn index selection in PD-2 line, which will contribute to the improvement in egg production and egg weight in terminal cross Vanaraja chicken variety.

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.

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.

The objective of the study was to identify the mostsuitable model for estimation of (co) variance components and genetic parameters of different growth traits in prolific Garole sheep. Growth data of 1,058 Garole lambs born to 49 sires and 208 ewe was collected from ICAR-Central Sheep and Wool Research Institute (ICAR-CSWRI), Avikanagar, India. The traits studied were birth weight (BWT), 3 month weight (3WT), 6 month weight (6WT), 9 month weight (9WT), 12 month weight (12 WT), average daily gain from birth to 3 month age (ADG1), average daily gain from 3 month to 6 month age (ADG2). Twelve different animal models were fitted to account for different direct genetic and maternal effects. Model including maternal permanent environmental effect, maternal temporary environmental effect and direct genetic effects (Model 8) was most appropriate model for BWT. For other traits model with direct genetic effect and common litter effect (Model 7) was found most suitable. From best model direct heritability estimates of 0.037±0.054, 0.148±0.075, 0.104±0.077, 0.079±0.083, 0.103±0.116, 0.137±0.072 and 0.045±0.071 were obtained for BWT, 3WT, 6WT, 9WT, 12WT, ADG1and ADG2, respectively. Maternal temporary environmental effect variance contributed highest to total phenotypic variance. It ranged from 0.347±0.040 for BWT to 0.451±0.083 for 9WT. Estimates of direct genetic correlation ranged from –0.047 for BWT-ADG1 to 1.00 for BWT-12WT, 6WT-12WT and 9WT-12WT. Phenotypic correlations were positive and varied from 0.119 for ADG1-ADG2 to 0.982 for 3WT-ADG1. The growth traits of Garole sheep have low to moderate heritability and were influenced by maternal temporary environmental effect due to sharing of common litter environment.

Traditionally, heritability has been estimated by correlations of close kin. It is likely to be biased by determinants such as non genetic factors, inbreeding, selection and shared environment. Whereas, an animal model takes into account all relationships in a pedigree and is therefore expected to provide estimates of quantitative genetic parameters with higher precision. Therefore, the egg production data in the current study was analyzed using animal model to have more precise and accurate estimates of genetic parameters. The heritability of growth and egg weight traits was moderate to high. Whereas the heritability was lower for egg number and ASM traits. The body weights were positively correlated with egg weights and negatively correlated with egg numbers traits. The egg number produced at different age intervals was positively correlated. The genetic correlation of EP40 and EP52 with EP64 were 0.83 and 0.92, respectively. Therefore, the part period egg production of EP52 would give better selection response for egg production at 64 than EP40. Therefore, the selection of higher egg numbers can be done earlier at 52 weeks rather than waiting for EP64.

The Chokla sheep, renowned as the finest carpet wool producer of India, plays an important role in supporting the rural economy of the arid and semi-arid regions of its native state of Rajasthan. This study was carried out to assess the lifetime reproductive efficiency of Chokla ewes by analyzing the records of 1,001 ewes bearing 3,541 lambs over a period of 22 years (1994–2016) to assess five traits, namely total lambs born (TLB; 3.38±0.11 lambs), total lambs weaned (TLW; 2.97±0.11 lambs), cumulative lamb weights at birth (TLBW; 9.59±0.37 kg), weaning (TLWW; 39.59±1.68 kg) and 12 months of age (TLAW; 50.15±2.51 kg) produced by an ewe in her lifetime. Period of birth of ewe had a significant effect on all the traits whereas season of birth, inbreeding coefficient and birth weight of ewe had no influence. REML procedures were employed to estimate the genetic parameters through an animal model. Analysis revealed low heritability estimates for the lifetime reproductive traits (TLB; 0.06±0.04, TLW; 0.05±0.04, TLBW; 0.09±0.05, TLWW; 0.05±0.04 and TLAW; 0.02±0.04), suggesting greater role of environmental and managemental factors. Positive correlation among cumulative lamb weights (0.51–0.92) suggested selection for birth weights would result in higher weights at subsequent life stages of lambs. The low heritability estimates and high CV% for all the traits suggest the suitability of a management focussed approach for improvement of lifetime reproductive performance of ewes.

The magnitude of risk for neonatal mortality (NM) due to non-genetic factors was assessed using data on 5,722 Malpura lambs born during 1991–2016 at ICAR-Central Sheep and Wool Research Institute, Avikanagar, Rajasthan. The association of non-genetic factors influencing lamb mortality was obtained by odds ratio (OR). The overall annual NM was 4.07% with around 3 times higher in hebdomadal (3.15%) than post-hebdomadal (0.93%) phase. In comparison to lambs with >3.50 kg birth weight, the OR varied from 2.03 (birth weight 3.01–3.50 kg) to 19.29 (birth weight

Malpura sheep is one of the heavy mutton type sheep breeds found in semi-arid region of Rajasthan. Objective of the study was to revise the earlier selection criteria and set up a new one for Malpura sheep. The data on 2,995 Malpura sheep descended from 188 sires and 1,021 dams for 11 years (2004–2014) was used to construct the indices using various combination of traits. Genetic parameters were estimated for the traits to be included in the analysis for the data. Estimate of additive genetic variance for 6 month live weight (6WT) was low (h2 = 0.19±0.04). It was recommended to incorporate external germplasm for enhancing the additive genetic variability of the flock. The selection indices were constructed and highest accuracy (51.9%) was observed for the index that involves weaning weight (WWT) and first greasy fleece weight (GFW). Estimated genetic gain after 1 generation post selection was measured to be 221 g in WWT and 81.753 g in GFW. Possibility of direct selection for single trait (6WT) was explored. Results revealed higher response for 6WT (897 g) and high correlated response for other traits such as WWT (0.566 kg), ADG1 (5.601 g), ADG2 (3.132g) and GFW (26.52 g) as compared to index selection. As milk yield of dam has strong influence on pre-weaning gain, preliminary selection at weaning followed by direct selection at 6 month age based on single trait selection (6WT) was recommended as selection criteria.

Two genetic variants (A and B) and three genotypes (AB, BB and AA) were found in studied sheep breeds. The average frequency of A and B allele was (0.59) and (0.41) respectively. The A allele was more frequent among the studied breeds except Patanwadi and Kendrapada breeds. There was no clear cut predominance of any of the genotype. The Patanwadi, Malpura, Dumba, Kendrapada and Chokla populations were not in Hardy-Weinberg equilibrium. These results suggested the presence of β-LG gene polymorphism and predominance of β-LG A type in majority of the studied breeds. From the above findings it may be concluded that the native sheep breeds depicts variation in β-LG exon II locus. Further, genotype and allele distribution pattern in different breeds may be due to different characteristic of milk of these breeds. The contrasting pattern of variation observed in present study compared to previous study in native sheep breeds also highlight the need for further studies using large number of animals from different geographic regions. The relationship between β-LG genetic variants and traits related to milk and cheese production characteristics in rest of Indian sheep breeds need to be explored.