Selection index for improvement of production and reproduction performance in southern Odisha goats

Introduction

Odisha is located at longitude 81° 31'-87° 30' East and latitude 17° 31'-20° 31' North. The whole state is divided into thirty districts and ten different agroclimatic zones varying in rainfall distribution and average temperature. Odisha is generally a water sufficient state with an average rainfall of about 1451 mm per year, which is almost three times of Indian annual average. Mansoon rainfall mostly occurs during the months of June to September. Agroclimatic zone climates have a major influence on pasture and feed availability, which in turn affects livestock productivity. Livestock will frequently have inadequate or poor-quality feed since vegetation in arid regions tends to have relatively little plant turnover. Wet seasons are frequently associated with an abundance of natural meadows and high-quality fodder. One of the primary obstacles to goat production in Odisha is inadequate and substandard feed. Only animals who are acclimated to their surroundings will survive in these places. Thus, research on the spatial patterns along Odisha's agroclimatic zones is necessary, as is an understanding of how indigenous inhabitants have adapted to the changing environment. Malkangiri, Narayanpatna, Ganjam types goats are reared in southern part of Odisha. The morphometrics, production and reproduction traits among these goat types are significantly variable. Therefore an attempt has been made for constructing selection indices. For smallholder farmers in rural areas, goats are a vital source of both food security and financial security. Women are crucial to the goat farming industry, which fosters family economic prosperity (Majumder et al., 2023) [5] . Nondescript goat populations are very useful since they are easily managed and adaptable to climate change.

Materials and Methods

Twenty villages were taken from each district for the study in Malkangiri, Koraput, Ganjam of Odisha targeting to three goat types viz. Ganjam, Narayanpatna and Malkangiri. Morphometrics, production and reproduction traits from 392, 346 and 352 goats from Ganjam, Narayanpatna and malkangiri types were evaluated in the present study. The work was carried out in the Department of Animal Breeding & Genetics, CVSc & AH, OUAT during 2021-2023. The data, thus collected were put to standard statistical analysis (Harvey 1996) [3] .

Ganjam goat

In a 9230 square km area, the natural range of the Ganjam goat spans latitudes of 19.40 to 20.170 N and longitudes of 84.70 to 85.120 E. The entire Ganjam district, the northern portion of Gajapati and the southern portion of Nayagarh district were included in this area, along with Rambha, Khalikote, Bhanjanagar, Belaguntha, Kullada, Odagaon, etc., which had large concentrations. The Ganjam breed of goat known as "Gola chheli" or "Lanka chheli", the only recognised goat breed that is native to Odisha, is primarily reared by Gola community. Since generations, raising Ganjam goats has been the community's primary source of income.

Narayanpatna goat

Animals of various ages and both sexes were analysed for body weight and conformation traits in ten villages of the Narayanpatna and Bandhugan blocks. Through conversations with the goat keepers, data on performance traits were collected. Goats from Narayanpatna are a medium size and most of them are dark brown or black in colour (Majumder et al., 2023) [5] . But there are also some brown, off-white and even mixed coloured animals. Resource poor tribal (Kondhs) people raise these goats for meat under extensive system without supplementation of additional grain or vegetation supplementation. Breeding is accomplished naturally. Female animals reach sexual maturity at the age of around 8 to 10 months. Adult male and female animals weigh around 30 kg.

Malkangiri goat

Morphological data were collected from goats of different regions of Malkangiri district and these are raised only for their meat. These goats are mostly reared by Koya tribals, but other community farmers also rear theses since generations. Reared under extensive system, these goats have been performing to their potency almost without any special management and health care. Malkangiri goats are predominantly brown. Black and mixed coat colour are seen in few cases. Bucks used for breeding had black neck ring (Majumder et al., 2023) [5] . However, all the three goat types are native to southern Odisha with almost similar management practices. As reared mostly by resource poor farmers and without much health management these goats live long with optimal production and reproduction performance level, the goats prove to be disease and climate resilient. Selection index was computed as follows, Index I = b1x1+b2x2+.....+bnxn Where, b1 was the partial regression coefficient or weighing factor for x1 x1 was the phenotypic measurement on the i th character.

Results and Discussion

The variances and covariances used for construction of the index in Ganjam goat are presented in Table 2 for I11. For Malkangiri goats the variances and covariances are shown in Table 3 for I21 and the variances and covariances used for construction of the index in Narayanpatna goat is given in Table 4 for I31 The index weighting factors (partial regression coefficients), heritability and efficiency of indices are presented in Table 5 for I11, I21 and I31. A selection index was constructed in Ganjam goats (I11) to improve the important reproductive traits like age at first kidding, weight at first kidding and kidding interval. Negative weightage (-1) was given to the characters 1 and 3 but body weight at first kidding had weightage 1. The efficiency (RHI) of this index was 0.592. There would be an expected decrease of 2.49 days in age at first kidding and 1.348 days in kidding interval per generation due to use of this index by imposing a selection pressure of i =1 (Table 5) Indices were also developed for Malkangiri and Narayanpatna goats for improvement of body weights at 12 months of age (I21 and I31). Although body weight is the prime character to be improved upon, additional body measurements like height at withers and heart girth having high correlation with body weight were incorporated in the selection indices developed for Malkangiri and Narayanpatna goats to increase the response in body weight as compared to selection for body weight alone as a single trait. It was evident that the efficiency and h 2 of most of these indices were high and indicated a possibility of increase in body weight if adopted (Table 5). Similar results were observed by Khadanga et al. (1987) [4] and Dash et al. (2010) [2] .

Acknowledgement

AcknowledgmentThe authors are thankful to the Department of Animal Breeding and Genetics, College of Veterinary Sciences and Animal Husbandry, Odisha University of Agriculture and Technology for conducting the study.

References

1. Dash SK, Rao PK, Patro BN. Selection index for improvement of production performance in goats. Indian Vet J. 2010;87:359-362.
2. Khadanga CR, Mishra PK, Patro BN. Selection index in Ganjam goats for improvement of meat production. Indian J Anim Sci. 1987;57(9):1008-1010.
3. Majumder S, Chinnareddyvari CS, Mishra C, Dash SK, Karna DK, Sahoo GR, et al. Sustainable utilization of non-descript goat populations of Southern Odisha. Pharma Innov J. 2023;12(1):921-923.
4. Majumder S, Dash SK, Samal L, Mishra C, Karna DK. Characterization, production and reproduction performance of Southern Odisha goats. Indian J Anim Res. 2023;57(11):1432-1437.
5. Majumder S, Ghosh T, Kumar A, Dash SK, Senapati MR, Samal L, et al. Genetic analysis of Malkangiri goats in its native tract. Indian J Anim Res. 2023;58(1):35-38.