The basic statistics consisting of mean, standard deviation, and standard error were computed as per Snedecor and Cochran (1989). The data collected were scrutinized, edited, collated, and grouped according to the districts, age group, and sex. Procedure frequency was used to analyze qualitative traits and general linear model was used to interpret quantitative traits in Statistical Package for Social Sciences (SPSS Vs.23). The model used for least square mean analysis was: Y i j k l = μ + D i + S j + A k + e i j k l

Where,

Yijkl = l^th observation of i^th district, j^th sex, k^th age group

Di = Effect of i^th district (i = 1 to 4)

Sj = Effect of j^th sex (j = 1, male and 2, female)

Ak = Effect of k^th age group (k = 1 to 7, birth, 3 months, 6 months 2- teeth, 4- teeth, 6- teeth and 8-teeth)

eijkl = Random error

Duncan’s multiple range tests as modified by Kramer (1957) was employed to make pair wise comparisons of least-square means.

Data was analyzed for the statistical correlation (two tailed test of significant) of body weight with biometrical measurements by using Pearson coefficient. Stepwise multiple regressions were used to predict body weight from linear measurements having positive correlations with body weight. Variables that best fitted the model were selected using R². One may define the “best model” as that which has a highest R² value.

The sheep genetic group is popularly known as Macherla sheep and attained its local name based on the native tract i.e., Macherla area of Guntur district. The locals informed that the animals existing from a long time and its legacy was known for the past 30-50 years. Total geographical area of Macherla sheep was 51790 km². The average flock size of Macherla sheep in the present study is 134.31±4.6 and the minimum flock size of the genetic group is 50. The demographic survey revealed that a total of 5,32,393 Macherla sheep were distributed across the breeding tract. Based on the demographic survey, Macherla sheep constitutes about 3.02% of total sheep population of Andhra Pradesh and 0.7% of total sheep population of India (DAHD 2019).

The coat color and other morphological characters of Macherla sheep are distinct from the other sheep genetic groups of Andhra Pradesh viz. Nellore sheep (Brown, Jodipi and Palla strains) and North Coastal sheep. The predominant coat color pattern in Macherla sheep was bi-color of black and white (44.41%) followed by brown and white (35.65%), brown (18.64%) and black (1.88%). Similar to Nellore sheep breed, Macherla sheep is also a hairy type sheep but the hair is relatively more in this genetic group. A thick and dense bundle of hair growth, predominantly on neck and dewlap regions followed by brisket, back and thigh region was evident in adult rams providing elegant look. The predominant head profile in both sexes is prominently convex and ears were pendulous. The males are horned and females are polled.

Body measurements are useful for the description of a breed objectively and to study the growth pattern of the breed. Biometric measurements indicate the skeletal growth of the animals. The least-squares means for BL, HW, CG, and PG at birth, three-months, six-months, twotoothed, 4-toothed, 6-toothed, and full mouth age groups pooled over sex of the animals and district showed an increasing trend and least square means of various body measurements are presented in Table 1.

The least square means compared between sexes at different ages revealed significant influence on all four body measurements with higher (P<0.01) values in males. Similar differences were noted in Nellore Palla sheep (Harini, 2017) and North coastal sheep of Andhra Pradesh (Gangaraju, 2010). The variation in measurements between the males and females increased with age, which might be due to the differences in body weights, sex hormones, and sexual dimorphism. Influence of district was significant on body length at all age groups except at four-toothed, six-toothed, and full mouth age. Guntur district recorded significantly higher body length at birth, three months, and four-toothed age while Prakasam district recorded higher body length at six months and two-toothed age. District has significant effect on height at withers at all age groups. Guntur district recorded higher HW during birth, three months, six months, and four-toothed age, Prakasam district recorded higher HW at six-toothed and full mouth age, whereas Krishna district recorded higher WH at twotoothed age. District has significant effect on chest girth at all age groups, except for birth and six-toothed age. The effect of district is significant on paunch girth at all age groups, except for three month and 6-toothed age groups. Previous literature revealed a significant influence of village, mandal, zone and district in North coastal sheep (Gangaraju, 2010), Nellore (Harini, 2017; Rajanna et al., 2012; Rani et al., 2014), and Macherla sheep (Choudary, 2013). This might be due to the differences in environment and feeding conditions of animals. The body measurements of Macherla sheep is hardly variable from the North coastal sheep of Andhra Pradesh (Gangaraju, 2010; Prasanna, 2019), Deccani sheep (Rajanna et al., 2012). However, Rani et al. (2014) reported slightly higher body lengths and heights in Nellore Jodipi sheep while Karthik et al. (2021) revealed lower body weights in Nellore brown sheep under farm conditions.

The least-squares means for FL, FW, EL, and TL at different ages pooled over sex of the animals and district are presented in Table 2. District has significant effect on FL and FW at all age groups except, for 3 months age. The influence of district was found for EL and TL at all ages except influence of district was found for EL and TL at all ages except for full mouth age for EL and at six-toothed and full mouth age for TL. Sex of the sheep exerted significant (P<0.05) influence on face length at below one year age (P<0.01) and have non-significant effect on adult age groups. Sex of the sheep exerted highly significant (P<0.01) influence for EL at birth, three months, four-toothed age. Sex of the sheep exerted significant (P<0.05) influence on tail length only at six months age group.

The body weights of Macherla sheep at all ages recorded in the present study (table 3) was similar to those presented by Choudary (2013). Nevertheless, relatively lower values were reported in Nellore Jodipi sheep (Rani et al., 2014), Nellore Brown (Karthik et al., 2021; Reddy, 2015), Nellore Palla (Harini, 2017), and North coastal sheep (Gangaraju, 2010; Prasanna, 2019) of Andhra Pradesh and other Indian Sheep breeds. The influence of district on body weight of Macherla sheep are found to be significant at all ages studied except for two-toothed and six-toothed ages. The mean body weights are highest in Guntur district at birth, three months, six months, two-toothed age, four-toothed, six-toothed, and full mouth age (50.36 kg).

Among sexes, males recorded higher (P<0.01) body weights than females, at all ages studied. Similar effect of sex on body weights also reported by Choudary (2013) in Macherla sheep, Gangaraju (2010) and Prasanna (2019) in North coastal sheep of Andhra Pradesh, Karthik et al. (2021) in Nellore Brown, Rani et al. (2014) in Nellore Jodipi, and Harini (2017) in Nellore Palla sheep of Andhra Pradesh.

The variation of body weights between different age groups and sexes might be due to the linearly increased body weight with the advancement of age consequently increasing the metabolic activity, muscular and skeletal growth, reproductive organs’ growth etc. The ideal birth weight had influence on the weaning weight to desirable as 17.80 kg. Heavier weaning weight indicates good mothering ability of the ewes and the growth potential of ram lambs. The mean adult body weight of Macherla sheep was 47.85 kg reflecting the breed’s massiveness with an ideal body frame work.

The reproductive performance of Macherla ewes from the farmers' flocks (Table 4) were within the normal range of species. The age at first mating was about 1 year (357 days in males, 354 days in females). The first lamb crop was obtained at about 1.5 years (548 days) within the species specificities mentioned earlier. It can be inferred that the life time lamb crop production would be maximum due to its potential reproductive traits of early age of first service/ mating. Adequate feeding resources, ideal management practices and production system might have attributed for the ideal reproductive traits (Karthik et al., 2021). The reproductive traits of local Macherla sheep ewes showed that the breed was capable of producing lambing crop at an early age with high prolificacy and short lambing interval provided all input resources are optimized.

The reproductive trait values are comparable and marginally lower than North coastal sheep of Andhra Pradesh (Gangaraju, 2010 and Anandarao, 2010) and other Indian sheep breeds and significantly lower than Nellore sheep (Rani et al., 2014, Karthik et al., 2021; Reddy et al., 2018b, Harini, 2017). The lambing Per centage observed in Macherla sheep (97.4 per cent) was higher than the other hairy sheep of south India such as Mandya, Nellore (Acharya, 1982).

The phenotypic correlation between body weight and linear body measurements pooled over the various ages and sexes was presented in Table 5. Present study revealed that positive, strong and significant associations were found between body weight and other linear body measurements. The associations are body length (r = 0.92), height at withers (r = 0.92), chest girth (r = 0.96), paunch girth (r = 0.92), face length (r = 0.85), face width (r = 0.48), ear length (r = 0.29), and tail length (r = 0.45). Among the body measurements, chest girth was the most strongly correlated trait with body weight (r = 0.96) than other body measurements facilitating the accurate estimation of body weight using chest girth. This highest association of chest girth with body weight was in agreement with the reports of Belete et al. (2017), Abera (2014), and Mesfin (2015) in indigenous sheep of Ethiopia. The ear length was less correlated to the body weight and other body measurements. Further, body weight was moderately correlated with face width and tail length.

Regression analysis is commonly used in animal research to describe quantitative relationships between response variable and one or more explanatory variables such as body weight and linear body measurements (body length, chest girth, height at wither etc.), especially during the lack of access to weighing equipment (Cankaya, 2008). In the present study, all age groups and sexes were polled for increasing accuracy of results and are presented in table 6. The results showed that the chest girth (CG) alone had highest R² (0.92) compared with other body measurements. It indicated that Chest girth was more reliable in predicting body weight than other linear body measurements at field level. The better association of body weight with chest girth was possible due to relatively larger contribution to body weight by chest girth consisting bones, muscles, and viscera (Thiruvenkadan, 2005). Regression analysis revealed that the combination of chest girth with height at withers and body length (BL + HT + HG) has equal R² (0.93) value compared with the other equations involving all body measurements (BL + HT + CG + PG + FL + FW + EL + TL). The scenario indicates that due to the difficulty in restraining animals under field conditions, the combination of chest girth with body length and height will be best suited for predicting body weight. Similar results were reported by Vani et al. (2018) in Nellore sheep and Michel et al. (2016) and Belete et al. (2017) in Ethiopian indigenous sheep.