Data on age and body weight at breeding, parity, previous litter size, days open and some descriptive body linear traits from 389 meat-type, prolific Black Bengal goats in Tripura State of India, were collected for 3 and 1/2 years (2007 to 2010) and analyzed using logistic regression model. The objectives of the study were i) to evaluate the effect of age and body weight at breeding, parity, previous litter size and days open on litter size of does; and ii) to investigate if body linear type traits influenced litter size in meat-type, prolific goats. The incidence of 68.39% multiple births with a prolificacy rate of 175.07% was recorded. Higher age (>2.69 year), higher parity order (>2.31), more body weight at breeding (>20.5 kg) and larger previous litter size (>1.65) showed an increase likelihood of multiple litter size when compared to single litter size. There was a strong, positive relationship between litter size and various body linear type traits like neck length (>22.78 cm), body length (>54.86 cm), withers height (>48.85 cm), croup height (>50.67 cm), distance between tuber coxae bones (>11.38 cm) and distance between tuber ischii bones (>4.56 cm) for discriminating the goats bearing multiple fetuses from those bearing a single fetus.

Data on some linear traits along with age, body weight (BW) at breeding, parity and previous litter size (LZ) of 1008 pregnant Black Bengal goats were analysed using one-way Analysis of Variance. Higher age, heavier BW at breeding, higher parity order resulted more (P < 0.01) chance of triplet or quadruplet births as compared to that of single birth. Larger previous LZ resulted larger (P < 0.01) LZ in subsequent kidding. Most of the linear traits were higher (P < 0.01 or P < 0.05) in goats bearing multiple foetuses than in the goats bearing single foetus. The results of stepwise discriminant function suggested that heart girth, punch girth, BW, distance between trochanter major and pelvic triangle area might be the predictive indices for higher LZ.

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Aim:The present study was conducted on prolific goat breed to identify body linear type traits that might be associated with prolificacy trait in goats.Materials and Methods: Two-stage stratified random sample survey based data were collected from 1427 non-pregnant goats with the history of single, twin and triplet litter sizes (LZ) between January 2008 to February 2011 for 3 years in 68 villages located in East and North East India. Data on sixteen body linear traits were analyzed using logistic regression model to do the step-wise selection for identifying the body linear traits that could determine LZ. An average value for each identified body linear trait was determined for classifying the goats into three categories: Goats having the history of single LZ, goats having the history of twin LZ and goats having the history of triplet LZ. Results:The LZ proportions for single, twin and triplet, were 29.50, 59.14 and 11.36%, respectively, with the prolificacy rate of 181.85% in Indian Black Bengal goats. A total of eight body linear traits that could determine LZ in prolific goats were identified. Heart girth (HG) measurement (>60.90 cm), paunch girth (PG) (>70.22 cm), wither height (WH) (>49.75 cm), neck length (>21.45 cm), ear length (>12.80 cm) and distance between trochanter major (DTM) bones (>12.28 cm), pelvic triangle area (PTA) (>572.25 cm 2 ) and clearance at udder (CU) (>23.16 cm) showed an increase likelihood of multiple LZ when compared to single LZ. Further, HG measurement (>62.29 cm), WH (>50.54 cm), PG (>71.85 cm) and ear length (>13.00 cm), neck length (>22.01 cm), PTA (>589.64 cm 2 ), CU (>23.20 cm) and DTM bones (>12.47 cm) were associated with increased likelihood of triplet LZ, when compared with that of twin LZ. Conclusion:HG measurement was the best discriminating factor, while PG, neck length, DTM bones, CU, PTA, WH and ear length measurements were other important factors that could be used for identifying prolific goats to achieve economic benefit out of prolificacy trait.

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