Veterinary World (Dec 2014)
Body linear traits for identifying prolific goats
Abstract
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 cm2) 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 cm2), 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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