Reliability of united score card for crossbred dairy cows of Kerala

Abstract

The research work was conducted to assess the reliability of Unified score card for cross bred cows of Kerala. One hundred and ninety six animals of University cattle farms of Mannuthy, Thumbunnuzhi and Thiruvazhamkunnu were selected for the study. As per the Unified score card by Purebred Dairy Cattle Association, the animals were judged for frame, dairy character, body capacity, feet• and legs and udder. The type components were again subdivided as described in the scorecard to improve the accuracy of judging score. The body measurements of individual animals like height at withers, body length, chest girth, height at withers, height at pins, length of quarter, width between angles of hook and slope of rump were taken. The animals were categorized into four age groups, four parities and three stages of lactation. The emphasis of each of the components of unified score card to milk production was compared and statistical analysis was carried out as per methods suggested by Snedcor and Cochran (1994). Effects of age, stage of lactation and parity on judging using Unified Score Card were worked out. The body measurements were also correlated with the score and milk yield. Age, parity and stage of lactation were found to be nonsignificant for final score. The scores of frame, dairy character and udder for different age groups showed no significant difference, whereas, scores of body capacity and feet and legs differed significantly. The scores of dairy character and body capacity differed significantly with parity. No significant difference was shown for scores of frame, feet and legs and udder. Frame was found to be positively correlated with other components, the least being with udder (r=0.127) and highest with feet and legs (r =0.254) which was highly significant (p<0.01). Dairy character was significantly correlated with body

capacity (r=0.169) and feet and legs(r=0.2S4) in addition to frame. Feet and legs was the only component to which udder showed positive significant correlation (pAge was found to be not significant for lactation yield (P~O.OS). The means of lactation yield differed significantly for different parities. All the type components were found to be positively correlated with lactation yield, all being significant. The standardized partial regression coefficients were highly significant for dairy character, udder. and body capacity whereas non significant regression coefficients were obtained for frame and feet and legs. Udder depth was having the highest regression coefficient (~=0.312) which was highly significant (p<0.01). Regression coefficients were significant and positive for skin (0.229), withers (0.188), ribs (0.174) and thighs (0.162). Both age and parity had significant positive correlation on body weight. Body weight was significantly (p<0.0 1) correlated with lactation yield with r=0.244. Height at withers, length, hip width girth and height at hook showed significant difference with age (p:SO.OS).The height at pins and slope were found to be not affected significantly by age. All the measurements except slope were significant and positive in correlation with body capacity. All height measurements, length and girth was found to be positively correlated with frame (p<0.0 1). Final score was having significant positive correlation with all height measurements (p:SO.OS). It was concluded that although the score card was found to be reliable on the production of crossbred cows of Kerala, the emphasis placed on type components was not in full agreement with what was prescribed by the purebred Dairy Cattle Association Dairy Cow Unified Score Card. Hence it was suggested that more weightage could be given to body capacity and dairy character compromising weightage on frame and feet & legs which necessitated further studies in this regard.