Udder Score Research Articles

Prediction of ewe litter size using udder scores, liveweights, and condition scores

Abstract The usefulness of udder score, liveweight, and condition score measurements and their changes during pregnancy for predicting ewe litter size was tested using discriminant analysis on records of 7 058 ewes from 13 flocks covering a range of breeds. When each variable was used individually to discriminate between ewes bearing singles and those bearing twins, udder score was the best predictor variable with 65% being correctly classified Prelambing liveweight was the next best predictor with 62% correctly classified, and mating liveweight, liveweight change during gestation, and condition score were similar, averaging 58% correctly classified. When all variables were used together in a combined index, the accuracy of prediction was only slightly improved (68%) over that achieved by udder scoring alone. For on-farm use, udder scores or prelambing liveweights could potentially be used to correctly classify about two-thirds of ewes.

Abnormal Mammary Development of the Young Dairy Heifer and Its Association with Future Performance

summary Palpation data for 22 Holstein heifer calves, whose udder development was judged abnormal by arbitrary standards, were obtained. Three udder type evaluation scores, assigned at three months after first calving, were also obtained for each of these animals and their contemporaries. Of 32 glands, on 22 animals, which were evaluated as abnormal as young heifers, 19 (59%) on 13 heifers were classified as blind when the animals came into production. The remaining nine animals had serious udder defects, recorded at the time of type evaluation. Type evaluation scores at three months after first calving for three udder characteristics were significantly different for 18 animals classified as abnormal during the palpation period, when compared with their 54 contemporaries. A second group of 179 animals which had low udder palpation grades as heifers tended to leave the herd at rates and for reasons somewhat different from those usually expected. A rather high percentage (31%) of the animals in the heifer group was sold as nonbreeders. There is some slight indication that the lack of the development of the mammary system, a secondary sex organ in the young heifer, may be associated with endocrine function, which may influence subsequent reproductive performance.

Effects of Vacuum Level and Milking Duration on Guernseys and Holsteins Differing with Respect to Lactation Number and Status of Udder Health. I. Udder Health

Summary Forty-eight animals, after a 4-week standardizing period immediately after calving, were assigned to be milked from the 5th to the 44th week of lactation at either 10, 13.5, or 17 in. of vacuum and for a “normal” or “twice normal” duration. Of these animals, 24 were Guernseys and 24 were Holsteins. Within each breed group, 12 were first-calf heifers and 12 had one or more previous lactations. Within each breed-lactation group of 12, six were selected for being “clean” of mastitis and six for being “infected.” The latter was based on the occurrence of a clinical case of mastitis and/or the occurrence of more than 500,000 leucocytes per milliliter of milk and/or the presence of mastitis organisms in the milk during the standardizing period. The following results were observed: 1. Animals milked at 13.5 in. of vacuum had greater weekly increases in chloride content of the milk than did those milked at 10 and 17 in. No effect of vacuum level on any of the other criteria studied could be ascertained. 2. Twice normal milking duration resulted in greater positive weekly changes in leucocyte number and chloride content of milk than did the normal milking duration. 3. Animals classified clean with respect to mastitis and first-calf heifers had fewer leucocytes, less pronounced weekly rates of increase in leucocytes, greater percentages of milk samples free of mastitis organisms and lower udder fibrosis scores than did animals classified infected and those with one or more previous lactations, respectively. 4. Holsteins in this experiment had on the average a higher chloride content in their milk samples than did Guernseys. 5. Teat-end morphology as indicated by scores had a tendency to change with an increase in vacuum level and milking duration; however, the differences in the scores were found not to be statistically significant.