Relationship among udder and teat morphology and milking characteristics.
Teat cup liner slips, manual milking machine adjustments, milk yields, and milking times were recorded during both morning and evening milkings for 8 d on 97 Holstein cows in The Pennsylvania State University dairy herd. Fore and rear udder heights (distance from floor to udder), udder levelness, distances between teats (before and after milking), teat lengths, teat diameters, and teat end shapes were measured on the same cows. Product-moment correlations among the morphological characteristics, linear slips, manual adjustments, milk yields, and milking times were determined. Residual correlations from a model including lactation number and DIM (linear and quadratic) were also calculated. The variation among cows in machine liner slips and manual adjustments within and across lactation number and DIM can be partially explained by udder and teat morphology. Wider teats were associated with increased linear slips and increased manual adjustments. More tilted udders (rear quarters lower than front quarters) were associated with increased liner slips and tended to be associated with increased manual adjustments. In addition, larger teat diameters and longer teats tended to be associated with increased liner slips.
Rogers
G W
GW
Department of Dairy and Animal Science, Pennsylvania State University, University Park 16802.
Spencer
S B
SB
D000818:Animals; D002417:Cattle / Q000033:anatomy & histology* / Q000502:physiology; D005260:Female; D007774:Lactation; D016018:Least-Squares Analysis; D008321:Mammary Glands, Animal / Q000033:anatomy & histology* / Q000378:metabolism; D008892:Milk / Q000378:metabolism; D012044:Regression Analysis