Udder morphology and milk yield of Lacaune dairy sheep.

Introduction: This study analyses udder measurements in Lacaune ewes, with a particular focus on the effects of the control year (2022-2023) and lactation order on various udder traits. The number of Lacaune ewes included in the study ranged from 57 to 86 for various variables, while the number of control measurements was between 49 and 111. Significant year-on-year variations were observed in teat size and position, with teats generally decreasing in size with age. The control year had a significant impact on udder length, width, and depth, as well as teat length and angle. Our findings indicate that optimal teat angles for milking are around 45°. The order of lactation (parity) had a significant impact on udder size, particularly udder depth and length, which increased by the third lactation. The older ewes exhibited longer teats and a more horizontal teat position, indicative of larger udder cisterns. The results of the udder cistern measurements taken using different methods showed that cistern size tends to increase with age. It was found that larger cisterns correlate with higher milk yields and faster milk letdown. Although the impact of lactation order on cistern measurements was not statistically significant, the 'from the bottom' method proved more effective for assessing cistern size. There was considerable variation in the milkability parameters, including machine-milked and total milk yield. The correlation between udder attachment and milk production was significant, which highlights the importance of a strong udder attachment for efficient milk yield. A notable positive correlation between udder width and milk production indicates that wider udders yield more milk in shorter periods. The study findings indicate that larger udder cisterns, particularly on the left side, are associated with greater milk production. As ewes age and progress through lactations, udder morphology improves, facilitating better milkability. These findings provide a scientific basis for the use of specific udder traits in the selection of ewes with enhanced milk production potential for the Lacaune breed.