Daily milk yield data have been shown to aid in early detection of ketosis, left displaced abomasum, and digestive disorders on fresh cows. However, in a recent University of California Cooperative Extension study, we observed that only 3 out of 45 dairies in California incorporated this technology on their operations. One of the challenges associated with using daily milk weights data to identify cows with health disorders is to ensure the correct identification of cows at milking. Healthy cows could show a drop in milk yield as a result of missing data during milking, or sick cows might not be identified if the software estimates yields of missing records. Two of the 3 dairies using milk meters only used this data to identify drops in production from multiparous fresh cows but not from primiparous cows. Postpartum milk yield generally increases more slowly for primiparous cows; thus, changes in milk yield are not as obvious.
If your dairy is not fitted with milk meters, there are alternative ways to collect valuable information on milk yield, such as evaluating udder fill or assessing milk flow during milking. Udder fill can be evaluated before milking by palpating the udder right above the base of the teats to assess the pressure in the gland cistern. It should be noted that when heifers have udder edema it could be difficult to assess udder fill. In our study 40% of the dairies reported to visually asses udder fill during fresh cow checks; but, none of the fresh cow evaluators touched the udder. Moreover, 33% of dairies evaluating udder fill performed fresh cow checks within 2 h after milking. Thus, even though palpating udders after milking might be useful to detect clinical mastitis, it does not provide milk production information that may be useful for early detection of other health problems. In our study, only 11% of the dairies collected information on milk flow during fresh cow milking. Fresh cow programs in California would likely gain value if milkers were trained on how to evaluate udder fill, and flagged suspicious cows to fresh cow evaluators.
Early detection of health disorders might improve if fresh cow evaluators and milkers are trained on how to evaluate udder fill and milk flow to estimate milk yield. Also, fresh cow evaluators should incorporate information on udder fill and milk flow before making treatment decision; i.e. cows with mild fever and showing adequate milk yield might not need treatment.