The effect of 2 different premilking stimulation regimens, with and without manual forestripping, on teat tissue condition and milking performance in Holstein dairy cows milked 3 times daily

摘要

The objectives were to study the effect of 2 differentpremilking stimulation regimens, with and withoutmanual forestripping, on teat tissue condition andmilking characteristics in dairy cows. In a randomizedcontrolled crossover study, 130 Holstein cows milked3 times daily were assigned to treatment and controlgroups. Premilking udder preparation for the treatmentgroup consisted of: (1) predipping with 1% iodine, (2)sequential forestripping of 3 streams of milk per quarter,(3) wiping of teats, and (4) attachment of the milkingunit. Premilking udder preparation for the controlgroup was identical except that the forestripping stepwas omitted. The mean tactile stimulation durationswere 16 s and 7 s for the treatment and control group,respectively. The time spent from first tactile stimulus(either forestripping or wiping of teats) to milking unitattachment was kept consistent at 90 s for both groups.The study lasted for 14 d with 2 periods, each consistingof a 2-d adjustment time followed by 5 d of data collection.Machine milking-induced short-term changes tothe teat tissue were assessed by palpation and visually.The following milking characteristics were assessedwith electronic on-farm milk meters: milk yield (MY),milking unit-on time (MUOT), 2-min MY (2MIN), andtime spent in low milk flow rate (LMF). Generalizedlinear mixed models were used to describe the effect oftreatment on the outcome variables. The odds of machinemilking-induced short-term changes to the teattissue were lower for cows that received forestrippingcompared with cows that were not forestripped (oddsratio = 0.31; 95% confidence interval = 0.22–0.42).Least squares means (95% confidence interval) for cowsthat were forestripped and animals that were not forestripped,respectively, were 12.7 (12.2–13.2) and 12.7(12.2–13.2) kg for MY and 6.1 (5.8–6.4) and 5.6 (5.3–5.9) kg for 2MIN. There was an interaction betweentreatment and MY for LMF. Time spent in LMF forcows that were forestripped and received no forestripping,respectively, were 18 (17–20) and 24 (23–26) s fora MY level of 10 kg; and 13 (12–14) and 15 (14–16)s for a MY level of 15 kg. The effect of treatment onMUOT was modified by parity. Milking unit-on timesfor animals in first, second and third or greater lactation,respectively, were 230 (219–243), 249 (236–262),and 260 (249–272) s for cows that were forestripped,and 245 (232–258), 252 (239–266), and 268 (257–281)s for cows that received no forestripping. In this study,cows that were forestripped had shorter MUOT, higher2MIN, lower LMF, and lower odds of exhibiting changesto the teat tissue after machine milking. We concludethat wiping of teats during premilking udder preparationalone and omitting forestripping of teats withoutcompensating for the loss in stimulation time may notprovide sufficient tactile stimulation to elicit the cows’maximum physiological milk-ejection capacity. Thiscan aggravate the adverse effects of vacuum-inducedforces on teat tissue during machine milking, diminishanimal well-being, and possibly affect udder health.