Effects of increasing milking frequency during the last 28 days of gestation on milk production, dry matter intake, and energy balance in dairy cows

Forty-eight Holstein cows were used in a randomized block design to evaluate different dry period lengths and prepartum milking frequencies (MF) on subsequent milk production, milk composition, solids-corrected milk production, dry matter intake (DMI), and energy balance. Lactating cows, milked 2 times/d, began a 7-d covariate period 35 d prior to the expected calving date. Cows were milked 0 times/d (0×), 1 time/d (1×), and 4 times/d (4×) for the last 28 d of gestation. If milk production decreased to less than 0.5 kg/milking or 1 kg/d, milking via machine ceased; however, teat stimulation continued 1 or 4 times/ d according to the treatment assignment. All cows were milked 2 times/d postpartum (wk 1 to 10). Prepartum DMI tended to be greater for 1× and 4× compared with Ox. Prepartum, cows milked 1× produced 17% less milk than cows milked 4× (5.9 and 7.1 kg/d, respectively). There were no differences in prepartum and postpartum body condition scores, body weights, and DMI. Postpartum milk production by cows following their third or greater gestation was greater for 0× and 4× compared with 1×. Postpartum milk production by cows following their second gestation was significantly decreased with increased MF (0× vs. 1× and 4×). Regardless of parity, postpartum solids-corrected milk was greater for 0× compared with 1× and 4×. Postpartum fat yield was greater for 0× vs. 4×, with 1× being intermediate. Postpartum protein yield was greater for 0× vs. 4×, whereas 0× tended to have greater protein yield than 1×. Postpartum energy balance was greater for 1× and 4× relative to 0×. Continuous milking (1× and 4×) resulted in a loss of milk production in the subsequent lactation for cows following their second gestation; however, for cows following their third or greater gestation, increasing the MF from 1× to 4× in the last 28 d of gestation alleviated the loss in milk production.