A retrospective study on the effects of dry period length on milk yield and postpartum health in Holstein dairy cows.

We retrospectively analyzed the effects of dry period length (DPL) on milk yield and postpartum health using 152 commercial dairy farm data, including 46,228 dairy cows in Hokkaido, Japan, and examined the optimal DPL. The DPL was divided into eight categories: ≤25, 26-35, 36-45, 46-55, 56-65 (reference), 66-75, 76-85, and ≥86 d. The total milk yields (the sum of milk yield during the 55 d before and the 305 d milk yield after calving) of cows with DPL of ≤55 d did not differ from the reference group.

Dynamic changes and importance of plasma concentrations of ether phospholipids, of which the majority are plasmalogens, in postpartum Holstein dairy cows.

Context: Ethanolamine plasmalogens (EPls) and choline plasmalogens (CPls) are classes of ethanolamine ether phospholipids (ePE) and choline ether phospholipids (ePC), respectively. EPls play crucial roles in maternal and breastfed infant bodies and stimulate gonadotropin secretion by gonadotrophs.

Aims: To estimate changes in and importance of plasma concentrations of EPls and CPls, utilising newly developed enzymatic fluorometric assays for ePE and ePC in postpartum Holstein cows.

Prediction of energy balance from milk traits of Holsteins in Japan.

We predicted the energy balance (EB) of Holstein cows in Japan from milk traits obtained by herd testing. Records covered 156 lactations of 102 cows. The number of artificial inseminations was highest, and the first conception rate was lowest in the low-EB group.

Effect of roll clearance of mechanical processing of corn silage harvested at the black-line stage of maturity on carbohydrate and protein utilization in dairy cows.

The experiment was conducted to evaluate the effect of roll clearance of mechanical processing of whole plant corn silage (CS) on carbohydrate and protein utilization in dairy cows. Treated CS was harvested at the black-line stage of maturity and chopped at a theoretical length of cut (TLC) of 9.5 mm without processing or at a TLC of 19 mm with processing at a roll clearance of 1, 3 and 5 mm.

Effects of length of cut and mechanical processing on utilization of corn silage harvested at the black line stage of maturity by lactating dairy cows.

The effects of length of cut and mechanical processing on corn silage utilization by dairy cows were evaluated. Corn silage treatments were harvested at the black line stage of maturity and chopped at a theoretical length (TLC) of 9.5 mm without processing (Control) or at a TLC of 19 mm with processing at roller clearances of 1, 3, or 5 mm.