Effects of an acute feed restriction at the onset of the seasonal breeding period on reproductive performance and milk production in pasture-grazed dairy cows

J Dairy Sci. 2010 Mar;93(3):1116-25. doi: 10.3168/jds.2009-2562.

Abstract

Reproduction and milk production responses were compared between dairy cows offered a high (HPA; n=453 in 4 replicates) or low (LPA; n=317 in 3 replicates) pasture allowance for the first 14 d after the planned start of mating (d 0 of experiment) in 2 seasonal, pasture-based dairy herds. Estimated pasture dry matter intake (DMI) between d -1 and 13 were 14.3+/-2.8 and 8.0+/-1.7kg of DM/cow per day for HPA and LPA cows, respectively. The LPA cows produced 22% less energy-corrected milk during the 14-d feeding treatment period, and milk yield remained less in LPA cows at d 53 despite all cows receiving pasture allowances to support DMI of 16kg of dry matter/cow per day from d 14 onwards. The 3-wk submission rate (percentage of cows inseminated at least once from d 0 to 20) and the 3- and 6-wk pregnancy rates of LPA cows (88, 45, and 71%, respectively) were lower than those of HPA cows (94, 53, and 78%, respectively), but conception rates to first (50%) or second (47%) service and final pregnancy rates (93%) did not differ between treatments. These results quantify the immediate and subsequent responses in reproductive performance and milk production to a severe restriction in DMI at the onset of a seasonal breeding period in pasture-grazed dairy cows.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Breeding*
  • Caloric Restriction / veterinary*
  • Cattle / physiology*
  • Dairying
  • Diet / veterinary*
  • Female
  • Lactation / physiology*
  • Milk / chemistry
  • Milk / metabolism*
  • Pregnancy
  • Pregnancy Rate
  • Progesterone
  • Random Allocation
  • Reproduction / physiology*
  • Seasons
  • Time Factors

Substances

  • Progesterone