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Virginia Cooperative Extension - Knowledge for the CommonWealth

Nutrition and Fertility

Dairy Pipeline: November 2005

Tina Horn Dairy Extension Agent, Augusta County

Cool weather usually brings about a push to get cows bred. Don't make the mistake of focusing only on heat detection, AI techniques, synchronization, and all other components of the reproductive program if you are not achieving the success you desire. Nutrition can also influence fertility at all stages with the most critical stages being the transition period and early lactation. Unbalanced rations fed in the transition group and early lactation even for a short amount of time can cause problems that may last way into lactation. Inadequate levels of energy in early lactation can slow the resumption of reproductive cycles, increase the time to first estrus, and reduce conception rates. Deficiencies in vitamin E and selenium can affect the immunity status and fertility can be reduced by an increase in retained placentas, metritis, and mastitis. And the effects of mineral imbalances on hypocalcemia are well documented. Excessive nutrients can also reduce reproductive performance, such as excessive protein in the diets of pre-fresh and early lactation cows.

Feed changes that typically occur during this time of year can cause real problems particularly for those groups of cows. Changes that may seem insignificant to you have the potential to effect not only production but reproduction. Remember to make those changes slowly, sample quickly, and adjust rations accordingly. Not doing this could also lead to ketosis, hypocalcemia, displaced abomasums, etc in early lactation, all of which are associated with a decrease in reproductive efficiency. Studies also show that these metabolic disorders can lead to more problems. A cow with hypocalcemia has been shown to be six times more likely to develop a retained placenta and three times more likely to develop metritis. The more nutritional imbalances the cow has during this time the more likely she is to be a problem breeder.

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