Consumption of endophyte-infected fescue seed during the dry period does not decrease milk production in the...

Area of Science:

• Animal Science
• Ruminant Nutrition
• Reproductive Physiology

Background:

• Ergot alkaloids from endophyte-infected grasses can suppress prolactin (PRL) secretion.
• Reduced PRL may negatively impact mammary function and milk yield in dairy cows.

Purpose of the Study:

• To determine the effects of endophyte-infected fescue seed consumption during late lactation and the dry period on mammary development and milk production.
• To assess the impact on prolactin secretion and subsequent lactation performance.

Main Methods:

• Twenty-four Holstein cows were assigned to control (endophyte-free fescue), bromocriptine (PRL inhibitor), or infected fescue treatments.
• Mammary growth, differentiation, and milk production were evaluated during the dry period and following lactation.

Main Results:

• Infected fescue and bromocriptine treatments reduced milk yield and PRL concentrations during the dry period.
• Mammary tissue analysis showed no significant negative effects on growth or development.
• Subsequent lactation milk yield was not compromised; bromocriptine group showed a 9% increase.

Conclusions:

• Feeding endophyte-infected fescue during the dry period did not impair mammary development or future milk production.
• This feeding strategy may allow for resource utilization without compromising lactation performance.