Effects of intake level and transition to calving on health, productivity, and key genes for gluconeogenesis in liver of dairy cattle

Jonathan Townsend, Purdue University

Abstract

During the period of transition from gestation to lactation, approximately 3 weeks precalving to 3 weeks postcalving, the dairy cow is subjected to physiological changes and experiences a higher disease incidence than any other time during her lifespan. Better understanding of the physiology of the transition dairy cow is essential for improved nutritional management of cows during this time period. Improved management of these cows should improve animal health and welfare, and in turn, dairy farm finances. A large part of the nutritional management of transition dairy cows focuses on improving dry matter intake and energy balance during this period. The work presented in this thesis focuses on effects of intake level and transition to calving on health, productivity, and key genes for hepatic gluconeogenesis in dairy cattle. Maximizing dry matter intake of Holstein dairy cows from day -14 relative to calving until day of calving provided no benefit over ad libitum feeding during that time period. Additionally cows with maximal dry matter intake demonstrated no advantage over cows that experienced restricted intakes during the same time period. Ad libitum fed cows also outperformed restricted dry matter intake cows. The results of this experiment point to a potential beneficial role for a mild depression in prepartum DMI. The physiological basis for this benefit is not understood at this time. Additionally, it appears that maximal intake prior to parturition does not produce optimal postpartum performance. Postpartum performance may be better indicated by a relative level of change in dry matter intake and energy balance rather than an absolute level of dry matter intake or energy balance. The current study points to the need for additional work in defining the level of the decrease in feed intake necessary to negatively affect the production and health of early lactation dairy cows and identifying the genetic characteristics of cows that appear to have greater voluntary dry matter intake.

Degree

Ph.D.

Advisors

Donkin, Purdue University.

Subject Area

Animal sciences

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