Management of Dry and Transition Cows to Improve Energy Balance and Reproduction

Abstract

Abstract. Fertility of dairy cows has decreased for the past several decades. Measures of energy balance (EB; e.g. change in EB, EB nadir, cumulative negative EB, or duration of negative EB) are related to reproductive performance. Our research group has concluded that modification of diets fed during the dry or transition period are unlikely to have significant effects on postpartum EB and fertility. Rather, more radical alterations in dairy management are needed if energy status of postpartum cows is to be improved. We have examined the potential to alter EB by shortening or eliminating the dry period. In an initial study, the effects of a 56, 28, and 0 d dry period on ovarian dynamics and reproductive performance of dairy cows were examined. Postpartum EB was improved by reducing the dry period; however, only significantly for the 0 d dry period. Cows on the 0 d dry period did not experience negative EB. Improvements in EB were a reflection of lower milk production and greater feed intake. Consistent with the improvements in EB, time to first ovulation and first service, first service conception rate, services per conception, and days open were all improved by reduction of dry period length. Because small animal numbers were used in the study, a second study was conducted on a commercial dairy with many more animals to determine if results from the initial trial could be duplicated. A comparison was made between a 55 and 34 d dry period. Shortening the dry period resulted in fewer days to first ovulation, fewer days open, and a greater percentage of cows pregnant at 150 days in milk, although the improvements in the latter two variables were only significant for cows in their third or greater lactation. A current study is being performed in a large commercial dairy to examine the effects of eliminating the dry period on reproduction utilizing a large commercial dairy. Key words: Energy balance, Transition cows, Reproduction, Dry period length (J. Reprod. Dev. 56: S22-S28, 2010) ertility has decreased for the past several decades during a period when there have also been dramatic changes in management, nutrition, milk production, and genetics in commercial dairy operations [1][2][3]. Energy balance has probably the bestestablished nutritional relationship with reproductive performance. Energy balance is the difference between energy consumed and energy required for maintenance, pregnancy and milk production. Postpartum EB is more closely related to energy consumed than milk yield [4,5]. Deficiencies in minerals, vitamins, or amino acids can adversely affect reproductive performance, but unlike energy, those deficiencies can be corrected relatively easily by increasing density of the nutrient in the diet. In contrast, there are limits to energy density of diets fed to dairy cattle. Feeding additional grain or fat, in an attempt to increase dietary energy density, can adversely affect feed intake, digestive processes, or both. Therefore, increasing energy intake by dairy cattle is very difficult to achieve. The ...

Does the circadian system regulate lactation?

“…This transition is the most stressful period of the cow's life and has a large impact on a cow's lactation production. As a result, , 80% of dairy -E-mail: kplaut@purdue.edu cow disease events occur in the first 3 weeks after a cow delivers a calf (Drackley, 1999;Mulligan and Doherty, 2008;Grummer et al, 2010;LeBlanc, 2010).…”

“…This transition is the most stressful period of the cow's life and has a large impact on a cow's lactation production. As a result, , 80% of dairy -E-mail: kplaut@purdue.edu 394 cow disease events occur in the first 3 weeks after a cow delivers a calf (Drackley, 1999;Mulligan and Doherty, 2008;Grummer et al, 2010;LeBlanc, 2010).Understanding how a cow sets her metabolic and physiological rhythms in response to changes in her physiology, nutritional status and/or environment will enable the development of simple approaches that maximize productive efficiency and minimize metabolic disturbances in dairy cows. The circadian system is a likely candidate as it is believed to have evolved to coordinate the timing of internal physiological and metabolic processes and synchronize this timing with the animal's environment.…”

Effect of vaccination against bovine herpesvirus 1 with inactivated gE-negative marker vaccines on the health of dairy cattle herds

“…Studies have shown improvement in reproductive performance with a shorter dry period in multiparous animals. Due to shorter dry periods, the postpartum negative energy balance is improved, resulting in fewer days to first ovulation and a greater success of artificial insemination (Watters et al, 2009;Grummer et al, 2010;Mansfeld et al, 2012). This may have an impact on the overall calving interval, which showed a decreasing trend in the vaccinated herds over the years, whereas an adverse trend was observed in nonvaccinated herds (Fig.…”

Effect of peripartum dietary energy supplementation on thyroid hormones, insulin-like growth factor-i and its binding proteins in early lactation dairy cows

“…Our results showed that feeding cows with an additional energy source succeeded to avoid severe postpartum blood IGF-I and thyroid hormone depression. Namely, after parturition high yielding dairy cows are exposed to NEB (Grummer et al, 2010). Thyroid hormones are positively correlated with energy balance in dairy cows during the early lactation period (Stoji} et al, 2001), and their concentrations decrease after calving.…”