Reproductive Management of Lactating Dairy Cows for First Postpartum Insemination

Abstract

Implementation of systematic breeding programs for fi rst postpartum insemination in dairy herds have become an integral part of the reproductive management of dairy cows, and they have allowed for increased insemination rates without compromising fertility. It is known that the fi rst 3 weeks past the end of the voluntary waiting period corresponds to the estrous cycle of greatest impact on reproduction of dairy herds. Therefore, assuring high pregnancy rate in this period is critical to optimize reproduction of dairy cows. This is related to the economic value of a pregnancy that is infl uenced by the day postpartum when the cow becomes pregnant, the need to manage large groups of cows without creating systems that might not be implemented due to diffi culty or lack of compliance, and the need to address defi ciencies in cow fertility such as poor estrous expression and detection.

Modification of the Standard 7-Day Ovsynch Protocol to Increase the Luteolytic and Synchronization Risks in Dairy Cows

“…Induction of ovulation in response to G1 at random stages of the estrous cycle occurs in only 50 to 66% of cows (3). Increased ovulatory response to GnRH is achieved when the Ovsynch protocol was initiated between days 5 and 12 of the estrous cycle (4). In order to synchronize cows to meet this ideal stage, presynchronization protocols (Presynch, PG-3-G, Double Ovsynch, and GGPG) have been developed (5,6).…”

Pathways of the dominant follicle after exposure to sub-luteal circulating progesterone concentrations are different in lactating dairy cows versus non-lactating heifers

“…Since the results indicate that a relatively high number of lactating dairy cows treated with exogenous progesterone for 7 days experience follicular arrest and hence risk of ovulating a compromised follicle, we suggest to inject these cows with GnRH at the moment of P4-insertion as was already suggested by Santos (2011). The latter will induce ovulation of the present DF within 2 days (Xu et al, 2000), followed by a synchronized initiation of a new follicular wave and emergence of a fresh DF (Ryan et al, 1998).…”

Comparison of PUFA Profiles in the Blood and in Follicular Fluid and its Association with Follicular Dynamics after PGF2α Induced Luteolysis in Dairy Cows

“…Several studies have shown a strong negative relationship between high milk production and fertility (2,3) particularly during the period of negative energy balance. The latter occurs in the early postpartum period due to the incapability of the cows to meet their energy needs (4). Implementation of dietary fats in the daily ration in an effort to ameliorate negative energy balance could increase (at least part of) cow's energy demands, leading to enhanced reproductive performance (5,6).…”