The Ohio Stockmanship & Stewardship program in Caldwell will delve into various topics, including Reproduction and Nutrition. Exploring the connection between these two aspects is crucial, as highlighted by a research project presented at the 2013 Range Beef Cow Symposium. The study examined the impact of post-artificial insemination (AI) nutrition on pregnancy outcomes, shedding light on the importance of maintaining proper nutrition during the critical stages of early embryonic development.
The research indicated that nutrition plays a significant role within the 21 days post-breeding. Maternal recognition of pregnancy occurs around days 15-17 post-insemination, making it crucial to avoid moving heifers during this period to ensure conception. However, relocating heifers within the first 5 days post-insemination does not affect conception rates. It was observed that placing heifers on early growth pasture forages compromised conception rates due to potential energy deficiency and temporary weight loss during early embryonic development.
To optimize pregnancy rates, it is recommended to maintain a positive plane of nutrition in heifers after breeding until day 25 when the embryo should be fully attached to the uterus. Spring-born heifers, developed in dry-lot pens, may experience a shift in diet quality and quantity when moved to pastures after AI. This transition can negatively impact metabolism, body weight gains, and reproductive efficiency.
A joint study conducted by Purdue University and the University of Wyoming investigated the effect of post-insemination nutrition on AI pregnancy rates. Heifers were fed at different maintenance requirements following estrous synchronization and AI.
The study revealed that heifers maintained on a high plane of nutrition (125% maintenance) for 21 days post-AI exhibited greater AI pregnancy rates compared to those on reduced nutrition (100% and 80% maintenance). Heifers on decreased nutrition had lower 2nd service AI pregnancy rates and overall breeding season pregnancy rates. Supplementing heifers transitioning to pasture with concentrated feedstuff can prevent post-AI weight loss and preserve pregnancy rates.
Additionally, the study examined the impact of nutrient restriction on early embryo quality. Nutrient-restricted heifers displayed poorer quality embryos that were developmentally delayed and had fewer live blastomeres. This emphasizes the sensitivity of the early embryo, oviduct, and uterus to immediate changes in nutrition. Balancing nutritional inputs is essential to maintain a positive energy balance without compromising reproductive parameters.
Understanding and managing the nutritional needs of breeding heifers is vital for improving herd fertility and longevity. By ensuring a consistent and appropriate plane of nutrition throughout the critical reproductive stages, farmers can enhance pregnancy outcomes and contribute to a successful breeding program.
Photo Credit: gettyimages-pamwalker68
Categories: Ohio, Livestock