There is a list of nutrients that are considered required to help ruminants perform bodily functions properly. Each is specifically designed for a unique function. At the recent Southwest Nutrition Conference held in Chandler, Ariz., professor Jose Santos of the University of Florida discussed the importance of choline in a transition dairy cows’ diet and the role it plays in production, reproduction, and health.
The transition period may arguably be the most critical stage of the lactation cycle for a dairy cow. During this time, cows are going through a multitude of hormonal and energy balance changes. It is during this period that choline, a multi-function B complex vitamin, comes into play, often in the form of rumen protected choline (RPC). Unprotected choline easily degrades in the rumen into trimethylamine compounds, resulting in limited supply of dietary choline to the small intestine for absorption. Because of this, RPC products have been included in dairy cow diets for quite some time as they are protected against microbial degradation.
Throughout the first week of lactation, dairy cows are more apt to extreme negative energy balances, which can cause severe metabolic diseases if not addressed. “This is the same period in which cows are most susceptible to hepatic steatosis or fatty liver,” Santos noted. With the help of RPC, disease incidence, such as fatty liver, can be reduced while maintaining or boosting milk yield.
Santos noted that a recent study showed that feeding choline ion up to 25.2 grams per day as RPC during the transition period tended to reduce risk of mastitis and retained placenta, improved feed efficiency, and elevated milk yield and energy-corrected milk when compared to non-supplemented cows.
“Most research in the area of choline nutrition in dairy cows used 12.9 grams per day of choline ion fed from approximately 255 days of gestation to 21 days postpartum. Nevertheless, there are indications from the literature that production responses to RPC are linear up to 25 grams per day of choline ion. In late gestation feed-restricted cows, supplementing up to 25.8 grams per day of choline ion as RPC linearly reduced the concentrations of triacylglycerol in hepatic tissue,” Santos explained. However, the optimal dosage of choline ion in the diet remains unsolved.
Not only is choline a nutrient requirement for cows, but it is also especially important for cows during the transition period as they undergo many hormonal and energy changes. The professor noted that when fed to prepartum cows under feed restriction and negative nutrient balance, RPC can reduce hepatitis triacylglycerol content and improve liver health and inflammation. “When supplemented to transition cows, RPC improved production performance for a period that extends beyond the days of supplementation,” Santos said in closing.
