By Jair Parales Giron and Adam Lock
The immediate postpartum period represents a significant metabolic challenge for high-producing dairy cows. During this time, cows experience reduced feed intake alongside increased energy requirements for milk production, leading to negative energy balance. To compensate, cows mobilize body energy reserves to obtain enough energy for milk production, but excessive mobilization can lead to metabolic disorders and poor production performance. Thus, increasing the energy intake in the immediate postpartum is critical to minimizing the severity of negative energy balance and enhancing animal performance.
We can increase the energy density of the postpartum cow’s diet by increasing dietary starch or adding fatty acid (FA) supplements and oilseeds like whole cotton seed (WCS). When using starch, choose sources with low rumen fermentability to prevent negative effects on the cow’s ability to take in nutrients and synthesize milk fats. When using fatty acid supplements, consider what types of fatty acids to include (such as palmitic acid, or PA, and oleic acid, or OA), their proportion to each other, and proportion of the total diet. For WCS, consider the dietary inclusion level. Past research from Dr. Adam Lock’s lab shows that blends of PA to OA at 60 to 70% to 20 to 30% respectively improve milk production response in early lactation when fed between 1.5% and 2% of diet dry matter.
Fatty acid supplementation in low starch vs high starch diets
In this study, we fed four diets to early lactation cows and compared both milk fat in pounds per day and 3.5% fat corrected milk in pounds per day.
Low starch (LS): 22% diet dry matter (DM) was starch
Low starch with FA (LSFA): 22% diet DM was starch, 2% of diet DM was a 70% PA and 20% OA supplement
High starch (HS): 28% of diet DM was starch
High starch with FA (HSFA): 28% of diet DM was starch, 2% of diet DM was a 70% PA and 20% OA supplement
Adding fatty acids to a low starch diet increased milk fat and 3.5% fat-corrected milk yield. Fatty acid supplementation did not increase these variables when combined with a high starch diet. Combining high starch and a FA supplement may negatively impact ruminal fermentation, reducing available nutrients for milk fat synthesis and increasing rumen production of specific fatty acids known to reduce milk fat synthesis in the mammary gland. Check the diet’s starch content before supplementing with fatty acids to early-lactation cows.
Fatty acid supplementation from whole cotton seeds or supplemental fat
In this study, we again fed four diets to early lactation cows but used different treatments. We compared a control treatment to a diet with supplemental whole cotton seeds, supplemental fatty acids, or both together.
Control (CON): A diet without WCS or supplemental FA
Whole cotton seed (WCS): 10% of diet DM was WCS
Fatty acids (FA): 1.5% of diet DM was a 60% PA and 30% OA supplement
WCS with FA (WCSFA): 10% of diet DM was WCS and 1.5% of diet DM was a 60% PA and 30% OA supplement
Adding WCS or FA to the diet increased milk fat and 3.5% fat-corrected milk yield compared to the control diet. However, feeding both resulted in a large increase in dietary FA, which may have negatively impacted nutrient digestibility, resulting in no further improvement compared to feeding them individually. Feeding WCS or FA is a good strategy to improve animal performance in early-lactation cows.
Source : msu.edu