Rations for close-up cows and fresh cows are arguably the most important and expensive rations on the farm. Investment in the nutrients given to these cows pays off in reduced metabolic disorders and a better transition into lactation.

Robin R. Rastani

Get those cows milking strong right out of the maternity pen, and they’ll peak higher and maintain that milk production throughout their lactations.

Amino acids are appearing in more rations every day. A metabolizable protein (MP) level of 1,200 to 1,300 g per day is implemented by many nutritionists in the field for cows and heifers in the close-up period, and reports back are that this strategy is successful.

Methionine acts as a methyl donor, making it an intermediate in the synthesis of carnitine, choline and phospholipids. Thus, it plays a key role in liver metabolism. Supplementation of methionine to cows in the close-up group has resulted in increased milk production postpartum with improvements as great as 6.5 lbs per day.

It is unclear if lysine is needed prepartum, as data are limited. Postpartum cows can benefit from a diet that is amino acid balanced for both methionine and lysine.

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Antioxidants, including Vitamin E, are beneficial to a transition dairy cow. Many nutritionists increase vitamin E supplementation during the transition period. Increased levels of vitamin E (2,000 to 4,000 IU per day) have resulted in improved measures of immune function or improved mammary gland health in many studies.

While not all of these studies show a significant improvement, none of the research done with high levels of supplemental vitamin E, fed prepartum, has shown negative effects.

Antioxidants have also shown beneficial results when fed to cows during the transition period. Recent research showed a decrease in plasma BHBA concentration and an increase in total antioxidant status when feeding an antioxidant prepartum.

The antioxidant prevents oxidation of unsaturated fats and fat-soluble vitamins in the feed, so cows are consuming more energy and vitamins from the feed.

B vitamins play a role in both energy and protein metabolism, and include biotin, thiamine, riboflavin, niacin, pantothenic acid, folic acid, pyridoxine and B12. While the rumen can synthesize B vitamins, it can also degrade them.

Biotin is a co-factor for microbial enzymes involved in propionic acid synthesis. A meta-analysis on feeding biotin determined that a 2.9 lb per day increase in milk yield occurred with biotin supplementation.

These studies included studies where biotin was fed for two weeks prepartum into lactation, as well as studies where feeding of biotin began immediately after calving. Improvements in hoof health are also reported with biotin supplementation.

Choline is often referred to as a vitamin in the B-complex family. However, choline is somewhat unique in that it is not an enzyme co-factor and its level of supplementation is greater than that of vitamins. Choline acts as a methyl donor in biochemical reactions.

As previously mentioned, methionine serves as a methyl donor for choline synthesis; therefore, choline and methionine can spare the requirement of each other. Choline is a component of phosphatidylcholine, a key phospholipid, and thus is important in maintenance of cell membranes, as well as in lipoprotein transport in the liver.

Previous work from controlled experiments has shown decreased liver triglyceride concentration and decreased plasma NEFA concentrations when rumen-protected choline was fed. These results translate into reduced ketosis at the farm level. In a recent presentation at the Cornell Nutrition Conference, data from a meta-analysis of 13 studies were shown.

These data show improved dry matter intake (40.0 vs. 41.6 lbs per day) and improved milk yield (70.9 vs. 75.8 lbs per day) when choline was fed prepartum and postpartum. There are no effects on milk composition.

Chromium is a micronutrient that aids in the regulation of glucose metabolism. Research has demonstrated that cows supplemented with chromium during the transition period had no negative impact on prepartum dry matter intake and an increase in postpartum dry matter intake and milk production.

Chromium has also been shown to reduce the incidence of ketosis, likely due to the improvement of tissue responsiveness to both glucose and insulin.

Monensin is an ionophore that enhances propionate production in the rumen. Data show that feeding monensin prepartum results in decreased blood BHBA and blood NEFA.

On-farm, these translate to a decrease in ketosis incidence postpartum. Monensin supplementation during the transition period results in increased milk yield and a reduction in bodyweight loss.

In summary, many nutrients have been evaluated through research and have benefits of reduced metabolic disorders and increased milk in early lactation. In this article I did not address all of the options, but rather some of the more common ones being discussed.

Each dairy farm faces different challenges, so different solutions will be needed for each. Work with your management team to arrive at the best options for your needs. PD

R. Rastani