Milk Producer - March 2010 - (Page 42)

RUMINATIONS By Barry Potter Supplemental boost Your cows can get a leg up on production and overall health with ample doses of vitamin E and selenium s the winter stretches into spring, your stored feeds become depleted of vitamin E—a nutrient vital to your dairy herd’s well-being. Supplementing your cows’ diets with this vitamin could improve their overall health as they approach calving, as long as you ensure they also get adequate amounts of the mineral selenium in their feed. Dairy scientists have long established that vitamin E and selenium work together. Research has shown vitamin E can lower the incidence of retained placentas, reduce clinical mastitis and improve milk quality. For maximum effect, however, cows also need enough selenium. For selenium-deficient areas, like much of North America, supplementing this mineral in feed or by injection before calving has been shown to benefit dairy animals. Why is vitamin E sometimes shorted in herd diets? It is one of the more expensive vitamins to add to a ration. Vitamin A, by comparison, is often included in mineral packages in vast doses of thousands of international units (IU) per kg. The vitamin E inclusion ranges from the hundreds to single-digit thousands of IU per kg. Making up this deficit can be worth your while. A recent study showed the positive impact of selenium and vitamin E supplementation during late pregnancy on the reproductive rate and milk production in first-lactation heifers. Researchers split 60 heifers into three equal groups. The control group received no extra selenium or vitamin E. At four weeks and two weeks before calving, the second group (T1) received 20 millilitres of selenium, and the third group (T2) was supplemented with 40 mL of selenium and 50 IU of vitamin E. Selenium concentrations in a cow’s blood typically decrease during the final 60 days of gestation. By injecting the heifers with selenium, concentrations increased significantly by calving day, as shown in Table 1. Feeds tend to lose vitamin E potency during storage. ence milk quality. In this trial, lower somatic cell counts (SCCs) demonstrated better milk quality, and potentially lower mastitis for heifers with more vitamin E and selenium. Table 2 indicates the T1 and T2 groups had lower SCCs than the control group. Treated heifers had fewer infected quarters at calving, and a More colostrum produced Heifers injected with selenium or selenium and vitamin E also produced more colostrum than the control group. The blood selenium concentration was higher as well. Vitamin E and selenium also influ- Table 1: Selenium concentrations in blood Selenium concentration Ruminations is prepared by Ontario Ministry of Agriculture, Food and Rural Affairs livestock technology specialists to provide information you can use on your farm. Control 72 56 111 T1 (20 mg) 67 78 135 T2 (40 mg) 69 92 145 4 Weeks before Calving Calving Day Colostrum 42 | March 2010 | MilkPRODUCER

Table of Contents for the Digital Edition of Milk Producer - March 2010

Milk Producer - March 2010
Contents
Editor's Notes
DFO Chair's Message
Provincial Perspectives
Dairy Update
DFC Policy
Farm Finance
DFC Promotion
Heating With Cow Power
Processor Spotlight
Issues Update
Research
Applied Science
Ruminations
Markets
New 'N' Noted
Back Forty

Milk Producer - March 2010