I want to start by wishing all the readers a Merry Christmas and a happy New Year!
    I realize this month’s topic may not apply to all dairy farms. However, for many Midwest dairy producers, we are entering a time when bovine somatotropin (BST) will no longer be available as a management tool. Well-managed herds with strong reproductive programs and plenty of replacements will make this transition with less disruption. Just as we discussed 20 years ago when herds started using BST, there are nutritional considerations as herds move away from this practice.
    Administering BST to dairy cows typically resulted in a direct increase in milk production and an increase in persistency of lactation. Research trials over the course of a lactation show about 10 pounds per cow per day when administering BST beginning day 50 to 60 postpartum. Within several weeks after starting BST, a 6- to 8-percent increase in dry matter intake (DMI) usually occurred. For the normal cow, this intake response was a predictable function of increased milk yield; the more milk in the bucket, the more feed in the manger.
    The ability to keep sufficient amounts of high-quality feed available at all times often dictated the success or failure of BST use. Herds that have been off BST for more than a few weeks have likely seen a reduction in DMI. Some herds are noticing more DMI consistency since stopping BST, particularly if they were on a full interval duration.
    Most herds have always strived to maximize DMI and feed efficiency. This becomes even more critical in a post-BST era. To capture lost milk, efforts to increase DMI are necessary. Forage quality may be improved by focusing on variety selection, harvest timing and practices. Evaluate feed bunk management for opportunities to enhance DMI, as well. This may range from stocking density to feed pushup to number of times per day cows are fed.
    A single group lactating ration has worked well for many farms as BST allowed for greater production persistency. In the absence of BST, it may be time to evaluate ration grouping strategies.
    Dr. Mike Allen from Michigan State University shared his hepatic oxidation theory (HOT) several years ago, which aimed to minimize body condition gain in late-lactation cows as their natural somatotropin levels decrease.
    The concept behind Allen’s theory is that cows partition nutrients differently depending on their stage of lactation and gestation. Consideration may be given to replace rapidly available carbohydrates with starch or sugar sources that are more slowly degraded. Another option is to implement fermentable fiber sources to reduce propionate production. Supplemental fat sources may also be evaluated and partitioned respectively.
    Work with your nutrition advisor to consider feeding strategies to mitigate production losses and changes in body condition of the herd. Several non-nutritional management factors may be implemented to try to capture some of the milk lost from BST removal. Examples include heat abatement, long-day lighting or multiple milking of fresh cows. Well-managed farms that focus on sound nutrition and cow comfort will find new ways to achieve outstanding production in a post-BST era.
    Barry Visser is a nutritionist for Vita Plus.