Effect of trace mineral source on lactation performance, claw integrity, and fertility of dairy cattle.

Two hundred fifty multiparous and primiparous cows were assigned to a study at approximately 70 d prepartum to determine the effect of trace mineral source on lactation performance, claw integrity, and fertility. Cows received treatments from 3 wk prepartum through wk 35 postpartum. Treatments consisted of 1) all supplemental Zn, Mn, Cu, and Co provided in sulfate form (Sulfate) and 2) 360 mg of Zn, 200 mg of Mn, 125 mg of Cu, and 12 mg of Co supplied daily by Sulfate minerals replaced with similar amounts of minerals supplied by Availa-4 (CTM).

Effects of a colostrum substitute and of dietary brewer's yeast on the health and performance of dairy calves.

We tested the effects of substituting a whey protein concentrate for dam's colostrum at first feeding and of 1% brewer's yeast in dry feed on calf health and performance. Eighty-four calves were assigned to four preweaning and eight postweaning treatments based on feeding either dam's colostrum or a whey protein concentrate at birth and either yeast or no yeast in the dry feed both before and after weaning. After the first feeding, all calves were fed colostrum through 4 d of age and an all milk protein milk replacer from d 5 to 46 of age.

Technical note: forage in vitro dry matter digestibility as influenced by fiber source in the donor cow diet.

Objectives of this study were to determine the influence of five donor cow diets that differed in source of fiber on true in vitro DM digestibility of eight forages. Test forages included two alfalfa (31.2 and 38.

Production of volatile fatty acids in the rumen and cecum-colon of steers as affected by forage:concentrate and forage physical form.

Contribution of cecal and ruminal VFA to metabolizable energy was investigated in steers with cannulas in both the rumen and cecum. Animals were fed ad libitum so that data would be applicable to the lactating dairy cow. Diets assigned within a 4 x 4 Latin square were: 20% long alfalfa hay and 80% concentrate; 15% pelleted alfalfa, 5% hay and 80% concentrate; 80% hay and 20% concentrate; 60% pellets, 20% hay and 20% concentrate.

Nutrient digestion in the large intestine as influenced by forage to concentrate ratio and forage physical form.

Digestion in the large intestine was investigated in four growing steers fitted with duodenal and ileal cannulas. Diets assigned within a 4 x 4 Latin square were: 20% long alfalfa hay and 80% grain; 15% pelleted alfalfa, 5% hay, and 80% grain; 80% hay and 20% grain; and 60% pellets, 20% hay, and 20% grain. Intake of DM was not affected by diet.