CASE STUDY: Effects of a Protected Vitamin and Choline Supplement in the Transition Period on Dairy Cow Metabolic Parameters and Health

Introduction

Mild micronutrient deficiencies can alter the susceptibility of animals to metabolic diseases (Bhaskaram, 2001). The ruminant animal relies upon microbial synthesis for a supply of water-soluble (B) vitamins and choline. Irregular feed intake patterns typically seen in dairy cows close to calving may contribute to vitamin inadequacies, resulting in a disruption of normal microbial vitamin production. There is an increasing amount of research suggesting that the supply of vitamins from microbial sources may not be adequate to meet requirements for nutrients such as choline and some of the B vitamins (Girard and Matte, 1999; NRC, 2001; Richards et al., 2002). Although the diet provides many nutrients in ample quantities, choline (Pinotti et al., 2002), folie acid (Santschi et al., 2004), and riboflavin (Zinn et al., 1987; Santschi et al, 2004) are nearly completely degraded by rumen microbes. Metabolic stress increases the rate of utilization of many of the water-soluble vitamins (Schek, 2003) and choline (Ziesel et al., 1995). The transition period is a time of dramatic increases in stress levels for dairy cows, and therefore represents a period of high vitamin turnover. Low feed intakes along with increased productive capabilities can often create many problems for the cow in the transition period. Benefits of an enhanced post-ruminal supply of watersoluble vitamins during the transition period have been previously reported. Girard and Matte (1999) determined that serum folates were low at parturition and increased over the 8 wk following parturition. Supplementation with very high levels of dietary folate in the periparturient period resulted in improved plasma folate status. Pinotti et al. (2003) showed that the provision of rumen-protected choline to dairy cows during the periparturient period reduced serum non-esterified fatty acids (NEFA). Such a reduction in NEFA may be associated with a decreased risk of several postpartum diseases (Piepenbrink and Overton, 2003). In contrast, supplying rumenunprotected B vitamins, other than biotin, to lactating dairy cows had little effect on intake, production and milk composition (Majee et al., 2003).

The current study was conducted to evaluate the effects of supplementation of a rumen-protected vitamin and choline blend to dairy cows during the transition period on metabolic and postpartum health parameters.

Materials and Methods

Animals and Treatments. The study was conducted at a privately-owned cooperative teaching facility monitored by the Ontario Veterinary College (OVC). All cows and heifers that entered the close-up pen from November 4, 2003, through March 24, 2004, were enrolled in the trial. Diets met the Cornell Net Carbohydrate and Protein System nutrient specifications, including those for all fat-soluble vitamins (Fox et al., 2004) and the feeding program was not altered for the duration of the trial. The only deviation from the routine program was the inclusion of the test vitamin and choline supplement (VC) in either the pre-fresh or the just-fresh lactating cow diet as required by the experimental plan.

The composition of VC is provided in Table 1. The supplement consisted of vitamins A, D and E, riboflavin, folic acid, and choline in a rumen-protected matrix of partially hydrogenated vegetable oils (Vicomb, Jefo Nutrition Inc, St. Hyacinthe, QC, Canada). The VC product was administered at a rate of 50 g/head per d during the prefresh period, and 100 g/head per d postcalving. To facilitate mixing, the VC product was premixed at a ratio of 1:9 with ground corn and the mixture was added to the total mixed ration replacing an equal amount of ground corn.