Effect of Different Combinations of Dietary Vitamin A, Protein Levels, and Monensin on Inflammatory Markers and Metabolites, Retinol-Binding Protein, and Retinoid Status in Periparturient Dairy Cows

Abstract

The objective of this study was to determine the effect of feeding different combinations of dietary vitamin A supplementation (0 or 110 IU/kg body weight), protein (10.3% or 12.2%), and an ionophore (monensin at 0 or 400 mg/day) on retinoid metabolism and immune function of dairy cows. Eighty multiparous Holstein dairy cows were studied from d -35 to +21 relative to expected parturition in a complete randomized block design with a 2 × 2 × 2 factorial arrangement of treatments. The significance of treatments was declared at p ≤ 0.05. Dairy cows receiving high crude protein (CP) diets with monensin had a greater retinol-binding protein serum concentration than cows receiving high CP diets without monensin (p = 0.04). Animals supplemented with vitamin A showed lower SCC (p = 0.04) and a higher thiobarbituric acid reactive substances concentration (p = 0.06) than cows non-supplemented. Moreover, cows receiving low crude protein diets had a greater haptoglobin concentration (p = 0.01). In addition, cows fed a high crude protein diet had a greater TNF-α expression in peripheral blood mononuclear cells (p = 0.04). Animals fed diets without monensin had a greater serum haptoglobin on day 3 postpartum than those fed monensin (p = 0.01). Moreover, dietary vitamin A increased serum 13-cis retinoic acid postpartum. We conclude that vitamin A, crude protein levels, and monensin fed during the close-up period affect milk somatic cell count, some vitamin statuses, and inflammatory markers during early lactation.

Keywords: gene expression; immune function; mastitis; periparturient; vitamin A.

Figure 1

Somatic cell count for multiparous Holstein dairy cows (n = 80, total) that were fed diets with crude protein levels (10.3%, n = 40 vs. 12.2% dry matter basis, n = 40), and within each crude protein group that was fed monensin (400 mg/day per head or none) and vitamin A (110 IU/kg body weight or none) during prepartum period (from day −35 to the day of calving). All cows received a common lactation ration postpartum. Dietary vitamin A interaction (p = 0.04).

Figure 2

Milk retinol concentration the first 21 days of lactation for multiparous Holstein dairy cows (n = 80, total) that were fed diets with crude protein levels (10.3%, n = 40 vs. 12.2% dry matter basis, n = 40) and within each crude protein group that was fed monensin (400 mg/day per head or none) and vitamin A (110 IU/kg body weight or none) during prepartum period (from day −35 to the day of calving). All cows received a common lactation ration postpartum. Dietary crude protein × time interaction (p = 0.04). Asterisks show significant difference at time point specified.

Figure 3

Serum haptoglobin concentration for multiparous Holstein dairy cows (n = 80, total) that were fed diets with crude protein levels (10.3%, n = 40 vs. 12.2% dry matter basis, n = 40), and within each crude protein group fed monensin (400 mg/day per head or none) and vitamin A (110 IU/kg body weight or none) during prepartum period (from day −35 to the day of calving). All cows received a common lactation ration postpartum. Dietary monensin × time interaction (p = 0.01). Asterisks show significant differences at time point specified.

Figure 4

Serum retinol-binding protein (RBP) concentration for multiparous Holstein dairy cows (n = 80, total) that were fed diets with crude protein levels (10.3%, n = 40 vs. 12.2% dry matter basis, n = 40), and within each crude protein group fed monensin (400 mg/day per head or none) and vitamin A (110 IU/kg body weight or none) during prepartum period (from day −35 to the day of calving). All cows received a common lactation ration postpartum. Dietary protein × monensin (p < 0.04). Different letters mean statistical difference between the treatments.

Figure 5

Serum 13-Cis retinoic acid concentrations (ng/mL) for multiparous Holstein dairy cows (n = 80, total) that were fed diets with crude protein levels (10.3%, n = 40 vs. 12.2% dry matter basis, n = 40), and within each crude protein group fed monensin (400 mg/day per head or none) and vitamin A (110 IU/kg body weight or none) during prepartum period (from day −35 to the day of calving). All cows received a common lactation ration postpartum. Dietary vitamin A × time interaction (p < 0.01). Asterisks show significant differences at time point specified.

Figure 6

Serum all-trans retinoic acid concentration (ng/mL) for multiparous Holstein dairy cows (n = 80, total) that were fed diets with crude protein levels (10.3%, n = 40 vs. 12.2% dry matter basis, n = 40), and within each crude protein group fed monensin (400 mg/day per head or none) and vitamin A (110 IU/kg body weight or none) during prepartum period (from day −35 to the day of calving). All cows received a common lactation ration postpartum. Dietary vitamin A × time interaction (p = 0.005) (p < 0.01). Asterisks show significant differences at time point specified.

Figure 7

Fold change of PBMC gene expression of tumor necrosis factor-α (TNF-α; Panel a) and intercellular adhesion molecule-1 (ICAM; Panel b) for multiparous Holstein dairy cows (n = 80, total) that were fed diets with crude protein levels (10.3%, n = 40 vs. 12.2% dry matter basis, n = 40), and within each crude protein group fed monensin (400 mg/day per head or none) and vitamin A (110 IU/kg body weight or none) during prepartum period (from day −35 to the day of calving). All cows received a common lactation ration postpartum. Dietary crude protein effect and dietary protein × vitamin A interaction (p = 0.04, 0.05, respectively).