Transference of passive immunity and growth in dairy calves born to dams with high or low somatic cell counts at dry-off and fed colostrum from cows with high or low somatic cell counts at dry-off

The purpose of this experiment was to evaluate the transference of passive immunity (TPI) and growth achieved by calves born to dams with low or high SCC at dry-off and fed with colostrum from cows with low or high SCC at dry-off. Forty multiparous (3.2 lactations; SD = 1.1), dry, and pregnant Holstein cows were used. The cows were separated into 2 groups based on the SCC in the last 3 monthly records before dry-off. An SCC of 200,000 cells/mL was used as the cut-off point to categorize cows with or without mastitis at dry-off, and 2 groups of 20 cows each were formed: L-cow cows (last 3 SCC before dry-off less than 200,000 cells/mL) and H-cow cows (last 3 SCC before dry-off greater than 200,000 cells/mL). At calving, 40 calves were obtained (20 calves born to L-cow cows [L-calf], and 20 calves born to H-cow cows [H-calf]; females = 21 and males = 19), and 40 colostrum units (20 from L-cow cows [L-col]; and 20 from H-cow cows [H-col]). The experimental design was a 2 x 2 factorial, with 2 factors and 2 levels within each factor (type of calf: L-calf and H-calf, and type of colostrum: L-col and H-col), determining 4 treatments (n = 10 per treatment): L-calfxL-col (L-calf fed with L-col); L-calfxH-col (L-calf fed with H-col); H-calfxL-col (H-calf fed with L-col); and H-calfxH-col (H-calf fed with H-col). Male and female calves were homogeneously distributed within each treatment. All calves received 4 L of colostrum, L-col or H-col depending on the assigned treatment, with an oro-esophageal tube within 3 h after birth. Yield, chemical composition and IgG were determined. The TPI and the apparent efficiency of IgG absorption (AEA) were also determined. Nutrient intake and body growth and development traits of the calves (BW, heart girth, and withers height) were determined in the first 30 d of life. The colostrum produced by L-cow presented a lower SCC compared with H-cow. Colostrum protein yield of L-cow was 0.21 kg higher than H-cow, and colostrum of L-cow had 24% higher IgG concentration. The TPI was not affected by the interaction calf type x colostrum type, and there was no effect of the colostrum type on the level TPI and AEA achieved by calves. However, an effect of calf type on TPI and AEA achieved was observed, as L-calf achieved greater TPI than H-calf (28.8 and 22.8 g IgG/L, respectively; SEM = 1.5), and L-calf presented a higher AEA than H-calf (30.0% and 24.5%, respectively; SEM = 1.4). The BW, heart girth, and withers height were not affected by calf type, colostrum type, or by the interaction calf type x colostrum type. We concluded that cows with high SCC at dry-off produced colostrum with higher SCC and lower IgG concentrations, but when ingested by calves it did not affect TPI, feed intake, growth, or development. Calves born to cows with high SCC at dry-off presented a lower AEA of IgG, which translated into a lower serum concentration of IgG, irrespective of type of colostrum that was fed.