Growth performance, faecal scores, and metabolic profiles of neonatal Holstein calves with extended transition milk feeding.

Transition milk, which is collected between the second and seventh milking after calving, during the transition from colostrum to normal milk, contains maternal leukocytes, growth hormones, cytokines, antimicrobial factors, and nutrients. It has been found to contain 15 immune system proteins, the concentrations of which gradually decrease during subsequent milkings. However, lactoperoxidase, which has been identified as a bactericide and bacteriostatic protein, is actually more abundant in transition milk than in colostrum. It has been suggested that feeding calves transition milk for two to six days after calving will improve their performance and boosts the immune system by stimulating earlier intestinal growth. However, transition milk is mostly overlooked by producers and is commingled with bulk tank milk, one reason being that limited information is available regarding the potential benefits of feeding transition milk to calves during the later weeks following calving. In addition, a short transition milk supply period may not show potential advantages in terms of performance and health parameters. Considering the limited information, the authors hypothesised that extended feeding of pure transition milk would result in increased performance and improved health status of dairy calves in the first weeks of life. Therefore, the purpose of their study was to investigate the growth performance and health status of Holstein calves fed transition milk for the first three weeks after calving.     

Twenty newborn Holstein calves without any health problems or dystocia were blocked by birthweight, sex, and parity and assigned to two groups: control (fed normal milk after day 5, n = 10) and transition (fed transition milk up to day 21, n = 10). The calves were housed in individual hutches and weighed to determine their growth rate, and blood samples were collected on days 1, 7, 14, and 21. Residual calf starter pellets were weighed daily to calculate the feed conversion efficiency. The calves were monitored and their faecal scores were recorded daily.

The results showed that feeding transition milk until 21 days of age improved the calves’ daily growth (508 ± 69.7g per day vs 321 ± 73.4g per day; P=0.001) and calf starter pellet feed conversion efficiency (3.09 ± 0.67g gain per g intake vs 1.34 ± 0.70g gain per g intake; P= 0.036). The calves’ faecal scores (2.55 ± 0.32 vs 2.51 ± 0.35; P= 0.867) and blood parameters were not affected by the transition milk feeding. No treatment × week interactions were observed in the calves’ growth performance, faecal scores, and blood parameters, except for the serum concentrations of aspartate aminotransferase and beta-hydroxybutyrate.

In conclusion: The results conclusively demonstrated that extended transition milk feeding up to three weeks of age will improve the growth performance of Holstein calves. The faecal scores and overall metabolic profiles were also not affected by feeding with transition milk. It is unclear though whether these benefits would continue later in life; however, the extended feeding of calves with transition milk, rather than commingling this milk with bulk tank milk, may improve the profitability of dairy farmers.