Supplementation of green tea extract on early-life behavior, health, and growth of Holstein heifer calves.

Caffeine is known to improve the vigor and survivability of premature babies, however, there is little information on its effects on neonatal dairy calves. Green tea extract has high natural caffeine content, with potential for additional polyphenol-related health benefits. The objective of this study was to determine how different doses of green tea extract, administered at birth, affect the vigor, behavior, health, and growth of dairy calves during their first 28 d of life, particularly those born from cows experiencing dystocia. Heifer calves were assigned to 1 of 3 treatments: (1) single (SNG; n = 42) 15-mL dose of green tea extract (Calf Perk, TechMix, LLC; containing 327.6 mg of naturally occurring caffeine, a minimum of 40% corn syrup as energy, 25% water, 1% vegetable oil to suspend the solution, and preservatives including cassia oil, xanthan gum, and citric acid), (2) 30-mL double dose (DBL; n = 39; 2 × 15-mL tubes of Calf Perk; 655.2 mg caffeine), and (3) control (CON; n = 39; 15-mL placebo of water, corn syrup, xanthan gum, and vegetable oil). Calves were given the treatment orally within 2 h of life, before colostrum feeding. Blood was sampled, and vigor scoring occurred between 0 and 72 h of life, while health scoring (including symptoms of respiratory illness and diarrhea) occurred at 24 h of life and then twice weekly until 28 d of age. The BW was recorded at birth and weekly for 28 d. The DBL calves (23.7 ± 0.22 of a possible 30-point vigor score) had moderately improved overall average vigor scores throughout the duration of the study compared with CON calves (23.1 ± 0.20), while SNG calves (23.1 ± 0.23) did not differ from CON calves. No differences were detected between treatment groups for instances of respiratory illness or diarrhea. No differences in ADG were detected in wk 1 (0.54 ± 0.03 kg/d) and 3 (0.49 ± 0.03 kg/d); however, in wk 2, SNG calves tended to gain more than CON calves (0.46 vs. 0.33 ± 0.05 kg/d). The SNG calves also tended to gain more than CON calves (0.98 vs. 0.87 ± 0.05 kg/d) in wk 4. As a result, SNG calves were heavier than CON (58.9 vs. 57.3 ± 0.50 kg) calves at 28 d of age, while DBL calves did not differ (57.3 kg). Although the effects of dystocia were considered for all outcomes measured, the effects of green tea supplementation on calves born from a dystocia calving compared with those from a eutocia calving remain unclear. Overall, a double dose of green tea extract supplementation was associated with improved vigor, whereas a single dose resulted in greater weight gain in calves.