Calf starter containing a blend of essential oils and prebiotics affects the growth performance of Holstein calves

摘要

Essential oils extracted from specific plants can exhibitantimicrobial properties that make them potentialantibiotic alternatives. The objective was to evaluatean essential oil and prebiotic combination (EOC) onthe growth, development, and health status of growingneonatal calves. Forty Holstein newborn calves wereblocked by birth date and alternately assigned to 1 of2 treatments. Treatments were a pelleted calf starter(CS) without (control) or with EOC at 44.1 ppm.Calves were fed the experimental CS for ad libitumconsumption from 3 d of age through the end of the70-d experiment. Calves were fed 2 L of whole milktwice daily to 10 d of age, then 3 L twice daily throughd 35, and then fed 3 L once daily with abrupt weaningoccurring after 42 d of age. The average daily gain(0.78 and 0.87 kg/d for control and EOC, respectively)was greater for calves fed EOC compared with calvesfed the control. Calves fed EOC demonstrated greaterdry matter intake (1.63 and 1.74 kg/d) compared withcalves fed the control. Feed conversion ratio (0.62 and0.65 kg of gain/kg of dry matter intake) was greater forcalves fed EOC compared with calves fed the control.At 70 d of age, calves fed EOC demonstrated increasedbody frame measurements (hip height, body length,heart girth, abdominal girth, and pastern) comparedwith calves fed the control. The incidence of scoursscore 4 (mild diarrhea) was 3.5 incidences lower forcalves fed EOC compared with calves fed the control,whereas the incidence of scours score 5 (severe diarrhea)for calves fed EOC was 0.5 incidences lower thancalves fed the control. Blood concentrations of IgG andIgM on d 14, IgA on d 28, and total serum proteinon d 42 were all greater for calves fed EOC comparedwith calves fed the control. The blood volatile fattyacid concentrations were greater for calves fed EOCcompared with calves fed the control, which indicatedenhanced ruminal development. Total-tract digestibilityof dry matter, crude protein, acid detergent fiber,neutral detergent fiber, starch, and many minerals wereincreased for calves fed EOC compared with calvesfed the control. The inclusion of an EOC blend intoa CS demonstrates promising benefits for enhancingcalf growth, ruminal development, gut health, nutrientdigestibility, and immunity. The use of an EOC blendcan be a plausible alternative to feeding subtherapeuticantibiotics for improving calf performance, health, andimmunity.