Using supplemental dietary yeast to promote calf growth
Stress affects the health and growth performance of cattle. Antibiotics are used in animals for disease treatment and prevention and as growth promoters. However, public concern about antibiotics has created the need to look into alternative dietary supplements.
Cattle experience significant stress levels at birth, weaning, transportation, and reception in the feedyard. This can have adverse effects on growth performance. Previous research shows yeast supplements as a promising alternative to antibiotics to combat the negative effects of stress. Two experiments were run to determine how supplemental dietary yeast influences the health and growth performance of cattle.
In the first experiment, 95 heifer calves were offered either creep feed with no yeast, or creep feed with yeast product added. Calves were offered the creep feed for 35 days before weaning. After weaning, calves had ad libitum, or “as desired,” access to forage and were fed a grain supplement for 42 days. Calf body weight gain before weaning was not different between the two groups. Calves that did not receive the yeast supplements had an increased weight gain compared to those receiving the yeast supplements. There was no difference in serum haptoglobin concentrations, an indicator of stress, between the two treatments.
In the second experiment, 97 late gestation cows were fed grain supplements with or without yeast supplements. Cattle were checked daily and their weights were recorded at calving. The birth weights of the calves were not different due to diet. However, calf body weight at 85 days old was greater in calves that received the yeast supplements. Cows and calves that received the supplements also had a lower neutrophil to lymphocyte ratio, another stress indicator.
The Bottom Line
Yeast supplements can increase calf body weight pre-weaning and reduce stress related to calving for both cows and calves.
Professor of Animal Science
University of Arkansas System
Division of Agriculture.
Kegley earned her BS in Animal Science from Virginia Tech and her MS and Ph.D. in nutrition from North Carolina State University.