Effects of Biofix® Plus PRO Supplemented in Liquid Feed on the Performance of Cow-Calf Pairs in South Central Florida

Cattle breeding difficulties across the Southern United States are often attributed to heat stress. Additional factors including mycotoxin consumption may negatively impact reproductive performance. Zearalenone (ZEN) is a mycotoxin associated with reproduction-related effects due to its estrogenic activity. Recent research has identified ZEN contamination in pastures in South Central Florida.

A trial was conducted at a commercial ranch in South Central Florida to evaluate the effects of Biofix^® Plus PRO (Biomin Holding GmbH, Austria) supplementation in a free-choice molasses-based liquid feed product (Westway Feed Products) on the performance of cow-calf pairs. Cows were randomly assigned to one of two treatment groups: Control (n = 194) or Treatment (n = 206). Liquid feed was provided ad libitum from December 2015 through October 2016 with the formulation adjusted over time to maintain intake goals. Biofix^® Plus PRO was supplemented to the Treatment group at an intended rate of 30 gram/head/day during the breeding period (December through April) and reduced to 15 gram/head/day through October.

Bulls were with cows from January through early April. Calves from the previous calving season were weaned in June. Treatment group calves weighed on average 24.0 kg more than calves in the Control group. Individual calf weights were not obtained in this commercial facility.

All cows were screened for pregnancy status (Control = 91.2% bred; Treatment = 90.3% bred; Z-score P=0.741) at weaning. Every fourth confirmed pregnant cow per group was identified for future pregnancy status evaluation (51 cows per group) and body condition score (BCS) determination (Control = 5.1 ± 0.1 SEM; Treatment = 5.9 ± 0.1 SEM; Unpaired t-test P<0.0001).

After 47 days, pregnancy status (Control = 100% bred; Treatment = 96% bred; Z-score P=0.162) and BCS (Control = 5.4 ± 0.1 SEM; Treatment = 6.1 ± 0.1 SEM; Unpaired t-test P<0.0001) were re-evaluated. Two Control cows (1 culled; 1 not caught) were not evaluated. One Treatment cow had calved prematurely and another was estimated to have lost her calf following the first pregnancy screen.

Live calf crop from tagged cows (Control = 96% Treatment = 90%; Z-score P=0.230) was determined in February 2017. One Control cow culled during the trial period and two Treatment cows identified as open in August were not included in calf crop calculations.

Biofix^® Plus PRO supplementation of molasses-based liquid feed significantly increased BCS in cows and increased weaning weights of calves in cow-calf pairs grazing pastures in South Central Florida.