An Evaluation of the Effectiveness of Antibiotic Treatment at a Prebreeding Estrus on Subsequent Reproductive Efficiency

An experiment was conducted to evaluate the effectiveness of a douche with an antibiotic formula to improve reproductive efficiency in dairy cows.

A total of 102 cows was utilized in the experiment. The 81 Holstein cows were divided into four groups. These groups were untreated cows which had normal post-calving recuperation (N-C), treated cows with had normal post-calving recuperation (N-T), untreated cows which had experienced post-calving complications (M-C), and treated cows which had experienced post-calving complications (M-T). The 20 Jersey cows were divided into treated and untreated groups (N-T and N-C). The treatment consisted of a nitrofurozone-neomycin mixture in a 7 to 1 ratio.

The effectiveness of the treatment was evaluated by comparing the interval to first heat, number of prebreeding heats, interval to first service, interval to conception, and conception rates resulting from one and two services.

The analysis indicates that there was no difference (P > .05) in days to first heat, number of prebreeding heats, or days to first service.

In the Holstein data, the M-T group had the highest conception rate. There was a difference (P < .05) in conception rates between the groups. There was no difference (P > .05) between conception rates of the N-C and N-T groups. However, the trend was for the N-T group to have higher conception rates.

In the Jersey data, there were no differences in conception rates between the two groups on first service or first and second service.

There was no difference (P > .05) between the groups in number of days to conception for the animal conceiving in two or less services in the Holstein data. However, it is the author's opinion that there would be a difference if the experiment had been continued. This is based on the fact that the majority of cows in group M-C were still open at the conclusion of the experiment. There were no differences (P > .05) between the groups in days to conception in the Jersey cows.