Economics of a dry-cow anthelmintic drenching programme for dairy cows in New Zealand. Part 1. Overall response in 47 herds

摘要: Trials were conducted on 47 seasonal supply dairy farms (>5500 cows) to assess the economics of a dry-cow anthelmintic drenching programme. The programme was administered during autumn/winter 1983 and consisted two treatments, first shortly after drying off (late April-early June) second before calving (mid-July-late August). The effects body condition cows over winter their subsequent milk production reproductive performance assessed. Overall, treatment did not result in worthwhile improvement cow winter. However, there small, but significant overall increase (2.24 kg milkfat/cow/lactation = 51.5 1 milk; P < 0.01). Young (3 years old) respond significantly better than mature cows, high quality (as assessed basis previous season's production) responded those poorer quality. pre-calving influence magnitude response. Calving data for year following trials indicated that conception rates time unaffected by drench programme. At prices prevailing at trials, proved be only marginally economic (∼ milkfat/cow required simply cover cost used). levels response individual herds involved varied considerably.