Milk progesterone profiles and their relationship with fertility, production and disease in dairy cows in Northern Ireland

Abstract

A detailed investigation was conducted to identify the main factors influencing the current poor reproductive performance in dairy herds in Northern Ireland. Nineteen herds were selected and a comprehensive database was established, comprising detailed information collected over a 2-year period. Milk progesterone monitoring (no.=1423 cows), based on twice weekly sampling, was included in this on-farm investigation. The mean interval from calving to commencement of luteal activity was 30·1 days and 13·4% (184/1378) of these cows had not commenced luteal activity by day 50post partum. In addition, there was a high incidence of abnormal progesterone profiles: delayed ovulation type I; 15·6% (242/1388), delayed ovulation type II; 11·7% (125/965), persistent corpus luteum type I; 19·4% (212/1121) and persistent corpus luteum type II; 11·9% (70/619). Delayed commencement of luteal activity and abnormal profiles were associated with reduced fertility performance manifested as increased interval to first AI service and ultimately prolonged calving interval. Delayed commencement of luteal activity and abnormal progesterone profiles, with the exception of ‘delayed ovulation type II’ profiles, were not associated with lower conception rates. Assistance at calving was associated with delayed commencement of luteal activity. Delayed commencement of luteal activity and delayed ovulation types I and II profiles were associated with indicators of nutritional stress and poorer production performance in early lactation. Retained foetal membranes were strongly associated with prolonged luteal phases (persistent corpus luteum types I and II profiles). While hormonal therapy may prove useful in treating cows with abnormal milk progesterone profiles, the prevention and treatment of associated diseases and the implementation of good management practices are likely to be more rewarding.

Dairy cows’ reproductive response to feeding level differs according to the reproductive stage and the breed

“…Normande cows had 79% of normal progesterone profiles, as observed in other higher fertility breeds such as Norwegian Red or Swedish Red and White (,75%; Petersson et al, 2006;Garmo et al, 2009). Holstein cows had only 54% of normal profiles, consistent with recent literature in this breed (Royal et al, 2000;McCoy et al, 2006). In our study, Normande cows resumed luteal activity 6 days earlier (geometric means) than Holstein cows; this breed difference is large compared to other studies in dairy cows (Horan et al, 2005;Petersson et al, 2006).…”

“…PLP profiles were scarce in Normande cows (7%), as observed in Swedish Red and White (6%; Petersson et al, 2006), Norwegian Red (10%; Garmo et al, 2009), Swedish Holstein cows (11%; Petersson et al, 2006) and also Friesian cows three decades ago (13%; Royal et al, 2000). Conversely, 23% of Holstein cows had at least one PLP as classically observed nowadays (Royal et al, 2000;McCoy et al, 2006). This confirms the Holstein-specific increase in prolonged luteal phases (Royal et al, 2000).…”

Associations between genetic merit for milk production and animal parameters and the fertility performance of dairy cows

“…The increased IFS and CI may have been in part due to the longer interval to commencement of luteal activity in these cows, previously reported by McCoy et al (2006) but is also likely to have been due to management reasons in higher genetic merit herds, where cows have an extended voluntary waiting period of 3 months or more before service (unpublished data from present study). Cows of superior genetic merit are also less likely to display heat at first ovulation (Westwood et al, 2002) with effects on interval to first service.…”

Effect of offering dairy cows diets differing in phosphorus concentration over four successive lactations: 2. Health, fertility, bone phosphorus reserves and nutrient utilisation

“…Milk progesterone concentrations were determined using an enzyme-linked immuno-sorbent assay kit (Ridgeway Science Ltd, Gloucestershire, UK), based on the method of Sauer et al (1986), as described in detail by McCoy et al (2006). Interval to the commencement of luteal activity was defined as the interval from calving to the first of at least two consecutive increases in milk progesterone concentration of .3.0 ng/ml (Darwash et al, 1997).…”