The association between Ostertagia ostertagi antibodies in bulk tank milk samples and parameters linked to cattle reproduction and mortality

Abstract

In Western Europe, gastrointestinal nematodes are widespread in dairy cattle. This study was carried out to evaluate the relationship between optical density ratio (ODR) measured on bulk tank milk with an indirect Ostertagia ostertagi ELISA and reproduction/mortality parameters. Data were collected between 2008 and 2010 from monitoring carried out on 1643 dairy herds (Normandy, Western France). ODR values of 3 samples from each farm taken from November 2008 to 2010 were averaged and then transformed into a categorical variable. Reproductive and mortality data were obtained from 1444 herds using cow records from government databases. Statistical analysis was carried out using ordinary logistic regression (OLR). The outcome variables were the case-control status of a herd for reproductive factors, age at first calving and inter-calving intervals, and mortality ratios of various age classes. The effect of the categorical ODR variable was studied and several potential confounder herd factors were used to improve the model fit. A significant relationship was found between high Ostertagia ODR levels and a late age at the first calving (>34.5 months) (odds ratio (OR)=1.94, p<0.001). No significant relationship was observed with OLR for inter-calving intervals although bivariate analysis showed that herds with high ODR levels had longer inter-calving intervals than herds with low ODR level (first inter-calving interval in herds with low vs. high ODR levels=412 days vs. 422 days, p<0.001; other inter-calving intervals=408 days vs. 413 days, p<0.01). A high ODR level was also associated with high mortality of calves between 0 and 30 days of life (mortality ratio>6%) (OR=1.43, p<0.05) and between 91 and 365 days (ratio>3%) (OR=1.72, p<0.01). No significant relationship was observed with multivariate approach for mortalities in other classes by age, but bivariate analysis showed that herds with high ODR level had higher mortalities than herds with low ODR levels (mortality between 31 and 90 days in herds with low vs. high ODR levels=1.89% vs. 2.91%, p<0.001; mortality after 365 days=1.67% vs. 2.93%, p<0.001). In conclusion, our results confirm the usefulness of ELISA as an indicator for production losses in dairy herds. This inexpensive tool could be advantageous, used to aid farmers and veterinarians to carry out appropriate control measures.

Short- and long-term association between individual levels of milk antibody against Ostertagia ostertagi and first-lactation heifer’s production performances

“…In fact, the effect of GIN on heifers' mortality disappeared while accounting for F. hepatica BTM PP (data not shown), suggesting that this association was related to cattle helminth infections rather than GIN infections. This agrees with previous observations reported at farm level (Delafosse, 2013) and could be related to the poor digestion, protein absorptions and, overall, poor cattle condition due to helminth infections (Hawkins, 1993), as well as other confounder factors that were not captured in the current study, such as other etiological agents and disease control practices involved in heifer's mortality. This may also explain why heifers with high levels of antibodies against GIN were more likely to lose their calf at first calving and to present a delay in their second calving (Mejia et al, 1999;Loyacano et al, 2002;Greer, 2008).…”

“…However, the use of pooled samples also makes the interpretation of these results difficult (Sekiya et al, 2013). In addition to these effects on milk production, cattle helminths could also reduce calving interval and number of breeding at conception and increase 71 the mortality rate in a dairy herd (Walsh et al, 1995;Stromberg et al, 1997;Sanchez et al, 2002a;Delafosse, 2013). Interestingly, although heifers represent a capital investment for dairy farmers and are among the most vulnerable to this type of infections and production losses, little has been done to explore impacts of helminth infections in first-lactation heifers, with very few, inconclusive studies available (Blanco-Penedo et al, 2012;Liedtke et al, 2013).…”

Eukaryotic Infections in Dairy Calves: Impacts, Diagnosis, and Strategies for Prevention and Control

“… 89 This disease poses significant challenges to the dairy industry due to its impact on calf health, growth, and overall productivity. 90 Understanding the epidemiology, clinical signs, diagnosis, and management of Ostertagiasis is crucial for effective control and prevention. 91 …”

Decision making on helminths in cattle: diagnostics, economics and human behaviour

“…In beef cattle, the quantification of antibody levels against GIN and liver fluke in meat juice obtained in the abattoir has been proposed, showing negative correlations with carcass weight and conformation score [ 15 ]. Studies have also shown negative relationships between helminth-specific antibody levels and reproduction and mortality indices at the herd level [ 16 , 17 ]. Most recently, negative correlations have been established between a bulk tank milk ELISA for lungworm infection and milk production.…”