Incidence and treatment of endometritis and effect of dietary marine seaweed extracts on reproductive function in spring-calving, pasture-based lactating dairy cows
|Title:||Incidence and treatment of endometritis and effect of dietary marine seaweed extracts on reproductive function in spring-calving, pasture-based lactating dairy cows||Authors:||White, Rachel||Permanent link:||http://hdl.handle.net/10197/13230||Date:||2022||Online since:||2022-11-07T11:04:49Z||Abstract:||Irish dairy production is built around a spring-calving, pasture-based system. A key element of this system is aligning peak herd energy requirements for lactation with peak pasture growth, and efficient reproductive performance is essential to achieve this. Fertility of dairy cows in Ireland has improved since the nadir of the 1990’s, due to strong emphasis on reproductive traits in the Economic Breeding Indexes and better reproductive management. In contrast to the USA, where fresh cow checks are routinely carried out in the 2 – 3 weeks after a cow has calved, very few farms in Ireland follow such protocols. As a result reproductive issues such as metritis and endometritis can largely go unnoticed and untreated. Such diseases are known to reduce fertility and increase the number of services required for conception, the days from mating start date to conception and the number of non-pregnant cows at the end of a breeding season. Vaginal discharge scoring (VDS) can be used to diagnose endometritis and gauge reproductive health status before the breeding season. This can help identify problem cows that would not be suitable for sexed semen, cows that may benefit from antibiotic treatment or increased time before AI. In Chapter 2, we investigated the incidence of endometritis and risk factors across five farms. Cows 21 days in milk (DIM) or more were examined for VDS; those with a score of =2 were randomly assigned to one of four treatments; Intrauterine Antibiotic (MET), Intrauterine Antibiotic plus anti-inflammatory (MET+AIN), synthetic Prostaglandin F2a (PG) or no treatment (CTL). An incidence rate of 28% was recorded across the five farms (n = 482/1695). Endometritis infection resulted in a reduced submission rate in the first 21 days of the breeding season and reduced risk of pregnancy by the end of the 12 week breeding season. Resolution of endometritis did not differ between the treatments, nor did treated animals exhibit a significant improvement in reproductive performance, suggesting the effect of endometritis lasts beyond clinical disease resolution. Overall, there were significant effects of herd and DIM when examining risks factors for endometritis. Chapter 3 examined the effect of a novel nutritional supplement extracted from marine seaweeds on measures of reproductive function in lactating dairy cows. Ascophyllum nodosum has been reported to improve immune function in monogastrics and it was hypothesised that the same could be true in cows. If immune function can be favourably affected in dairy cows during the stressful transition period, it could reduce persistent inflammation and reduce incidence of diseases such as endometritis. The supplement was fed at 4 inclusion rates to identify any potential dose response (0, 35, 70 or 105 g/day). Blood samples were collected on days -14, 0, 7, 14 and 28 relative to parturition to analyse energy metabolites and indicators of health and inflammation, and VDS was recorded fortnightly form week 2 to 8 post calving. Supplementation was found to reduce temporal blood IL-1ß concentration at the highest inclusion rate. Vaginal discharge scores were also reduced across all weeks in primiparous cows that received high levels of supplementation, and were significantly lower at 8 weeks in milk which would coincide with the beginning of the breeding season. In conclusion, endometritis is a disease of concern for Irish dairy farmers and needs to be carefully managed to mitigate subsequent fertility losses. In the absence of reliable treatment options further research into preventative measures is warranted. Our research suggests marine seaweed extracts could be incorporated into transition cow diets to reduce endometritis incidence in primiparous cows, and to moderate the immune response in all cows. Future research should test these finding in larger populations of cows, and also examine effects of marine seaweed extracts on other markers of immune function||Type of material:||Master Thesis||Publisher:||University College Dublin. School of Agriculture and Food Science||Qualification Name:||M.Agr.Sc.||Copyright (published version):||2022 the Author||Keywords:||Endometritis; Seaweed; Fertility||Language:||en||Status of Item:||Peer reviewed||This item is made available under a Creative Commons License:||https://creativecommons.org/licenses/by-nc-nd/3.0/ie/|
|Appears in Collections:||Agriculture and Food Science Theses|
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