Prevent Endometritis to Maximise Dairy Cow Fertility
20 December 2020
Endometritis (commonly known as whites) is an infection of the inner lining of the uterus and affects around 15% of dairy cows, although some herds can experience up to a 60% incidence.
Cows with endometritis have reduced fertility, such as an average increase in days to first service by seven days, a four-week delay in conception, increased early embryonic death, reduced follicle growth and an increased risk of cysts developing.
Endometritis is costly as it has a significant detrimental impact on milk output per cow as well as increasing the herd culling rate because of poor fertility.
Although some cows can be easily identified as they have an obvious discharge, around 75% don’t show outward visible signs. A pre-breeding scan at 4 weeks after calving will pick these up early. This allows any cows which are going to self-heal enough time and gives problem cows enough time to be treated before breeding commences. Research has shown that earlier treatment leads to better fertility results. However, even when successfully treated, affected cows will still have reduced fertility therefore, prevention is better than cure. A good target for a well transitioned herd is to have under 10% of cows at the 4-week stage with endometritis.
Prevention of endometritis requires a multi-pronged approach.
The transition diet is crucial when it comes to preventing endometritis. Retained placentas are a known risk factor for endometritis. As calcium balance around calving is a risk factor for retained placentas, controlling milk fever in the dry cow period is crucial. Ensuring cows receive adequate protein and minerals (especially vitamin E and selenium) to support the immune system in the dry period will help reduce the risk of retained placentas/metritis and risk of endometritis.
Body condition score (BCS
Research has shown thin cows (BCS 2.75) two weeks before calving are almost 7 times more likely to develop endometritis than cows with BCS of 3.5 to 3.75. On the other hand, over conditioned cows are more likely to suffer metabolic issues, reduced energy intakes and difficult calvings, which increases the risk of endometritis. This highlights the importance of monitoring diets throughout lactation to maintain correct BCS throughout achieving a target BCS of 3.25-3.5 at drying off and maintaining this throughout the dry period.
Cows in negative energy balance in early lactation have decreased resistance to infection and therefore are more likely to develop endometritis. In addition to this these cows are less likely to commence cycling early in lactation which would naturally clear-up endometritis. Achieving high intakes in the dry period and a problem free calving alongside a well formulated fresh cow diet will create an opportunity for the cow to achieve high energy intakes in early lactation.
Hygiene at calving
Clean calving boxes are very important. Contractions naturally pull contaminated air into the birth canal. If high levels of bacteria are present in the calving pen the level of bacteria is higher leading to an increased risk of infection and therefore endometritis developing.
Assistance at calving
Aim for unassisted calvings as unnecessarily pulling calves can lead to trauma and increase risk of endometritis. Use of easy calving bulls will reduce need for assistance. Where assistance is required the use of hygienic equipment and proper technique is critical to reduce risk of endometritis. Over conditioned cows will have excessive fat in the pelvic canal and therefore are at an increased risk of difficult calvings.
Working with your nutritionist to formulate transition and lactation diets to prevent metabolic issues and control BCS alongside good management can help reduce endometritis rates whilst also maximising milk in early lactation.
by Adam Smyth, Commercial Nutritionist