Non-return rates: A lot of farmers are concerned that the hot weather last week is going to have an impact on fertility, potentially reducing conception rate and increasing embryo loss. Others are seeing more cows come cycling at unusual times such as 30 or 50-day repeats. It’s hard to separate out which of these are normal irregular heats or abnormal irregular heats because a percentage of cows will have irregular heats anyway. In every way, it’s better to be seeing these cows now, rather than a month’s time when the breeding season has ended. However, to get a handle on how the breeding season is going, it’s good to work out the non-return rates. These are the percentage of cows that don’t repeat. The easiest way to work it out is to download the breeding chart from ICBF Herdplus. Sort the cows based on insemination to first, second and third insemination. The non-return rate is the percentage of cows bred more than 21 days that haven’t repeated. It should be in the mid to high 60% range. In some cases it can get worse as the season goes on, which indicates a problem either with the herd or some other factor such as heat detection, AI technique, semen quality, bull performance, etc.

Thermoduric: There are a couple of factors impacting thermoduric bacteria in milk. Test results are usually presented in text messages as THD and the results should be less than 500 cfu/ml. These thermoduric bacteria are resistant to heat so will survive the pasteurisation process. They are commonly identified as little bits of cream on the top of drinking milk, but this is actually bacteria. Thermodurics also cause problems in the manufacture of cheese. The bacteria itself is present in the environment and so can make its way into the milk through poor hygiene at milking, such as dirty teats or through inadequate cleaning of the milking parlour meaning thermoduric bacteria survive in the plant itself and then contaminate the milk. The summer months can often see a spike in thermoduric bacteria as dry, dusty roads mean teats are actually dirtier than they look and these dust particles contaminate the milk. Farmers that wash teats or pre-spray teats before milking, but don’t dry them, could actually be causing more harm than good. So if pre-spraying or washing, make sure to dry with a paper towel before putting on clusters. In terms of cleaning, high quantities of hot water and the correct quantity of detergent is key. A 10 degree increase in temperature of the hot wash was found to have increased the reaction rate of chemicals by between two and eight times.

Weather: Farmers that are in areas prone to burning up in summer are beginning to get a bit concerned that they are facing a period of lower grass growth. There is no real rain in the forecast for the next 10 days or so and many parts of Munster and south Leinster haven’t had rain for about two weeks. Plenty of other locations have had more than enough rain during that time so it’s very localised. Soil moisture deficits in parts of the south east are up to 50mm, but most of the south east is in or around 30mm which is normal, for now.