Farm Ireland
Independent.ie

Saturday 21 October 2017

Early breeding results are not good

Dr Dan Ryan

The weather continues to place stress on spring breeding programmes. Unseasonably low temperatures and cold winds have led to poor grass-growth rates and grazing conditions, in particular on heavy land.

The fact that farmers were still wearing their winter coats at the end of May is perhaps the best barometer of the working environment.

Breeding cows today will result in cows calving in the second week of March next year. It is now essential to ensure you have a full picture of the reproductive status in your herd. Some farmers who believe they are overstocked are willing to cull all empty cows after a shortened breeding programme. But this approach may result in unacceptable levels of culling.

The Food Harvest 2020 vision of a 50pc increase in food production has resulted in an unplanned strategy for increased milk production inside the farm gate. Farmers should base potential for expansion on their ability to maintain herd health with the required financial investment in land, stock, housing and milking facilities.

This past winter has shown the implications of treating silage resources as an inventory cost on the business. The big challenge this year will be to build a 20pc silage reserve in the event of an extended winter.

Many farmers have been forced to graze silage ground which would have been fit in two-to-three weeks. High nitrogen uptake in this grass has resulted in severe milk yield reductions, with cows scouring. This will reduce heat detection and pregnancy rates.

It is essential to continue diet supplementation with concentrates where grass supply on the grazing platform is restricted.

Checks employing USART (ultrasonographic assessment of the reproductive tract) technology are revealing an unacceptable percentage of non-cycling maiden heifers and undetected heats in dairy cows, which is giving a false impression of pregnancy rates to the first service. Remember that embryonic death beyond 25 days of pregnancy may delay the return to heat by nine weeks.

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It is noteworthy that the risk of embryonic death can be eight times greater in those cows carrying twins.

If your breeding programme began in the middle of April, it is now opportune to implement a USART scan of the herd. This will identify problem breeders, undetected heats, embryonic deaths, cows carrying twins and the proportion of the herd pregnant for the first three weeks of the breeding season.

An analysis of USART scan data collected by CowsDNA over the past month for breeding programmes which began in April has revealed the following results:

* The proportion of cows fit for breeding when greater than 45 days calved was 72pc instead of the 90pc target;

* The submission rate for fit cows greater than 45 days was 77pc instead of the 95pc target;

* Seven per cent of cows had embryonic mortality beyond 21 days served;

* Undetected repeats to the first 21 days of AI were 26pc;

* Pregnancy rate to the first 21 days of AI was 37pc;

* Submission rate in maiden heifers was 72pc, which was primarily explained by a high proportion of non-cycling heifers in some herds.

Maiden heifers have experienced poor management on many farms because of the fodder crisis. Scanning with USART has revealed delayed puberty or heifers reverting to a non-cycling state. This explains the poor heat detection rate on maiden heifers.

The blind synchronisation of heats with prostaglandin or progesterone is a waste of money.

Some farmers have resorted to selling maiden heifers because of fodder shortage and a feared fodder shortage for the forthcoming winter.

Those maiden heifers at an average of 350kg are making €400 in the mart.

Do not lose focus on your breeding programme now. Make decisions on when to cull cows when your breeding programme is complete.

With the current milk price, there is an excellent profit margin available in milk production from grazed grass.

Extra supplementation with concentrates to maintain herd health is essential to optimise reproductive performance. Please ensure that mineral supplements are from a reputable source.

The sheer madness of the Nitrates Directive has resulted in phosphorus deficiency on many farms. This will have a negative effect on the reproductive performance of dairy cattle.

Some vets have diagnosed brittle bones in cattle because of phosphorous deficiency, which is a major welfare issue.

Dr Dan Ryan is a breeding management consultant and can be contacted at CowsDNA.com

Irish Independent