DROUGHT CREATES NEW CHALLENGES ON DAIRY FARMS
Farm visits over the past month centre on the challenge created by the drought. The landscape was best described by one farmer whose sister couldn’t understand why so many fields in Kilkenny had been sprayed with Roundup for reseeding! Very few farmers dare utter the word “rain” as the memories of its’ devastating impact over the past eighteen months still reverberate on many farms throughout Ireland.
The dry weather has enabled excellent quality silage and hay to be harvested with excellent harvesting conditions for winter wheat and barley. Indeed, it is a sight to behold the number of small square balers which have come out of retirement over the past month.
Many dairy farmers are now resorting to feeding to zero grazing baled silage and extra supplementation of concentrates to accommodate the grazed grass deficit.
A dairy farmer in Whitechurch, County Cork described the reality of his 100 cow dairy herd. Currently, he is milking 110 dairy cows consisting of Holstein Friesian X Jersey crosses in a grass based spring calving system. The drought has resulted in a current estimate of 5kg of grazed grass dry matter intake. Normally, less than 1kg of concentrates would be fed daily at this time of year, but this has now been pushed up to 5kg per day. Zero grazing has been introduced by harvesting fresh grass from an outside farm. Bales of first cut silage made in May and June are also being introduced to the diet.
In my opinion, this farmer has taken the correct approach to herd management. He has kept body condition score close to 2.8 which is excellent at this stage of the production cycle. This in turn has been mirrored with less than 5pc embryonic death for cows served between 25 and 70 days of pregnancy.
The reality on most dairy farms is that breeding programmes are still in place.
Stock bulls are running with the herd and will be there until the middle of August. Many farmers contemplate removing the bull earlier each year, but May and June calvers still pertain. The market for late calvers was not good this year, but has been more profitable than culling cows in late lactations in previous years.
The risk of pregnancy losses through embryonic death can be as high as 10pc for cows served between 20 and 35 days. You cannot afford to stress cows by reducing dry matter intake in a drought situation. Cows need to gain body condition score now in preparation for the dry cow period.
The hidden cost of a single embryonic death at this stage of the breeding programme can be up to €800. When a cow undergoes embryonic death when she is over 25 days pregnant, it can take six to nine weeks for the cow to repeat. Obviously, these cows will not calve next spring if left unattended. Scanning cows now will enable you to identify cows with embryonic death. These cows can then be induced into heat to allow another opportunity for breeding.
Stock bulls are present in the majority of dairy herds. We have visited a number of farms in the past fortnight where stock bulls were dangerous. The current heat stress period will exacerbate the risk with stock bulls. It is essential to realise that the farm is a mini factory which entails risk to visitors. With children on school holidays and the “cousins visiting from Dublin”, please ensure farm safety is kept a priority.
The drought also increases the demand by cows for water. Ensure a plentiful clean supply of water. This can be a problem on some farms with falling water tables, inadequate water pressure and small water troughs relative to the cows requiring water. Cows are easily stressed in hot weather. With an inadequate supply of water, reproductive performance will be impaired in this hot weather. Also the duration and intensity of heats will decrease and pregnancy rates will decrease. Thankfully, breeding programmes are near an end!
Finishing on a positive note, I recently scanned a Holstein Friesian dairy herd in East Waterford where excellent management of a high EBI herd resulted in excellent reproductive performance. This herd used AI solely, with 107/115 cows confirmed pregnant between the first 54 days of the breeding season. This was an extraordinary result. The farmer explained that he was faced with a fodder shortage over the winter period. He started to feed concentrates during the dry cow period to maintain body condition score and continued this regime post calving. This herd had excellent body condition score at the time of scanning and there was a positive impact of selecting for higher EBI on reproductive performance.
Dr. Dan Ryan is a bovine Reproductive Physiologist and can be contacted at www.reprodoc.ie
Article written by Dr. Dan Ryan in The Farming Independent August 6, 2013.