With the dairy breeding season currently in full swing on most Irish dairy farms, Kevin O’Hara, Teagasc Ballinrobe, looks at some of the key targets farmers need to achieve over the coming weeks.
Most dairy herds in Ireland typically start breeding from May 1st. At this stage, earlier herds have completed two or three weeks of artificial insemination (AI). The aim here is that 90% of all cows to be served would have been inseminated by the end of week three. This is a key figure for farmers to aim for if a compact calving spread is to be achieved next spring. The six-week calving rate figure is key for all milk producers but especially spring milk herds where cows are typically dried off in late December.
In order to achieve this, farmers should be using heat detection aids such as tail painting, scratch cards, electronic heat detection collars and/or a vasectomised/teaser bull where needed. Time spent physically monitoring cows will be the key element to ensuring the 90% submission rate is achieved. It has been proven that the more time spent monitoring cows the higher the submission rate, so this will be the key driving factor for the entire breeding season.
Dairy Beef Index
Many farmers have now adopted the use of the Dairy Beef Index (DBI) to try and increase monetary output from calf sales by using dairy sexed semen on the cows/heifers they want to breed from and using high DBI index bulls on cows which they do not intend to breed replacements from.
This is a very useful index as it factors in calving difficulty, gestation length, calf quality and carcass weight, which allows the end feeder of the animal to make a better margin. This can be useful as a repeat customer may be willing to pay more for a quality calf and is a guaranteed market in years where calf sales can be sluggish.
Selecting bulls from the DBI list is simple. All bulls are rated on a star and monetary value system, with five being the highest ranked and highest monetary value and one star being the lowest ranked and lowest monetary value bulls available. Bulls of all breeds are compared on this rating. Breeds which you may not have used before due to perceived calving issues or long gestation may actually suit your current system, possibly giving a higher value calf to sell and thus a better end product for the purchaser.
Non cyclers
Many farmers would complete a pre-breeding scan in April to check for cows who may have underlying issues which are stopping them from cycling. Issues such as uterine infections, retained cleanings or even poor body condition scores are the most common.
If this scan has not been completed, any cows which have not been seen cycling at the end of week three should be assessed by either the farmer’s vet or in some cases the scanning technician. These cows may require some additional aid to get them to start cycling; this can be in the form of wash out or a hormonal treatment such as the use of a CIDR or PRID. These are all typically prescription only, so consultation with your vet is essential.
In cases where body condition score (BCS) is below optimum, cows should be given additional feed supplement in the parlour or – in certain cases – put on once a day milking to help build up condition and hopefully allow the cow to cycle naturally. This is extremely beneficial to first time calvers, as they are under the most pressure in the herd.
Lameness can be a major issue to cow fertility and is a major issue where cows are walking long distances to and from the milking parlour. Cows which become lame in the breeding season should be assessed immediately, as they will lose condition rapidly and may become non cycling shortly afterwards.
Finally, where farmers are using stock bulls to clean up after AI, time should be spent ensuring the bull is fit for purpose. This includes in good BCS, no signs of lameness, with good mobility and most importantly fertile.
Research suggests that up to 5% of bulls are completely infertile and a further 15-20% will be partially or periodically infertile.
To address this bulls should be fertility tested. If this is not an option, good data recording should take place with regards when cows were served and monitored subsequently to see if any repeats are occurring.
Source: BBC