A STRICT policy of culling and vaccination has eliminated Bovine Virus Diarrhoea (BVD) from a Carmarthenshire beef herd.

BVDcauses abortion, infertility, a failure to thrive and often death in cattle, and is one of the most economically significant viral diseases affecting cattle in Wales.

At Lan Farm, Cynwyl Elfed, the farm’s vet, Helen Scott, identified the disease in the suckler herd three years ago. Farmer Philip Jones had been battling calf pneumonia and BVD was found to be an underlying cause.

Awhole herd investigation identified two persistently infected (PI) calves – animals born with the BVD infection. Persistently infected animals are the biggest threat to the herd because they are infected before birth and are infectious for the rest of their lives. They have the potential to shed the BVD virus and transmit the disease when they come into contact with other animals.

Blood samples were taken from all the cows and calves at Lan Farm and this detected a further PI and an inconclusive animal.Adecision was taken to cull the PIs and vaccinate the cows. The calves were vaccinated to combat respiratory problems.

Tag and test ear tags were used on calves born in the following two years. The virus can be detected through a plug of tissue taken from the ear at tagging.

“All the tests came back negative and through a programme of vaccination Philip no longer has a BVD problem in the herd,” Helen told farmers during an open day at Lan Farm, a Farming Connect demonstration farm.

“Because of vaccination, spending is slightly higher overall, but the improvement in herd health has negated this.”

Next year Philip, who runs 100 spring-calving suckler cows, is aiming for accredited BVD-free (vaccinated) herd status. He also wants to improve liveweight gain and is already achieving good results.

“There is a dramatic improvement associated with better immunity, everything that calves are now putting into their mouths is going towards growing rather than fighting illness,” explained Helen, a vet at the Carmarthen Veterinary Centre.

Philip has also worked with Helen and ruminant technical adviser, Delana Davies, on improving his herd – fertility in particular.

In 2009 scanning revealed that 25 cows were empty and one of Philip’s bulls was found to be infertile.

“Following this we scan little and often, scanning heifers at nine weeks. That little bit of expense gives me peace of mind,” Philip admitted.

Bulls are also nowtested annually for fertility.

Having tackled the disease issue it was vital to keep the herd disease free, but with the tradition of running a flying herd, sourcing replacements became a challenge.

Philip explored his options in discussions with Delana and realised that artificial insemination (AI) gave him the best option to breed his own replacements, with a particular emphasis on developing the maternal genetics within the herd.

AI also allows Philip to use female sexed semen in the herd to enable selection of bulls known to produce daughters that have better calving ability, fertility and longevity, as well as halving the number of matings required to produce replacements.

With the easier calving potential of heifer calves born, heifers can also be safely bred to calve at 24 months. Calving heifers successfully as two-year-olds rather than three-year-olds would save £9,800 in a 70-cow herd just in keep costs for the heifers alone.

Further potential benefits of £2,450 per year could accrue from a reduction in the replacement rate as a result of using more reliable maternal genetics. There is a potential extra income of £3,248 from incorporating top 10% carcass genetics into the dam line.

“There are a lot of financial benefits to be gained from using this technology,” said Delana.

The next challenge from using AI was heat detection, but as Philip’s herd is block calving this gave the job a start and finish time for heat detection and insemination. Philip was keen to use technology and implemented the Silent Herdsman technology on 30 cows and Genus RMS on 30 cows.

Artificial insemination also allows hybrid vigour to be introduced into the herd, potentially increasing maternal performance by 14.8%.

“There is an additional performance increment from making use of hybrid vigour over the mid point between the two breeds, so you effectively get this extra performance for free,” Delana explained.

“The greatest responses from hybrid vigour are to be found in reproduction, health and longevity.”

Farming Connect, delivered by Menter a Busnes, is funded through the Rural Development Plan 2007- 2013, financed by the European Agricultural Fund for Rural Development and the Welsh Government.