Cotswolds-based agriculture supplier, StowAg, opened its doors in early October to 250 local farmers to host an information-packed ‘Cattle Winter Housing’ event. It provided practical, expert advice from the industry’s leading suppliers in addition to live demonstrations and an impressive product display.
Rumenco technical adviser, Laura Drury, highlighted the ‘disproportionate’ role that trace minerals play. Accounting for just 5 per cent of the total ration, these nutrients play vital roles within the body.
There are a number of recognised problems associated with deficiencies; low copper (or high molybdenum) is commonly associated with anoestrus, poor conception, embryonic death and delayed puberty, she said. Low iodine can be responsible for stillbirths, abortion and weak calves. Low zinc with lameness, mastitis and disease susceptibility. Low selenium with retained placenta, metritis, extended calvings, depressed immune function and poor conception rates.
An analysis of 320 grass silage samples from 2018 has shown high levels of potassium and low levels of copper, zinc, iodine and selenium. This year’s straw is very low in minerals. “The results of this analysis obviously have important considerations for rationing and subsequent supplementation,” she pointed out. “These averaged silage results alone do not meet the optimum intake levels for cows particularly with reference to magnesium and trace minerals. Individual forage analysis is beneficial as results will vary across the UK.”
Supplementation of copper for dry cows is recommended in the pre-calving period. Zinc, copper, iodine and selenium supplementation is recommended for the calves. There is an opportunity to ‘plug’ the forage gap by out-wintering cattle on fodder crops. These can provide up to 70 per cent of an animal’s dry matter intake (DMI) providing an adequate fibre source is available.
Norbrook Southern GB veterinary adviser, Matt Swanborough, detailed the complex life cycle of the liver fluke along with its detrimental effects within an individual and herds.
Liver fluke has a relatively long and complex life cycle lasting about 20 weeks, he commented. The adult fluke (around the same size as a £1 coin) sits in the bile duct feeding and producing a large number of eggs. These eggs pass out onto the ground. Miraciduim (free-swimming larvae) develop within that egg before they hatch and seek out their intermediate snail host, he explained. Within the mud snail host, the liver fluke goes through two further developmental phases including multiplication, before remerging five weeks later as large numbers of cercariae. Cercariae then form into little cyst like structures that wait on herbage ready to be eaten by stock.
“Once ingested, immature fluke migrate to the liver where they tunnel their way through leaving considerable tissue damage on their way to becoming adults.
“While it was speculated that the liver fluke risk may have been reduced this year due to the prolonged dry conditions, be careful not to discount liver fluke quite yet. During hot weather, stock can often be seen congregating around sources of water which will often provide the perfect habitat for the mud snail.
“Where possible a liver fluke control plan should be double pronged in order to be effective. Environmental control in order to reduce the risk of infection, alongside strategic treatment with flukicides. Farmers are encouraged to develop a plan that is tailored to their farm.”
Norbrook’s Closamectin, a combination of closantel (flukicide) and ivermectin (wormer) is available as both a soluble injection and a pour-on. Ideal for winter housing the pour-on helps to ensure maximum productivity throughout the housing period. Studies have shown closantel to be effective against fluke which are resistant to triclabendazole, he concluded.
*The full report from the event can be found on the Farmers Guide website (Livestock news).