UK Farmers could be losing £309 a cow/lactation from post-calving disorders if they mirror their North American counterparts, according to Pfizer Animal Health’s, Robert Bell.

Mastitis and lameness are costing about £80/cow/lactation occurring at an incidence of 40% and 38% respectively, Mr Bell told visitors to an open day at Stanton Bros Farms, Ilderton, Ontario, Canada. “Loss of production is the biggest cost, but when you consider vet and drug charges, discarded milk and delayed conception it all adds up.

“The focus has often been on nutrition during the transition stages and although this is crucial to cow health, it is also important to focus on feed delivery, stocking density, group changes and cow comfort which all affect feed intake,” he says.

“Data shows first lactation production drives lifetime milk, if you get it wrong from the start this will have long-term implications,”

And one of the biggest problems is stocking rate and feeding space, according to Mr Bell. “When a cow is restricted from getting to the feed face when fresh food is delivered she will not come back later. Cows are allelomimetic, meaning they like to perform the same activity at the same time, essentially having negative effects on milk yield.”

Effects of overcrowding are apparent within days, says Mr Bell. “Cows stocked at 100% give 43kg/day compared to just 41kg for those stocked at 145%. And cows stocked at 145% have also been shown to lie more than an hour less a day, reducing rumination significantly in overcrowded cows.”

And for every 10% increase in stocking density above 80% you can get 0.73kg less milk a day from a first calved heifer in the first 85 days, says Mr Bell. “Stocking density is the biggest factor in transition cow health, with cows ideally stocked between 75-85%.

“Aggressive behaviour also increases with stocking rate and it is often the low ranking cows ending up with health problems, with one study finding 60% of low ranked cows lame, compared to 18% of high ranked cows.

Stocking rate is just one aspect of housing, but Mr Bell says dead end alleys and pen moves can also compromise production and health.

“Dead ends hinder cow flow within a pen, ultimately increasing the level of interactions between cows and if this occurs in an already overstocked pen, production effects, particularly on low ranking cows will be even more significant.

“Moving cows and mixing groups also has a major effect on DMI and often producers underestimate the time its takes for an animal to adapt to its environment, taking up to a week,” says Mr Bell.

Overstocked herds should consider building more cow accommodation. ” This may seem like an extreme decision, but if you were to calculate the loss of performance from overstocking, it wouldn’t take long to pay off,” he says.