While everyone would prefer to see cows out grazing, it’s just not possible for most farmers at the moment. Therefore, milking cows are indoors on cubicles and eating silage. What are the health effects of this?

Silage is a poor replacement for grass. It is lower in energy and protein so cows will be in negative energy balance for longer than if they were eating grass. This means they will be milking off their back, or losing body condition. While this happens after calving anyway, a nutrient-deficient diet will mean it lasts for longer.

Some body condition score (BCS) loss after calving is normal, but problems occur where the loss is greater than 0.5 of a score.

Where this happens, fertility is compromised and the cow will be harder to get back in calf.

So to prevent this, extra supplement will need to be fed. Where higher energy forages are available such as chopped beet, maize or wholecrop, they should be fed to milking cows. Some farmers, particularly those who routinely milk over the winter, are set up with feed stocks and diet wagons to cater for different feeds.

But for most dairy farmers, silage and meal will be the only option. Depending on silage quality, 5kg or 6kg of meal might need to be fed to fulfil dietary requirements for cows producing about 20 litres of milk per day. Feeding any more than this to recently calved cows is out of the question. It will likely lead to stomach upsets and acidosis as more than half of the diet could be meal.

Mastitis

Cows under stress from cold and wet and dirty cubicle beds from snow blowing into sheds has meant that many herds are seeing a spike in cases of mastitis. Unfortunately, this was to be expected. In terms of prevention, cubicle beds should be cleaned and limed twice a day and passages should be scraped at least four times a day or as often as necessary to keep clean.

The purpose of liming cubicles is to increase the pH on the cubicle bed which inhibits the growth of bacteria. It also helps to soak up moisture, which helps to prevent the growth of bacteria. Hydrated lime has a higher pH than ground limestone. It increases the pH of the bed to 12.4, which kills all bacteria. For this reason it is a registered disinfectant.

Ordinary ground limestone raises the pH to 8.4, which is not high enough to kill staph and strep bacteria. Cost-wise, hydrated lime is generally more expensive than ordinary cubicle lime because it goes through extra processing. The recommendation is to use no more than 170g per bed, which is equivalent to a fistful of lime per cubicle. Using too much hydrated lime could cause sores or teat end damage.

Other types of cubicle disinfectants are available also. Stalosan F works in the opposite way to lime in that it reduces the pH. While significantly more expensive than ordinary lime, less of it is used and farmers who use it tend to find it effective. Sawdust and untreated peat, while comfortable for cows, are not disinfectants and if not removed and replaced regularly could actually spread mastitis causing bacteria.

With mastitis, early detection is crucial for a successful outcome. With cows in sheds, the risk is high so they need to be stripped at every milking to help spot mastitis early. Teats should be methodically disinfected with a good-quality teat spray or teat spray after every milking.

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