Do's and don'ts of calf rearing

Cattle and calves succumb when disease pressure overcomes their immune system, which can be caused by a range of factors such as poor nutrition or environment stressors. Disease levels can nevertheless be significantly reduced by adhering to AHDB's calf rearing checklist below which should be completed every six months and preferably with a vet.

Environment

* Do not underestimate the impact of the environment; if the housing is poor, even high levels of immunity will not prevent infection.

Nutrition

* Calves actively need sufficient colostrum soon after birth. Feed three litres within two hours of birth, followed up by a similar sized feed within 6-12 hours of birth. Blood test bought-in calves to make sure they have received adequate amounts of colostrum.

* Provide concentrates from birth. Feed a good-quality starter feed (18% crude protein fresh weight, 12MJ ME/kg DM) to promote rumen development. This needs to be free from dust and mould and offered in clean troughs.

* Use good-quality milk replacers. Milk replacers should contain 20-26% crude protein and 18-20% fat to achieve optimal growth rates. Calves less than two or three weeks of age are better able to digest powders with milk-based proteins (eg dried skimmed milk, dried whey, delactosed whey, casein) than egg-based or plant-based powders

(soya, wheat gluten, pea). Generally higher quality ingredients are more expensive.

* Feeding regime should be consistent. Calves should be fed at the same time each day at the same temperature, at the same concentration and with the same product to avoid digestive upsets.

* Milk replacer or whole milk fed between 37-39°C. When preparing milk powder, it should be made up with warm water. Water used to mix milk replacer should always be below 50°C to avoid damaging the proteins which are essential to calf performance. Milk should be fed between 37-39°C to stimulate a strong oesophageal groove

reflex, which helps prevent milk entering the rumen.

* Calves fed at least two milk feeds per day until four weeks of age. Feed a minimum of 750g/day of milk replacer. It is a legal requirement to feed calves under 28 days at least two liquid feeds per day.

* Fresh, clean water available at all times from birth. All calves must be provided with fresh, clean water from birth. For each 1kg of dry feed, a calf requires five litres of water.

* Fresh straw available in racks. Chopped straw should be offered from three days of age. Hay and silage can lead to calves having a potbellied appearance.

* Bought calves given two litres of electrolytes on arrival as they frequently become dehydrated during transport.

Health

* Herd health plan reviewed each year with vet.

* Bought-in calves have a known disease status. Disease in the early stages of life can affect long-term performance of the animal. Test for BVD to ensure calves are not persistently infected (PI) with the virus.

Medicines

* Sick calves should be isolated from the rest of the youngstock. Such pens should ensure there is no physical contact between the diseased calf and the rest of the herd. The sick pen should be very clean, warm, have clean water available at all times and provide no additional stress to the calf. Isolated calves should be fed last to minimise disease spread.

*Vaccination programme – Vaccination protocols are an essential part of herd health planning and should be developed by the farmer and vet together.

* Medicine storage – Check vaccines are stored in the fridge at 2-8°C or according to medicine instructions. Check medicine cupboard for out of date medicines and dispose via your vet.

* Record cases of disease and levels to drive continual improvements. Target <15 cases of pneumonia per 100 calves reared to weaning; < 10 cases of scour per 100 calves reared to weaning; < two calves die per 100 calves reared to weaning.

* Antibiotic use for therapeutic use only. Timely mass medication of a group of animals to eliminate or minimise an expected outbreak of disease, when in contact with a sick animal and preventative use of drugs to healthy animals before exposure to a stressful event.

Housing

* Ventilation – Air space is just as important as floor space. Removal of stale, exhaled air to provide a supply of fresh air and an airy, pleasant atmosphere when entering the calf shed. Airflow should be above calf level to minimise chills. Ammonia smells in the calf shed are a sign of poor air quality. Using smoke bombs can be used to detect stale air, as smoke should travel up and out of outlet area to clear within 30-45 seconds. Slow movement of smoke throughout the building indicates a high risk of pathogen transfer from one affected animal to an entire group due to poor air flow.

* Minimise draughts – Calf housing needs plenty of fresh air even in cold weather, however it is important that draughts at calf level are avoided as they can impact on growth rates as they start using energy to keep warm instead of to grow. Solid barriers that extend from the floor to above calf level can offer protection from draughts. If calves are housed in an exposed or tall building, consider making lower covered areas where they can keep warm. Most calf houses would benefit from mechanical ventilation with a fan which draws air in from

outside and distributes it down the length of the building through a duct.

* Humidity – High moisture levels in calf sheds promote the survival of harmful bacteria.Wet floors or sweat and dirt on calf coats are signs of high humidity. Relative humidity levels should be below 75% and key to reducing the spread of disease and reducing pneumonia pathogen survival time. Assess drainage and storage facilities in feed preparation area, as moisture from the feed preparation area, including equipment washing facilities, can cause excess moisture in the calf house.

* Effective drainage is key to ensuring calf pens remain dry. Pen floor gradients need to be at least one in 20. Ideally, igloos and hutches should be placed on a gravel bed to allow good drainage. Ensure water drinkers are not leaking.

* Calf housing – House calves with other calves of similar ages. They must be group housed from eight weeks of age, to increase social development and growth rates, and on dry clean bedding, preferably deep bedding which maintains heat. Temperature in the calf shed should also be monitored daily to assess whether the lower critical temperature (LCT) has been reached, which is the temperature at which a calf needs extra energy to keep warm. Calf jackets should be used when temperatures fall below 15°C for calves less than three weeks of age

* Calving hygiene – Poor hygiene in the calving area and calf shed has an adverse effect on calf health and performance. Therefore, clean clothes should be worn and boots dipped in disinfectant when entering the calf shed.

Calving area cleaned out as regularly as possible and kept well bedded. When a calf is born it has no immunity, therefore, cleanliness is a necessity, so calving ropes should be cleaned, disinfected and well maintained. Ensure hands are either washed or gloved before assisting in any calvings.

* Navels – Dip navels as soon as possible after birth, using a clean dip cup and 7% iodine solution. This aids the drying and closure of this potential infection route. Studies have shown that calves with undipped navels have an 11% higher mortality rate than those with dipped navels. Pens steamed cleaned using an appropriate disinfectant and have a resting time between batches of calves.