Rearing Dairy Calves
Rearing dairy heifers is expensive and time-consuming with reward for your investment often seeming a long way in the future. In fact, the break-even point at which the amount of milk produced by a cow covers the cost of rearing her is often not reached until midway through her second lactation. The average age at first calving in the UK is 26 months, however 23-24 months is considered optimum. Calving earlier carries benefits – these animals tend to live longer, give more milk and have less problems in later life. However, it is not just about breeding earlier – these animals need to be the correct weight. Good objectives for rearing heifers include: breeding at 400 days of age at 400 kg of body weight, and then calve at 700 days at around 670 kg of body weight. For every 70 kg of additional body weight at calving, an average additional 1,000 kg of milk could be expected in the first lactation.
But how can these early calving ages be achieved? Calf growth rate is key:
5 C’s of Calf Rearing
Feeding sufficient good quality colostrum will set your calves on the right track. 4 litres instead of 2 litres in the first 6 hours (split into two feeds if needed) will improve daily live weight gains, reduce age at first conception and improve lifetime yields. Test colostrum quality using a Brix refractometer with colostrum below 22% being discarded. Ensure colostrum is harvested hygienically – colostrum contaminated with bacteria will deteriorate in quality quickly and could act as a source of infection of disease causing bacteria. Source: AHBD, Calf Management. 2018.
Good early growth is key – aim for 0.85kg/day for the first three months. Measuring calf weights at least twice during the weaning period will help to establish if their growth rate is sufficient. Cold weather can also negatively impact growth rates – feed an extra 50g of milk replacer or 0.33L whole milk per day for each 5⁰C drop below 15⁰C. Calves also need access to a good dry starter feed and quality straw to ensure rumen development.
Think about everything from calving pen to calf accommodation. Cleaning, drying and disinfecting as thoroughly and frequently as possible will reduce incidences of calf disease and improve calf health and growth rates. Focus particularly on feeders, teats and milk buckets.
Ample clean and dry straw will help calves to thermo-regulate in cold weather. Provision of clean, fresh water is also vital especially in periods of warm weather.
Consistency starts with milk – it is important to measure powder and water accurately as this is vital to a milk clot forming in the abomasum. A consistent routine should not be underestimated – calves thrive when milk is fed at the same temperature, concentration, quantity and time of day.
Calf rearing tends to be something that is going un-monitored on farms. Recently, we have been working with Zoetis to provide our clients with regular Calf Tracker visits dedicated to calf health. During these visits:
• Calves are weigh-taped to calculate daily live weight gain.
• Incidences of mortality, pneumonia and scour are recorded to identify potential areas of improvement.
• Success of immune transfer from colostrum is monitored by blood sampling new born calves. If you would like us to get more involved with your calf rearing, please speak with your vet or ring the practice.
[Note Image Source: AHBD, Calf Management. 2018.]