Thursday, 1 September 2016

Calving time pivotal to invest in future performance


To be successful farmers must always have an eye on the future, remembering that the decisions made today will have not only have an impact this year, but in years to come. Pre-weaning nutrition for young calves is where foresight can literally pay off.

Taking the time to ensure that young stock are reared well is particularly important for dairy farmers, as the future productivity of these heifers is closely related to their weight at first calving.

Research carried out in New Zealand showed heifers produced an additional 0.12 kg of MS in their first lactation for each additional kilogram of bodyweight at first calving. Australian researchers reported an increase of 8.7, 4.1 and 4.4 litres for every kilogram increase in live-weight of heifers at first calving and by the third lactation it had increased to 23 and 21 litres in two of the studies.

A recent review published in the Journal of Dairy Science investigated the effects of pre-weaned calf nutrition and growth on first-lactation. The authors found a synergistic relationship between pre-weaning liquid and starter dry matter intake and future milk, fat and protein production. They also reported a positive relationship between first lactation performance and pre-weaning average daily weight gain.

Taking the time to ensure that the calf is well cared for between birth and weaning is vital if she is to play a productive role in the herd. Ensuring sufficient intake of high quality colostrum in the first few hours of life is essential as colostrum contains vital antibodies the calf needs to absorb which protect the calf against disease. The ability of the calf to absorb these antibodies declines rapidly in the first 24 hours after birth.

Colostrum provides a rich source of readily digestible nutrients including fats and sugars that provide a critical source of energy for the calf in the hours following birth. Additionally, colostrum provides many proteins that provide the amino acids essential for the development of muscle tissue, vitamins and minerals, which play an essential role in many physiological processes including immune function, growth and development.

Both colostrum and subsequent milk or Ravensdown Calf Milk Replacer, are the predominant source of nutrients young pre-weaned calves require until such time as the rumen is functioning and able to digest solid feeds. Stimulating the early development of the rumen is an important factor in minimising stress around weaning, ensuring that calves do not suffer a growth check when milk is removed, and supporting weight gain both prior to and post weaning.

Encouraging the consumption of a high quality grain based feed, from four days of age supports the development of the rumen papillae, responsible for absorbing the volatile fatty acids, and helps to maximise the surface area available for absorption of volatile fatty acids in the mature ruminant that is predominantly fed pasture.

These starter feeds often contain a coccidiostat, which helps protect calves against the debilitating disease coccidiosis. Severely infected calves will show symptoms such as bloody and/or watery diarrhoea, depression, dehydration and weight loss. Even if clinical signs are not present, the destruction of the gut lining resulting from the infections has a negative effect on calf performance, with a reduction in feed efficiency, where calves continue to consume feed but just don’t grow at the expected rate, or eat less due to the feeling unwell. Using a coccidiostat will help to control coccidiosis infection and ensure calves remain protected until they have the opportunity to develop their own immunity.

Adequate water intake is also essential for rumen development and growth, so it is essential that clean fresh water is always available for calves.

After weaning, growth rates can be maintained while calves transition to a grass based diet by continued feeding of a nutrient dense finishing feed. Encouraging good growth and development through the first two years of the heifer’s life will help to ensure that she gets in calf by 15 months of age, optimises milk production in her first lactation and is likely to survive longer in the herd.

If you are under pressure to reduce the cost of rearing calves this season remember that calf feed is only a small component of the cost of rearing a heifer to first calving, which is estimated at $1400. In other words, the investment you make in your calves in the first few months of their lives will pay dividends in years to come.