Feature JANUARY 2020 www.irishfarmersmonthly.com The 4 essential aspects of proper calf management Aislínn Campbell, InTouch feeding specialist, NI, examines the key elements of proper calf management Calf management always needs to be a top priority on farms. We cannot afford to make mistakes in this period as deficiencies can be difficult to correct. Calves, and especially replacement stock, are the future milking herd, and issues early in life can have adverse effects further down the line regarding delayed calving age and milk yield. Regardless of your production system, getting the basics right is crucial. We need to focus on four key areas: • Colostrum • Nutrition • Rumen development • Environment Colostrum The three words that are critical when it comes to colostrum are ‘get in early.’ The quality of the colostrum or the ability of the new-born calf to absorb its benefits reduce quickly with time. Colostrum is the first nutrient source a calf will receive and supports the calf’s immune defence. The first hour is when the calf can absorb these antibodies most readily, so we need to get colostrum into the calf as soon as possible. The capability to absorb these antibodies declines rapidly after the first hour and completely stops at 24 hours. A good way to remember is to use the well-publicised rule of ‘3-2-1,’ which is at least three litres of colostrum within two hours of birth for the first feed. The only exception to this is Holstein calves, which will require four litres. A second feed should then be given within eight hours before transitioning on to milk/milk replacer. Quality of colostrum also needs to be taken into account, and it can be measured with several devices that are freely available and quite inexpensive. Nutrition A calf is best able to convert feed into weight gain in the first few months. Beyond this point that ability will decline, so we need to make sure we get the most out of this short period. A calf should, at least, double its birth weight before weaning at 10 weeks, meaning a 40 kilograms calf needs to gain 0.6 kilograms per day. This can be a difficult target to reach. A calf should be fed for 15% of its body weight, so for a 40-kilogram calf that is six litres per day. It should be noted that the abomasum is not large enough to deal with six litres of milk at once, so the feed should be split. Milk replacer should be aligned with weight targets and, as it has a lower fat and energy content than whole milk, it will need to be fed at a higher rate. It is also worth paying attention to temperature, as a lot of milk/milk replacer volumes and target weight gains are based at 15oC when a lot of calf houses at this time of year are not even close to this. In this, even more milk/milk replacer is required to achieve the target weight gain. Temperature should also not be confused with airflow. Calves require 325 grams of milk solids for maintenance. Milk is 12.5% dry matter, which equates to 2.6 litres. So, a calf of 40 kilograms being fed four litres can only gain 200 26