Mrs Brown says this starts from day one of a heifer’s life with the feeding of colostrum. “Six litres of colostrum within the first six hours of life is absolutely essential; and at least three litres should be fed within the first two hours. Thereafter continue feeding colostrum for the first three days after birth at a rate of 10 to 12 per cent of body weight per day, to provide local protection in the intestine and subsequently reduce potential scour incidences.”
Mrs Brown says then it is important to offer a good quality, palatable calf starter at three days of age to ‘kick start’ rumen development.
“Choose a starter comprising cereal sources and digestible undegradable protein (DUP) to optimise growth and stimulate rumen papillae growth.
“It should offer ME 13 MJ/kg DM, protein 199 to 200g/kg DM, 75-80g DUP/kg DM and 210g/kg DM starch. The grain produces propionic and butyric acids which are rapidly digested in the developing rumen, rather than forage which produces acetic acid which is slowly digested and so not as effective in calves.”
Mrs Brown says water must be offered with the starter. “Water helps increase intakes and further stimulate the rumen development.” (See table).
|Daily gain (g)||0.31||0.18|
|Calf starter intake (kg)||11.8||8.2|
|Scour days per calf||4.5||5.4|
Source: Kertz et al
In terms of forage, Mrs Brown says barley straw has a thicker waxycuticle which under goes very little degradation compared to wheat straw, while the inner layers have less lignin and are more degradable. “These layers are accessed more easily in wheat straw so if kept clean and dry this is better for feeding. Chopping to about 19mm length will increase intakes once the calves start nibbling and again it contribute towards improving health, rumen development and growth.
“Hay is frequently fed, however it has less lignin and therefore ‘scratch’ than straw, consequently it does not stimulate rumen development so efficiently and calves often look ‘gutty’. Barley straw and hay do not chop as easily as wheat straw so practically they are harder to manage when looking for intake.”
At weaning, Mrs Brown says the only change the calf should experience at weaning is milk removal. “Introducing calves to groups of five prior to weaning can help to increase concentrate intakes by 50 per cent and subsequently step up overall performance. Calves should not be moved until 10 to 14 days after weaning and again this should be the only change which occurs at this stage, this will reduce stress and therefore minimise risk of disease, especially coccidiosis and pneumonia.
“The next consideration will be changing from starter to rearer, a decision frequently dependent on the farming enterprise and management restrictions. Ideally calves will remain on starter until after weaning and any movements have been made in order to reduce potential stress and avoid any growth checks.
“Rearer should be based on the heifer requirements and forage fed. For example, heifers on a straw diet should be fed a pellet with a minimum 24 per cent crude protein (CP) and 13MJ ME at 3kg feed rate to ensure good growth. Heifers fed a hay diet can be offered a 20 per cent CP pellet.”
Mrs Brown advises not feeding heifers silage until six months of age. “Silage’s high level of acidity does not help rumen development and or make for optimum digestion. Dry forages are better utilised and will not be as acidic.
“Once silage is introduced, reduce the rearer to 16 to 18 per cent CP depending on silage protein analysis, but energy levels must be controlled to stop heifers becoming too fat. If silage is particularly good quality, then straw may need to be introduced to the mix to maintain the balance. Target the overall diet to have an energy density of 9.7MJ/kg DM and overall CP of around 14 per cent of the DM content.