As this issue comes to press, the yearling run is coming to a close and we are in the middle of the fall calf run. Feedlots across the country are filling and are faced with the dual challenge of keeping cattle, particularly newly weaned calves healthy and on feed. Most managers recognize the value of a strong working relationship with their veterinarian and rely on his/her advice to develop their vaccination and treatment protocols. Similarly, most of the larger feedlots rely on nutritionists to develop feeding protocols for starting cattle on feed and subsequent nutritional management. However, this is not always the case with smaller feeders. With this column I will try to address some of the concepts that nutritionists follow when starting newly weaned calves.
To start let’s remind ourselves of the characteristics of the animal we are dealing with. Depending on your operation, you could be faced with starting calves that were derived from one of three sources. First, you may be backgrounding your own calves that you just weaned. A second source may be calves purchased directly from cow-calf operations that may or may not have been pre-conditioned. The third and most common source is calves that have been purchased through auction markets. Now there are obvious differences between these groups in terms of the degree of stress experienced from weaning, transportation, mixing, time off feed, etc., that will influence how calves go on feed. Nevertheless, these groups share a number of characteristics that need to be understood if you want to get each group off to a healthy start. For example, it is critical to remember that these calves are recently weaned and likely miss “mom.” Their diet up to this point has been a combination of milk and grass; furthermore they may have been off feed for 12 to 48 hours. Confinement in new facilities brings on issues with mixing, pecking order development and learning to eat/drink from feed bunks and water bowls.
In short, these calves regardless of source are under some degree of stress. From a feeding management perspective, this stress manifests itself primarily in the form of poor initial dry matter (DM) intakes. Ideally calves that are settled on feed should be eating at 2.5 to 2.7 per cent of body weight on a DM basis. For 500-pound calves, this equates to 12.5 to 13.5 pounds of DM. If we look at a group of newly weaned calves from multiple owners, it is not uncommon to see initial DM intakes averaging 1.5 to 2.0 per cent of body weight or 7.5 to 10 pounds of DM. At this level of intake, particularly the lower end, these calves are barely consuming sufficient feed for maintenance and are particularly susceptible to a wide array of disease challenges.
To get these calves eating it is important to provide them on day one with access to good-quality grass or grass/legume hay draped over the feed bunk or hay feeders. Calves will readily recognize this hay and start eating. This is important as it helps them get the rumen working. Hay feeding should continue for at least three to four days.
The starter ration should be fed as early as day two by feeding five to six pounds per head along with long-stem hay and then gradually letting the calves come up to full feed. Ideally they are eating at 2.5 to 2.7 per cent of body weight (dry matter basis) by day 21.
The starter ration typically consists of forage (50 to 60 per cent), grain (35 to 45 per cent) and supplement (five per cent; DM basis). Ideally a majority of the forage is good-quality processed grass or grass/legume hay. Too high a proportion of silage can limit DM intake. The starter ration should be formulated to 12 to 13 per cent crude protein, ideally using all-natural protein sources. Dried distillers grains at 10 to 15 per cent of the ration (DM basis) are an excellent source of both protein and energy for starting calves. Dietary energy values typically range from 66 to 68 per cent total digestible nutrients or approximately 0.9 to 1.0 mega calorie of net energy for gain per kilogram DM.
It is common to have a separate supplement for starting calves that includes an ionophore (i.e. monensin) or coccidiostat (i.e. amprolium or decoquinate) to minimize issues with coccidiosis.
Supplements that incorporate urea to enhance crude protein levels are not recommended. Supplemental trace mineral (i.e. copper, zinc and manganese) and vitamin (A, D, E) levels are elevated by 15 to 25 per cent, particularly if the operation brings in a large number of high-risk calves. In such cases, your nutritionist may recommend inclusion of a source of chelated trace minerals in order to boost the immune status of the calves.
While space issues limit the extent of this discussion, I hope it is evident that from a nutrition perspective, the No. 1 goal when starting newly weaned calves is to get them eating. The target is 2.5 per cent or better of their body weight (DM basis) of a balanced ration as quickly as possible. Working with a qualified nutritionist is a good first step in achieving this goal.