With limited pasture growth this summer, stretching the grazing season without harming the perennial forage stand is a concern. In the drought conditions we are experiencing, forages mature more rapidly than in a normal year. Fibre levels increase rapidly. This reduces energy content in the grasses. With higher fibres, the stems become coarser and the cows are less willing to consume the entire plant of some species.
Rotational grazing will help to maintain forage quality. Creep feeding calves when they are more than 50 days of age will also reduce total forage requirements. Supplemental feeding dry hay is another option, but is it better to save the hay to feed over the upcoming winter to the lactating cows?
The key consideration is how to reduce the number of pounds of high quality pasture grass to keep the cows in good condition and have the calves maintain a good growth rate. Calves that are 150 days of age have a fully functional digestive system and can be weaned. This accomplishes two things. First, the nutritional requirement of a dry cow is 25% lower than for a lactating cow. Second, calves that are placed in a dry lot pen, are not consuming the limited pasture forage .
Weaned calves can be fed a hay or silage along with rolled grain. A 500 pound calf requires a ration with a 15% protein content to develop bone and muscle. The amount of energy needed depends on the rate of gain. Adding an ionophore such as Rumensin or Bovatec will improve feed efficiency and daily gain. Building a ration to obtain 2 to 2.5 pounds of gain per day is attainable.
With a lower nutrient requirement, the cow is able to maintain or improve body condition prior to winter. A cow that is 200 pounds lighter (one body condition score) than optimal does not have the fat layer under the hide that is used as insulation against the cold. A cow that is thin going into winter requires approximately 1400 pounds of additional hay to keep warm. This year with hay prices anticipated to be higher than last year, this could increase winter feeding costs by $100 or more per cow.
For more information on feeding cows and calves with limited pasture and feed supplies, contact Barry at 403-741-032 or firstname.lastname@example.org.