When can I start my cattle on pasture?

agri_news

By Gary Sliworsky
OMAFRA Rep.

“When can I start my cattle on pasture?” This question runs through everyone’s mind as spring approaches. If you turn cattle out too soon, the grass will not support the livestock. Once the grass is set back at the beginning of the season, it will be less productive throughout the entire grazing season. If you leave it too late to let the animals out to grass, you use more stored feed. Hay is about twice the cost of pasture, so this has a significant impact on the pocket book.
Initial grass growth is very slow. The new small leaves can produce only small amounts of energy from photosynthesis. Plant energy comes mainly from root reserves. Cool temperatures are also limiting growth. A rule of thumb often suggested is to wait until the grass plant has three leaves before starting to graze. When the plant has reached the 3-leaf stage, the photosynthesis in the leaves is providing sufficient energy to support the plant. The plant will then be able to recover from the grazing and rapidly grow new leaves.
To achieve optimum performance on pasture, the grazing animal must be able to get a mouth full of palatable, nutrient rich food with each bite. If the bite is small, it will take more bites to get the required nutrition. This is likely to result in less than optimum performance. Cattle spend about one-third of their day eating, one-third ruminating and digesting the feed, and then rest the remaining one-third. For cattle, these three time periods each total about 8 hours. It takes longer to digest low quality forage than high quality forage. The lower the quality of the forage they are consuming, the more time they need to spend ruminating. This increased ruminating time is at the expense of the eating and resting time.
If we have a grazing season with abundant to excessive moisture, the grass will be lush but full of moisture. The animal will then need to consume more pounds of pasture to get the same amount of dry matter intake as they would with normal grass moisture levels. Therefore, in a year of abundant growth it is very important to do every thing you can to encourage intake. Ideally we want to get animal dry matter intakes of about 2.5% of body weight. It takes about
1.75% of body weight dry matter intake to keep the animal alive. The extra intake over and above this provides the growth and weight gain. If you think about your own eating habits, we want the animal to have “second helpings” at every meal. When we have second helpings, either we are really hungry or the food tastes really good! Having quality forage that tastes great is the easiest way to increase intake and maximize performance on pasture.
Managing the available forage throughout the grazing season to provide for big bites of high quality nutritious forage will optimize livestock performance. Start the grazing season on the right foot with grass that is growing well and yet be able to get to all your pastures before they start to mature and the forage quality diminishes.
Refer to the pasture section of the forage page at http://
www.omafra.gov.on.ca/english/crops/field/forages.

Dates to Remember
April 21 – RR Cattlemens’ Spring Sale, Stratton