The making of a ruminant

Successful weaning of calves can be accomplished in a number of ways, but the basic concepts of developing a ruminant remain the same.

Many calf raisers are looking at alternatives to a traditional six- to eight-week weaning age. In the end, it is still all about developing a ruminant where a pre-ruminant once stood. So how can we do this in a way that develops a healthier, stress-free animal in a cost effective way? A recent set of Care Schools set out to cover this topic as part of the overall program.

The first critical component to making a ruminant is not about the feed at all. It’s about the water! By one week of age, all calves should have access to fresh, clean water at all times. In addition, a divider should be placed between water and calf starter buckets to help keep the water clean and starter dry. A study cited in Hoard’s Dairyman in 2006 shared the critical requirement for water in young pre-ruminant calves. The study covered calves from birth to 4 weeks. Daily gains over this period of time were .68 lbs./day for calves with free choice access to water versus .4 lbs./day for calves with no access to additional water (outside of milk/milk replacer). A new study from Cornell (submitted for publication in the Journal of Dairy Science) found that an increase of 1-pound average daily gain as a calf translated to an extra 850 lbs. of milk production in the first lactation and 2,280 lbs. of milk in the 2nd and 3rd lactation. Calves with access to free-choice water also had higher starter intake and less scour days/calf.

The second critical component to making a ruminant is calf starter. Calf starter is the first solid food that the calf will receive, and it is also the most important for rumen development. Calf starter should be introduced to calves at day four or five and should be high quality and highly palatable. How important is palatability? A study by Porter, Warner and Kertz (2007 Professional Animal Scientist) found gains in intake, ADG and ruminating when calves were feed coarse mashed starter vs. pelleted starter. Calves should be provided as much starter as they will clean up while it is still fresh. Starter is what bridges the gap between energy needs of the growing calf and the energy provided through milk/milk replacer. Starter is also the dry feed that develops the rumen. Hay DOES NOT develop rumen papillae (small finger like projections that drastically increase the rumen surface area and ability for the rumen to absorb nutrients).

Research out of Penn State, shows how drastic the difference is between calves fed milk and grain vs. those fed milk and hay. In fact, they showed that the rumen development of a 4-week-old calf on milk and grain is greater than that of a 12-week-old calf fed milk and hay. The reason is in the fermentation acids that each of these dry feeds produces. Hay produces acetic acid which rumen walls do not use for papillae growth and development. Grain produces butyric acid with does enhance the development of the rumen walls and papillae. For this reason, it is recommended that good quality hay be feed no earlier than 5 weeks of age.

Successful weaning can occur when Holstein calves are consuming 2 lbs. of starter for two days in a row and Jerseys consuming 1 lb. of starter for two days in a row.

Remember that the rumen only composes 25% of the stomach capacity at birth. By 3- to 4-months of age the calf’s rumen will compose 65% of the stomach capacity. As calf raisers, we want the calf to reach this level in an efficient, low stress way, so we need to make sure that we have done all we can to prepare the rumen prior to weaning with good quality water and starter. Let’s get these calves off to a good start as they grow to become our future herd.

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