Poor Quality Roughage
Exposing Animals to Poor-Quality Foods with Mom Improves Intake and Preformance
By Beth Burritt
Animals expected to produce and reproduce on poor-quality roughage may be hindered by feeding them high-quality diets early in life. If poor-quality forages are part of your operation, replacements should be exposed with their mothers early in life to poor-quality forages.
1. Offspring born during the late winter or early spring should be exposed to standing
dead forage or shrubs about a month to six weeks after birth.
2. If ammoniated straw is part of your winter feeding program, young animals should be exposed with their mothers to ammoniated straw early in life (the first 3 to 4 mos.). Exposing animals to poor-quality roughage or ammoniated straw with their mother later in life may be beneficial but I am unaware of any research on this topic.
3. Offspring not born until late spring or early summer when green forage is abundant can be exposed with their mothers to pastures not grazed the previous year, giving them a mix of standing dead and green forage.
4. For exposures to poor-quality forages to be effective, young animals probably require longer exposures (a month or more) to poor-quality foods compared with high-quality foods like grain. Unfortunately, I am not aware of any data on the optimal length of exposure to poor-quality foods to increase productivity on poor-quality forages.
5. If poor-quality foods don’t provide mother and her offspring adequate nutrition, providing limited amounts of high-quality supplements will boost nutrition but will encourage and enable mom and her offspring to eat poor-quality foods.
Benefits of early exposure to poor-quality foods
1. Intake: Yearling goats exposed to blackbrush with their mothers from 1 to 4 months
of age ate 20% more blackbrush than goats exposed to blackbrush at 4 months of age
without their mothers (Distel and Provenza, 1991)
2. Preference: Early exposure also affects preference for poor-quality foods. When yearling goats were fed alfalfa pellets free choice, goats that had been exposed to blackbrush with mom from 1 to 4 months of age ate 30% more blackbrush than goats that had not been exposed to blackbrush without mom until 4 months. (Distel and Provenza 1991). Similar results have been reported for sheep and poor-quality grass hay (Distel et al. 1994).
3. Weight changes: Five-year-old cows wintered on ammoniated straw and alfalfa gained 81 lbs from December to March provided they had been exposed to ammoniated straw with their mothers early in life. Cows without exposure lost 48 lbs during the same period. Interestingly, weight differences between the two groups persisted over the summer. The following November, cows experienced eating ammoniated straw weighed 48 lbs more than inexperienced cows. Differences in weight for the two groups of cows persisted for 3 years (Wiedmeier et al. 2002). A little exposure to ammoniated straw can go along way. Cows on this study were exposed as calves to ammoniated straw during late gestation and early lactation. After weaning, they were fed high-quality diets until 2.5 years of age. They did not see ammoniated straw again until 5 years-of-age. Their brief exposure to straw in utero and soon after birth enabled them to out perform cows naive to ammoniated straw when both groups were wintered on ammoniated straw.
4. Milk production and post-partum interval: Cows with prior exposure to ammoniated straw bred back 9 days sooner and produced 20% more milk than cows without exposure (Wiedmeier et al. 2002).
5. Digestibility and Nitrogen Recycling: Lambs exposed to poor-quality roughage from 1 to 4 months of age with their mothers digested poor-quality forages to a greater extent (55.1% vs. 50.6%) than lambs without exposure to poor-quality foods. Lambs experienced with poor-quality roughage also recycled nitrogen more efficiently than lambs without experience (Distel et al. 1994, 1996).
Distel, R.A. and F.D. Provenza. 1991. Experience early in life affects voluntary intake of blackbrush by goats. J. Chem. Ecol. 17:431-450.
Distel, R.A., J.J. Villalba, and H.E. Laborde. 1994. Effects of early experience on voluntary intake of low-quality roughage by sheep. J. Anim. Sci. 72:1191-1195.
Distel, R.A., J.J. Villalba, H.E. Laborde and M.A. Burgos. 1996. Persistence of the effects of early experience on consumption of low-quality roughage by sheep. J. Anim. Sci. 74:964-968.
Wiedmeier, R.D., F.D. Provenza, and E.A. Burritt. 2002. Exposure to ammoniated wheat straw as suckling calves improves performance of mature beef cows wintered on ammoniated wheat straw. J. Anim. Sci. 80:2340-2348.