Timely attention to sheep nutrition can boost number of lambs

Increasing the plane of nutrition for ewes — a practice known as "flushing" — two to three weeks prior to breeding and three weeks into the breeding season can improve lamb crop in some instances.

Flushing works best on mature ewes that are in moderate to good body condition. Very thin or overly fat ewes have a lower response. Ewes that are maintained in good condition on relatively high planes of nutrition throughout the year are also less likely to respond to flushing.

Time of breeding season also influences the response to flushing. It is more beneficial to flush early or late in the breeding season, when ovulation rates are naturally lower, compared to the middle of the breeding season.

Flushing not only increases the number of ovulations, or eggs, in the ewe, but also improves survival of the lamb embryo. What happens is that more eggs are available for fertilization and those that are fertilized have an improved chance to survive the delicate early life stage. The end result is that more lambs are born.

What is needed in the ewe's diet

Corn is usually used, but other options can work; one is irrigated pasture. What is actually needed is an increase in energy content of the ewe’s diet. Protein levels in the diet are also usually increased at this time.

Under maintenance conditions, a 154-pound ewe will need:

  • About 2.6 pounds of dry matter (dried feed), including:
    • 1.5 pounds TDN (energy)
    • 0.25 pound of protein

During flushing, that same ewe will need:

  • 4 pounds of dry matter, including:
    • 2.3 pounds of TDN
    • 0.36 pound protein

This is according to Nutrient Requirements of Domestic Animals.

One pound of corn (90% TDN, 10% protein) can provide this extra energy (0.9 pound TDN) and protein (0.1 pound CP). Increasing productivity through nutrition may improve return per ewe.

Previously titled
Flushing ewes: Don’t start too late or stop too soon

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