By Britt Hicks
A Florida study recently showed feeding heifers three times per week might lower labor costs significantly and not significantly hinder development or pregnancy rates.
The development of heifers is an important economic consideration in a cow-calf operation. Research has shown heifers which calve by two years of age have greater lifetime productivity than heifers which calve at an older age.
Thus, heifers must be maintained at an adequate plane of nutrition to reach puberty and conceive by 14 to 15 months of age. Since the management of first-calf heifers affects their productivity for the remainder of their lifetimes, supplementation of heifers is a common practice.
Frequency of supplementation is an important management and economic option to consider when designing supplementation programs for beef cattle fed forage-based diets. Numerous research studies have shown that supplementing cattle with high protein supplements, such as cottonseed meal, either three times or once weekly usually gives similar performance compared with daily feeding.
In contrast, low-protein, grain-based supplements should be fed daily to reduce the disruption of rumen function due to starch, which results in decreased forage intake and digestibility.
However, little data is available on the effects of supplementing heifers at different intervals on growth and reproductive performance. University of Florida research in 2008 showed feeding an energy supplement based on digestible fiber by-products daily instead of three times weekly enhanced the nutritional and metabolic status of forage-fed Brahman-crossbred females. This was predominately wheat middlings and soybean hulls at 20% crude protein as-fed basis.
Additional Florida research examined the effects of daily versus three-days-per-week supplementation on age at puberty, estrous synchronization response, and pregnancy rates of yearling Brangus and Angus heifers fed Bermudagrass round bale silage ad libitum.
In this study, 60 heifers were supplemented with dried distiller's grains and soybean meal to gain approximately 1.5 pounds per day either daily-fed or three times per week.
These researchers reported heifers supplemented daily had similar daily gains as compared to 3X-fed heifers (1.82 vs. 1.79 pounds/day).
In addition total silage offered and total supplement consumption was similar between treatments.
This data supports previous research conducted in cows showing that three-day-per-week supplementation does not significantly affect cow performance.
However, heifers supplemented daily tended to have a greater percentage reach puberty with 60% by the time of AI breeding compared to 3X-fed heifers at 40%.
The authors say it is unclear if this difference is due to the feeding regimen or just due to the limited number of heifers in the study. In addition, the estrous response tended to be greater in daily supplemented heifers at 77% than in 3X-fed heifers at 57%.
In contrast, synchronized pregnancy rates (43% vs. 57%, P = 0.30) and total 28 day AI pregnancy rates (63% vs. 70%, P = 0.59) were similar between daily supplemented and 3X-fed heifers, respectively.
Hicks is area extension livestock specialist for the Oklahoma Panhandle Research & Extension Center.