Grazing sorghum-sudangrass swaths

University of Nebraska researchers swath-grazed steers in eastern Nebraska on a sorghum-sudangrass hybrid from November 2023 to January 2024, comparing treatments of offering new forage once or twice per week.

The researchers report treatment groups were similar in average daily gain (ADG), with both groups gaining, on average, 0.45 pounds (lb.) per day (see Table 1). Forage utilization, with those fed once per week at 57.1% and those fed twice per week at 61.1%, was not significantly different.

There was a difference in carrying capacity, with steers allocated new forage twice per week grazing fewer acres. When steers were allocated new forage once per week, carrying capacity was 5.8 animal unit months (AUM) per acre. Carrying capacity increased to 6.8 AUM per month when steers were given new forage twice per week.

Through the winter, crude protein (CP) content of the forage remained consistent, but there was a decline in digestible organic matter (DOM) of about 14 percentage points due to exposure to the elements (see Table 2).

“For producers considering swath-grazing as a winter-feeding strategy, allocating new forage more frequently can increase field carrying capacity by 17%, likely due to reduced trampling loss with more frequent allocations,” researchers conclude. They caution, however, to take the decrease in DOM into account.

For more information, see the UNL Beef Cattle Research Report online at https://bit.ly/03research1.

Supplementing grazing cows with corn silage

Researchers at Kansas State University (K-State) analyzed effects — on cows and pastures — of supplementing corn silage to fall-calving cows grazing Bermuda grass pastures.

Angus-cross cows were allocated to Bermuda grass pasture and either not supplemented or supplemented corn silage at 1% of body weight on a dry-matter (DM) basis. For each treatment, four pastures were each stocked with a first-calf heifer, a 3- to 5-year-old cow and a cow 6 years old or older. The females averaged 155 days of gestation at turnout.

Those supplemented silage (32%-42% DM and 7.83% CP) were fed daily in fenceline bunks. Cows were weighed prior to turnout; at the midpoint of the trial; and two weeks prior to the estimated average calving date of the herd. Supplementation was adjusted after each weighing.

Researchers collected body weight, body condition score (BCS), hair score, hair length and rump fat measurements at each weigh date.

After the last weigh date, all cows were moved to calving pastures consisting of a mixture of Bermuda grass, tall fescue and prairie grass.

The researchers report that in this trial, supplementation had no effect on cow-calf performance, calf birth weight or milk output (see Table 3). It did, however, result in 31% more forage available in pastures (see Table 4).

“The greatest advantage,” the researchers conclude, “comes from a greater amount of forage available, which may offset periods of drought or allow producers to increase stocking rates on their property.”

For more information read the full research report in Kansas Agricultural Experiment Station Research Reports: Vol. 10: Issue 2 at https://bit.ly/03research2.

Mitigating the effects of ergot alkaloids

Supplementation with 5-hydroxytryptophan has potential to normalize serotonin levels and feed intake of cattle grazing ergot alkaloids, according to a March 2024 Journal of Animal Science article by researchers at the State University of Western Parana in Brazil and the universities of Kentucky and Tennessee.