A University of Illinois study earlier this year looked at the effects of two rates of postweaning weight gain on the reproductive performance of 452 Angus and Angus-Hereford weanling heifer calves.
Calves weighed 192 kilograms (422 lbs.) and were fed either 3.7 or 3.0 kilograms of corn per day from weaning to breeding. Postweaning gain of heifers receiving three kg was .43 kg per day, while the heifers fed the high ration gained .62 kg per day.
The treatments resulted in individual postweaning weight gains ranging from .07 to 1.17 kg per day. These gains were lower than expected, likely due to the grazing of fungi-infected tall fescue and muddy conditions.
Read Also
VIDEO: Green Lightning and Nytro Ag win sustainability innovation award
Nytro Ag Corp and Green Lightning recieved an innovation award at Ag in Motion 2025 for the Green Lightning Nitrogen Machine, which converts atmospheric nitrogen into a plant-usable form.
Heifers receiving high ration were 26 kg heavier, had 0.15 centimetres more fat thickness, five percent greater pelvic area and tended to have greater hip height than heifers receiving the lower
ration.
Nearly 10 percent more heifers in the high group reached puberty before the start of the breeding season.
No significant differences were found in pregnancy rate or calving difficulty between treatment groups.
Average milk production was 10 percent greater for heifers fed the high corn ration than for the low-fed heifers and resulted in heavier calves at 54, 104, and 153 days of age.
Based on other research, it appears likely that heifers in the high group were near the optimum postweaning gain (0.62 kg) for expression of maximum milk
production.
– Nutrition Update
Wheatgrass potential
Due to improper grazing management, much of Saskatchewan’s mixed prairie is functioning well below its productive potential, says Jim Romo, associate professor, department of crop science and plant ecology at the University of Saskatchewan.
“Overgrazing is the main reason for this situation,” Romo says. “Overgrazing occurs when plants are re-grazed before their root and shoot growth and carbohydrate reserves have recovered from a previous defoliation.”
Romo says the length of time required for plants to recover from grazing can vary from days to years, depending on timing and intensity of grazing, as well as other factors. Grazing also influences winter survival of grasses.
Northern wheatgrass, the dominant species in heavy soils of the brown and dark brown soil zones of Saskatchewan and Alberta, is known to decrease under improper grazing on mixed prairie.
To correct this problem through increased understanding, Romo initiated a study to determine the effects of grazing at different times of the growing season.
His project, supported by the Saskatchewan Agriculture Development Fund, found that for optimum, sustained productivity, northern wheatgrass should be grazed in a deferred-rest rotation grazing system, with rest applied every second year.
“Grazing could begin in mid-June, with livestock moved to a new paddock every 21 days until early to late September. This grazing system would require eight to 10 paddocks. Grazing of regrowth would be minimized by the three-week occupation periods.
“This grazing rotation would enable strict control of the timing and frequency of defoliation while attaining full use of the vegetation,” says Romo.
“A full season of rest would enable the vegetation to recover its vigor and protective cover.”
Romo says little information is available on the rest requirements of any forage species, even though this factor plays such an essential role in the health and productivity of rangeland and pasture.
– Saskatchewan Agriculture
