Toxic endophyte-infected tall fescue is particularly detrimental to the productivity of spring-calving beef cow herds. A recent study published in the journal, Grasses, compares the productivity of two spring-calving herds – one raised entirely on toxic endophyte-infected tall fescue (E+) and the other raised largely on endophyte-free or novel, non-toxic endophyte-infected tall fescue (E-/NE+).
With eight years of data and over 2,300 unique cow-year production records, the results indicate that cows raised on non-toxic forage had improved pregnancy and calving rates and weaned larger calves.
| Forage type | SE | P Value | ||
| E+ | E-/NE+ | |||
| Cows | ||||
| Body weight, lb | 1133 | 1235 | 29 | 0.04 |
| BCS pre-breeding | 5.1 | 5.5 | 0.1 | 0.02 |
| BCS first pregnancy check | 5.4 | 5.5 | 0.1 | 0.53 |
| BCS second pregnancy check | 5.4 | 5.7 | 0.2 | 0.33 |
| Calves | ||||
| Birth weight, lb | 73 | 82 | 2 | 0.02 |
| WW, lb | 560 | 613 | 18 | 0.02 |
| ADG, lb day-1 | 2.12 | 2.27 | 0.07 | 0.07 |
Calving rates for cows grazing primarily on E-/NE+ pastures had greater (P=0.02) calving rates (93.5%) than cattle grazing E+ pastures (88.8%). There was an 18% improvement (P=0.002) in conception to artificial insemination for cows on E-/NE+ forage.
As previous studies have shown, spring-calving herds are more susceptible to the effects of ergot alkaloids due to the simultaneous exposure to toxins and heat stress during the breeding season. In current market conditions, 5% improvements in calving rates and calves that are 50 lb heavier at weaning can have a significant impact on farm profitability.
More information is described in the open-access paper here: https://www.mdpi.com/2813-3463/4/3/29
~ Dr. Gabe Pent, Virginia Tech and the Alliance for Grassland Renewal
The Alliance for Grassland Renewal is a national organization focused on enhancing the appropriate adoption of novel endophyte tall fescue technology through education, incentives, self-regulation and promotion. For more resources or to learn more about the Alliance for Grassland Renewal, go to www.grasslandrenewal.org
The Alliance for Grassland Renewal 