Cow and Calf Performance, per Hectare Productivity, and Persistence of Crownvetch under Grazing1
- J. C. Burns,
- W. A. Cope and
- E. R. Barrick2
Crownvetch (Coronilla varia L.) has been observed to be somewhat less sensitive to midsummer stress in the Piedmont region of the Southeastern USA than other cool season legumes and has produced good ruminant daily gains. These factors suggest that crownvetch offers potential as a grazing forage, yet quantitative data on animal responses and stand persistence are lacking.
The objective of this study were to further evaluate crownvetch as a grazing forage b.y considering cow and calf performance from pure stands as compared with that from tall rescue (Festuea arundinacea, Schreb. cv. ‘Ky 31’) and to determine the per hectare productivity [(total digestibue nutrients (TDN)], calf gain and animal days) and the persistence of crownvetch when continuously grazed.
Calf daily gains (kg/head/day) from crownvetch averaged 0.96 for the two-year evaluation phase compared with 0.67 from tall rescue (P ≤ 0.05). Cows grazing crownvetch also averaged 0.96 kg/head/day compared to 0.31 from tall rescue (P ≤ 0.05) with consistently higher average daily cow and calf gains from crownvetch throughout the grazing season.
Crownvetch yielded 3,375 and 325 kg/ha of TDN and calf gain respectively, when stocked at 2.63 (season average) cow-calf units/ha.
By the end of the fourth year (spring 1972) crownvetch stand counts in the grazed paddocks were reduced 86%, as estimated from fixed points, or 89%, as estimated from random points. Crownvetch stands in plots fenced off and harvested mechanically (not grazed) after 2 years of grating were reduced only 59% which is considerably less than that from continuous grazing.
The animal-gain data indicated that crownvetch is a very satisfactory forage for grazing. However, agronomically, crownvetch failed at this location when continuously grazed. Stands were extremely difficult to establish and were severely weakened at the end of the second grazing season. Before crownvetch can be agronnomically reliable for grazing in much of the Piedmont region, considerable effort must be given to increasing seedling vigor thereby aiding stand establishment and to develop more persistent plants to prolong stand survival.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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