Biomass Yield and Nutritive Value of Rye (Secale cereale L.) and Wheat (Triticum aestivum L.) Forages While Grazed by Cattle

Management strategies that integrate crops and livestock may lengthen the productivity of seasonal pasture systems in agroecological zones with short growing seasons. The biomass yield and nutritive value of fall-planted rye (Secale cereale L.) and wheat (Triticum aestivum L.) forages were determined in an integrated crop–livestock system under rotational cattle (Bos taurus L.) grazing and organic conditions for seven weeks during the spring and summer in Minnesota, USA. Rye yielded greater forage biomass at the beginning of the grazing interval, while wheat yielded greater forage biomass in the latter part of the grazing interval. In general, wheat had greater crude protein and less neutral detergent fiber, compared to rye, throughout the grazing interval. The predicted total tract neutral detergent fiber digestibility of forages was ≥50 g 100 g⁻¹ of neutral detergent fiber for at least the first four weeks of the grazing interval, indicating high forage digestibility in immature forages. Results from this study suggest that rye may provide more forage biomass for grazing earlier in the spring at the expense of lower nutritive quality, compared to wheat. Thus, the biomass yield and nutritional value of rye and wheat forages vary during the grazing interval, which informs producers of grazing schedule modifications in order to meet the nutritional demands of cattle.