Hay Nutritional Quality and Grassland Bird Nesting: Impact of Delaying First Hay Cut on Dairy and Beef Production in Ontario

Perennial forage production exists in Ontario to support the livestock industry, but also provides nesting habitat for grassland birds such as the threatened Bobolink (Dolichonyx oryzivorus) and Eastern Meadowlark (Sturnella magna). Delaying hay harvest until July 15 or later allows most nestling birds to leave the nest, but the nutritional value of hay decreases substantially. This project estimated the nutritional and economic impact of delaying the first hay cut until after July 15 on beef and dairy production in Ontario, Canada. Forage crops were sampled across Ontario, analysis of nutritional value performed, and effects on production and economics modelled. 634 samples were collected over 13 weeks at 16 sites from May 21 to August 14 during 2014 and 2015. As expected, nutritional quality declined over the season. Crude protein decreased by 5.2%, total digestible nutrients by 7.7%, neutral detergent fibre digestibility (NDFd48) by 20.1%, while lignin increased by 3.5%, neutral detergent fibre by 13.1%, and acid detergent fibre by 9.9%. Estimated yearly milk production decreased 10.9 kg or C$7.87/dairy cow for each day of delay in harvest (2017 values). Estimated growth of backgrounding beef steers decreased 1.56 kg or C$5.49/head for each day of delay in harvest. This translated into lost revenue per acre for backgrounding steers of C$31 per acre and C$45 per acre for over wintering beef cows for a delay from mid-June to mid-July. Some agri-environmental incentives in Canada, US and Europe offset the reduced revenue due to lower quality forages. This analysis informs farmers about the cost of practices to benefit grassland birds and provides empirical data on how to structure stewardship incentives for these practices.