Utilizing a multi-index decision analysis method to overall assess forage yield and quality of C3 grasses in the western Canadian prairies
Citation
Zhang, J., Iwaasa, A.D., Han, G., Gu, C., Wang, H., Jefferson, P.G., Kusler, J. (2018). Utilizing a multi-index decision analysis method to overall assess forage yield and quality of C3 grasses in the western Canadian prairies. Field Crops Research, [online] 222 12-25. http://dx.doi.org/10.1016/j.fcr.2018.03.007
Plain language summary
Throughout the year seasonal changes of forage quality and yield has a major impact on grazing livestock production. The ability to have accurate evaluation on quality and quantity of forage is useful to determine when and how to best utilize and graze the forage. However, forage quality and yield can vary with forage species, harvest seasons and yearly climate conditions, thus numerous factors over the growth of the plant can affect forage characteristics. Research (2008–2010) was conducted in Swift Current, Saskatchewan, measuring forage quality and quantity for nine grasses (Awn wheatgrass, Canadian wildrye, Green wheatgrass, Hybrid bromegrass, June grass, Meadow bromegrass, Needle and thread grass, Northern wheatgrass and Western wheat grass) harvested in June, August and October. Several statistical methods were used to understand different interrelationships, patterns and attributes among forage quality indicators for the different grasses and which are more important based on the yearly climate condition and harvest season interactions. Results showed that no one grass was able to have the ideal forage quantity and quality among the different years and harvest seasons. Different yearly and seasonal rankings of forage quality and yield among the different grasses require the need for more flexible production tactics and adaptive management techniques to be considered within the western Canadian prairie region. For instance, Northern wheatgrass can be recommended to be mixed with high quality forages due to its high yield in any harvest season. Meadow bromegrass can be recommended to be mixed with high yield forages due to its high quality in summer and fall. These findings will provide valuable information for forage breeders, and livestock and forage managers to maximize grass utilization efficiency while balancing yield and quality
Abstract
Seasonal dynamic of forage quality and yield has a major impact on livestock production. A sound evaluation on quality and quantity of forage is useful for cost-effective utilization of forage. However, forage quality and yield can vary with forage species, harvest seasons and yearly climate conditions. To improve forage use efficiency, a field experiment (2008–2010) was conducted in Swift Current, Saskatchewan, Canada. Dry matter yield and quality indicators (fiber, protein, digestibility and minerals) were measured for nine cool-season grasses harvested in June, August and October. The interrelationships and attributes among quality indicators were determined by principal component analysis (PCA) and the weights of quality indicators were calculated by entropy weight (EW) method. To synthesize different attribute indicators into a comprehensive index that reflects quality ranking of different forage species, an integrated multi-index decision analysis method, i.e., PCA-based TOPSIS with EW, was used in this paper. The evaluation process and results showed that the interrelation patterns and positive or negative attributes for quality indicators were consistent with years and harvest seasons, whereas the rankings of most grasses in yield and comprehensive quality varied with years and harvest seasons. According to the yearly and seasonal rankings of forage quality and yield, flexible production tactics and adaptive management techniques should be considered within the western Canadian prairie region. For instance, Northern wheatgrass (Agropyron dasystachyum) can be recommended to be mixed with high quality forages due to its high yield in any harvest season. Meadow bromegrass (Bromus Riparius) can be recommended to be mixed with high yield forages due to its high quality in summer and fall. These findings will provide valuable information for forage breeders, and livestock and forage managers to maximize grass utilization efficiency while balancing yield and quality.