Yield and quality of Maralfalfa forage during long days on three dairy farms in northern Puerto Rico

Abstract

An experiment was conducted to evaluate the dry matter yield and quality performance of Maralfalfa forage obtained at six harvest intervals (HI; 40, 50, 60, 70, 80, 90 d) on three dairies in northern Puerto Rico during the long day season. The 40-day harvest interval was significantly (P < 0.05) inferior in dry matter yield to those of 60, 80, and 90 days; no significant (P < 0.05) differences in yield were observed among intervals of 40, 50 and 70 days. The 40-day interval showed the highest forage quality as indicated by crude protein content, digestibility in vitro of dry matter and neutral detergent fiber, and estimated net energy, index of relative forage quality and theoretical milk production. Although significant (P < 0.05) differences were observed in some of these criteria between 40- and 50-day harvest intervals, the latter maintained a good nutritional value in contrast to drastic losses in quality observed with the longer harvest intervals under study. The simple regression equations between digestibility in vitro of dry matter and of neutral detergent fiber versus harvest interval showed a decrease in digestibility of 2.7 and 3.0 percentage points for each additional 10 days of harvest interval, respectively.