Abstract
The experiment was carried out to investigate the relationship between palatability and feed compositions of first-cut hay in four tropical grasses. Species of Chloris gayana Kunth cv. Asatsuyu (Rhodes), Panicum maximum Jacp. cv. Natsukomaki (Guinea), Panicum coloratum L. cv. Tamidori (Colored guinea) and Sorghum sudanense (Piper) Stapf cv. Sugarslim (Sudan) were sown on May 25, 2001. The sowing rates were 6 kg/10a (Sudan), 1 kg/10a (Guinea) and 2 kg/10a (Rhodes and Colored guinea) . Plants were harvested for making hay by tight bale from July 22 to July 25. The dry matter yield and some plant characters in the firstand second-cuts were investigated on July 19 and August 24, respectively. The palatability on Japanese Black breeding cattle was evaluated with intake rate by using cafeteria method and with selective intake speed. Dry matter yield in Colored guinea tended to be lower than in other three grasses both in the first- and second-cuts. The palatability was higher in Colored guinea than in other three grasses, evaluated by two methods and it was considered to be correlated with high leaf blade ratio, lower NDF content and higher in vitro dry matter digestibility in Colored guinea than in other three grasses. Among the other three grasses, the palatability in Sudan tended to be high by the intake rate from cafeteria method, while the palatability evaluated by the selective intake speed was the lowest in Sudan, because cattle were observed to be reluctant in grazing lower internode parts of Sudan. From the above results, although Colored guinea was lower in dry matter yield than other three tropical grasses, the palatability with intake rate by using cafeteria method and with selective intake speed was the highest among four tropical grasses. It is suggested that Colored guinea can be proposed to produce a good-quality hay among tropical grasses in the Southwestern warm region in Japan.
