Studies on the evaluation of the palatability and digestibility of forage sorghum (Sorghum bicolor Moench, Sorghum sudanense Stapf) in Japanese black cows

Summary The nutrient requirement of domestic animals varies with the aim of feeding, and accordingly the ration composition varies with the nutrient requlrements. The nutrient intake is determined by the nutritive value of the feed and feed intake. On the other hand, the variation of forage sorghum is extremely large, including grain-type, dual-purpose-type, sorgo-type and sudan-type sorghum and sudan grass. Using this variation and considering the diverse feeding purpose and the large variation in nutrient requirement, I evaluated the palatability and digestibility of forage sorghum. 1. Evaluation of the palatability of forage sorghum Palatability was evaluated by the cafeteria method and paired comparison method. Furthermore, I simplified the paired comparison method for palatability test and applied it for the breeding of forage sorghum. (1) Evaluation of palatability by the cafeteria method Six varieties of sorghum silage and one corn silage ("P3352") were used as test material. Palatability trials using the omit-system of the cafeteria method were conducted on six adult female Japanese black cows, and the follwing palatability order was obtained; "P3352" (corn) >"F6-3A-5"NE"Suzuho"NE"BR48">"Sugar graze">"FS902" >= "Tentaka" There was a significant difference in palatability among the sorghum types, the grain-type and dual-purpose-type sorghum tended to exceed the sorgo-type sorghum in Palatability. Also, the cows on the panele showed a significant degree of agreement in selection behaviour, which showed that the cows were selecting sorghum based on some common cognizance. (2) Evaluation of palatability by paired comparison method Ten varieties of sorghum silage and one corn silage ("P3352") were used as test material. Palatability trials using the paired comparison method were conducted on a panel of six adult female Japanese black cows, and the following balatability order was obtained; High palatability group "P3352"(a)>"F6-3A-5"(b) >= 'Suzuho" (b) >"BR48" (c) >=' GS401" (c, d)