Herbage intake and body weight gain of Japanese Black and Holstein steers under intensive grazing.
Ochiai K. | Shioya S. | Togamura Y. | Kobayashi H. | Harashima N. | Sato K. | Nishida T.
Herbage intake, TDN intake and daily liveweight gain of Japanese Black and Holstein steers under intensive grazing were estimated in May and July for three years using chromic oxide dilution method and in vitro digestibility estimation of forage. Six to seven steers were grazed on 0.9 - 1 ha of perennial ryegrass (Lolium perenne L. Var. Friend) or orchard grass (Dactylis glomerata L. Var. Akimidori) dominant mixed pasture. The pasture was divided into 40 paddocks. The cattle are allowed on one paddock in the morning and on another in the evening. Therefore only the small paddock area per head per day, 0.8a was rationed to the animals. The digestibility of the forage remained relatively high, that is, 77-80% in May and 72-75% in July. there was no significant deference between the DM feacal output in May and June, but the DM feacal output of the Japanese Black steer was significantly smaller than that of the Holstein steer. Also, the DM intake per metabolic body size and the daily gain of the Holstein steer were significantly higher than those of the Japanese Black steer. The relationship between the daily liveweight gains and the energy intake for both Japanese Black and Holstein resulted in similar values to those calculated by US NRC's equations. Therefore the US NRC's energy requirement estimation for cattle may be used for estimating animal liveweight gains under intensive grazing.Show more [+] Less [-]