Effects of grass forage species and long-term period of low quality forage diet feeding on growth performance, nutrient utilization and microbial nitrogen yield in growing wether lambs.
Six growing lambs were used to evaluate the feeding value of two forage-based diets in a long-term feeding period by measuring body weight (BW) gain, digestibility, nitrogen (N) retention and microbial N (MBN) yield. The animals were fed imported low-quality timothy hay (TH) with concentrate diet (THD) or imported low-quality Italian ryegrass straw (IR) with concentrate diet (IRD) for 9 months. The forages were offered at 2% BW, and concentrate was fed at 40% of forage intake. The BW gain averaged 82.6 and 66.2 g/day for THD and IRD, respectively, without showing significant difference. Average forage intake (% BW) was significantly greater for IR than for TH, although it was not affected by feeding periods. The digestibility did not differ between diets or periods. The numerically greater (P = 0.06) ratio of retained N to absorbed N for IRD than that for THD was prominent. Neither diet nor period had significant effect on MBN supply and efficiency of MBN synthesis. The results suggest that the IR-based diet can be also used for long-term periods of feeding to growing ruminant animals as a grass hay-based diet without any detrimental effects on nutrient utilization and growth performance.
The United Graduate School of Agricultural Sciences, Tottori University, Tottori, Japan.
Da-Hye
DH
Kim
Grassland and Forage Research Center, National Institute of Animal Science, Cheonan, Korea.
Ki-Choon
KC
Choi
Faculty of Life and Environmental Science, Shimane University, Matsue, Japan.
Sang-Houn
SH
Song
Faculty of Life and Environmental Science, Shimane University, Matsue, Japan.
Toshiyoshi
T
Ichinohe
D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena / Q000502:physiology*; D000818:Animals; D004063:Digestion / Q000502:physiology; D008129:Lolium; D008297:Male; D009584:Nitrogen / Q000378:metabolism*; D031784:Phleum; D012756:Sheep / Q000254:growth & development* / Q000502:physiology*; D015430:Weight Gain
D009584:Nitrogen
feeding period; forage diet; growing lamb; microbial supply; nitrogen balance