Rotational grazing system for beef cows on dwarf napiergrass pasture oversown with Italian ryegrass for 2 years after establishment

Abstract

We examined an intensive rotational grazing system for dwarf and late‐heading (DL) napiergrass (Pennisetum purpureum Schumach) pasture in a summer period, and an oversown Italian ryegrass (IR) pasture in a winter period for the 2 years following establishment. Four 0.05‐ha paddocks of DL napiergrass pasture (20 m × 25 m) were established on 6 May 2002. They were rotationally grazed for 1 week, followed by a 3‐week rest period by 2–3 breeding or raising beef cattle (Japanese‐Black) for three and six cycles in a summer period during the first and second years of establishment, respectively. In the IR pasture, which was established by oversowing IR in both years, rotational grazing by 3–4 animals was conducted in March and April for two cycles of grazing for 1–2 days in each paddock in 2003 and for 3–5 days in all four paddocks in 2004. In the DL napiergrass pasture before grazing, the plant height, leaf area index and the ratio of leaf blade to stem were highest in the hot summer season, while tiller number increased and herbage mass tended to increase as grazing occurred, except for the first grazing cycle both years, and for one paddock in the second year. Herbage consumption, rate of herbage consumption and dry matter intake tended to decrease in three paddocks from the first to the third cycle in the first year, while herbage consumption and rate of herbage consumption tended to increase as grazing occurred in the second year. Dry matter intake averaged 10.2–14.5 and 15.4–23.2 g DM kg−1 liveweight (LW) day−1 over the four paddocks in the first and second year, respectively, and average daily gains were 0.09 and 0.35 kg head−1 day−1 in the first and second year, respectively. In the oversown IR pasture, herbage consumption tended to increase as grazing occurred, and the average daily gains were 1.49 and 1.36 kg head−1 day−1 in 2003 and 2004, respectively, except for the LW decrease during the first cycle in early March 2004. The carrying capacities on DL napiergrass pasture and IR pasture were estimated at 1016 and 208 cow‐days (CD) ha−1, respectively (annual total 1224 CD ha−1) in the first year and at 1355 and 207 CD ha−1, respectively (annual total 1562 CD ha−1) in the second year. Thus, DL napiergrass pasture oversown with IR can expand the grazing period for beef cows to late November, March and April, in addition to the summer season for the 2 years following establishment.

Effect of Repeated Application of Manure on Herbage Yield, Quality and Wintering Ability during Cropping of Dwarf Napiergrass with Italian Ryegrass in Hilly Southern Kyushu, Japan

“…DM yield of DL Napiergrass was determined randomly for two plants per replicated plot by defoliating plants using a hand sickle at 10 cm above the ground [1]. Above-ground samples were hand-separated by scissors into leaf blade (LB), stem inclusive of leaf sheath (ST), and dead parts, and oven-dried at 70 • C for 4 days to determine DM yield.…”

“…Temperate species of Italian ryegrass (IR; Lolium multiflorum Lam.) harvested as a winter crop can be oversown into dwarf Napiergrass pasture [1,5] since IR has the opposite seasonal growth pattern to DL Napiergrass. The cropping combination of DL Napiergrass with annual IR needs to be determined for the sustainable production in several years at the elevated area (>300 m above sea level) of southern Kyushu, where dairy and beef cow farming operations are concentrated.…”

“…The dwarf genotype of late-heading type (DL) Napiergrass (Pennisetum purpureum Schumach) harvested as a summer crop plays an important role in providing high biomass, vigor, palatability, and digestibility for livestock feed in southern Kyushu, Japan [1][2][3][4]. Temperate species of Italian ryegrass (IR; Lolium multiflorum Lam.)…”

A New Strategy for Utilizing Rice Forage Production Using a No-Tillage System to Enhance the Self-Sufficient Feed Ratio of Small Scale Dairy Farming in Japan

“…The toxicosis caused by HV was reduced after processing into hay because drying reduces cyanamide contamination of HV [17]. IR is also a common winter annual grass forage in Japan, which has good productivity in upland field conditions [18,19], and it is also used as a cover crop in rice paddy fields [6]. However, little information is available on IR productivity in paddy fields after rice harvest or in mixed culture with HV.…”

Genotypic differences in forage quantity and quality of canopy strata in napiergrass (Pennisetum purpureum Schumach)

“…Dwarf type napiergrass (semi-dwarf [dwarf late-heading type; DL]) originated from Florida, in the United States (Sollenberger et al, 1988), was then brought to the Dairy Promotion Organization (DPO) in Thailand, and was finally introduced to Japan in 1996 (Ishii et al, 1998). Although the DL napiergrass has been adopted in tropical and subtropical countries, it has been recently introduced and examined for growth attributes and adaptability to be more suitable for grazing use than normal variety of napiergrass in temperate Japan (Mukhtar et al, 2003;Ishii et al, 2005). In vitro dry matter digestibility (IVDMD), crude protein concentration, and overwintering ability of DL napiergrass were superior to the normal napiergrass genotype in various tropical and sub-tropical areas in the world (Tudsri et al, 2002).…”