Beef Production on Pasture and Lucerne

During a span of 20 years, eight farmlet-scale experiments conducted in the Manawatu used a simple system of grazing management to maximise pasture growth and utilisation. Farmlets of 1.6 ha were stocked annually with 12 Friesian bulls (7.4 wintered/ ha) from early November at 3 months-of-age (70-80 kg liveweight (LW)) until slaughter during December - March at 16 - 19 months (350 - 420 kg LW). The grazing management system involved seasonal adjustment in pasture spelling intervals, and an increase in grazing pressure in spring by addition of 3-month-old weaner bulls followed by the progressive removal of 'finished' animals during summer. With this control over feed supply and demand and the inherent capacity of growing bulls to cope with changes in feed availability, old permanent pasture producing approximately 13 t dry matter/ha/yr was conver ted to approximately 1000 kg/ha/yr of net carcass weight gain. Using loafing pads in winter to reduce treading damage on wet soils and increase pasture utilisation and growth, increased annual LW gain (LWG)/ha by 2%. Controlling the intensity of defoliation in summer through timely removal of bulls for slaughter increased average daily gain (ADG) during autumn and winter, but annual LWG/ha by only 1%. Pastures renewed with improved cultivars and species produced more forage in summer (red clover), autumn (prairie grass) and winter, identified as per iods of feed deficit for old permanent pastures. Strategic inputs of nitrogen (N) fertiliser (100 kg N/ha/yr) in autumn or in spring on old permanent pasture, in conjunction with irrigation (approximately 250 mm/ season) during November - March, and in combination with cool season active grasses, all increased annual meat output by up to 12% above that possible from old permanent pasture, by extending the duration of stocking in summer, increasing ADG, or a combination of both. While these gains are important, the studies highlighted the very high levels of output sustained from year-round all-grass grazing systems based on principles for maximising pasture growth and utilisation. Those high yields remain a benchmark in terms of the biological efficiency of growing and converting pasture to animal product, although the economic optimum was at a lower stocking rate and level of output. Keywords: dairy beef, grazing systems, liveweight gain, pasture utilisation

Section: Resultsmentioning

confidence: 99%

High production dairy-beef cattle grazing systems: a review of research in the Manawatu

Cosgrove¹,

Clark²,

Lambert³

2003

“…In the Waikato where barley was overdrilled into lucerne, Elliott (1967) recorded an average increase over three years of 950 kg dry matter (DM)/ha from two cuts in late May and August, In two further years no increase in production was recorded. Croy and Weeda (1974) reported a much larger increase of 2400 kg DM/ha from overdrilling oats when grazed twice over winter.…”

Section: Ntrodljcitonmentioning

confidence: 99%

Autumn Overdrilled Tama Ryegrass and Cereals to Supplement Lucerne in the Central North Island

Baars¹,

Douglas²

1975

Two experiments were conducted in which cereals and 'Grasslands Tama' ryegrass were overdrilled into lucerne in autumn, in one experiment following a prior light cultivation. The highest production was obtained from barley and oats when left uncut from sowing until early spring. Barley was distinctly superior to oats, ryecorn and Tama ryegrass when two cuts were taken in late winter and early spring. Tama ryegrass and to a lesser extent oats depressed lucerne growth, when they were growing and after their disappearance. Nitrogen doubled the weed content, where there was inadequate competition from overdrilled species.

“…Interpretation of most liveweight gain data is confounded by periods of limiting nutrition, whether deliberately applied as a treatment or simply as a consequence of seasonal pasture growth (e.g., Cosgrove & Brougham 1988). Also the relatively short-term duration of many trials, based on seasonal (e.g., Clark 1991;Goold & Weeda 1985) or annual production results (Croy & Weeda 1974), gives no information on age or weight at maturity. These limitations of existing data can be explained in part by commercial and research interest in emphasising gain per unit area rather than gain per animal, in order to conduct trials within a framework of economic relevance.…”

Section: Introductionmentioning

confidence: 99%

Nutritional options and implications for maximum growth rate of steers

Cosgrove¹,

Muir²,

Lambert³

1995

Estimates of age and weight at mature size are required for the development of decision-support and mathematical models to describe beef growth. Interim results from an experiment designed to quantify the liveweight gain of steers from weaning to mature size are reported in this paper. Three groups of 28 steers have been fed for 2 years from weaning (8 months) to 32 months of age on the following treatments: resident, ryegrass-white clover based pasture (R); a high quality pasture option based on annual ryegrass in winter and spring, and red clover and lotus in summer and autumn (HQ); and a 70% maize grain : 30% silage diet offered under feedlot conditions (F). Average daily gains from weaning to 30 months of age and liveweight at 30 months were 0.69 kg/hd/day, and 709 kg, 0.78 kgfhdlday and 772 kg, and 0.91 kglbdlday and 858 kg for R, HQ and F treatments, respectively. Feedlot steers had a greater fat depth over the 12113th rib than either of the pasture fed treatments, when measured at the same age. In addition, both pasture groups have shown seasonality in liveweight gain, with periods of low liveweight gain in late autumn and winter of the second and third years. Results are discussed in relation to the nutritional contrasts between treatments. Keywords: feedlot, cattl.e, liveweight gain, potential growth