Development of profitable milk production systems for northern Australia: a field assessment of the productivity of five potential farming systems using farmlets

Abstract

Farmlets, each of 20 cows, were established to field test five milk production systems and provide a learning platform for farmers and researchers in a subtropical environment. The systems were developed through desktop modelling and industry consultation in response to the need for substantial increases in farm milk production following deregulation of the industry. Four of the systems were based on grazing and the continued use of existing farmland resource bases, whereas the fifth comprised a feedlot and associated forage base developed as a greenfield site. The field evaluation was conducted over 4 years under more adverse environmental conditions than anticipated with below average rainfall and restrictions on irrigation. For the grazed systems, mean annual milk yield per cow ranged from 6330 kg/year (1.9 cows/ha) for a herd based on rain-grown tropical pastures to 7617 kg/year (3.0 cows/ha) where animals were based on temperate and tropical irrigated forages. For the feedlot herd, production of 9460 kg/cow.year (4.3 cows/ha of forage base) was achieved. For all herds, the level of production achieved required annual inputs of concentrates of ~3 t DM/animal and purchased conserved fodder from 0.3 to 1.5 t DM/animal. This level of supplementary feeding made a major contribution to total farm nutrient inputs, contributing 50% or more of the nitrogen, phosphorus and potassium entering the farming system, and presents challenges to the management of manure and urine that results from the higher stocking rates enabled. Mean annual milk production for the five systems ranged from 88 to 105% of that predicted by the desktop modelling. This level of agreement for the grazed systems was achieved with minimal overall change in predicted feed inputs; however, the feedlot system required a substantial increase in inputs over those predicted. Reproductive performance for all systems was poorer than anticipated, particularly over the summer mating period. We conclude that the desktop model, developed as a rapid response to assist farmers modify their current farming systems, provided a reasonable prediction of inputs required and milk production. Further model development would need to consider more closely climate variability, the limitations summer temperatures place on reproductive success and the feed requirements of feedlot herds.

Farm-scale nitrogen, phosphorus, potassium and sulfur balances and use efficiencies on Australian dairy farms

“…Potassium surpluses were generally of a similar order to those determined for N. In turn, S surpluses tend to be similar to those determined for P. Very few studies have considered K balances on dairy farms and none appear to have measured S balances. Fangueiro et al (2008) reported K surpluses between 52 and 107 kg K/ha for a range of commercial dairy farms in Northern Portugal, while Chataway et al (2010) found that K surpluses ranged between 22 and 156 kg K/ha in five contrasting farmlets in south-east Queensland; both lower than those determined in this study.…”

“…In a paddock-scale N fertiliser study in south-east Victoria, Eckard et al (2007) reported N surpluses of between 48 and 229 kg N/ha and N-use efficiency between 30 and 50%. In a 4-year farmlet study with differing stocking rates and feed and fertiliser inputs in south-east Queensland, Chataway et al (2010) reported N surpluses between 178 and 600 kg N/ha and use efficiencies between 16 and 25%. In south-west Western Australia, Staines et al (2011) reported N surpluses from a dairy farmlet study, which ranged between 72 and 779 kg N/ha and use efficiencies between 17 and 50%.…”

“…The few nutrient balance studies that have been undertaken in Australia have generally concentrated on P or N on dairy farms within a geographically limited region (Lawrie et al 2004;Ovens et al 2008) or have quantified nutrient balances as part of smaller-scale farmlet or paddock studies (Eckard et al 2007;Chataway et al 2010;Staines et al 2011). Additionally, there has been no systematic methodology development, and differences in methodology between these studies make comparison difficult.…”

A collective artefact design of decision support systems: design science research perspective

“…4. Development of the design artefact 4.1 Practical problem context and relevant analysis Decision making in agricultural industries, particularly livestock-based businesses in Queensland, Australia, has been faced with rapid changes due to the effect of climate change, government regulations and changes in farming methods (Chataway et al, 2010), resulting in the disuse of many DSS applications (Kerr, 2004). This disuse was due to the lack of fit to the needs of decision makers' contextual variables.…”

The effects of stocking rate, residual sward height, and forage supplementation on forage production, feeding strategies, and productivity of milking dairy cows

“…Dairy grazing systems have established their economic sustainability and competitiveness through effective pasture production and usage. Systems that maximize pasture utilization reap benefits in terms of productivity and profitability (Chataway et al, 2010;Ramsbottom et al, 2015), thereby maintaining resilience against market prices and climate threats (Fariña and Chilibroste, 2019). Strategies aimed at increasing the SR directly impact the amount of grass harvested (Baudracco et al, 2011), reducing the milk production costs without compromising homegrown forage production.…”