Optimized Dairy Grazing Systems in the Northeast United States and New Zealand. II. System Analysis

Abstract

Factors that optimize milk production from Northeast United States and New Zealand grazing systems are compared using a linear programming model. The objective function maximized gross margin per hectare of land farmed. The experimental design compared the optimum characteristics of each system over a range of milk prices. The Northeast has a shorter grazing season and lower cropping costs than New Zealand. The optimum pasture area was 49% of the farm for Northeast systems. Gross margins declined rapidly above 55% or below 36% pasture area. The optimum stocking rate was 1.13 cows/ha, or 2.3 cows/ha of pasture. Optimum per cow production was higher for Northeast [7105 kg of fat-corrected milk (FCM)] than New Zealand (5710 kg of FCM) systems. This was related to lower grain relative to milk prices in the Northeast. New Zealand, all-pasture systems gave the lowest cost per unit of milk but also gave the lowest gross margin across all milk price scenarios. The best use of purchased feed in New Zealand systems was to support increased stocking rate rather than per cow production. Optimum grazing management practices were similar for supplemented New Zealand and Northeast systems. All-pasture New Zealand systems are characterized by short lactations and long autumn rotations to transfer pasture in situ for winter feeding. Higher costs per unit of milk produced will be an inevitable consequence of maximizing gross margin at high milk prices in New Zealand systems.

Trade-offs between profit, production, and environmental footprint on pasture-based dairy farms in the Waikato region of New Zealand

“…Profit increases with system intensity, but there is little additional benefit moving from PS3 to PS5 ($15 ha − 1 ), compared to moving from PS1 to PS3 ($456 ha −1 ). This is in line with previous research given that, in the extreme, farm profit can actually fall with farm intensification, as benefits for pasture utilisation and milk production per hectare accruing to higher stocking rates are offset by the cost of supplement required to maintain them (McCall and Clark, 1999;Macdonald et al, 2011).…”

Fatty acid and fat‐soluble antioxidant concentrations in milk from high‐ and low‐input conventional and organic systems: seasonal variation

“…Five farms representing the main non‐organic, ‘low‐input’ system found in the UK were selected. All farms used a New Zealand‐type production system26 with spring block calving, in which cows were grazed throughout the lactation and no, or low levels of concentrate and/or other feed supplements included in the diet (see Table 1). As with the organic spring block calving herds, cows were only housed when not lactating between November and February.…”

“…These studies did not include non‐organic, low‐input systems in comparisons. However, an increasing number of dairy farms in Europe, New Zealand/Australia and North America are adapting ‘lower‐input’ production methods similar to those used in organic farming, but do not comply with all input restrictions prescribed by organic farming standards 26. Most importantly, these systems use mineral NPK fertilizers, but often at reduced levels compared with conventional high‐input systems.…”

Relationship between dairy cow genetic merit and profit on commercial spring calving dairy farms

“…as well as significance of the regression coefficients from zero for herd financial performance on the dairy production sub-index, fertility sub-index and overall conformation estimated in a multiple regression model that also included the confounding variables of herd size, stocking rate and quantity of purchased feed PTA 5 predicted transmitting ability. Associations between non-genetic factors and financial performance Non-genetic factors previously reported to be associated with financial performance on pastoral dairy farms include stocking rate (Macdonald et al, 2008), calving date , feed cost (McCall and Clark, 1999;Shalloo et al, 2004), length of grazing season (Dillon et al, 2005a) and land type (Shalloo et al, 2004). Many studies have investigated the relationship between farm size and technical efficiency, although much of this research originates from mainly confinement dairy systems (Smith et al, 2000;Oleggini et al, 2001).…”