Development of LIME-NZ: a generic tool for prompt estimation of economic impacts of disease for New Zealand livestock

AIMS

To develop a simple and robust generic tool to measure the impacts of livestock diseases on New Zealand dairy, beef and sheep farms using enterprise gross margin models.

METHODS

The most recent (2018-2020) livestock production benchmarking data was extracted from industry-led economic surveys. Gross margin models were built for each enterprise type, accounting for 11 dairy farm types and 16 farm types for beef and sheep. Disease parameters, including changes in mortality, reproduction performance, milk yield, price of animals and culling rate, as well as additional expenses for veterinary intervention, were applied to the infected compartment of the herd/flock using the assumed annual within-herd disease incidence. Farm-level disease impacts were estimated as the difference in annual profit between the baseline and infected farm. The baseline gross margin models were validated against the industry data. The disease impact models were validated using a recently published study on bovine viral diarrhoea (BVD). The impact assessment tool, LIME-NZ, was developed using the statistical software R and implemented in the web-based R package Shiny. The input parameters can be varied interactively to obtain a range of disease impacts for uncertain disease parameters.

RESULTS

The baseline gross margin models demonstrated reasonable accuracy with a mean percentage error of <14% when compared with the industry reports. The estimated annual impacts of BVD were comparable to those reported in the BVD study, NZ$38.5-140.4 thousand and $0.9-32.6 thousand per farm per year for dairy and beef enterprises, respectively.

CONCLUSIONS

LIME-NZ can be used to rapidly obtain the likely economic impacts of diseases that are endemic, recently introduced or at increased risk of introduction in the New Zealand context. This will aid communication and decision-making among government agencies and the livestock industry, including veterinarians and livestock producers, about the management of diseases, until refined information becomes available to improve decision-making.

Is relaxing broiler breeder growth restriction cost-effective?

Broiler breeders are subjected to feed restriction programs to control excessive growth. However, current levels of feed restriction and concomitant growth restriction are becoming severe, raising welfare and suboptimal reproductive performance concerns in underfed breeders. To circumvent the issue, our previous studies investigated the effects of new strategic growth curves, with various degrees of relaxed growth restrictions, on broiler breeders and their progeny's performance. The broiler breeder study was conducted with 40 Ross 708 broiler breeder pullets reared on 1 of 10 target growth trajectories using a precision feeding (PF) system. The growth trajectories were designed with 2 levels of the amount of prepubertal BW gain and 5 levels of pubertal growth timing. The prepubertal BW gain (g1) was estimated from the breeder-recommended standard BW gain (Standard g1) target, or 10% higher (High g1). The pubertal growth timing (I2) was advanced such that it happened at I2-0% = 22.29 wk, I2-5% = 21.16 wk, I2-10% = 20.05 wk, I2-15% = 18.94 wk, I2-20% = 17.82 wk of age. Two broiler experiments with different maternal ages (35 and 42 wk) were conducted as the extension of the breeder experiment to evaluate the intergenerational effects of a reduced degree of maternal prepubertal phase growth restriction and earlier maternal pubertal phase growth on offspring growth and development. The current paper investigated the economic aspects of implementing the growth curves using the partial budget analysis. Increasing prepubertal BW gain by 10% and advancing the pubertal growth phase by 20% (scenario 10) could increase margin over feed and chick cost for the hatching egg producers by CDN$1.97/hen. For broiler chicken supply chain as a whole, the highest differential margin over feed and chick cost was for maternal growth scenario 10 from 42-wk-old hens. The latter margin over feed and chick cost was greater than that of breeder-recommended maternal growth (from 35-wk-old hens) by $0.1053/kg live chicken under the current economic situation.

Private management costs of Popillia japonica: a study of viticulture in Italy

The Japanese beetle (Popillia japonica) is classified as a high-priority pest in the European Union and is reported to have caused extensive damage to grapevine leaves in Italy. As there are few studies, which measure the beetle's socio-economic impact, we conduct a first descriptive assessment of grapevine farmers' perception of the beetle's impact and assess the pest's effect on private management costs using a partial budgeting approach. Our sample includes data from 65 producers and 118 vineyard plots. In terms of farmers' perception, we find that farmers anticipate increased management costs and believe a further spread of the beetle will lead to at least moderate yield and quality damages for the majority of plots (58-91%). While farmers do not expect to stop grapevine cultivation for the majority of vineyard plots, affected farmers they believe it is likely to very likely for 29% of plots. We also find that affected farmers rate their vines' resilience higher than unaffected farmers do. Using a partial budgeting approach, we find that a Japanese beetle infestation leads on average to a net income decrease of around €2727 per hectare. This decrease is due to an average increase in labor costs of around €1715. Additionally, an average yield reduction that results in a revenue loss of around €966 and additional control costs of around €47 per infested hectare, further contribute to the net income decrease. Even though the small number of observations does not allow us to make conclusions about the beetle's impact on the Italian viticulture sector as a whole, our findings provide first insights and demonstrate the need for environmentally friendly and effective control products that can replace labor-intensive manual control measures, which are currently applied in Japanese beetle infested vineyards.

Reproductive Performance and Partial Budget Analysis of a Prostaglandin or a Modified Ovsynch Protocol in Autumn Calving Dairy Herds

Simple Summary

In autumn calving dairy herds cattle must conceive within a restricted timeframe to maintain the seasonality of calving. Cattle not observed in estrus prior to the mating start date are frequently treated with a single prostaglandin injection even though its relative effectiveness is unknown. The perceived cost of other treatments, such as a modified Ovsynch protocol, may be a reason why they are less favored. This study compares the reproductive and economic outcomes associated with treating cows not observed in estrus prior to breeding with a modified Ovsynch protocol, in comparison to a single prostaglandin injection. The main inputs influencing profitability are identified, and differences in dry-off strategy are considered. From the analyses, cows treated with a modified Ovsynch protocol had a greater likelihood of conception at the beginning of, and throughout, the breeding season. Differences in barren rate and the amount of milk produced were the main variables affecting profitability, the latter strongly influenced by drying-off policy. Farmers and advisors should consider the relative performance of their breeding strategies as well as their own management policies to optimize reproductive and economic performance.

Abstract

In autumn calving dairy herds, treatment of cattle not observed in estrus prior to the breeding season is common. Routinely, a single prostaglandin or a modified Ovsynch (MOFT) protocol are used—without evidence of their relative effectiveness. This study compares the effects on conception, associated timing, and profitability of administering cows with prostaglandin or MOFT treatment. A hundred and ninety-two Holstein-Friesian cows from three herds without an observed estrus within 28-days before mating start date were randomly treated with d-cloprostenol (PGOD) or an 8-day MOFT protocol. The association of treatment and calving-breeding start-date interval (CBSI) on the risk of conception were investigated. Partial budget, sensitivity analysis, and Monte Carlo simulation was used to assess economic performance, identify critical input variables, and explore the effects of input uncertainties on model output. There was a significant association between MOFT treatment and conception during 21 and 84 days after mating start date, compared to PGOD. MOFT treatment was associated with a mean net benefit of £58.21 (sd £19.42) and £27.29 (sd £17.75) per cow for herds with a fixed or variable dry-off date, respectively. The relative profitability of an MOFT protocol is dependent on its effects on barren rate and herd dry-off strategy.

Economic Analysis for Commingling Effects of Insect Activity in the Elevator Boot Area

Boot areas in commercial grain elevators and feed mills contribute to commingling of insects with grain that moves through the elevator leg. A partial budget and stochastic dominance model were developed to improve pest management decision-making and risk analysis assessment from commingling effects of insect activity in the boot area. Modified pilot-scale bucket elevator legs, containing residual wheat or corn, were infested with varying insect pest densities prior to clean grain transfers. Appropriate grain discounts were applied to grain samples obtained from clean grain transfers over either: 1) insect-free and untreated boots, 2) infested and untreated boots, or 3) infested and chemical-treated (β-cyfluthrin) boots. The insect-free boots simulated performing clean-out of the boot area. Partial budget analysis and stochastic dominance modeling indicated that boot sanitation (cleanout) about every 30 d, avoiding costly grain discounts from insect commingling, is the preferred choice. Although chemical spray treatments of the empty boot may reduce insect populations of some boot residual grains, boot cleanout always had lower and usually zero insect pest populations in the boot residual grain, providing higher facility operational net income without the use of chemicals.