Effect of pen stabilisation on cleanliness of slaughter cattle

Summary

Prolonged wet weather conditions in Australian feedlots can destabilise pen surfaces and make it difficult for heavy machinery to enter and regularly clean pens. Lime and cement stabilisation was investigated to determine its effectiveness in improving pen foundation.

Winter dominant rainfall combined with soft (clay) pen foundations complicates heavy equipment access to feedlot pens during wet conditions. Depending on the severity of the winter, this may mean conventional equipment such as front-end loaders and skid steers cannot easily access pens for cleaning. Alternatively, when machinery, such as excavators, are brought into muddy pens, the pens are often over excavated, resulting in an increased pen repair cost when dry conditions return.

Two major issues are associated with over excavation of the manure layer, both of which incur economic costs to feedlot operators. The first issue is removal of clay and gravel foundation material, which requires additional labour for pen repair before cattle can be reintroduced. The second issue is the introduction of inorganic (clay and gravel) materials into the manure, which depreciates the potential fertilizer or compost value of the manure.

This project determined that lime and cement stabilisation of newly constructed feedlot pens was not an effective method of improving pen stabilisation.

Objectives

Determine the impact of feedlot pen surface stabilization on:
(1) Cattle cleanliness (dag load) and washing requirements at slaughter
(2) Meat safety
(3) Cattle productivity (carcase weight gains and offal yields)
(4) Meat quality ouputs (colour, pH Decline, dark cutters, marbling, etc)
(5) Animal welfare outputs (Incidence of lameness based on and retrospective analysis of
Emergency Kills and feedlot animal health data)
(6) Animal health outputs ( post mortem animal health data, and feedlot animal health data, etc).
(7) Feedlot costs as:
a. Pen cleaning interval and time
b. Quantity and composition of feedlot manure removed
c. Cost of pen cleaning and pen surface maintenance

Key findings

Cleaning of the pens was conducted four times during the trial, with the final cleaning following an extended wet winter. The final milestone was brought forward and survey of pens was conducted earlier than the proposed date due as the lime/cement stabilisation construction had visually deteriorated.

Results of the surveys report that the stabilised row had more pits in the surface than the control row in comparison to the original surface survey. Analysis of the feedlot and processor data indicated that the control row performed better overall than the stabilised row. Many variables may have influenced the results of the trial, with particular focus on the movement of cattle between trial pens and other feedlot pens which were not assessed, and the different time spent in the trial pens by lots.

It is recommended future research be conducted with greater control over the construction of the pens and the operations in the pens (a smaller scale trial may be easier to manage and reduce variability), and a focus on consistency with data collection between the pens.

Benefits to industry

This project investigated novel ways to stabilize feedlot pens during wet winter feedlot conditions. Although the practice was not successful it has paved the way for further investigation of management practices to ameliorate the effects of wet weather on feedlot cattle production and profitability.

MLA action

Informed by the results of this study, MLA has shifted its focus to determining the value proposition of covered housing and shelter systems that provide protection against both rainfall and heat episodes.

Future research

No further research is planned in cement stabilization of feedlot pens.