S. D. Lukefahr

Repeatability of antler characteristics in mature white-tailed deer in South Texas: consequences of environmental effects

Abstract Antler traits are both genetically determined and environmentally influenced. However, the degree to which environmental factors affect antler expression has rarely been quantified. We captured 30 to 150 male white-tailed deer (Odocoileus virginianus) annually at 7 South Texas sites during 1985 to 2009 to determine repeatability of antler traits from a semiarid environment with variable rainfall. Repeatability is defined as the intraclass correlation between repeated measures of the same trait over time. Repeatability was moderate to high (0.42–0.82) for all antler traits. Overall, number of antler points had the lowest repeatability, whereas inside spread of main beams and length of main beams had the highest repeatability. Repeatability of total antler score and number of antler points from sites with variable rainfall was 16% and 24% lower than sites with consistent rainfall, respectively. Sites with variable rainfall had 13–18% higher repeatability when enhanced nutrition was available. Studies of cervids reveal a tendency for lower repeatability of antler traits as the environmental conditions become more variable. The association between repeatability and variable environmental conditions illustrates the magnitude of environmental effects and supports the role of antlers as an honest advertisement of individual condition or quality. Our results help to understand potential of microevolution in antlers and have implications for sexual selection and harvest management.

Limitations of intensive meat rabbit production in North America: A review

This paper documents underlying causes for the poor track record of the commercial meat rabbit industry in North America, relative to the success of several other species (cattle, swine, chickens and turkeys). For over half a century, efforts have been ongoing to develop a viable commercial meat rabbit industry. The progress has not been significant; rather, an accumulation of serious obstacles has targeted the species (e.g., high labor demand, no tradition of rabbit meat consumption, and nutritional limitations and behavioral constraints). Critical biological behaviors associated with the doe rabbit [e.g., short gestation and (or) underdeveloped neonates, cannibalism, territorialism, and pseudo-pregnancy] require that does be permanently placed into individual cages. These behaviors underpin the inability of management to offset labor by employing cost-effective automated feeding and management systems. As a consequence, labor costs per rabbit are high; rabbit meat is generally not competitive with more ...

Optimum Stocking Rate, Monitoring, and Flexibility

On the Ground This case study demonstrates the importance of adaptive management to the resilience of a ranch. With a combination of strategic livestock and grazing management, especially adjusting the stocking rate to variability in forage production, we were able to increase the grazing capacity and the profitability of the ranch, even during drought. The major concern during the drought should not be the productivity or profitability of the ranch, but rather the integrity of the plant communities and the herd in order to re-establish the production cycle following the severe drought. Managing flexible grazing management programs with proper monitoring of weather, forage standing crop, cattle condition, and markets to make informed and timely decisions largely determines the resilience and profitability of the operation.

Optimum Stocking Rate, Monitoring, and Flexibility Key components of successful grazing management programs

On the Ground This case study demonstrates the importance of adaptive management to the resilience of a ranch. With a combination of strategic livestock and grazing management, especially adjusting the stocking rate to variability in forage production, we were able to increase the grazing capacity and the profitability of the ranch, even during drought. The major concern during the drought should not be the productivity or profitability of the ranch, but rather the integrity of the plant communities and the herd in order to re-establish the production cycle following the severe drought. Managing flexible grazing management programs with proper monitoring of weather, forage standing crop, cattle condition, and markets to make informed and timely decisions largely determines the resilience and profitability of the operation.

Strategic Grazing Management for Complex Creative SystemsOptimum Stocking Rate, Monitoring, and Flexibility: Key components of successful grazing management programs

On the Ground This case study demonstrates the importance of adaptive management to the resilience of a ranch. With a combination of strategic livestock and grazing management, especially adjusting the stocking rate to variability in forage production, we were able to increase the grazing capacity and the profitability of the ranch, even during drought. The major concern during the drought should not be the productivity or profitability of the ranch, but rather the integrity of the plant communities and the herd in order to re-establish the production cycle following the severe drought. Managing flexible grazing management programs with proper monitoring of weather, forage standing crop, cattle condition, and markets to make informed and timely decisions largely determines the resilience and profitability of the operation.