β-agonist Regulate Skeletal Actin Gene Expression Post-transcriptionally

Previously reported studies have provided evidence that ractopamine regulates the expression of skeletal α- actin, but the molecular mechanisms underlying these effects are poorly understood. This was the first study to look specifically at the effects of ractopamine on the transcriptional regulation of a contractile protein in myotube cultures. Our model was sufficient to evaluate the anabolic effects of ractopamine in porcine skeletal muscle. However, we were unable to identify a cis-acting DNA element within the cloned porcine skeletal α-actin promoter that conferred transcriptional responsiveness to ractopamine in porcine skeletal muscle. Thus, it appears that ractopamine promotes the accumulation of skeletal α- actin mRNA in porcine skeletal muscle via a posttranscriptional mechanism. Elucidation of the mechanism whereby ractopamine increase skeletal muscle growth will aid in the development of new strategies, both genetic and pharmacological, to improve lean tissue deposition in livestock species

Incidence of Infectious Bovine Keratoconjunctivitis

During 2003 an unusual number of calves showed signs of Infectious Bovine Keratoconjunctivitis (IBK), with 39.6% of the herd infected at the Rhodes Farm. Infectious Bovine Keratoconjunctivitis (IBK), commonly known as pink eye, is a contagious disease caused mostly by the bacteria Moraxella bovis, although other agents have been identified as a cause of IBK. Previous studies have shown that factors such as increased sunlight exposure, dust, tall grasses, and high populations of face flies (Musca autumnalis) facilitate M. bovis infection. Some of the symptoms associated with pink eye are reddening of the eyeball, swelling of the eyelid lining, followed by watery discharges. The study of this bacterial infection is important due to its effects on cattle performance, specifically weight gain. This preliminary analysis of data collected in the summer and fall of 2003 reveals the severity, persistence, and incidence of the disease. The analysis of the data also suggests a heritability (h2 = .180), which is similar to the narrow sense heritability obtained at the USDA Meat Animal Research Center, Clay Center, NE, taking into consideration the small size of our data

Standard Genetic Nomenglature of the Pig, with Glossaries

Genetics includes the study of genotypes, phenotypes and the mechanisms of genetic control between them. Genetic terms describe the processes, genes and traits with which genetic phenomena are described and examined. The genetic process terminologies are thoroughly discussed in the previous chapters. Therefore, in this chapter, we will only list the terms for genetic processes and concepts in Appendix I (a general genetic glossary), and concentrate the discussion on pig gene and trait terminologies (Appendix 10; a glossary for pig diseases and defects is also included (Appendix III)