Life Sciences Commons^™

Kisspeptin Receptor Agonist (Ftm080) Increased Plasma Concentrations Of Luteinizing Hormone In Anestrous Ewes, Brian K. Whitlock, Kelly A. Chameroy, Rebecca R. Payton, Shinya Oishi, Nobutaka Fujii, Joseph A. Daniel

Brian K Whitlock, PhD, DVM, DACT

Kisspeptin (KP) and the KP receptor (Kiss1r) are integral to central regulation of the gonadotropic-axis. The demonstration that intravenous infusion of KP can stimulate gonadotropin secretion and ovulation in seasonally anestrous female sheep offers a means of manipulating the reproductive axis. However, KP may be of limited clinical use because of the short circulating half-life. Kiss1r agonists with increased half-life and similar efficacy to KP in vitro potentially may provide beneficial applications in breeding management of many species. However, many of these agonists have not been tested in vivo. This study was designed to test and compare the effects of …

Effect Of Meloxicam On Gain And Inflammatory Response Of Calves Castrated By Banding Post-Weaning, Brian K. Whitlock, Peter D. Krawczel, Jeff A. Carroll, Nicole C. Burdick Sanchez, Jeff W. Dailey, Joseph A. Daniel, Johann F. Coetzee

Brian K Whitlock, PhD, DVM, DACT

Castration may detrimentally affect the health and performance of weaned calves, and painful procedures are increasingly becoming a public concern. The objective of this study was to determine the effects of castration (by banding) with or without administration of meloxicam, a non-steroid anti-inflammatory, on performance and inflammatory response in weaned beef calves. Forty-eight (weaned) beef calves [10.0±0.2 mo old; 304±6 kg BW] were blocked by age, BW, wither height, scrotal circumference, and source, then randomly assigned to 1 of 3 treatments (n=16 calves per treatment: 1) intact bulls (BULL), 2) castration by banding (BAN), or 3) castration by banding with …

Effect Of Meloxicam On Gain And Behavior Of Calves Castrated By Banding Pre-Weaning, Joseph A. Daniel, Peter D. Krawczel, Brian K. Whitlock

Brian K Whitlock, PhD, DVM, DACT

The objective was to determine if oral meloxicam (M; a non-steroid anti-inflammatory) administered at castration of pre-weaning calves affected ADG or behavior. Prior to castration (14 d), Angus bulls were assigned to bull (BULL; n = 7; age 106 ± 6 d; BW = 174.2 ±7.7 kg; scrotal circumference 17.7 ± 0.4 cm), castrated (BAN; n = 12; age = 105 ± 5 d; BW = 144.5 ± 7.6 kg; scrotal circumference = 16 ± 0.4 cm) or castrated with meloxicam (BAN+M; n = 13; age = 121 ± 6 d; BW = 145.8 ± 6 kg; scrotal circumference = …

Meloxicam Mediates Short-Term Behavioral Changes Of Castrated Calves, Peter D. Krawczel, Jeff A. Carroll, Nicole C. Burdick Sanchez, Jeff W. Dailey, Joseph A. Daniel, Johann F. Coetzee, Brian K. Whitlock

Brian K Whitlock, PhD, DVM, DACT

Castration may detrimentally affect the health and performance of weaned calves and painful procedures are increasingly a public concern. Therefore, practical pain mitigation is critical. The objective was to determine the effects of castration (by banding) with or without administration of NSAID, meloxicam, on the behavior of weaned beef calves. Forty-eight (56 d post-weaning) beef calves [10.0 ± 0.2 (mean ± SE) mo old; 304 ± 6 kg BW] were blocked by multiple factors then randomly assigned to 3 treatments (n = 16 calves per treatment: 1) intact bulls (BULL), 2) castration by banding (BAN), or 3) castration by banding …

Divergence In Thyroid Hormone Concentrations Between Juveniles Of Marine And Stream Ecotypes Of The Threespine Stickleback (Gasterosteus Aculeatus), Jun Kitano, Sean C. Lema

Sean Lema

Background: Hormones regulate the expression of multiple phenotypic traits. Therefore,

divergence in hormone concentrations may lead to evolutionary changes in the coordinated

physiological and behavioural traits that comprise an organism’s integrated phenotype. Adults

of marine ecotypes of threespine stickleback (Gasterosteus aculeatus) have higher concentrations

of the thyroid hormone thyroxine (T4) than adults of stream-resident ecotypes (Kitano

et al., 2010). Thyroid hormones are well-established mediators of osmoregulation and migratory

behaviours in fish, and the difference in T4 concentrations indicates that changes in thyroid

hormone signalling may underlie the evolutionary and ecological divergence of migratory and

non-migratory ecotypes.

Questions: Is the variation …

Hormones And Phenotypic Plasticity: Implications For The Evolution Of Integrated Adaptive Phenotypes, Sean C. Lema, Jun Kitano

Sean Lema

It is generally accepted that taxa exhibit genetic variation in phenotypic plasticity, but many questions remain unanswered about how divergent plastic responses evolve under dissimilar ecological conditions. Hormones are signaling molecules that act as proximate mediators of phenotype expression by regulating a variety of cellular, physiological, and behavioral responses. Hormones not only change cellular and physiological states but also influence gene expression directly or indirectly, thereby linking environmental conditions to phenotypic development. Studying how hormonal pathways respond to environmental variation and how those responses differ between individuals, populations, and species can expand our understanding of the evolution of phenotypic plasticity. …