The objectives of this project were to see whether heart rate, respiration rate, blood pressure, and vocalization could be used to evaluate stress of castration in pigs. Six groups of pigs 1, 2, 4, 8, 16, and 24 d of age were used in the study, a total of 172 pigs. Half of each group of pigs received lidocaine before castration, injected subcutaneously over the testicle and infiltrated around the cord; the other half were left as controls. Pigs castrated without lidocaine had a higher heart rate (P < .02) and higher frequency of highest energy (HEF) measurements of vocalization (P < .05). Incising the scrotum and severing the spermatic cord elicited the greater heart rate response (P < .05) to castration without anesthetic, whereas HEF was lower during cutting of the cord. Both the heart rate and HEF data suggest that castration without anesthetic is of greater stress for pigs 8 d of age or older. Respiration rate was not a viable measure of stress associated with castration.

No abstract

This work extends our previous observation that the fungus Candida albicans secretes micromolar levels of farnesol and that accumulation of farnesol in vitro prevents the yeast-to-mycelium conversion in a quorumsensing manner. What does farnesol do in vivo? The purpose of this study was to determine the role of farnesol during infection with a well-established mouse model of systemic candidiasis with C. albicans A72 administered by tail vein injection. This question was addressed by altering both endogenous and exogenous farnesol. For endogenous farnesol, we created a knockout mutation in DPP3, the gene encoding a phosphatase which converts farnesyl pyrophosphate to farnesol. This mutant (KWN2) produced six times less farnesol and was ca. 4.2 times less pathogenic than its SN152 parent. The strain with DPP3 reconstituted (KWN4) regained both its farnesol production levels and pathogenicity. These mutants (KWN1 to KWN4) retained their full dimorphic capability. With regard to exogenous farnesol, farnesol was administered either intraperitoneally (i.p.) or orally in the drinking water. Mice receiving C. albicans intravenously and farnesol (20 mM) orally had enhanced mortality (P < 0.03). Similarly, mice (n ‫؍‬ 40) injected with 1.0 ml of 20 mM farnesol i.p. had enhanced mortality (P < 0.03), and the onset of mortality was 30 h sooner than for mice which received a control injection without farnesol. The effect of i.p. farnesol was more pronounced (P < 0.04) when mice were inoculated with a sublethal dose of C. albicans. These mice started to die 4 days earlier, and the percent survival on day 6 postinoculation (p.i.) was five times lower than for mice receiving C. albicans with control i.p. injections. In all experiments, mice administered farnesol alone or Tween 80 alone remained normal throughout a 14-day observation period. Finally, beginning at 12 h p.i., higher numbers of C. albicans cells were detected in kidneys from mice receiving i.p. farnesol than in those from mice receiving control i.p. injections. Thus, reduced endogenous farnesol decreased virulence, while providing exogenous farnesol increased virulence. Taken together, these data suggest that farnesol may play a role in disease pathogenesis, either directly or indirectly, and thus may represent a newly identified virulence factor.Candida albicans is a dimorphic commensal fungus which is localized primarily in the gastrointestinal tract (20). It is a medically important opportunistic pathogen, particularly for immunocompromised individuals (16), and can invade a wide range of organ systems during systemic infections. For healthy, immunocompetent individuals, it is an opportunistic pathogen only. However, Calderone and Gow (6), Navarro-Garcia et al. (33) have detailed the contributions of virulence factors in candidiasis. These virulence factors could either promote Candida invasion or affect host defense mechanisms. It is likely that the virulence of C. albicans is multifactorial. Therefore, pathogenesis is the sum of the attributes of the fungus, ...

Three experiments were conducted to evaluate the effect of different management strategies on body temperature of feedlot steers finished in the summer months. In Exp. 1, 24 crossbred steers were chosen to assess the effect of altered feed intake and feeding time on tympanic temperature (TT) response. Managed feeding (MF) treatments were applied for 22 d only and provided 1) ad libitum access to feed at 0800 (ADLIB), 2) feed at 1600 with amount adjusted so that no feed was available at 0800 (BKMGT), 3) feed at 1600 at 85% of predicted ad libitum levels (LIMFD). During heat stress conditions on d 20 to 22 of MF, LIMFD and BKMGT had lower (P < 0.05) TT than ADLIB from 2100 through 2400. A carryover effect of limit-feeding was evident during a severe heat episode (d 36 to 38) with LIMFD steers having lower (P < 0.05) TT than ADLIB. In Exp. 2, TT were obtained from 24 crossbred steers assigned to three treatments, consisting of no water application (CON), water applied to feedlot mound surfaces from 1000 to 1200 (AM) or 1400 to 1600 (PM). From 2200 to 0900 and 1200 to 1400, steers assigned to morning sprinkling treatment had lower (P < 0.05) TT than steers assigned to afternoon sprinkling treatment. In Exp. 3, 24 steers were utilized in a 2 x 2 factorial arrangement of treatments with factors of feeding time [0800 (AMF) and 1400 (PMF)] and sprinkling (WET and DRY). Tympanic temperatures were monitored under hot environmental conditions on d 30 to 32 and 61 to 62. A feeding time x sprinkling interaction (P < 0.001) was evident on d 30 to 32, although AMF/DRY steers had the highest (P < 0.05) TT. On d 61 to 62, TT of PMF steers was higher (P < 0.05) than AMF between 1500 to 1800. Use of sprinklers can effectively reduce TT of feedlot cattle, whereas shifting to an afternoon vs morning feeding time was most beneficial when bunks were empty several hours prior to feeding.