A. Comin

Short communication:Hair cortisol concentrations in Holstein Friesian and Crossbreed F1 heifers.

The aim of this study was to evaluate the hypothalamic-pituitary-adrenal (HPA) axis activity of Holstein-Friesian and crossbreed F1 heifers by analysis of the cortisol concentrations in hair samples. Cortisol, the primary hormone of the HPA axis, is the biological endpoint for the investigation of the HPA response. The study was conducted on 290 prepubertal heifers; 142 heifers were pure Holstein-Friesian and 148 were crossbreed F1 heifers obtained from the 3-way rotational system with Swedish Red and Montbéliarde breeds. Extraction was performed on the hair using methanol, and cortisol concentrations were determined by a radioimmunoassay method. Cortisol concentrations measured in regrown hair of crossbreed F1 heifers were significantly lower than those in hair of Holstein-Friesian heifers. This result helps us to better understand the differences in HPA activity and allostatic load between Holstein-Friesian and crossbreed F1 heifers and allows us to better assess the adaptability of these animals to the environment and the importance of crossbreed traits for profitability in dairy farming.

Reducing treatments in cattle superovulation protocols by combining a pituitary extract with a 5% hyaluronan solution: Is it able to diminish activation of the hypothalamic pituitary adrenal axis compared to the traditional protocol?

Traditional superovulation protocols that include multiple gonadotropin treatments are time-consuming and labor intensive. These protocols require multiple handling and restraining of embryo donors. This will likely increase the risks of injuries in both animals and humans and induce stress that may lead to a reduced superovulatory response. These are more evident when working with cattle that are rarely handled or raised on extensive grazing. The objectives of this experiment were to compare the efficacy of a split-injection protocol of porcine pituitary-derived porcine FSH (pFSH) preparation (slow release [SR] group) to the traditional 4-day treatment with pFSH administered twice daily (C group) and to determine the concentrations of cortisol in the hair as a marker of activation of the hypothalamic-pituitary-adrenal (HPA) axis during the two superovulatory treatments. Thirty-two heifers were stimulated twice in a 2 × 2 crossover design and compared for ovarian response and numbers and characteristics of recovered ova-embryo among treatments. No differences between SR and C groups were found in terms of percentage of responsive animals (100% vs. 93.8%) and ovulation rate (83.7 ± 1.1 vs. 79.5 ± 1.0%). A positive correlation was found between the number of follicles responsive to pFSH (2-8 mm) at the beginning of treatments and the superovulatory response, and no differences were found in these follicular populations between the two treatment groups. The numbers of CLs, ova-embryos, fertilized ova, transferable and freezable embryos recovered per cow were found to be significantly higher in SR compared with C group (14.0 ± 1.6 vs. 10.6 ± 1.0, 12.1 ± 1.6 vs. 7.6 ± 1.0, 11.1 ± 1.1 vs. 7.3 ± 1.0, 9.6 ± 1.4 vs. 6.6 ± 1.0, and 9.4 ± 1.4 vs. 6.0 ± 1.0 for SR and C group, respectively). The SR group produced also a significantly greater number of excellent- and/or good-quality embryos compared with the C group. The concentrations of cortisol in the hair at Days 14 and 21 were significantly greater in the C compared with the SR group (P < 0.05). In conclusion, these results indicate that the dilution of gonadotropin in a 0.5% hyaluronan solution, reducing the administration frequency, improves the quantitative and qualitative superovulatory response of Marchigiana heifers [corrected]. Further studies using other breeds of cattle are needed to verify the results herein obtained and to confirm the lower activation of the hypothalamic-pituitary-adrenal axis caused in the donor by the split-injection protocol.

Experimental indicators of ergonomic wellness and quality of life: salivary and hair cortisol

P. L. Esposito, A. Comin, T. Peric, M. Montillo, M. Mascolo, G. Tubaro and A. Prandi SPRINT, University of Udine, via Petracco 8, 33100 Udine, Italy Department of Food Science, University of Udine, via Sondrio 2, 33100 Udine, Italy Department of Neurology, Hospital of San Giorgio, via Gemelli 10, 33170 Pordenone, Italy Department of Civil Engineering and Architecture, University of Udine, via delle Scienze 206, 33100 Udine, Italy

Hair cortisol and testosterone concentrations and semen production of Bos taurus bulls

Abstract The experiment was aimed to evaluate the usefulness of hair cortisol concentrations (HCC) in revealing the activation of the hypothalamic-pituitary-adrenal (HPA) axis due to the passage of young bulls from genetic rearing stations to artificial insemination (AI) centre and the influence of this passage on hair testosterone concentrations (HTC). Hair samples on 33 yearling bulls were collected at the time of arrival (ST1) to the AI centre and 3 more hair samples (ST2, ST3, ST4) were collected at monthly intervals. After the end of quarantine each animal was submitted to the standard procedures for collection and production of semen. Overall HCC were significantly affected by period of collection (p < .01). In particular, HCC was higher in samples obtained after finishing the quarantine period (ST2) compared with those obtained on ST1. After ST2, the HCC decreased reaching at ST4 a value similar to that recorded at ST1. An effect of sampling time on HTC was not found (p > .05). The effect of breed was observed only for HTC that was higher in PRI than BS (p < .01). The HCC group have not influenced the semen variables (p > .05). On the contrary, the effect of breed was evident. The results of this study replicated the effects of a major environmental stressor on mean cortisol concentrations assessed in hair, and add to the growing body of evidence that HCC is an effective and simply collected marker for long-term activity of the HPA system in response to persistent environmental challenge.

Hair cortisol concentrations in New Zealand white rabbits subjected to surgery

The aim of this study was to assess hair cortisol concentrations in New Zealand white rabbits (Oryctolagus cuniculus) that were subjected to relocation and surgery to evaluate HPA-axis activity; in addition, we used this marker of cortisol secretion to evaluate the allostatic load of animals undergoing surgery. After a period of acclimatisation, which lasted 40 days from their arrival at the enclosure, 19 rabbits were subjected to T1–T12 dorsal arthrodesis (RS), 19 were sham-operated (SS), and 19 were non-operated (CON). Hair samples were collected at the time of arrival (ST1) at the animal facility, and seven other sets of hair samples were collected at 40day intervals from the same area of skin for a period of 240 days as re-shaved hair (anagen phase): immediately before surgery (ST2) and after the surgery (ST3, ST4, ST5, ST6, ST7, and ST8). The transition from the rabbitry to the animal breeding facility led to a significant increase in cortisol concentration (ST2) in all of the groups. At ST3, the RS group presented higher cortisol concentrations than those of the SS group and the CON group. At ST4, the experimental groups showed similar values that remained constant until ST8. The results show that the management of rabbits undergoing surgery should be evaluated very carefully, and hair cortisol concentrations may provide a means of avoiding the dangerous cumulative effects of additional stressors close to surgery.