Endocrine and Ovarian Changes in Response to the Ram Effect in Medroxyprogesterone Acetate-primed Corriedale Ewes During the Breeding and Nonbreeding Season

Two experiments were performed to determine the endocrine and ovarian changes in medroxyprogesterone acetate (MAP)-primed ewes after ram introduction. Experiment 1 was performed during the mid-breeding season with 71 ewes primed with an intravaginal MAP sponge for 12 days. While the control (C) ewes (n = 35) were in permanent contact with rams, the ram effect (RE) ewes (n = 36) were isolated for 34 days prior to contact with rams. At sponge withdrawal, all ewes were joined with eight sexually experienced marking Corriedale rams and estrus was recorded over the next 4 days. The ovaries were observed by laparoscopy 4–6 days after estrus. Four weeks later, pregnancy was determined by transrectal ultrasonography. In eight ewes from each group, ovaries were ultrasonographically scanned; FSH, LH, and estradiol-17β were measured every 12 hours until ovulation or 96 hours after estrus. The response to the rams was not affected by the fact that ewes had been kept or not in close contact with males before teasing. No differences were found in FSH, LH, estradiol-17β concentrations, growth of the ovulatory follicle, onset of estrus, ovulation rate, or pregnancy rate. Experiment 2 was performed with 14 ewes during the nonbreeding season. Ewes were isolated from rams for 1 month, and received a 6-day MAP priming. Ovaries were ultrasonographically scanned every 12 hours, and FSH, LH, estradiol-17β, and progesterone were measured. Ewes that ovulated and came into estrus had higher FSH and estradiol-17β levels before introduction of the rams than did ewes that had a silent ovulation. The endocrine pattern of the induced follicular phase of ewes that came into estrus was more similar to a normal follicular phase, than in ewes that had a silent ovulation. The follicle that finally ovulated tended to emerge earlier and in a more synchronized fashion in those ewes that did come into estrus. All ewes that ovulated had an LH surge and reached higher maximum FSH levels than ewes that did not ovulate, none of which had an LH surge. We conclude that (a) the effect of ram introduction in cyclic ewes treated with MAP may vary depending on the time of the breeding season at which teasing is performed; (b) patterns of FSH, and estradiol-17β concentrations, as indicators of activity of the reproductive axis, may be used to classify depth of anestrus; and (c) the endocrine pattern of the induced follicular phase, which is related to the depth of anestrus, may be reflected in the behavioral responses to MAP priming and the ram effect

Acoustic characteristics of vocalisations emitted by the domestic rabbit (Oryctolagus cuniculus) during copula ejaculation and electro-ejaculation with or without anaesthesia

[EN] Vocalisations can be used as reliable indicators of pain, but little information is available in rabbits, where acoustic tools for farming environments can be used for welfare judgements. The aim of this study was to compare vocalisations produced during copula ejaculation and electro-ejaculation (EE), with or without general anaesthesia, in domestic rabbits. Vocalisations of nine New Zealand white adult males were digitally recorded. The number of males vocalising and vocal characteristics including high, low, maximum and fundamental frequencies and duration of the vocalisations were analysed. There were no differences in the number of males vocalising or any vocalisation parameter between the 1st and 2nd ejaculation while copulating, even though the fundamental frequency increased in all males in the 2nd ejaculation (P=0.008). More males vocalised while mating than while being electro-ejaculated (P=0.03), and all vocalisation parameters were greater during EE than while mating (P=0.004). The use or not of anaesthesia during EE did not modify any of the parameters evaluated. It was concluded that: 1) more males vocalised during copula ejaculation than while being electro-ejaculated; 2) bio-acoustic analysis allowed us to identify aversive utterance vocalisations, which are characterised with higher frequencies, that those from non-aversive stimulus; and 3) at least with the anaesthetic combination and the responses studied, anaesthesia had no effect on the acoustic characteristics of the vocalisation emitted during EE in rabbits.Orihuela, A.; Ungerfeld, R. (2019). Acoustic characteristics of vocalisations emitted by the domestic rabbit (Oryctolagus cuniculus) during copula ejaculation and electro-ejaculation with or without anaesthesia. World Rabbit Science. 27(3):157-162. https://doi.org/10.4995/wrs.2019.10809SWORD157162273Abril-Sánchez S., Freitas-de-Melo A., Damián, J.P., Giriboni J., Villagrá-García A., Ungerfeld R. 2017. Ejaculation does not contribute to the stress response to electroejaculation in sheep. Reprod. Domest. Anim., 52: 403-408. https://doi.org/10.1111/rda.12922Abril-Sánchez S., Crosignani N., Freitas-de-Melo A., Terrazas A., Damián J.P., Beracochea R., Silveira P., Ungerfeld R. 2018. Sedation or anaesthesia decrease the stress response to eletroejacuation and improve the quality of the collected semen in goat bucks. Animal, 12: 2598-2608. https://doi.org/10.1017/s1751731118000320Aguirre F.V., Vázquez R.R., Hallal C.C., Orihuela A., Flores S.M., Flores P.I. 2015. Stress induced by electro-ejaculation in domestic rabbits. XXIV Congress of the Latin American Association of Animal Production. November 9-13. Puerto Varas, Chile. pp. 271.Cools R., Roberts A.C., Robbins T.W. 2008. Serotoninergic regulation of emotional and behavioural control processes. Trends Cogn. Sci., 12: 31-40. https://doi.org/10.1016/j.tics.2007.10.011da Silva Cordeiro A., Näs I.D., Oliveira S., Violaro F., Almeida A.D., Neves D. 2013. Understanding vocalization might help to assess stressful conditions in piglets. Animals, 3: 923-934. https://doi.org/10.3390/ani3030923Damián J.P., Ungerfeld R. 2011. The stress response of frequently electroejaculated rams to electroejaculation: hormonal, physiological, biochemical, haematological and behavioural parameters. Reprod. Domest. Anim., 46: 646-650. https://doi.org/10.1111/j.1439-0531.2010.01722.xDamián J.P., Ungerfeld R. 2010. Vocalizations are reliable indicators of pain during electroejaculation in rams. In Proc.: 44th Congress of the International Society for Applied Ethology, 4-7, August, Uppsala, Sweden, pp.184.Dawkins M.S. 1998. Evolution and animal welfare. Q. Rev. Biol., 73: 305-328.Donovan J., Brown P. 1998. Anesthesia. Curr. Protoc. Immunol., 27: 141-145.Fumagalli F., Damián J.P., Ungerfeld R. 2015. Vocalizations during electroejaculation in anaesthetized adult and young Pampas Deer (Ozotoceros bezoarticus) males. Reprod. Domest. Anim., 50: 321-326. https://doi.org/10.1111/rda.12494Giuliano F., Allard J. 2001. Dopamine and Male Sexual Function. Eur. Urol., 40: 601-608. https://doi.org/10.1159/000049844Hull E.M., Muschamp J.W., Sato S. 2004. Dopamine and serotonin: influences on male sexual behavior. Physiol. Behav., 83: 291-307. https://doi.org/10.1016/s0031-9384(04)00357-9Jürgens U. 1979. Vocalization as an emotional indicator a Neuroethological Study in the Squirrel Monkey. Behaviour, 69: 88-117.Manteuffel G., Puppe B., Schön P.C. 2004. Vocalization of farm animals as a measure of welfare. Appl. Anim. Behav. Sci., 88: 163-182. https://doi.org/10.1016/j.applanim.2004.02.012Morton E.S. 1977. On the occurrence and significance of motivation-structural rules in some birds and mammals sound. Am. Nat., 111: 855-869. https://doi.org/10.1086/283219Ohl, D.A., 1993. Electroejaculation. Urol. Clin. North Am., 20: 181-188.Orihuela A., Aguirre V., Hernández C., Flores-Pérez I., Vázquez R. 2009a. Effect of Anesthesia on Welfare Aspects of Hair Sheep (Ovis aries) During Electro-Ejaculation. J. Anim. Vet. Adv., 8: 305-308.Orihuela A., Aguirre V., Hernández C., Flores-Pérez I., Vázquez R. 2009b. Ejaculation on the Serum Cortisol Response, Heart and Respiratory Rates in Hair Sheep (Ovis aries). J. Anim. Vet. Adv., 8: 1968-1972.Seyfart R.M., Cheney D.L. 2003. Meaning and emotion in animal vocalizations. Annals of the New York Academy of Sciences 1000: 32-55.Watts J.M., Stookey J.M. 1999. Effects of restraint and branding on rates and acoustic parameters of vocalization in beef cattle. Appl. Anim. Sci., 62: 125-135. https://doi.org/10.1016/s0168-1591(98)00222-6Watts J.M., Stookey J.M. 2000. Vocal behaviour in cattle: the animal's commentary on its biological processes and welfare. Appl. Anim. Behav. Sci., 67: 15-33. https://doi.org/10.1016/s0168-1591(99)00108-2White R.G., DeShazer J.A., Tressler C.J., Borcher G.M., Davey S., Waninge A., Parkhurst A.M., Milanuk M.J., Clemens E.T. 1995. Vocalization and physiological response of pigs during castration with or without a local anesthetic. J. Anim. Sci., 73: 381-386. https://doi.org/10.2527/1995.732381

Perspective of research on ovine reproduction in Latin America within the framework of the present productive tendencies

World sheep production is undergoing important changes. In Latin America –and mainly due to decrements in international wool prices– ovine population declined and other sheep products are either appearing or increasing in importance. “Specialties” rather than “commodities” increasingly dominate markets. Productive systems have to adapt to this new reality. That is to say, processed meat or dairy products, rather than simple mutton production, is the prevailing trend. Latin-American research in ovine reproduction has improved both quantitatively and qualitatively since the end of the 80´s, but regional coordination on research policies does not exist. Approximately 10% of the indexed scientific articles dealing with ovine reproduction during the 90´s came from Latin America. According to new productive needs, we propose to priorize research on the following topics: mating period control, in such a way that lamb production becomes independent from seasons; increase in prolificacy; factors determining early embryo viability; postpartum management; semen freezing and improving both intra-uterine insemination and embryo transfer techniques

Antler velvet is thicker in adult than in yearling pampas deer (Ozotoceros bezoarticus): a histological study

Background: Antlers are lined by soft velvet tissue during antler growth. Later, the velvet is shed before rut onset. There are no detailed histological descriptions of the growing velvet, nor whether the velvet changes according to stag age. Our aims were to: 1) describe the basic histology of pampas deer antler velvet from adult and yearling males; and 2) determine the influence of age and time of antler growth on velvet’s tissues morphometry. Materials and methods: Samples were collected from 10 stags allocated in two groups, either adult (3–5 years old, n = 5) or yearling males (2 years old, n = 5). The day of antler cast was recorded for each animal. In spring, the stags were anaesthetised and velvet samples were collected from the third tine’s distal end. Samples were described qualitatively and a restricted morphometrical analysis of the antler velvet was performed. Results: The number of keratinocyte layers and the thicknesses of: total epidermis, corneum, intermediate and basale epidermal strata, total dermis, superficial and deep dermis were determined. Age and days after antler casting positively influenced in conjunction epidermal thickness (p = 0.037), and tended to influence both stratum intermedium (p = 0.076) and stratum corneum (p = 0.1) thicknesses. Age influenced stratum corneum thickness (p = 0.04). The pampas deer antler velvet lacked both sweat glands and arrector pili muscles. Conclusions: The deep dermis was densely irrigated but displayed abundant and well developed collagen bundles. Both total epidermal and stratum corneum thicknesses related positively to the age of the animals but were not to the time since antler cast.

Short oestrous cycles in sheep during anoestrus involve defects in progesterone biosynthesis and luteal neovascularisation

Anoestrous ewes can be induced to ovulate by the socio-sexual, 'ram effect'. However, in some ewes the induced ovulation is followed by an abnormally short luteal phase causing a so called, "short cycle". The defect responsible for this luteal dysfunction has not been identified. In this experiment we investigated ovarian and uterine factors implicated in male-induced short cycles in anoestrus ewes using a combined endocrine and molecular strategy. Prior to ovulation, we were able to detect a moderate loss of thecal expression of steroid acute regulatory protein (STAR) in ewes that had not received progesterone priming (which prevents short cycles). At and following ovulation we were able to identify significant loss of expression of genes coding key proteins involved in the biosynthesis of progesterone (STAR, CYP11A1, HSD3B) as well as genes coding proteins critical for vascular development during early luteal development (VEGFA, VEGFR2) suggesting dysfunction in at least two pathways critical for normal luteal function. Furthermore, these changes were associated with a significant reduction of progesterone production and luteal weight. Additionally, we cast doubt on the proposed uterine-mediated effect of prostaglandin F2α as a cause of short cycles by demonstrating both the dysregulation of luteal expression of the PGF receptor, which mediates the luteal effects of PGF2α, and by finding no significant changes in the circulating concentrations of PGFM, the principal metabolite of PGF2α in ewes with short cycles. This study is the first of its kind to examine concurrently, the endocrine and molecular events in the follicular and early luteal stages of the short cycle

Forage allowances offered to pregnant ewes until middle and late gestation: Organ priorities on foetus development

Effect of forage allowance before conception and until mid or late gestation was evaluated for effects on foetal and neonatal weights, carcass, nervous systems, metabolic and reproductive organ weights, body dimensions, and variation in intensity of the effects among organs. Effects of two forage allowances, HFA: high forage allowance (2.9 - 3.8 kg of dry matter (DM)/kg bodyweight (BW)) and LFA: low forage allowance (1.4 - 2.6 kg DM/kg BW) were evaluated from 23 days before conception until 70 or 122 days postpartum. On gestation day 70, nine ewes per treatment, each carrying one male foetus, were euthanized and their foetuses were removed. The foetuses were weighed, their carcass and organ weights were recorded, and their external genitalia dimensions were measured. Nine additional lambs per treatment were euthanized 12 hours after birth and the same data were recorded. Hearts from day 70 LFA foetuses were lighter, their external genitalia were smaller, and their foetal weight tended to be less than in HFA. Newborn lambs from LFA ewes had lighter carcasses, livers, kidneys, adrenal glands and testes, shorter penises, but higher brain to liver weight ratios than in HFA. The cerebellum, brain, and heart weights of LFA and HFA newborn lambs did not differ. Low forage allowance until late gestation influenced both foetal and lamb weights and affected organ weights differentially. Thus, the treatments induced differences in prioritization of nutrients, with the central nervous system receiving the highest priority, and carcass and external genitalia the lowest. Keywords: foetal programming, intrauterine growth restriction, lambs, undernutritio

Evaluating the effect of phenolic compounds as hydrogen acceptors when ruminal methanogenesis is inhibited in vitro – Part 1. Dairy cows

Some antimethanogenic feed additives for ruminants promote rumen dihydrogen (H2) accumulation potentially affecting the optimal fermentation of diets. We hypothesised that combining an H2 acceptor with a methanogenesis inhibitor can decrease rumen H2 build-up and improve the production of metabolites that can be useful for the host ruminant. We performed three in vitro incubation experiments using rumen fluid from lactating Holstein cows: Experiment 1 examined the effect of phenolic compounds (phenol, catechol, resorcinol, hydroquinone, pyrogallol, phloroglucinol, and gallic acid) at 0, 2, 4, and 6 mM on ruminal fermentation for 24 h; Experiment 2 examined the combined effect of each phenolic compound from Experiment 1 at 6 mM with two different methanogenesis inhibitors (Asparagopsis taxiformis or 2-bromoethanesulfonate (BES)) for 24 h incubation; Experiment 3 examined the effect of a selected phenolic compound, phloroglucinol, with or without BES over a longer term using sequential incubations for seven days. Results from Experiment 1 showed that phenolic compounds, independently of the dose, did not negatively affect rumen fermentation, whereas results from Experiment 2 showed that phenolic compounds did not decrease H2 accumulation or modify CH4 production when methanogenesis was decreased by up to 75% by inhibitors. In Experiment 3, after three sequential incubations, phloroglucinol combined with BES decreased H2 accumulation by 72% and further inhibited CH4 production, compared to BES alone. Interestingly, supplementation with phloroglucinol (alone or in combination with the CH4 inhibitor) decreased CH4 production by 99% and the abundance of methanogenic archaea, with just a nominal increase in H2 accumulation. Supplementation of phloroglucinol also increased total volatile fatty acid (VFA), acetate, butyrate, and total gas production, and decreased ammonia concentration. This study indicates that some phenolic compounds, particularly phloroglucinol, which are naturally found in plants, could improve VFA production, decrease H2 accumulation and synergistically decrease CH4 production in the presence of antimethanogenic compounds

The "Ram Effect": A "Non-Classical" Mechanism for Inducing LH Surges in Sheep

During spring sheep do not normally ovulate but exposure to a ram can induce ovulation. In some ewes an LH surge is induced immediately after exposure to a ram thus raising questions about the control of this precocious LH surge. Our first aim was to determine the plasma concentrations of oestradiol (E2) E2 in anoestrous ewes before and after the "ram effect" in ewes that had a "precocious" LH surge (starting within 6 hours), a "normal" surge (between 6 and 28h) and "late» surge (not detected by 56h). In another experiment we tested if a small increase in circulating E2 could induce an LH surge in anoestrus ewes. The concentration of E2 significantly was not different at the time of ram introduction among ewes with the three types of LH surge. "Precocious" LH surges were not preceded by a large increase in E2 unlike "normal" surges and small elevations of circulating E2 alone were unable to induce LH surges. These results show that the "precocious" LH surge was not the result of E2 positive feedback. Our second aim was to test if noradrenaline (NA) is involved in the LH response to the "ram effect". Using double labelling for Fos and tyrosine hydroxylase (TH) we showed that exposure of anoestrous ewes to a ram induced a higher density of cells positive for both in the A1 nucleus and the Locus Coeruleus complex compared to unstimulated controls. Finally, the administration by retrodialysis into the preoptic area, of NA increased the proportion of ewes with an LH response to ram odor whereas treatment with the α1 antagonist Prazosin decreased the LH pulse frequency and amplitude induced by a sexually active ram. Collectively these results suggest that in anoestrous ewes NA is involved in ram-induced LH secretion as observed in other induced ovulators

Use of meloxicam with or without dipyrone in non-surgical embryo recovery in hair sheep: Effects on animal welfare.

Abstract: The aim of this study was to determine the effectiveness of meloxicam with or without dipyrone on the welfare of ewes subjected to non-surgical embryo recovery (NSER). Two studies were carried out using 51 multiparous Santa Inês ewes. All animals received a standard oestrous synchronization treatment and a superovulatory protocol. In Study 1, 12 ewes received meloxicam (GM) before cervical transposition (1 mg kg-1 , i.v.), repeated 24 h after (1 mg kg-1 , i.m.), while the other 10 received a saline solution, remaining as a control group (GC1). In Study 2, ewes were allocated into a group of 15 ewes treated as GM of Study 1 associated with dipyrone (GMD; 50 mg kg-1 , i.m.) before cervical transposition, 12 h, and 24 h after, or a control group (GC2) of 14 ewes treated with saline solution. In both studies, heart and respiratory rates (RR), cortisol, glucose, total proteins, albumin and globulins blood concentration were recorded before sedation (BS), after sedation (AS), after cervical transposition, immediately after collection (IAC), and 0.5, 1.5, 3, 6, 12, 24 and 48 h after embryo collection (hAC). In Study 1, RR tended to be greater in GC1 (p = .08), serum total proteins and globulins values were lower and serum albumin values were greater in this group than GM (p = .003, p < .0001, and p < .0001, respectively). In Study 2, treatment of GMD tended to reduce the glycaemia at AS (p = .052) and reduced it at 3hAC (p < .0001), and 6hAC (p = .03). It also tended to reduce cortisol concentrations (p = .10). The other variables varied with NSER without interaction with the experimental treatments. In conclusion, in this study condition, NSER in sheep induced transient changes indicative of stress and possibly pain, therefore, affecting animal welfare. The administration of meloxicam was ineffective to reduce those responses, and the association of dipyrone had only slight effects without modifying the main welfare indicative responses in ewes subjected to NSER