Domestic animal endocrinology最新文献

The present study investigated the effect of a single administration of long-acting follicle simulation hormone (FSH) on testicular blood perfusion as measured by pulsed-wave Doppler ultrasonography, testicular echotexture, and circulating testosterone (T), estradiol (E2), and nitric oxide (NO) in the plasma of rams in the non-breeding season. Twelve Ossimi rams were subjected to either a single administration of long-acting FSH subcutaneously (FSH group; n = 6) or the vehicle (control group; n = 6). Assessment of testicular hemodynamics at the level of the supratesticular artery was performed just before administration (0 h), and at 4, 24, 48, 72, 96, and 168 h after FSH or the vehicle administrations. Testicular volume (TV), and echotexture of testicular parenchyma including pixel intensity and heterogeneity were derived by the computer analysis software. Concentrations of T, E2, and NO were measured using commercial kits. Results revealed significant decreases (P ˂ 0.05) in the values of Doppler indices (resistive index: RI and pulsatility index: PI), especially at 48 h after administration of FSH (RI: 0.42 ± 0.02, PI: 0.56 ± 0.04) compared to their values in the control group (RI: 0.54 ± 0.03, PI: 0.77 ± 0.04). FSH administration induced significant decreases (P ˂ 0.05) in the pixel intensity of testicular parenchyma. Testicular volume and T concentrations were not significantly changed (P ˃ 0.05). Concentrations of E2 increased significantly (P ˂ 0.05) at 48 h and 72 h after FSH administration. (30.07 ± 5.23 pg/ml, 29.93 ± 1.44 pg/ml, respectively) compared to their values before FSH administration (14.63 ± 1.37 pg/ml). Concentrations of NO increased significantly (P ˂ 0.05) in the FSH group between 4 h to 48 h compared to the values in the control one. In conclusion, a single administration of long-acting FSH enhanced testicular blood perfusion as measured by pulsed Doppler ultrasonography in rams during the non-breeding season. Concurrently, significant increases in the concentrations of E2 and NO were found.

Stress is a state of disturbed homeostasis evoking a multiplicity of somatic and mental adaptive reactions resulting from any of the 5 freedoms of animals being violated. Many environmental forces disrupt homeostasis in farm animals, such as extreme temperatures, poor nutrition, noise, hunger, and thirst. During stressful situations, neuronal circuits in the limbic system and prefrontal cortex are activated, which lead to the release of adrenalin and noradrenalin. The hormones released during stress are needed for adaptation to acute stress and are regulated by many genes. This review examined molecular regulation, breed differences, and genes involved in stress control in farm animals. Major molecular regulation of stress, such as oxidative, cytosolic heat shock, unfolded protein, and hypoxic responses, were discussed. The responses of various poultry, ruminant, and pig breeds to different stress types were also discussed. Gene expressions and polymorphisms in the neuroendocrine and neurotransmitter pathways were also elucidated. The information obtained from this review will help farmers mitigate stress in farm animals through appropriate breed and gene-assisted selection. Also, information obtained from this review will add to the field of stress genetics since stress is a serious welfare issue in farm animals.

Studies have shown that ghrelin played direct actions in ovarian function, but the direct role of ghrelin in corpus luteum (CL) of pregnant sows has remained obscure. The study aimed to examine the expressions of ghrelin and its functional receptor (GHSR-1a) in the CL of sows during pregnancy, and evaluate the role of ghrelin in CL function of pregnant sows. Immunohistochemistry analysis showed that ghrelin and GHSR-1a are both predominantly localized in the luteal cells of pregnant sows CL. Strong immunoreactivity for ghrelin and GHSR-1a is detected at days 20 (early) and 50 (middle), but weak immunoreactivity is observed at days 90 (late) post mating. Similarly, there is a significant effect of pregnant phase on the expression (mRNA and protein) of ghrelin and GHSR-1a in the CL, with higher levels at days 20 (early) and 50 (middle), and lower values at 90 (late) post mating. In vitro, treatments of luteal cells with ghrelin (from 0.01 to 10 ng/mL) are promoted cell viability and P4 secretion in a dose-dependent manner. Ghrelin is also accelerated the LH-induced P4 secretion in luteal cells. Moreover, ghrelin is induced the release and mRNA expression of LH, and increased the release of prostaglandin (PG)E₂, but reduced the secretion of PGF_2α in luteal cells. In conclusion, the presences of ghrelin and GHSR-1a in the porcine CL during pregnancy, and the stimulatory effect of ghrelin on luteal cells suggest positive regulation by ghrelin in CL function of pregnant sows.

Previous studies showed that coat color significantly affects hair cortisol levels but not serum cortisol and serotonin levels in heifers and dairy cows under heat stress conditions. As a follow-up study, we tested whether both serum and hair cortisol and serotonin levels in winter-housed dairy cows were affected by coat color (black vs white). Twenty multiparous high-yielding dairy cows (DIM = 110 ± 25, milk yield = 35 ± 2.1 kg) were assigned to one of the following groups: 1) black coat color (BCC; over 85% of coat black, n = 14) and 2) white coat color (WCC; over 85% of coat white, n = 6). The experimental period lasted 60 d (from December to February), during which the animals were kept in a building with free stalls that had dry river sand bedding. Blood was harvested for 3 consecutive days at the end of the study. Hair was harvested from the forehead of each individual at the beginning and on the end-day of the study. Cortisol and serotonin hormones were measured in serum and hair. Data were analyzed using t-test. The results revealed that cows with BCC had lower hair cortisol and higher hair serotonin levels than those with WCC (P < 0.05). No differences in serum cortisol levels were observed between cows with WCC and BCC (P > 0.05). The serum serotonin level was lower in cows with WCC compared to the BCC group (P < 0.05). Taken together, coat color significantly affected stress levels indicated by higher hair cortisol and lower hair serotonin levels in WCC cows in addition to lower serum serotonin levels in the corresponding animals. This feature of coat color should be considered as a management tool, particularly in countries with long winters.

Herein, we examined the effect of the type of housing (individual vs group housing) of anestrus female goats on plasma cortisol concentrations and socio-sexual behaviors during first contact with photo-stimulated male goats and determined the impact on sexual and reproductive responses after 15 d of contact with photo-stimulated males. Therefore, after weaning, 10 females each were individually and group-housed, respectively. Ten bucks were rendered sexually active by exposure to artificially long days (16 h of light and 8 h of darkness per day) for 2.5 mo. During the naturally increasing photoperiod, 15-mo-old females were exposed and maintained with males. On day 0, during the first contact with males, individually- and group-housed females exhibited similar plasma cortisol concentrations (22.6 vs 27.4 ng/mL, respectively). Likewise, socio-sexual behaviors did not differ between examined groups on day 0. Moreover, the interval from first contact with males to the first estrus, short and normal ovulatory cycles, ovulation, fertility, and prolificacy rates were similar between differently housed females. Furthermore, mounting attempts did not differ between males in contact with either female group. In conclusion, individually- and group-housed anestrus females displayed elevated and similar plasma cortisol concentrations during first contact with photo-stimulated males and similar socio-sexual behaviors and reproductive responses when exposed to photo-stimulated males.

Health and welfare are inextricably linked within efficient and sustainable dairy production, and several potential risk factors may affect the well-being of dairy cows, including chronic stress. Although auditory stimuli could be used as a tool to decrease the potential stress that cows might experience, it is seldom applied to livestock production systems due to the perception that enrichment is an unnecessary expense. This study aimed to explore the effect of auditory stimuli as a form of enrichment in a Holstein herd by monitoring fecal glucocorticoid metabolite (fGCM) concentrations (a non-invasive, stress-associated biomarker). Cow activity level and milk yield were also measured. Nine cows in their second and third lactation were divided into 3 groups, using a Latin Square experimental design, exposing each cow group to each of the 3 treatments, namely constant exposure (CE), limited exposure (LE), and no exposure (NE) to classical music. FGCMs were quantified using a group-specific enzyme immunoassay detecting 11,17-dioxoandrostanes. Compared to LE and NE animals, cows exposed to constant music had significantly lower fGCM concentrations (P = 0.012), as well as higher milk yields (P < 0.0001) and lowered activity levels during the morning (P = 0.005) and the evening activity period (P = 0.048). These findings indicate that auditory stimuli in the form of classical music may have a positive effect on the welfare of cows as well as milk yield, which hold economic benefits for the producer and potentially reduces the number of cows needed for profitable production.

The majority of beef cattle in the United States often receive at least one anabolic implant resulting in improved growth, feed efficiency, and environmental and economic sustainability. However, the physiological and molecular mechanisms through which anabolic implants increase skeletal muscle growth of beef cattle remain elusive. The objective of this study was to identify transcriptional changes occurring in skeletal muscle of steers receiving anabolic implants containing different steroid hormones. Forty-eight steers were stratified by weight into 1 of 4 (n = 12/treatment) implant treatment groups: (1) estradiol (ImpE2; 25.7 mg E2; Compudose, Elanco Animal Health, Greenfield, IN), (2) trenbolone acetate (ImpTBA; 200 mg TBA; Finaplix-H, Merck Animal Health, Madison, NJ), (3) combination (ImpETBA; 120 mg TBA + 24 mg E2; Revalor-S, Merck Animal Health), or (4) no implant (CON). Skeletal muscle biopsies were taken from the longissimus 2 and 10 d post-implantation. The mRNA abundance of 94 genes associated with skeletal muscle growth was examined. At 10 d post-implantation, steers receiving ImpETBA had greater (P = 0.02) myoblast differentiation factor 1 transcript abundance than CON. Citrate synthase abundance was increased (P = 0.04) in ImpETBA steers compared to CON steers. In ImpE2 steers 10 d post-implantation, muscle RING finger protein 1 decreased (P = 0.05) compared to CON steers, and forkhead box protein O4 decreased (P = 0.05) in ImpETBA steers compared to CON steers. Interleukin-6 abundance tended to be increased (P = 0.09) in ImpE2 steers compared to both ImpETBA and CON steers. Furthermore, interleukin-10 mRNA abundance tended to be increased (P = 0.06) in ImpTBA steers compared to ImpETBA steers. Leptin receptor abundance was reduced (P = 0.01) in both ImpE2 and ImpTBA steers when compared to CON steers. Abundance of phosphodiesterase 4B was increased (P = 0.04) in ImpTBA steers compared to CON steers 2 d post-implantation. Taken together, the results of this research demonstrate that estradiol increases skeletal muscle growth via pathways related to nutrient partitioning and mitochondria function, while trenbolone acetate improves steer skeletal muscle growth via pathways related to muscle growth.

The stress caused by sound is inevitable. The stress caused by noise and the positive effects of music can affect the endocrine of animals and their welfare. In this study, a total of 72 hybrid piglets (Large White × Duroc × Min pig) were randomly divided into 3 groups, including music (Mozart K.448, 60–70 dB), noise (recorded mechanical noise, 80-85 dB), and control (natural background sound, <40 dB) groups. S-IgA (secretory immunoglobulin A), IL-6 (interleukin-6), IL-8 (interleukin-8), and positive emotion-related behaviors were used as indicators to discuss whether noise induced stress and inflammation in piglets or whether music could have positive effects. Six hours of auditory exposure were given daily (10:00–16:00), which lasted for 56 days. Behavioral responses of the piglets were observed, and the concentrations of salivary S-IgA and serum IL-6 and IL-8 were measured. The results showed that the concentration of S-IgA increased in the noise and control groups on the 57th day (P < 0.05); S-IgA concentration in the music group was unchanged after long-term music exposure. The concentrations of IL-6 and IL-8 showed that long-term noise exposure might lead to stress and inflammation in piglets. Tail-wagging and play behaviors of the piglets in the music group were significantly greater than those in the noise and control groups, which implied that long-term music exposure improved the emotional state of the piglets in a restricted and barren environment.

Early embryos of rodent species and rabbits but also farm animals such as pigs, horses and cattle produce estrogens, which are considered important regulators of the implantation process. In cattle, the exact stage at which embryonic estrogen synthesis commences is yet unknown. However, this information is regarded as important to consider a possible role of embryonic estrogens in preimplantation development. Therefore, in this study, we first used quantitative reverse transcription PCR to examine the mRNA expression of the enzymes required for the conversion of cholesterol into free and sulfonated estrogens (CYP11A1, CYP17A1, HSD3B, CYP19A1, and SULT1E1), the cholesterol carrier protein STAR, and the estrogen receptors ESR1 and ESR2 in in vitro produced morulae and unhatched blastocysts (d 6–9). Only in the blastocysts, were the mRNAs of the entire estrogen biosynthesis chain and of both estrogen receptors clearly present, whereas mRNA specific to ESRs was already detectable in the morulae. We also examined the expression of the corresponding enzymes in blastocysts at the protein level. None of the enzymes were detectable by capillary-based western analysis. Immunofluorescence methods were established for the detection of CYP17A1, CYP19A1, and SULT1E1. CYP17A1 was observed in the inner cell mass and trophectoderm, whereas CYP19A1 and SULT1E1 were present only in trophectoderm. An attempt to detect estrogen sulfotransferase activity was unsuccessful. Despite clear evidence that some elements of the estrogen biosynthetic pathway are also present at the protein level, it remains to be clarified whether the enzyme cascade underlying estrogen production is already functional in unhatched blastocysts.

High circulating progesterone concentrations decrease the responses to stressful situations in farm ruminants. We hypothesized that administering a single dose of long-acting progesterone formulation reduces the stress response of anestrous ewes to weaning. The aim of this study was to compare the behavioral, cortisol, and blood protein responses to weaning of anestrous ewes treated or not, with a single dose of a long-acting progesterone formulation. A complementary aim was to characterize the bioavailability of progesterone after this treatment. Thirty-six multiparous single-lambing Corriedale ewes and their lambs were used in this study. The lambs were weaned at 6:30 h when they were 65 d old (d0), and were taken to another paddock without chemical, visual or auditory contact with their mothers, while the ewes remained in the same paddock. Immediately before weaning, while 19 ewes received oil based long-acting progesterone formulation, other 17 ewes remained as controls, receiving sunflower oil. Twelve ewes from each group were used for behavioral recordings, the other 5 untreated ewes and 7 treated ewes were used to characterize the cortisol response and the progesterone profile. Behaviors were recorded every 10th min for 3 h in the morning and 3 h in the afternoon on day minus 3, d0 and d2, and expressed as percentage of recordings each animal displayed each behavior on each day. Treated ewes were recorded more times standing up than ewes on the day of weaning (P < 0.05), but the reverse result was found 2 d after (P < 0.01). Treated ewes were recorded more times lying down than control ewes on d2 after weaning (P < 0.0001), when treated ewes were observed fewer times walking than control ewes (P = 0.0004), as also happened the day of weaning (P < 0.0001). On the day of weaning, treated ewes grazed and paced less than control ewes (P = 0.001 and P = 0.009). Treated ewes ruminated more than control ewes on the day of weaning (P = 0.02) and 2 d later (P = 0.0002). Control ewes also secreted more cortisol than progesterone-treated ewes (P = 0.03), with no effect of the treatment on the concentration of total proteins, albumin or globulins. While control ewes never had luteal progesterone concentrations (>0.5 ng/mL), treated ewes achieved luteal progesterone concentrations 2 h after its administration, and remained well above luteal levels until 15 h after administration. The administration of a single dose of long-acting progesterone formulation appears to be a viable choice in reducing the stress to weaning in ewes. Ewes treated with progesterone coped better with weaning, returning to their normal basal behavior earlier than untreated ones, and secreting lower cortisol levels.