Female Saanen Goats Research Articles

Effect of High Energy Intake and Treatment with Galanin on Gonadotropin Levels in Female Goats

: Background: Galanin is an orexigenic agent and has been demonstrated to be a putative regulator of gonadotropin secretion. It is well known that this orexigenic peptide probably plays a vital role in the regulation of reproduction; however, the underlying mechanisms have not been fully elucidated.Objectives: The goal of this study was to determine the role of galanin in the regulation of gonadotropins in goats, which were subjected to either high or low energy diets.Materials and Methods: Adult female Saanen goats were randomly divided into 2 groups. Animals in the two groups were fed either a 100% or a 150% energy content diet, respectively, for a month. On the first day of the experiment, all animals received an intravenous injection of 1 µg galanin/kg body weight. On the second day, each animal was administered 2 µg galanin/kg body weight. Blood samples were withdrawn by jugular venipuncture at 30-minute intervals, 3.5 h before and 3.5 h after galanin injection. In order to determine the concentration of LH and FSH, plasma was isolated and subjected to radioimmunoassay in order to determine the concentrations of relevant gonadotropin hormones.Results: The intravenous administration of 1 µg galanin/kg body weight to goats who were subjected to a high-energy feed significantly reduced circulating LH and FSH levels. It contrast, this dose had no effect on goats subjected to the lower energy diet. The injection of galanin at a dose of 2 µg/kg body weight had no influence on mean plasma concentrations of gonadotropins in goats fed either of the two diets.Conclusions: The results indicate that galanin is not a principal hypophyseal regulator in the secretion of gonadotropins in Saanan goats. It may be inferred that in the same animal model galanin has a gonadotropin-reducing effect when its in vivo concentration increases. Implication for health policy/practice/research/medical education:High energy intake and peripheral galanin injection could decrease gonadotropins secretion. Thus, it can be concluded that galanin is a metabolic signal for GnRH-LH/FSH axis in high-energy feed goats. Please cite this paper as:Aboutalebi F, Khazali H. Effect of High Energy Intake and Treatment with Galanin on Gonadotropin Levels in Female Goats. Int J EndocriolMetab. 2011;9(2): 271-5. DOI: 10.5812/Kowsar.1726913X.1748 © 2011 Kowsar M. P. Co. All rights reserved.

Ultrasonographic examination of the spleen in 30 goats

The ultrasonographic appearance, location and size of the spleen in 30 healthy female Saanen goats are described. The intercostal spaces of the left thoracic wall were scanned with a 5.0 MHz linear transducer in standing goats. The appearance of the splenic parenchyma, the position of the ultrasonographically visible dorsal and ventral margins of the spleen and the distance between them, the thickness of the spleen and the diameter of the splenic vessels were determined. The spleen could be visualised in at least one examination position and it always lay between the rumen and abdominal wall. The spleen bordered the lung dorsally and was located adjacent to the left abdominal wall in the last intercostal space and area immediately caudal to the last rib. The spleen had an echogenic capsule, and its parenchyma showed a homogenous fine echotexture / echo pattern throughout the whole visible part of the spleen. The splenic vessels were seen within the parenchyma. The visible dorsal margin of the spleen ran from cranioventral to caudodorsal. The distance from the dorsal margin of the spleen to the midline of the back was greatest in the 8th intercostal space (19.7 ± 4.19 cm) and smallest in the region immediately caudal to the last rib (7.0 ± 1.07 cm). The size of the spleen was smallest in the 8th intercostal space (3.1 ± 1.24 cm) and greatest in the 11th intercostal space (8.7 ± 2.78 cm). The thickness of the spleen ranged from 2.2 ± 1.14 cm caudal to the last rib to 6.4 ± 1.78 cm in the 11th intercostal space.

Chondrosarcoma in the humerus of a goat

The clinical, radiographical and histo-pathological findings of a chondrosarcoma in the humerus of a goat are discussed. An 11-year-old female Saanen goat was admitted for evaluation of chronic, progressive left forelimb lameness. Clinical examination revealed signs of pain in the shoulder region. Radiographs of the scapulohumeral joint showed a large lytic lesion of the proximal third of the humerus with cortical destruction, intralesional calcification and marked periosteal reactions. Differential diagnoses included aggressive bone lesions as seen with osteomyelitis or a primary bone tumour, such as osteosarcoma, chondrosarcoma or fibrosarcoma. The goat was euthanatized for humane reasons because of the poor prognosis. On the basis of the histopathological findings, the lesion was diagnosed as grade II chondrosarcoma. The tumour had already spread to the lungs and the left prescapular lymph node at the time of diagnosis.

11 FERTILITY EVALUATION OF THE GOAT SEMEN DILUTED IN CITRATE-EGG YOLK EXTENDER WITH HIGH OR LOW EGG YOLK CONCENTRATION, COOLED AND STORED AT 5°C FOR 24 HOURS

This experiment was designed to evaluate, in vitro and in vivo, the cooling resistance of the goat semen diluted in citrate-egg yolk extender with high (20%) or low (2.5%) concentration of egg yolk. The experiment was conducted at Dairy Goat Station of the Animal Science Department (Federal University of Viçosa, MG, Brazil), during the natural breeding season (March to June). Four bucks of the Alpine (n = 2) and Saanen (n = 2) breeds were used as semen donors. The bucks did not have apparent abnormalities of the reproductive tract and the fertility was proved based on andrologic examination and the records from the previous breeding season. The semen was collected by the artificial vagina method and a fresh sample was analyzed for the sperm cell motility and concentration. Therefore, the semen was diluted in citrate-egg yolk extender with high (T1 = 20%) or low (T2 = 2.5%) concentration of egg yolk, cooled and stored at 5°C for 24 h, before being used either for quality analysis or for AI. Reproductive-age female Saanen and Alpina goats (n = 68) were inseminated via cervix with cooled semen from T1 (n = 32) or from T2 (n = 36). The parametric data from cooled semen quality (sperm cell motility, vigor, hyposmotic swelling test, morphology, and supravital staining) were analyzed by ANOVA, for the main effect of the treatment, using the SAEG 9.0 program (UFV, 2005). The differences between means were accessed by the Student-Newman-Keuls test. The qualitative data from pregnancy rate were tested by chi-square (Ayres et al. BioEstat 2.0, 2000). The mean ± SEM for each quality test of the cooled semen, as well the P-value for comparisons between treatments were as follows: motility, 68.6 ± 15.5 and 78.0 ± 5.6% (P < 0.05); vigor, 2.5 ± 0.6 and 3.2 ± 0.3 (P < 0.05); supravital staining, 59.4 ± 17.3 and 71.2 ± 10.6% (P < 0.05); and hyposmotic test, 42.3 ± 15.8 and 56.3 ± 11.6% (P < 0.05), respectively, for T1 and T2. The pregnancy rate was higher (P < 0.05) in goats inseminated with cooled semen from T2 (66.7%) than in those inseminated with T1 (31.25%). The number of the offspring did not differ (P > 0.05) between treatments (1.3 ± 0.5 and 1.4 ± 0.5 kids, forT1 andT2, respectively). The interpretation was that the goat semen diluted, cooled, and stored in citrate-egg yolk extender prepared with a low (2.5%) concentration of egg yolk produced higher pregnancy rate and the tests of semen quality were sensitive to assess this difference. Financial support was provided by CnPQ (Brazil).

The Effect of Galanin on the Mean Plasma Concentrations of LH and FSH in Female Goats Fed Different Levels of Their Energy Requirements.

The existence of a close relationship between energy status and reproductive function is well documented, but its underlying mechanisms remain to be fully unfolded. Galanin is an orexigenic agent and has been demonstrated as putative regulator of gonadotropin secretion in rats, but whether galanin acts similarly in ruminants is unknown, therefore the goal of this study was to determine whether galanin affects the mean plasma concentrations of LH and FSH in the female saanen goats fed different energy content in diets. Nine female saanen goats were randomly divided into 3 groups. Animals of all groups were fed either 50%, 100%, or 150% energy content in diet for a month. After a month, goats received 1 μg galanin/kg body weight into their jugular vein. Blood samples were collected every 30 minutes from jugular vein of all goats 4 h before and 4 h after injection of galanin. Blood plasma was assayed for plasma LH and FSH concentrations by RIA. Injection of galanin only in 150% dietary energy intake significantly decreased the mean plasma concentrations of LH and FSH whereas in 50% and 100% dietary energy intake, injection of galanin had no effect on the mean plasma concentrations of LH and FSH. These results indicated that galanin may negatively affect mean plasma concentrations of LH and FSH in the female saanen goats only with positive energy balance. (poster)

The Saanen goat as an animal model for post-laryngectomy research: practical implications

A modern way of voice rehabilitation after total laryngectomy includes the use of shunt valves and tracheostoma valves. Problems of fixation to the surrounding tissue are a major drawback in the use of the shunt valve, heat and moisture exchange (HME) filters and, especially, the tracheostoma valve. To solve these problems different tissue connectors were developed. The main objective was to test the feasibility of these prototypes in a new animal model. Here we discuss the results, problems and complications of the selected Saanen goat model. In this prospective laboratory study, 19 healthy adult female Saanen goats (Capra hircus) were used and observed post-surgically for 12 weeks. Selection criteria such as comparable anatomy to humans and easy handling were used for animal model development. Also a literature search using the Medline and the ISI Web of Science databases was performed. The anatomy of the Saanen goat was investigated in a separate postmortem study. Surgery consisted of a laryngotracheal separation and implantation of a tracheo-oesophageal and tracheostoma tissue connector with fibrin tissue glue. Postoperative care consisted of frequent stoma care, monitoring appetite, weight, vital signs and administration of antibiotics, analgesics and mucolytic agents. All animals survived the surgical procedure. However, postoperative care was extensive, labour intensive and was accompanied by several complications. Eleven animals died spontaneously before the end of the experiment. The tracheostoma tissue connector caused signs of local infection in all cases. There was no evidence of infection around the tracheo-oesophageal tissue connector in 18 cases. It was concluded that the use of goats in this tracheostoma model was associated with major complications and should, therefore, only be used for short-term experiments with intensive care. Additional research is needed to see if clinical application of the tissue connectors is possible in the future.

Soft-tissue response to injectable calcium phosphate cements

In this study, the soft tissue reaction to two newly developed injectable calcium phosphate bone cements (cement D and W) was evaluated after implantation in the back of goats. For one of the cements (cement D) the tissue reaction was also investigated after varying the concentration of accelerator Na 2HPO 4 in the cement liquid (resulting in cement D1 and D2). Eight healthy mature female Saanen goats were used. The cement was applied 10 min after mixing while it was still moldable and plastic. The material was given a standardized cylindrical shape. Thirty-two implants of each cement formulation were inserted and left in place for 1, 2, 4, and 8 weeks. At the end of the study, eight specimens of each material and healing period were available for further analysis. Two specimens were used for X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) and six specimens were used for light microscopical evaluation. XRD and FTIR showed that the cements did set as microcrystalline carbonate apatite with the disappearance of monetite from the cements during implantation. Histological analysis showed that after 8 weeks of implantation around all materials a thin soft-tissue capsule was formed (thickness ranging from 5 to 15 cell layers) with almost complete absence of inflammatory cells. Only in some specimens a slightly higher inflammatory reaction was observed. This was due to cement surface defects and a zone of dispersed particles near the cement–soft tissue interface. There was almost no resorption of the material after 8 weeks of implantation. In a few 4 and 8 weeks samples, small areas of calcification were found in the fibrous capsule surrounding the implants. On the basis of our observations, we conclude that the tested cements were biocompatible and can be used next to soft tissue.

Effects of duration of photoperiod on the rumination behavior of goats

Experiments on rumination behavior were conducted with adult female Saanen goats (BW 21.0 kg) to observe the effects of a single short (1 h; 23:00–24:00 h) or long (23 h; 00:00–23:00 h) photoperiod per day. The jaw movements of three goats tested were continuously recorded when they were housed in a cage with the continuous feeder to investigate the effects of duration of photoperiod on rumination behavior during both photoperiodic forms i.e. 1 h light vs. 23 h light per day. In the short photoperiod experiment the results showed that under these conditions, number of boli, ruminating time, number of mastications, masticating time, and resting time per hour differed ( P < 0.05-0.01) between the light and the darkness periods. Number of boli and ruminating time per hour decreased during the 1 h light period, and increased during the 2 h before the 1 h of light in the short photoperiod experiment compared with other times. However, they did not vary between the 1 h of darkness and the light period in the long photoperiod experiment. It is concluded that rumination circadian rhythm is affected by light per se and most by mastication behavior as elicited by light.

Physiological effects of exercise in male and female Saanen goats at the same body weight but different feed intake

Effects of treadmill exercise in males were 25% higher respiration rates (RR) in comparison to females ( P < 0.05). After 1 h exercise RR increased around 6-fold ( P < 0.001). With feed, RR increased gradually ( P < 0.001); comparisons were 1.0:1.3:3.9 with low (400 g), medium (600 g) and high (1200 g) feed intake, respectively. Rectal temperature (RT) showed differences between sexes ( P < 0.1) but males were less tolerant (0.2 °C higher) than females. At different levels of feed, RT increased gradually by 0.2 and 0.4 °C at medium and high levels, respectively, compared to low feeding ( P < 0.001). Rump skin temperature (RST) showed difference between sexes ( P < 0.1); the male was 0.2 °C higher than female. Loin skin temperature (LST) differed between feeds ( P < 0.001), increasing gradually by 0.5 and 0.9 °C at both medium and high feeding level compared to low. Ear skin temperatures (EST) in males were 0.6 °C lower than females. It is concluded that an increase in level of feed intake experienced by the goat during exercise was followed by significant increases in the RR, RT, RST and LST.

Incomplete Urinary Excretion of 3-Methylhistidine in Young Female English Saanen Goats.

Incomplete Urinary Excretion of 3-Methylhistidine in Young Female English Saanen Goats.

ヤギの血漿プロラクチン濃度および脳波に及ぼすp-chloroamphetamineの影響

Effects of p-chloroamphetamine (PCA) on plasma prolactin (PRL) concentration and on the electroencephalograms (EEGs) were investigated with 6 non-lactating female Saanen goats, which were accommodated with 20±2° and 14 hours of lighting per day (350 lux at the head when standing) for 3 months. The plasma PRL concentration was determined by double-antibody radioimmunoassay. Power spectral analyses were carried out for EEGs recorded by bipolar leads from the frontal region. The frequency ranges of 1.25-3.75Hz, 3.75-7.50Hz, 7.50-15.00Hz and 15.00-30.00Hz were tentatively defined as δ, θ, α and β bands, respectively. The ratio of power in each band to the total power was calculated.When 0.05 and 0.10mg of PCA per kg of body weight were infused into the external jugular vein in 6 goats, the plasma PRL concentration in 2 goats increased 5 and 20 minutes after the infusion. On the other hand, when 0.25mg of PCA/kg was infused, the plasma PRL concentration in all the 6 goats increased from 5 to 15 minutes after the infusion.The power spectral analysis of the EEGs in 3 goats, indicated the mean ratio of the δ band tended to increase and that of the θ band tended to decrease during 2 hours after the infusion of 0.1mg of PCA/kg. When 0.25mg of PCA/kg was infused, however, the mean ratio of the δ band also tended to increase, but those of the α and β bands tended to decrease during an hour and half after the infusion. These results suggest that the increase in plasma PRL concentration by PCA did not accompany the activation of the brain, but rather occurred during a drowsy state of the brain.

Involvement of melatonin in the seasonal changes of the gonadal function and prolactin secretion in female goats.

Ovarian cyclicity in the goat continues under short days (8L: 16D), while it ceases for 150-200 days under long days (16L: 8D). During the anovulatory period under long days, prolactin secretion is enhanced. Experiments were conducted to investigate the role of the pineal gland in the photoperiodic control of the gonadal function and prolactin secretion in the goat. Firstly, the effects of the abolition of the diurnal change in melatonin secretion on the photoperiodic responses of the gonadal axis and prolactin secretion were examined. Female Saanen goats, reared under short days (8L:16D, 22 +/- 2 degrees C) for 5 months, were bilaterally superior cervical ganglionectomized (SCGX) to denervate their pineal gland. One month after surgery, both SCGX and intact control goats were divided into two groups. Animals in group 1 were maintained under short days and those in group 2 were transferred to long days (16L:8D). In group 1, both SCGX and intact goats ovulated periodically and basal plasma levels of prolactin were maintained throughout the day. In intact controls, exposure to long days blocked ovulation and increased prolactin secretion for the first 150-200 days of exposure. The animals became photorefractory after this time; ovulation recurred and prolactin secretion was suppressed. The continuous melatonin secretion appeared simultaneously with the photorefractoriness. Superior cervical ganglionectomy abolished or weakened the suppression of gonadal axis and eliminated the increase in prolactin secretion induced by the exposure to long days in intact animals. Secondly, the effect of melatonin replacement by timed melatonin infusion on prolactin secretion was examined in SCGX goats to establish that the effect of SCGX could be ascribed to the abolition of the diurnal change in melatonin. Ovariectomized SCGX Shiba goats (n = 5) were infused with melatonin (20 micrograms/h, s.c.) daily for 8 h (the long-day-type infusion) and for 16 h (the short-day-type infusion) to mimic the nocturnal profiles of plasma melatonin under long days and short days, respectively. The long-day-type melatonin infusion for 9 days accelerated prolactin secretion, inducing a nocturnal rise in plasma prolactin; this was comparable to that observed in intact controls under long days. On the other hand, by the short-day-type infusion, the plasma prolactin concentrations were maintained at a low level throughout the day as were observed in intact goats under short days. The prevailing photoperiod appeared to have no distinct effect on these prolactin responses to exogenous melatonin, which were indistinguishable under long and short days.(ABSTRACT TRUNCATED AT 400 WORDS)

Superior cervical ganglionectomy prevents gonadal regression and increased plasma prolactin concentrations induced by long days in goats.

The effects of the abolition of the diurnal change in melatonin secretion on the photoperiodic response of the gonadal axis and prolactin secretion to long days were examined in female goats. Female Saanen goats, reared under short-day conditions (8 h light: 16 h darkness; lights on at 05.00 h) at 22 +/- 2 degrees C for 5 months, were bilaterally superior cervical ganglionectomized (SCGX). One month after surgery, both SCGX and intact control goats were divided into two groups. Animals in group 1 were maintained under short days and those in group 2 moved to long days (16 h light: 8 h darkness; lights on at 05.00 h). In group 1, both SCGX and intact goats ovulated periodically and basal plasma prolactin levels were maintained throughout the day. In intact controls, exposure to long days suppressed ovulation and increased prolactin secretion for the first 150-200 days of exposure. The animals became photorefractory after this time; ovulation recurred and prolactin secretion returned to basal levels. Superior cervical ganglionectomy abolished or weakened the suppression of gonadal function and eliminated the increase in prolactin secretion induced by exposure to long days in the intact controls. These results suggest that the pattern of melatonin secretion under long days is necessary to induce the photoperiodic response of gonadal function and prolactin secretion to long days and that, under natural conditions, melatonin regulates the seasonal changes in gonadal function and prolactin secretion by mediating the effect of long days.

Photoperiodic control of prolactin secretion in the goat.

Effects of photoperiods on prolactin (PRL) secretion were investigated by keeping female Saanen goats under artificial long days (16L8D) or short days (8L16D). Exposure to experimental photoperiods was started in December 1980 (day 0) and continued for about a year. Plasma PRL of the long-day group was elevated to the levels much higher than those of the short-day group. Effects of photoperiods on the diurnal fluctuation of plasma PRL were also evident on selected days when blood samples were taken at short intervals (day 24 and 118): being enhanced under long days and damped under short days. In July and August 1981, a marked elevation of PRL levels was noted in both groups, probably due to high ambient tem-perature which might have masked the effects of short-days. In the long-day group, goats were anovulatory when PRL levels were high (day 78-148), however, by day 200 they re-sumed estrous cyclicity spontaneously in association with the decrease in plasma PRL, sug-gesting that there might be an intrinsic mechanism which gradually increases the critical day lengths.

Inhibition of growth hormone release by rumen distension in female goats.

Six rumen-fistulated, overnight-fasted, female British Saanen goats were used. In preliminary experiments on two of the goats, evidence was obtained that inflation of a balloon with water in the cranial sac of the rumen was accompanied by inhibition of GH release. In a definitive series of experiments on the other four goats (one goat on 1 day = one experiment), a total of 96 experiments were carried out, 48 of which were balloon inflations with 2.5 litres water at 37 degrees C in the cranial sac of the rumen for 40 min and 48 were control experiments on alternate days. It was found that the mean plasma GH concentration of the samples taken at the end of the 40-min inflation period was significantly (P less than 0.05) lower than the mean value of the samples taken at the start of inflation. Mean control values at the start and finish of inflation were not significantly different. There were no significant differences between mean plasma insulin concentrations at the start and finish of inflation in experimental and control groups. It is concluded that distension of the cranial rumen in the goat is a signal which can inhibit the release of GH.

Ventricular septal defects in three familially-related female Saanen goats.

Ventricular septal defects were diagnosed in 3 familially-related Saanen goats, a 4-year-old doe and 2 female kids aged 18 weeks, by clinical examination, electrocardiography, phonocardiography and thoracic radiography. Findings were contrasted with those from 3 clinically normal goats. Cardiac catheterisation was attempted on the 2 affected kids before euthanasia. Blood pressure tracings and selective contrast cardioangiography successfully demonstrated the defect in one case, but the other died shortly after anaesthetic induction. The adult goat, suspected paternal grand-dam of the affected twins, died without premonitory signs at 4.5 years of age. Necropsy confirmed the diagnosis in all 3 cases.

A cytogenetic study of a Barbary sheep (Ammotragus lervia) x domestic goat (Capra hircus) hybrid.

An account is given of stillborn male twins born to a female Saanen goat (Capra hircus) and a Barbary ram (Ammotragus lervia). The cytogenetics of the cultured hybrid cells are described and attention is drawn to the high proportion of cells which lacked one chromosome.