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1.
This work was performed to determine the predatory capacity in vitro of the nematophagous fungus Duddingtonia flagrans (isolate AC001) on cyathostomin infective larvae of horse (L3). The experimental assay was carried out on plates with 2% water-agar (2% WA). In the treated group, each plate contained 1.000 L3 and 1.000 conidia of the fungus. The control group without fungus only contained 1.000 L3 in the plates. Ten random fields (4 mm diameter) were examined per plate of treated and control groups, every 24 h for seven days under an optical microscope (10× and 40× objective lens) for non-predated L3 counts. After 7 days, the non-predated L3 were recovered from the Petri dishes using the Baermann method. The interaction there was a significant reduction (p < 0.01) of 93.64% in the cyathostomin L3 recovered. The results showed that the D. flagrans is a potential candidate to the biological control of horse cyathostomin L3.  相似文献   

2.
Horses are hosts to a wide variety of helminthes; the most important are the cyathostomin, or small strongyles. The viability of a fungal formulation (pellets) using the nematode-trapping fungus Monacrosporium thaumasium was assessed in biological control of horse cyathostomin. Two groups (fungus-treated and control) consisted of six mares in each group, crossbred (ages of 2.5 and 3.5 years), were placed in pastures of Cynodon sp. naturally infected with horse cyathostomin larvae. In the treated group, each animal received 1g/10 kg body weight (0.2g/10 kg live weight of fungus) of pellets of sodium alginate matrix containing the fungus M. thaumasium orally, twice a week for 6 months. In the control group, animals received (1g/10 kg body weight) of pellets without fungus. The egg count per gram of feces showed difference (p<0.01) in the animals treated with the fungus in relation to the control animals during all months of the experiment. The EPG percentage decrease were 87.5%, 89.7%, 68.3%, 58.7%, 52.5% and 35.2% during June, July, August, September, October and November, respectively. In faecal cultures, there was difference (p<0.05) among animals treated with fungus was found in relation to the control animals during all the experiment month, with percentage reduction of 67.5%, 61.4% and 31.8% in September, October and November, respectively. Difference (p<0.01) was observed in the recovery of infective larvae from pastures that were collected up to 20 cm from the dung pats in pastures in the group treated with the fungus in relation to the control group with a reduction of 60.9% and between 0-20 and 0-40 cm from the faecal pat reduction (p<0.01) was about 56% in the group treated with the fungus M. thaumasium in relation to the control group pasture. There was no difference (p>0.05) between the average weight gains in both animal groups. The treatment of horses with pellets containing the nematophagous fungus M. thaumasium can be effective in controlling cyathostomin in the tropical region of southeastern Brazil.  相似文献   

3.
One isolate of predator fungi Duddingtonia flagrans (AC001) was assessed in vitro regarding the capacity of supporting the passage through pigs' gastrointestinal tract without loss of the ability of preying infective larvae Oesophagostomum spp. Fungal isolates survived the passage and were efficient in preying L3 since the first 8 h of collection (p < 0.01) in relation to the control group (without fungus). Compared with control, there was a significant decrease (p < 0.01) of 59.6% (8 h), 71.7% (12 h), 76.8% (24 h), 81.0% (36 h), 78.0% (48 h), 76.1% (72 h), and 82.7% (96 h) in means of infective larvae Oesophagostomum spp. recovered from treatments with isolate AC001. Linear regression coefficients of L3 of recovered Oesophagostomum spp. regarding the collections due to time were −0.621 for control, −1.40 for AC001, and −2.64 for NF34. Fungi D. flagrans (AC001) had demonstrated to be promising for use in the biological control of pig parasite Oesophagostomum spp.  相似文献   

4.
The aim of the present study was to carry out molecular epidemiological investigation on enterotoxigenic Escherichia coli (ETEC) K99 and Salmonella spp. in diarrheic neonatal calves. Fecal samples were obtained from 220 diarrheic calves at 9 farms related to four governorates in central and northern Egypt. E. coli and Salmonella spp. isolates were examined for E. coli K99 and Salmonella spp. using PCR. ETEC K99 was recovered from 20 (10.36 %) out of 193 isolates, whereas Salmonella spp. was recovered from nine calves (4.09%).Multivariable logistic regression was used to evaluate the risk factors associated with both infections. ETEC K99 was significantly affected by age (P < 0.01; OR: 1.812; CI 95%: 0.566–1.769), colostrum feeding practice (P < 0.01; OR: 5.525; CI 95%: 2.025–15.076), rotavirus infection (P < 0.001; OR: 2.220; CI 95%: 0.273–1.251), vaccination of pregnant dams with combined vaccine against rotavirus, coronavirus and E. coli (K99) (P < 0.001; OR: 4.753; CI 95%: 2.124–10.641), and vitamin E and selenium administration to the pregnant dam (P < 0.01; OR: 3.933; CI 95%: 0.703–1.248).Infection with Salmonella spp. was found to be significantly affected by the animal age (P < 0.05; OR: 0.376; CI 95%: 0.511–1.369), Hygiene (P < 0.05; OR: 0.628; CI 95%: 1.729–5.612), and region (P < 0. 01; OR: 0.970; CI 95%: 0.841–1.624).The results of the present study indicate the importance of PCR as rapid, effective and reliable tool for screening of ETEC and Salmonella spp. when confronted with cases of undifferentiated calf diarrhea. Moreover, identification of the risk factors associated with the spreading of bacteria causing diarrhea may be helpful for construction of suitable methods for prevention and control.  相似文献   

5.
A grazing experiment was undertaken to evaluate the effect of PEG supplementation on the fatty acid composition of milk from Sarda sheep grazing sulla. Twenty-four late-lactating sheep (12 per group), were paired and split into two groups: group control (CON), dosed daily with a quenching gun with 200 ml of water, and group PEG, dosed with 200 ml of a 50/50 w/v water solution of PEG. The sheep grazed two 0.8 ha plots of sulla under a rotational grazing scheme.The contents of c-9, t-11 CLA and t-11 C18:1 in milk fat were on average 40% higher (P < 0.01) in the PEG group than in the CON group. This can be explained by the higher biohydrogenation activity of ruminal bacteria in the PEG group, due to the partial inactivation of the tannins. Odd-branched chain fatty acids (OBCFA) were higher in PEG than in the control group (+ 20%; P < 0.01) and this confirms the hypothesis that tannin in sulla reduced ruminal microbial activity. Both linoleic (C18:2 c-9 c-12) and linolenic (C18:3 c-9 c-12 c-15) fatty acids were lower (P < 0.05) in milk from PEG, than in the CON-group (− 12% and − 30% for linoleic and linolenic acids, respectively). The mitigating effect on tannins of PEG increased the ratio of ω6/ω3 by 24%; (P < 0.01) and total trans FA content in milk by 20% (P < 0.01). In conclusion, condensed tannins in sulla at flowering are conducive to lower c-9, t-11 CLA and t-11 C18:1 but also lower total trans FA, ω6/ω3 ratio and higher linoleic and linolenic acid.  相似文献   

6.
Bovine tuberculosis (bTB) is a continuing problem in British herds. Micro-nutrients are important for the maintenance of well-functioning immune system. The aim of this study was to determine whether the selenium, copper and vitamin B12 status of cattle was associated with Mycobacterium bovis (M. bovis) infection. Between 2002 and 2005, 200 cattle (43% dairy, mean age 4.6 years), reactors according to the standard interpretation of the tuberculin test, and 200 in-contacts (41% dairy, mean age 4.4 years) non-reactors, which had been in contact with cattle with bTB, were selected from herds in England and Wales. Levels of the seleno enzyme glutathione peroxidase (GSHPx), copper and vitamin B12 were measured in blood. Confirmation of bTB infection was made by bacteriological culture and histopathology following a detailed postmortem. Levels of selenium and copper were also measured in a random sample of 63 livers. bTB was confirmed by culture/histology in 23/200 (11.5%) of in-contacts and 110/200 (55%) of reactors. In blood drawn at recruitment, GSHPx was lower in cattle with confirmed bTB compared to other cattle (geometric means 59.7 u/mL versus 78.9 u/mL red blood cells (RBC), p < 0.01). Vitamin B12 was similar (geometric means 161.5 pmol/L versus 165.5 pmol/L, p = 0.62) and copper was similar (geometric means 14.4 μmol/L versus 14.1 μmol/L, p = 0.55). In logistic regression models including all micro-nutrients simultaneously and controlling for age, sex, animal production class, herd size, number of reactors, postmortem laboratory and seasonal trends, lower levels of GSHPx (adjusted OR 0.42, 95% CI 0.21–0.81 per 100 u/mL RBC, p = 0.01) and higher levels of copper (adjusted OR 1.69, 95% CI 1.21–2.36 per 5 μmol/L, p < 0.01) were associated with an increased risk of confirmed bTB but there was no association with vitamin B12. There was evidence for a stronger association between confirmed bTB and GSHPx in in-contacts (adjusted OR 0.21, 95% CI 0.06–0.79 per 100 u/mL RBC) compared to reactors (adjusted OR 0.50, 95% CI 0.21–1.23 per 100 u/mL RBC) (p = 0.08 for interaction). Lower liver copper was associated with a higher risk of confirmed bTB (adjusted OR 0.15, 95% CI 0.02–1.0 per 5000 μmol/kg dry mass, p = 0.05) but there was no association between liver selenium and bTB. Trace micro-nutrient status may affect susceptibility to M. bovis infection in cattle. Further studies are needed.  相似文献   

7.
Factors associated with parasitism by helminths and protozoans in 500 dogs presented to three veterinary clinics in the municipality of Rio de Janeiro from November 2003 to September 2004 were evaluated. Dogs were submitted to physical examination and owners were interviewed about the animal's management. One fecal sample from each dog was examined by centrifugal flotation and sedimentation methods followed by the safranin–methylene blue staining technique. Positive results for gastrointestinal parasites were detected in 46.4% of the examined samples. Infection with protozoans (29.6%) was more frequent than with helminths (23.2%). Cryptosporidium sp. (26.2%) and Ancylostoma sp. (15.2%) were the most frequent parasites. Logistic regression analysis showed that age (p < 0.001), access to soil (p < 0.001), hygiene of the environment (p = 0.001), illness (p = 0.007), owner's level of education (p < 0.006) and veterinary clinic (p = 0.043) were associated with gastrointestinal parasite infections in dogs. Treatment and control are especially important for puppies. Adult dogs should be submitted to fecal examination before treatment, placing special emphasis on those that present one or more factors associated with infection.  相似文献   

8.
The objectives of this study were to characterize the glycemic and insulinemic responses of Thoroughbred broodmares fed late spring pasture only or a mixture of pasture and a high starch or low starch feed and to test hypotheses about differences in the glycemic and insulinemic effects of these dietary regimes. A group of 15 mares were divided into three treatment groups; pasture and high starch feed (PHS), pasture and low starch feed (PLS), and pasture only (PO) and maintained in these groups for 4.5 months prior to this study. These groups were maintained on a single pasture that was temporarily divided into three sections. The study protocol was conducted over two days. On day 1 the mares were fed their respective treatments and on day 2 all mares were allowed access to pasture only. On both days plasma glucose and insulin were measured in samples taken over a 7.5 h period. Baseline measurements for glucose and insulin were not different between any of the treatment groups on either day (P > 0.05). The baseline insulin concentrations of these pasture-kept mares (26.7 ± 8.3 mIU/L) were high compared to those reported from stall-kept horses. Plasma glucose and insulin on day 1 were influenced by treatment group, sample time, and an interaction between treatment and time (P < 0.05). On day 2 there was no significant influence of treatment group (P > 0.05). Glucose and insulin rose to higher (P < 0.01) peak concentrations in the PHS group on day 1 when compared to the PLS and PO groups, with no difference (P > 0.05) detected between the PLS and PO groups. These results are reflected in greater areas under the concentration-time curves for glucose and insulin in the PHS group on day 1 (P < 0.05). On day 2 there were no differences in any of the glucose and insulin characteristics for any of the treatment groups (P > 0.05). These results indicate a clear difference in the glycemic and insulinemic effect of the PHS feed compared to the PLS and PO groups. Of further interest are the glucose and insulin characteristics of these pasture-kept mares that indicate a low insulin sensitivity and high insulin secretory response. This study provides further information on factors influencing glycemic and insulinemic responses in horses.  相似文献   

9.
The present study characterized the luteal status and the dynamic of the conceptus during the first 20 days of gestation in mares with different ages and degrees of endometrial degeneration. Total area of the corpus luteum (CL), luteal vascularity, CL area with blood signals, progesterone concentrations (P4), embryonic vesicle diameter, number of embryonic location changes, embryonic fixation position and uterine contractility were evaluated. In Experiment 1, mares ≤6 years of age (Young group, 5.6 ± 0.2 years, n = 7 mares) and mares ≥15 years of age (Old group, 17.2 ± 0.9 years, n = 6 mares) were used to investigate the effect of age. In Experiment 2, the luteal and embryonic parameters were compared between mares with minimal (Mild group, endometrial category I, n = 9 mares) and severe (Severe group, endometrial category III, n = 7 mares) endometrial degeneration. The Old and Severe groups had greater (p ≤ 0.04) total CL area and reduced luteal vascularity (p ≤ 0.04) than the Young and Mild groups, respectively. However, P4 levels and CL area with blood signals were similar (p ≥ 0.8) between the groups. A negative effect of age (p < 0.01), but not of endometrial degeneration (p = 0.6), was found for the embryonic vesicle diameter. The conceptus mobility was high (p > 0.1) until day 14 of gestation in the Severe group, while a reduced number of changes of the embryo location was detected earlier (p < 0.05) in the Old group. In conclusion, the newly formed CL of aged mares and mares with severe endometrial degeneration suffered a structural remodelling to safeguard the local blood supply and the continuous P4 output during early gestation. Moreover, an earlier reduction of the embryonic mobility and a delayed development of the conceptus were associated with advanced age, regardless of the degree of endometrial degeneration.  相似文献   

10.
In experiment 1, 6 pregnant mares received a concentrate that contained a trace mineral premix that provided 14.3 mg Cu, 40 mg Zn, 28 mg Fe, 28 mg Mn, 0.08 mg Co, 0.16 mg I, and 0.16 mg Se/kg concentrate (group A). Seven mares received the same concentrate plus 502 mg Zn and 127 mg Cu once daily (group B). No differences (P > .05) in foal growth data, or Cu, Zn, and Fe concentrations of mare milk, mare serum, or foal serum were observed. In experiment 2, 6 pregnant mares received the same concentrate as group A (group C), and 8 mares received the same concentrate fortified with 4× the trace mineral premix (group D). Group C mares had higher serum Zn concentration at 1 day (P < 0.01) and 56 days (P < 0.04). Group C mares had higher milk Fe concentration at 28 days (P < .01), and group D mares had higher milk Cu concentration at 56 days (P < .01). Group C foals had higher serum Cu concentration at 14 days (P < .03). The results from this study provide no evidence to indicate that supplementing late gestating and lactating mares with higher dietary trace mineral levels than those recommended currently by NRC has any influence on foal growth and development, or on the Cu, Zn, and Fe concentrations of the mare milk, mare serum, or foal serum.  相似文献   

11.
Skeletal muscle genes are potential candidates for production and meat quality. Screening a subtracted cDNA library constructed with mRNA obtained from longissimus dorsi muscles of F1 hybrids Landrace × Yorkshire and their female parents Yorkshire, we isolated two partial sequences coding for the H3-K4-specific methyltransferase (KIAA1717) and skeletal muscle myosin regulatory light chain (HUMMLC2B) genes. Database search revealed KIAA1717 and HUMMLC2B encoded proteins with SET domain and EF-hand calcium binding motif, respectively. In the present work we identified their partial polymorphisms and two SNPs, one (C1354T) at the 3′ untranslated region (UTR) of KIAA1717 and one (A345G) at the SINE (PRE-1) element of HUMMLC2B, both created/disrupted a restriction site for endonuclease Msp I. The selected pigs were genotyped at the KIAA1717 C1354T and HUMMLC2B A345G sites by means of a PCR-RFLP protocol. Significant associations were observed for the KIAA1717 C1354T polymorphic site with meat marbling (longissimus doris (p < 0.05), biceps femoris (p < 0.01)) and intramuscular fat (p < 0.01). HUMMLC2B A345G were significantly associated with meat pH (longissimus doris (p < 0.05), biceps femoris (p < 0.01)), drip loss (p < 0.01), water holding capacity (p < 0.01) and meat color value (longissimus doris (p < 0.01), biceps femoris (p < 0.05)). Further studies are needed to confirm these preliminary results.  相似文献   

12.
Gastric Helicobacter spp. are associated with chronic inflammation and neoplastic transformation in humans as well as domestic and laboratory species. The present study examined the association of Helicobacter heilmannii (Hhe) infection in pet cats with feline gastric mucosa associated lymphoid tissue (MALT) lymphoma. Tissues were collected via gastric biopsy or at necropsy from 47 pet cats with clinical signs of gastrointestinal disease, including vomiting and inappetance, and classified as gastritis (14/47), lymphoma (31/37), or normal (2/47). Tissues positive for argyrophilic organisms with Warthin–Starry stain (29/47) were assessed by fluorescent in situ hybridization (FISH) for the presence of Hhe strains 1–4 as well as with a fifth probe that detected Helicobacter salomonis, Helicobacter bizzozeronii, or Helicobacter felis. A significant association of positive Warthin–Starry status with Hhe infection was found in cases of sick cats (22/29; p < 0.05 by Chi-square; χ2 = 7.034). Interestingly, a significant association between Hhe status and a diagnosis of lymphoblastic or lymphocytic lymphoma was observed as well in a subset of 24 Warthin–Starry positive lymphoma cases: of lymphoblastic lymphoma cases, 13/17 were positive for Hhe (p < 0.05; χ2 = 4.854). Hhe strains 2 and 4 were most commonly found (18/29 and 17/29, respectively) among sick cats, although a higher than expected number of cats was also positive for Hhe1, which initial reports have described as rare in cats and common in humans. The association found between a positive Hhe status with the presence of feline gastric lymphoma, especially lymphoblastic lymphoma, argues for the need to conduct prospective studies to better identify the frequency and strain distribution of Hhe infection in both healthy and clinically ill cats, particularly those cats with gastric lymphoma.  相似文献   

13.
The funnel-shaped cranial portion (infundibulum) of the oviduct is contiguous with the ovulation fossa in mares. An accumulation of fluid in the infundibular area was discovered by transrectal ultrasonic imaging and was studied daily in both oviducts of 12 mares from day –10 to day 10 (day 0 = ovulation), and from day –6 to day 6 during 35 estrous cycles of young, intermediate, and old mares (n = 8 mares/group). The infundibulum was identified by processes (fimbriae) and folds in the pocket of fluid. The amount of fluid accumulation was scored from 0 to 3 (nil to maximum). Frequency of detection of fluid in the infundibular area increased between day –10 (46% of oviducts) and day –3 (88%), and decreased between day –3 and day 7 (8%; P < .002). The day-to-day profile for changes in the score for amount of fluid was significant (P < .0001) and similar to the profile for frequency of detection of the infundibulum. The profiles for the two infundibular end points and scores for endometrial echotexture (an indicator of edema) were similar to the reported profile for systemic estradiol concentrations. The frequency of infundibulum detection was greater (P < .0009) for the side ipsilateral to the preovulatory follicle and ovulation (51%) than for the opposite side (36%). No difference among ages was found for either oviductal end point. Results indicated that changes in the amount of fluid accumulation in the infundibular area and endometrial edema were estrous cycle dependent and similar to previously reported changes in systemic concentrations of estradiol.  相似文献   

14.
The aim of the study was to evaluate the protection generated in mice against Toxoplasma gondii brain cyst burden by vaccination with T. gondii cytoskeleton proteins using Lactobacillus casei as adjuvant. One hundred and sixty-eight NIH mice were randomly allocated into eight groups of 21 mice each. Animals were immunized as follows: in group 1 with Toxoplasma lysate antigen (TLA) in Freund's modified adjuvant, containing L. casei (FMA), in group 2 with Toxoplasma cytoskeleton proteins (TCPs) in FMA, in group 3 with FMA, in group 4 with phosphate buffered saline (PBS), in group 5 with L. casei dead by heath (Lc), in group 6 with Freund's complete adjuvant (FCA), in group 7 with TLA in FCA, and in group 8 with TCP in FCA. Mean brain cyst burden (±S.E.M.) was assessed in mice 8 weeks after challenge with T. gondii Me49 strain (20 cysts per mouse). The percentages of reduction in cyst burden per brain (P < 0.01) as compared with the group 4 (control: mean 3181 ± 97.5) were 77.25% (724 ± 98) in group 1, 88.02% (381 ± 97.5) in group 2, 38.92% (1943 ± 130.3) in group 3, 44.31% (1771.4 ± 102) in group 5, 59.28% (1295.2 ± 99.1) in group 7 and 55.69% (1409.5 ± 89.9) in group 8. In order of importance, the best protection was obtained in groups 2, 1, 7, 8, 5 and 3. Noticeably the mice inoculated with L. casei alone showed a significant reduction in T. gondii brain cysts (P < 0.01), while those animals treated with FCA alone did not. Additionally, IgM anti-T. gondii antibody levels, as determined by ELISA 2 weeks after challenge, were highest in group 2 (P < 0.01) than in the other seven groups. Results suggest that T. gondii cytoskeleton proteins with L. casei as adjuvant constitute a good anti-toxoplasmosis vaccine candidate.  相似文献   

15.
Mortality records of indigenous and upgraded pigs, reared under subtropical hill agro climatic conditions, were collected for the period of 11 years (1993–2003), analyzed and the mortality pattern was correlated with genetic group, age of pigs, climatic factors and causes of death. Results revealed that there was significant (p < 0.05) difference in mortality between the indigenous (6.05%) and upgraded (5.64%) pigs. The mortality percentage was significantly (p < 0.05) higher in both genetic groups between 0 and 4 months of age compared to seven months and above age groups. Among different seasons, significantly (p < 0.05) higher mortality was observed during post-monsoon and winter compared to other seasons. The overall mortality percentage was 4.74, 5.25, 7.51 and 6.56 during pre-monsoon, monsoon, post-monsoon and winter seasons, respectively. Indigenous pigs recorded significantly (p < 0.05) higher pre-weaning mortality (14.26%) than the upgraded (9.58%) pigs. Among different causes, digestive disorders accounted to significantly (p < 0.05) higher mortality followed by miscellaneous and respiratory disorders. The study developed a linear regression model, which could fairly predict the mortality pattern based on the rainfall, relative humidity and temperature (R2 = 58.3%).  相似文献   

16.
The objective of this experiment was to examine the effects of feeding a vitamin A deficient diet (VAF) to pigs at different times on day 100 of foetal and days 0, 1 and 2 of neonatal development. Three treatments included a control (n = 12), VAF for 100 days before mating and during the first month of pregnancy (n = 13; VAF–control), and VAF during the oestrous cycle before mating and throughout pregnancy (n = 13; control–VAF). On day 100 of pregnancy, maternal liver and plasma retinol concentrations were reduced in both groups of gilts fed a vitamin A free diet compared to controls (P < 0.001 and P < 0.01, respectively). Day 100 foetal liver retinol concentrations were not affected by dietary treatment, whereas foetal plasma concentrations were higher in foetuses carried by gilts fed the VAF–control diet (P < 0.05). Piglets born to mothers fed the control–VAF, but not the VAF–control diet had consistently lower hepatic and plasma liver retinol concentrations (P < 0.05). Moderate reductions in maternal vitamin A at either stage of pregnancy did not affect pregnancy rate, litter size, progesterone secretion or the allometric relationships between foetal or neonatal organ and total body size. Reduced vitamin A during conception and early pregnancy, but not during later pregnancy, was associated with increased within-litter uniformity in birth weight (P < 0.05) and a tendency for fewer low birth weight piglets, but this needs to be confirmed in a greater number of sows. The mechanism underlying this effect is not known, but appears to not involve an alteration in progesterone production.  相似文献   

17.
The objective of Experiment 1 was to determine a dose and frequency of gonadotropin-releasing hormone (GnRH) antagonist administration to effectively suppress serum luteinizing hormone (LH) concentration and to delay ovulation when administered to mares. The objectives of Experiment 2 were 1) to determine the effects of subcutaneous or intravenous administration of a GnRH antagonist or oral altrenogest on serum LH concentration in the estrual mare; and 2) to determine the effectiveness of human chorionic gonadotropin (hCG) in inducing ovulation in mares with suppressed LH concentrations. In Experiment 1, mares (N = 20) were randomly assigned and treated with either 5% mannitol (control, single subcutaneous injection, 1 mL, at time 0; n = 5); low-dose GnRH antagonist (single subcutaneous injection, 0.01 mg/kg, at time 0; n = 5); frequent low-dose GnRH antagonist (subcutaneous injections, 0.01 mg/kg, at 0, 6, 18, and 24 hours; n = 5); or high-dose GnRH antagonist (single subcutaneous injection, 0.04 mg/kg, at time 0; n = 5). Both the frequent low-dose and high-dose GnRH antagonist treatments resulted in significantly lower LH concentrations compared with controls at 90, 102, and 114 hours after treatment (P < .05). In Experiment 2, mares (N = 38) were randomly assigned and treated with subcutaneous sterile saline (control), altrenogest (oral), subcutaneous GnRH antagonist, or intravenous GnRH antagonist. LH concentration for the altrenogest group was lower than the control group at 3, 4, 18, and 30 hours after treatment (P < .05). LH concentration for both the subcutaneous and intravenous GnRH antagonist groups were lower compared with the control group at several time points (P < .05). Based on these data, dose but not frequency of administration of a GnRH antagonist lowered LH concentration in the estrous mare but did not delay ovulation. In addition, serum LH concentrations can be lowered and ovulation effectively postponed in mares treated with altrenogest followed by administration of hCG. This indicates that serum LH concentrations can be lowered and ovulation effectively postponed in mares treated with altrenogest followed by administration of hCG.  相似文献   

18.
Sixteen West African dwarf goats weighing 5.0–5.6 kg were used in an experiment that lasted 112 days to investigate the utilization of citrus pulp based diets and E. cyclocarpum. A control diet which contained 88.5% dried brewers' grains (DBG) and other three experimental diets in which DBG was replaced with dried citrus pulp (DCP) at 25, 50 and 75% levels, respectively constituted the four treatments. The goats were divided into four groups of four animals each to balance for variation in live weight before they were assigned to the four different experimental diets. Significant differences (P < 0.05) were obtained in growth rate with (22.14–34.02 g/d) the highest and lowest value from 50 and 75% DCP inclusion respectively. The digestibility coefficients of DM, Ash, NFE, NDF, ADL, cellulose and hemicellulose increased with increasing levels of dried citrus pulp in the diets and were highest at 75% level of replacement. However, the CP digestibility of 83.85% was highest in the control diet and was significantly (P < 0.05) different from other diets containing citrus pulp. Nitrogen intake (g/d) decreased significantly (P < 0.05) with increasing levels of dried citrus pulp in the diets from 45.57–33.28 and was lowest in the control diet. Nitrogen balance also followed the same trend, being highest (42.07 g/d) at 25% DCP and lowest at 75% DCP. The Packed cell volume (PCV), haemoglobin concentration (Hb), red blood cells (RBC), white blood cells (WBC) and total blood protein (TBP) were significantly (P < 0.05) different across the dietary treatments at the start and end of the trial. The values for PCV, RBC, MCH, glucose and total protein decreased slightly in the control diet. Serum glutamate pyruvate transaminase (SGPT) values also increased significantly (P < 0.05) with increasing levels of dried citrus pulp in the diets at the end of the experiment and were highest (6.50 IU/L) at 75% level of citrus pulp. Therefore, the efficient utilization of citrus pulp and E. cyclocarpum by WAD goats was attained at the 50% level of inclusion in the diets.  相似文献   

19.
Two cloned mares, produced from the same sample of skin fibroblasts, were bred during four breeding seasons from their second year of age, as embryo donors, in exactly the same conditions, using the same stallions for both cloned mares. The aim of this study was to test the embryo donor potential of cloned mares and to compare the results obtained from two cloned mares of the same mare with other embryo donor mares (n = 31–39 per breeding season) at the same stud. For both cloned mares, 19 embryos were recovered by 43 collection attempts (44%) (7/22 for one; 12/21 for the other), 16 (84%) pregnancies (5/7 for one, 11/12 for the other) were obtained at day 14 post-ovulation (D14), and 12 (3/7 for one; 9/12 for the other) foals were born. One cloned mare was a less efficient donor mare than the other (p < .05), In control donor mares, 623 embryo collections were performed, with a recovery rate (80%—496/623) significantly higher than for cloned mares. The recovery rate in the subpopulation of 2–5-year-old control donor mares (same age of cloned mares) (89%—127/143) and The recovery rate in the subpopulation of 12 control mares bred with the seven same stallions as clones (55%—17/31), were both higher than for cloned mare (p < .05). The success rate of transfer was not different between embryos produced by cloned mares (84%—16/19) and those produced by control donor mares (79%—392/496). However, the foaling rate per embryo collection was significantly lower for cloned mares (28%—12/43) than for control donor mares (52% - 325/623) (p < .05).  相似文献   

20.
The influence of progesterone, luteinizing hormone (LH), and estrogen on the mare's estrous cycle has been well researched and documented, but other endocrine profiles have not received as much attention. To evaluate endocrine concentrations in fat-conditioned (body condition score [BCS] of 7–8) versus moderately conditioned mares (BCS of 5–6), 24 mares were allotted to and maintained in respective groups from late gestation until pregnancy was confirmed after breeding on the second postpartum estrus. Serum concentrations of thyroxine (T4), insulin-like growth factor-1 (IGF-1), and leptin were assayed to characterize circulating blood concentrations. Additionally, LH and progesterone serum concentrations were assayed to evaluate the estrous cycle status of the mares. Leptin and progesterone concentrations were not different (P > .05) between the groups. Nevertheless, serum concentrations of T4 were higher (P < .01) and IGF-1 concentrations lower (P < .01) in moderately conditioned as compared with fat-conditioned mares during times of ovulation and the interovulatory period. Furthermore, serum concentrations of LH were found to be different between the groups only when the estrous cycle approached the second ovulation (P < .0001). Results of this study suggest that mares maintained in a BCS of 5 or greater are similar in terms of reproductive efficiency. Although the circulating serum concentrations of T4 and IGF-1 are different after parturition, their influence does not affect reproductive capabilities of mares with a BCS of 5 or greater.  相似文献   

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