首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
The effect of water restriction in Awassi ewes was assessed under two physiological conditions: lactating and dry, over a 3-week-period (August–September, 2002). Eight dry and eight lactating Awassi ewes (with their lambs) were assigned to one of two watering regimes: watered once every three days and daily watering, respectively. Weather data, body weight and rectal temperature were recorded. Venous blood was sampled on the watering day of the water-restricted group, and subjected to haematological, biochemical and electrolytes analysis. Ewes under water restriction lost more weight and had higher packed cell volume, haemoglobin, serum cholesterol, urea, creatinine, total protein and albumin as compared to daily-watered animals. However, lactation seemed to have no significant effect on these serum components. As for blood pH and electrolytes, Na+ and Cl− were significantly higher under water restriction; whereas significantly lower K+ and Ca++ but higher pH and Cl− were observed in lactating animals. Finally, lower cortisol concentrations were observed in water-restricted animals, warranting further studies on the hormonal adaptation to long term water stress. It was concluded that water restriction induces similar changes in blood physiological indicators in dry and lactating Awassi ewes; while lactation beyond the first month post partum seems to mostly affect blood electrolytes.  相似文献   

2.
The antigenic polypeptides in Salmonella Enteritidis (SE) were chronologically recognized by the chicken immune system, using Western immunoblotting. Broiler chicks challenged at three days of age with SE strain carrying the most prevalent plasmid profile of 14.1 and about (approximately) 50 kb were bled at 17, 24, 31, 38 and 45 days of age. Pooled sera of blood collected at each age was reacted by Western immunoblotting with banded polypeptides of three predominant SE strains that acquired the following respective plasmid profiles: 14.1 kb; 14.1 and approximately 50.0 kb; and 1.8, 14.1 and approximately 50.0 kb. The immunoblots of each pooled sera collected at a specific age against the three SE strains were similar. More specifically, the early immune response at 17 days of age had antibodies recognizing only one polypeptide in the three SE strains namely, the 35.8 kDa. At 24 or 31 days of age, the acquired immunity to infection had antibodies recognizing five similar polypeptides in the three SE strains namely, the 14.4 (fimbriae protein), 21.5 (fimbriae protein), 30.5, 35.8, and 66.2 kDa. At 38 and 45 days of age, the antibodies recognized additional polypeptides namely, the 41.5 and 55.6 kDa, respectively. The recognition of the 41.5 and 55.6 kDa polypeptides at 45 days of age was associated with higher invasiveness of SE to spleens and livers (15.6%) and in higher cecal colonization (59.4%) in comparison to absence of recognition to the two polypeptides at 31 days of age associated with low infectivity to spleens (0%), livers (3.1%), and ceca (9.4%).  相似文献   

3.

This study aimed to evaluate the effect of progesterone (P4) device reutilization in long and short protocols for transcervical timed artificial insemination (TAI) in Santa Inês ewes. A total of 275 multiparous lactating ewes were blocked according to body weight (BW, 49.1?±?7.3 means ± SE), body condition score (BCS, 2.9?±?0.4; scale of 1–5), and days postpartum (50?±?8.2 days), and allocated to one of the treatments. The treatments were arranged in a factorial design, in which the factor 1 was the P4 device type (new or a device of 0.3 g of P4 previously used by 11 days), and the factor 2 was the short or long TAI protocol (P4 device remained by 7 or 11 days, respectively). At device removal, all ewes received 300 IU eCG and 6.70 mg of Dinoprost tromethamine. After TAI protocol, ewes remained with ram by 21 days. There was no interaction between factors in any variables. Ewes that received a new P4 device delayed (P?=?0.05) to show estrus compared with ewes receiving a previously used P4 device, but it did not affect pregnancy rate. The long protocol tended to increase pregnancy rate compared with short protocol (33% vs. 24%, respectively; P?=?0.07). However, the pregnancy rate at the end of reproductive period was similar in both groups (about 84%). Thus, the use of long protocols tended to improve reproductive performance, and the reused P4 device did not affect pregnancy rate.

  相似文献   

4.
The aim of the present study was to determine the normal ranges of the most commonly used serum biochemical parameters of sheep reared under Greek breeding conditions, as well as to test for the effects of the age and reproductive status of the animals on the normal values of these parameters. In total, 200 clinically healthy Chios sheep from 10 farms were used in the experiment. For the determination of the effect of age 150 sheep were assigned in three groups. Group A consisting of 50 lambs aged 2-6 months (mean +/- SD: 4.15 +/- 1.08), group B of 50 non-pregnant ewes into lactation aged 1-3 years (mean +/- SD: 2.12 +/- 0.86) and group C of 50 non-pregnant ewes into lactation aged more than 3 years (mean +/- SD: 5.98 +/- 1.66). For evaluating the effect of reproductive status 50 pregnant ewes in dry period were used, 15-30 days before the expected day of lambing (group D), along with the 100 non-pregnant ewes into lactation of groups B and C (group E). Blood sampling was performed once, in dry ewes from December to January, and in lambs and lactating ewes from March to May. The results showed that of the 14 biochemical parameters determined in serum, six were significantly affected by the age and eight by the reproductive stage of the animals.  相似文献   

5.
Copper oxide wire particles (COWP) have been used to reduce infection of Haemonchus contortus in hair breed lambs in southeastern USA without signs of copper toxicity. However, copper sensitivity among breeds and regions varies. The objective was to determine the effectiveness and safety of COWP in lactating Polypay ewes and their offspring grazing alfalfa/bluegrass pasture in a rotational grazing system. Mature Polypay ewes were administered 0, 0.5, 1, or 2 g (n=8 or 9/dose) COWP approximately 60 days after lambing in mid-July 2005. Their offspring were administered 0 (n=6), 0.5 or 0.75 g (n=9), 1 or 2 g (n=6) COWP 2 weeks later in late July. The primary gastrointestinal nematode was H. contortus (70%). Between Days 7 and 35, FEC were greater in 0 and 0.5 g COWP groups compared with ewes administered 2 g COWP (COWP x day, P<0.004). PCV decreased in all groups of ewes between Days 0 and 21 (day, P<0.001). Aspartate aminotransferase (AST) activity, a measure of liver copper levels, and body weight was similar among groups of ewes. FEC decreased within 7 days in COWP-treated compared with untreated lambs and remained low throughout experiment (COWP x day, P<0.05). PCV increased in COWP-treated lambs between Days 7 and 35 and decreased in untreated lambs between Days 0 and 21 (COWP x day, P<0.009). AST activity was similar among groups of lambs. Administration of 2 g COWP to ewes prevented a rise in FEC, but a dose of 0.5 g was ineffective as an anthelmintic. Administration of all doses of COWP to lambs decreased FEC and increased PCV compared to untreated lambs. There were no signs of copper toxicity in ewes or lambs. Alternative suppression of H. contortus infections may be necessary in ewes, but COWP was effective in H. contortus management for lambs.  相似文献   

6.
The toxicity of serpentine phosphate and superphosphate for non-pregnant dry ewes, pregnant ewes and lactating ewes was investigated by oral dosing. An attempt was made to reproduce a natural episode of poisoning by exposing pregnant and lactating ewes to topdressed pasture. A total dose in the range of 1200 to 1800 g of serpentine phosphate was required to kill two ewes and it was concluded that natural episodes of poisoning with this material are unlikely. The toxic process was similar to that caused by superphosphate. The LD50 of superphosphate was estimated to be in the range of 5 to 6 g/kg and a dose in the range of 200 to 300 g was sufficient to kill most sheep. The apparently greater susceptibility of pregnant and lactating sheep to poisoning suggested by the study of natural outbreaks was not demonstrated in these experiments, but the numbers of experimental animals may have been too small to detect differing susceptibility. The clinical disease resembled that seen in natural episodes; anorexia, diarrhoea, progressive depression and death in a period of 5 to 8 days after the start of dosing. Sublethal doses produced a transient diarrhoea and, in two sheep, a severe wool-break. The principal biochemical changes were hyperphosphataemia and evidence of renal failure (oliguria, uraemia, azotaemia). Gross lesions were not consistently present but included abomasal ulceration and renal cortical swelling and pallor. The histopathological evidence of renal tubular obstruction by flocculant eosinophilic casts was characteristic.  相似文献   

7.
The toxicity of serpentine phosphate and superphosphate for non-pregnant dry ewes, pregnant ewes and lactating ewes was investigated by oral dosing. An attempt was made to reproduce a natural episode of poisoning by exposing pregnant and lactating ewes to topdressed pasture.

A total dose in the range of 1200 to 1800 g of serpentine phosphate was required to kill two ewes and it was concluded that natural episodes of poisoning with this material are unlikely. The toxic process was similar to that caused by superphosphate.

The LD50 of superphosphate was estimated to be in the range of 5 to 6 g/kg and a dose in the range of 200 to 300 g was sufficient to kill most sheep. The apparently greater susceptibility of pregnant and lactating sheep to poisoning suggested by the study of natural outbreaks was not demonstrated in these experiments, but the numbers of experimental animals may have been too small to detect diiering susceptibility.

The clinical disease resembled that seen in natural episodes; anorexia, diarrhoea, progressive depression and death in a period of 5 to 8 days after the start of dosing. Sublethal doses produced a transient diarrhoea and, in two sheep, a severe wool-break.

The principal biochemical changes were hyperphosphataemia and evidence of renal failure (oliguria, uraemia, azotaemia). Gross lesions were not consistently present but included abomasal ulceration and renal cortical swelling and pallor. The histopathological evidence of renal tubular obstruction by flocculant eosinophilic casts was characteristic.  相似文献   

8.
A survey on the prevalence and intensity of infection with gastrointestinal helminths of Dorper sheep in relation to age and weather factors was carried out on a ranch in Kajiado district, a semi-arid area of Kenya for a period of 13 months (May 1999 to May 2000). Faecal samples from lambs (3 months to 1 year), yearlings (1-2 years) and adult breeding ewes (2-4 years) were examined for helminth egg output and helminth genus composition at 3-week intervals. The results indicated that the prevalence of strongyle and tapeworms infections were highest for lambs, followed by the adult breeding ewes and then for the yearlings. In all age groups the proportions of infected animals were higher during the wet season than in the dry season for both nematodes and tapeworms. The mean strongyle egg counts were higher during the dry season for lambs, but were higher during the wet season for the other age groups. Mixed strongyle infections were detected, with Trichostrongylus (55 %), Haemonchus (28 %), Cooperia (10.5 %) and Oesophagostomum (6.5 %) being the most frequently encountered genera throughout the study period. The trends in strongyle faecal egg counts indicated the occurrence of hypobiosis, with resumption of development towards the end of the dry season and at the onset of the short rains in October and November. Self-cure was also observed in September and November in all age groups, although less frequently in lactating ewes. The prevalence and intensities of infection with gastrointestinal helminths in this area appeared to be influenced by the age of the host and weather factors.  相似文献   

9.
Toxoplasma gondii, an intracellular protozoan parasite, is one of the major causes of infectious abortion in sheep. To further understand the pathogenesis of toxoplasmosis, serum, amniotic and allantoic fluids and foetal stomach contents were collected from experimentally infected pregnant ewes to determine pathogen numbers and other markers of infection. Fifteen pregnant ewes (90 days of gestation) were each orally inoculated with 3000 sporulated oocysts of T. gondii. Serum samples were collected weekly following challenge. Amniotic and allantoic fluids and foetal stomach contents were collected at 21, 25, 28, 33 and 35 days post-infection. Characteristic placental lesions were detected in 1 of 4 challenged ewes at day 25, 3 of 4 challenged ewes at day 28 and in all challenged ewes at days 33 and 35 post-infection. T. gondii was detected only sporadically in amniotic and allantoic fluids before 35 days of infection, by real-time PCR, and only in ewes with placental lesions. At 35 days post-infection, high numbers of parasite were detected in both amniotic and allantoic fluids. An increase in the number of fluids from challenged animals with IgM and IgG was detected over time, except for IgG in allantoic fluid, which was detected in all samples from day 21 post-infection. IgG in amniotic and allantoic fluids was shown to be specific for T. gondii, and reacted with antigens with an apparent molecular mass of approximately 22 kDa and 30 kDa. Results suggest a maternal source of immunoglobulin in the allantoic fluid and a foetal source of immunoglobulin in the amniotic fluid early in infection but that both sources may contribute immunoglobulin to both fluids at a later stage.  相似文献   

10.
Three experiments were conducted to investigate experimentally the occurrence of periparturient nematode egg rise in ewes and the hormonal modulation of Haemonchus contortus infections. In the first experiment, fall-bred and winter-bred pregnant (n = 4 and 14, respectively) and nonpregnant (n = 5 and 29, respectively) ewes were treated with anthelmintic and were pastured together on fields that were contaminated with H contortus. Three weeks before lambing, all ewes were placed in concrete pens; fecal egg counts for the winter-bred group were obtained on alternate days. Pregnant and lactating ewes had significantly larger numbers (P less than 0.01) of H contortus eggs than did the nonpregnant controls 1 week before and after lambing. Lactating, fall-bred ewes had significantly (P less than 0.01) more adult worms in their abomasum through natural acquisition than the nonpregnant controls. In the second experiment, fall-bred and winter-bred, helminth-free, pregnant (n = 4 and 8, respectively) and nonpregnant (n = 3 and 15, respectively) ewes were inoculated on 5 alternate days, beginning 70 days after breeding with 20,000 infective H contortus larvae. The ewes were maintained on concrete pens throughout pregnancy. Fecal egg counts were significantly (P less than 0.05) greater in pregnant ewes, beginning 1 week before lambing until 1 week after lambing. Abomasums of lactating ewes from both lambing seasons yielded significantly (P less than 0.01) more adult worms at necropsy than nonpregnant ewes. In the third experiment, ewes were ovariectomized (n = 15) or sham-operated (n = 9); half of the control ewes were bred.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

11.
This study aimed to evaluate the effectiveness of hormonal treatments on ovarian activity and reproductive performance in Barki and Rahmani ewes during non‐breeding season. Forty‐eight multiparous ewes, 24 Barki and 24 Rahmani ewes were divided into two groups, 12 lactating and 12 dry ewes for each breed. Controlled internal drug release (CIDR) device was inserted in all ewes for 14 days in conjunction with intramuscular 500 IU equine chronic gonadotrophin (eCG) at day of CIDR removal. Data were analysed using PROC MIXED of SAS for repeated measures. Breed, physiological status and days were used as fixed effects and individual ewes as random effects. Barki ewes recorded higher (p < .05) total number of follicles, number of large follicles, serum estradiol concentration and estradiol: progesterone (E2:P4) ratio compared to Rahmani ewes. Lactating ewes recorded higher (p < .05) number of small follicles and lower concentration of total antioxidant capacity (TAC) compared to dry ewes. Number and diameter of large follicles recorded the highest (p < .05) values accompanied with disappearance of corpora lutea at day of mating. Serum progesterone concentration recorded lower (p < .05) value at day of mating and the highest (p < .05) value at day 35 after mating. CIDR‐eCG protocol induced 100% oestrous behaviour in both breeds, but Rahmani ewes recorded longer (p < .05) oestrous duration compared to Barki. Conception failure was higher (p < .05) in Barki compared to Rahmani ewes. In conclusion, CIDR‐eCG protocol was more potent in improving ovarian activity in Barki compared to Rahmani ewes, but this protocol seems to induce hormonal imbalance in Barki ewes that resulted in increasing conception failure compared to Rahmani ewes.  相似文献   

12.
AIM: To determine the effect of increasing doses of long-acting injectable vitamin B12 plus selenium (Se) given pre-mating on the vitamin B12 and Se status of ewes and their lambs from birth to weaning. METHODS: Four groups of 24 Poll Dorset ewes each were injected 4 weeks pre-mating with different doses of a long-acting vitamin B12 + Se product, containing 3 mg vitamin B12 and 12 mg Se per ml. The treatment groups received 5 ml (15 mg vitamin B12 + 60 mg Se), 4 ml (12 mg vitamin B12 + 48 mg Se), 3 ml (9 mg vitamin B12 + 36 mg Se), or no vitamin B12 or Se (control). Twelve of the twin-bearing ewes per group were selected for the study. Efficacy of the product was evaluated from changes in the concentrations of vitamin B12 in serum and liver, and of Se in blood, liver and milk in the ewes during gestation and lactation, and in their lambs from birth to weaning. Pasture samples in paddocks grazed by the ewes and lambs were collected at about 2-monthly intervals from 200-m transects. RESULTS: The flock was Se-deficient, as the mean initial concentration of Se in the blood of ewes was 182 (SE 20.3) nmol/L. Compared with untreated controls, all doses significantly (p < 0.01) increased concentrations of Se in the blood of ewes for at least 300 days. Selenium concentrations in milk were likewise increased throughout lactation, as were those in the blood and liver of lambs. The mean concentration of vitamin B12 in the serum of ewes was initially > 1,000 pmol/L, but this decreased within 28 days to < 460 pmol/L. Treatment with the 5-ml and 4-ml doses raised serum vitamin B12 concentrations of ewes for at least 176 days (p < 0.01), while their lambs had significantly greater concentrations of vitamin B12 in serum and liver for less than 37 days after birth. Tissue concentrations and duration of elevation of both vitamin B12 and Se were proportional to the dose administered. The mean concentrations of Se and cobalt (Co) in the pastures were 32 and 74 microg/kg dry matter (DM), respectively. CONCLUSIONS: Injecting ewes from a Se-deficient flock 4 weeks prior to mating with 48 or 60 mg Se and 12 or 15 mg vitamin B12 increased and maintained the Se status of ewes for at least 300 days, and of their lambs from birth to weaning. The vitamin B12 status of ewes was increased for at least 176 days and that of their lambs for less than 37 days. Due to the proportional nature of the response to increasing dosage, the dose rate of the formulation tested can be adjusted according to the severity of Se and Co deficiency in a flock. CLINICAL SIGNIFICANCE: A single subcutaneous injection of vitamin B12 + Se administered pre-mating to Se-deficient flocks is likely to prevent Se deficiency in ewes and their lambs until weaning, as well as increase the vitamin B12 status of ewes and their lambs until 5 weeks after lambing.  相似文献   

13.
Our study aimed to investigate responses to supplementation of calcium (Ca), magnesium (Mg) and sodium (Na) to lactating ewes and lambs grazing barley forage from lamb marking to weaning. A 10-ha paddock sown to barley was subdivided into eight plots as four replicates of two treatments. Merino ewes (n = 104) with lambs at foot were stratified to the eight plots (13 ewes and 21 lambs/plot) based on number of lambs (twin or single) and ewes' weight. Supplemented groups had access to mineral supplements (30 g/ewe/day) supplying 12 g/ewe/day ground limestone, 12 g/ewe/day Causmag® and 6 g/ewe/day coarse salt in a ratio of 2: 2: 1 by weight (as fed) from day 0 (a day before lamb marking) after sample collection. Control groups were not supplemented with minerals. Blood, milk and urine samples from ewes and blood from lambs were collected at different time points, namely, a day prior to lamb marking (day 0), 14 days after the commencement of study (day 14), and 28 days after the commencement of study (day 28). Weight of the lambs was also recorded at each time point. We found that the concentration of the forage minerals (Ca, Mg and potassium (K)) was lower on day 28 than on day 0 (P < 0.025). Liveweight gain was greater in the first 14 days compared with the second weight gain period (P < 0.001). The interaction of time and treatment was significant for liveweight (P < 0.001). Due to the improvement in weight gain of supplemented lambs, we recommend that mineral supplementation during late lactation is beneficial considering the low cost of minerals, even though the mineral content of the forage was not deficient.  相似文献   

14.
The main purpose of the study was to investigate whether the feeding system applied has any effect on the status of blood selenium (Se) and vitamins A and E in dairy sheep. In total 200 dairy sheep from 10 flocks were used in the study (20 animals per flock). Group A consisted of 100 sheep (five flocks) reared under the intensive feeding system and group B of 100 sheep (five flocks) reared under the semi-intensive feeding system. The 100 sheep of each group consisted of 25 lambs aged 3-6 months, 25 ewes 1-3 years, 25 ewes more than 3 years and 25 non-lactating ewes in late gestation. Another purpose was to evaluate the potential effect of the age and the reproductive stage of the animals on these parameters. To determine the effect of age, 150 of these animals were divided into three subgroups: 50 lambs, 50 non-pregnant lactating ewes aged 1-3 years and 50 non-pregnant lactating ewes aged more than 3 years. For the evaluation of the effect of the reproductive stage the 50 non-lactating ewes in late gestation and the 100 non-pregnant lactating ewes were used. Blood samplings were performed once, between December and January for non-lactating ewes in late gestation and March to May for lambs and lactating ewes. Whole blood Se and vitamin E and A serum concentrations were determined. The main conclusion is that the feeding system significantly affects Se and serum vitamin A concentration, as they were higher in the intensive one. It was secondly concluded that age affects the serum concentrations of vitamin A.  相似文献   

15.
AIM: To quantify the effects of clinical Johne's disease on the performance of Romney, Merino and Merino x Romney-cross ewes. METHODS: The performance of ewes was compared using eight birth cohorts (1971-1978). Merino and Merino-cross genotypes included New Zealand Merino and Australian Superfine Merino sources. Intensive monitoring of Johne's disease was undertaken over the production years 1975-1982. Positive diagnostic evidence of Johne's disease was established post mortem from lesions of granulomatous enteritis associated with high numbers of acid-fast bacilli. Over years, data on a total of 2,341 Romney ewes and 1,292 Merino and Merino x Romney-cross ewes were recorded, consisting of annual records of liveweight (LWT), greasy fleece weight (FWT), number of lambs born per ewe per year (NLB), and lifetime productivity of ewes. RESULTS: A total of 82 (3.5%) Romney ewes and 62 (4.8%) Merino and Merino x Romney-cross ewes were diagnosed with clinical Johne's disease over the 8-year monitoring period, equivalent to 0.9% and 1.2% annual cases for these breeds, respectively, of the ewes present at mating. The percentage of clinical cases (p<0.04) and the age at death from Johne's disease (p<0.02) were lower for Romneys than for Superfine Merinos. The mean age of death from Johne's disease was 3.41 (standard error (SE) 0.06) years, lower than the mean disposal age from the flock of 5.03 (SE 0.02) years for clinically normal ewes (p<0.001). In their final year of production, ewes with clinical Johne's disease had lower LWT by 5.3 kg (10.5% of the mean; p<0.001), lower annual FWT by 0.54 (SE 0.10) kg (14.2%; p<0.001), fewer NLB by 0.15 (SE 0.07) lambs (13%; p<0.05), and lower litter weaning weights by 3.6 (SE 1.3) kg (15%; p<0.01) compared with clinically normal ewes. The size of the production losses associated with Johne's disease depended on the age to which ewes survived. Considering all production years of ewes (up to 8 years), the total weight of lambs weaned by ewes with clinical Johne's disease was 30.9 (SE 3.4) kg lower (46%; p<0.001) than the total from clinically normal ewes. CONCLUSIONS: Clinical Johne's disease led to significant losses in LWT, FWT, NLB, and in the lifetime production of ewes, amounting overall to a 46% reduction in productivity (p<0.001). CLINICAL RELEVANCE: Productivity losses from clinical cases of Johne's disease would be of considerable economic importance in flocks with a high incidence of the disease. The lack of good diagnostic tests for Johne's disease in the live animal, and the lack of active surveillance programmes, has made it difficult to establish the true prevalence of Johne's disease in sheep flocks in New Zealand, and its economic consequences.  相似文献   

16.
A series of experiments were conducted to investigate the elimination of swainsonine in the milk of lactating ruminants following a single dose oral exposure to swainsonine (locoweed; Oxytropis sericea) and to assess subsequent subclinical effects on the mothers and their nursing young. In a preliminary experiment, lactating ewes were gavaged with locoweed providing 0.8 mg swainsonine/kg BW (n = 4; BW = 75.8 +/- 3.6 kg; lactation = d 45) and lactating cows were offered up to 2.0 mg swainsonine/kg BW free choice (n = 16; BW = 389.6 +/- 20.9 kg; lactation = d 90). Serum and milk were collected at h 0 (before treatment), 3, 6, 12, and 24 for ewes, and h 0 (before treatment), 6, 12, 18, and 24 for cows. Swainsonine was highest (P < 0.05) by h 6 in the serum and milk of ewes. Consumption of at least 0.61 mg swainsonine/kg BW induced consistent (> 0.025 microg/mL) appearance of swainsonine in cow serum and milk. In response to the results obtained in the preliminary experiment, a subsequent experiment utilizing lactating ewes (n = 13; BW = 74.8 +/- 6.4 kg; lactation = d 30) and cows (n = 13; BW = 460.8 +/- 51.9 kg; lactation = d 90) was conducted. Each lactating ruminant was gavaged with a locoweed extract to provide 0 (control), 0.2, or 0.8 mg swainsonine/kg BW and individually penned with her nursing young. Serum and milk from the mothers and serum from the nursing young were collected at h 0 (before treatment), 3, 6, 9, 12, 24 and 48 (an additional sample was obtained at h 72 for ewes and lambs). Serum and milk swainsonine was higher (P < 0.05) in the 0.8 mg treated groups and maximal (P < 0.05) concentrations occurred from h 3 to 6 for ewes and h 6 to 12 h for cows (P < 0.05). Rises in alkaline phosphatase activity indicated subclinical toxicity in the treated ewes (P < 0.05). Following a single dose oral exposure to 0.2 and 0.8 mg swainsonine/kg BW provided by a locoweed extract, swainsonine was detected in the serum and milk of lactating ewes and cows, and rises in serum alkaline phosphatase activity were observed in the ewes. Neither swainsonine nor changes in alkaline phosphatase activity was detected in the serum of the lambs and calves nursing the ewes and cows dosed with swainsonine.  相似文献   

17.
The effects of protein supply and reproductive status on circulating antibody responses and local inflammatory cell counts were investigated in parasitized sheep, with local immune responses assessed through a recently refined abomasal cannulation methodology. We hypothesized that if breakdown of immunity has a nutritional basis, then protein scarcity would result in a breakdown of immunity to Teladorsagia circumcincta in both periparturient and non-reproducing (barren) ewes. Twin-bearing and barren, abomasally cannulated ewes were fed at either 0.8 or 1.3 times protein requirements from 3 weeks before until 6 weeks after parturition (n = 6). All sheep were trickle infected at a rate of 10,000 infective larvae (L3) per day, for 3 days per week throughout the experiment. Faecal egg counts remained virtually zero in all barren ewes, whilst protein supplementation reduced faecal egg counts in the periparturient ewes during most of the periparturient period. Final worm burdens, taken at 6 weeks into lactation, were lower for the barren ewes than for the lactating ewes, whilst protein supplementation reduced worm burdens in the latter. Protein supply did not affect mucosal mast cell counts, which were consistently higher for the barren ewes than the periparturient ewes, but were temporarily decreased around parturition. Barren ewes and protein supplemented lactating ewes had higher globule leukocyte counts than the unsupplemented lactating ewes. Protein supplementation increased eosinophil counts in the lactating ewes though only during the later part of the lactation period. Plasma IgA anti-L3 antibody was similar for all ewes, but IgE anti-L3 antibody was higher for the protein supplemented periparturient ewes compared to the unsupplemented periparturient ewes and all barren ewes. It is likely that the combination of low protein requirements and large body protein reserves did not result in breakdown of immunity to T. circumcincta for the barren ewes. These results suggest that changes in mucosal mast cell and eosinophil counts are not necessarily associated with changes in host resistance to T. circumcincta. However, the data support the view that increased globule leukocyte counts and plasma IgE anti-L3 antibody may be associated with nutritionally improved expression of immunity in periparturient ewes.  相似文献   

18.
Estrus synchronization in sheep with synthetic progestagens   总被引：1，自引：1，他引：0  
Sixteen female sheep of Degua breed were assigned to receive either the full dose of norgestomet ear implant and injectable solution containing norgestomet and estradiol valerate (n = 8) or half the dose (n = 8). The ear implants were removed in both groups on day 12. All ewes received an intramuscular administration of 500 IU PMSG at implant withdrawal. Synchronized ewes were individually hand mated twice at 48 and 60 hours after implant removal. One ewe in each group however refused mating on both occasions. Pregnancy diagnosis was conducted by bimanual external palpation 90 to 100 days post mating. The conception rates (3/7, 42.85%) and (5/7, 71.42%) were recorded in the two treatment groups, respectively. All eight ewes lambed between 145 to 153 days post mating. In group I ewes carried only singletons (prolificity rate 1.0) whereas in group II two ewes delivered twins, producing 7 lambs with prolificity rate of 1.4 (N.S). From this preliminary investigation it appears that the lower dose of norgestomet ear implants offers better option for estrus synchronization accompanied by higher fertility.  相似文献   

19.
The experiment involved 40 mid-lactating Comisana ewes. The animals were housed in straw-bedded pens and assigned to a control group (n = 10) and two test groups of 15 subjects each. Control ewes were never moved from their pen and peers throughout the experiment period, whereas test animals were subjected to either regrouping (RG) or regrouping and relocation (RGRL) three times at weekly intervals (d 7, 14, and 21 of the trial). Three behavioral recordings were conducted after each social and pen exchange over a 6-h period (1000 to 1600). Animals from groups RG and RGRL were bled immediately before each regrouping and relocation and 15 and 60 min afterward. The phytohemagglutinin skin test was performed at d 9, 16, and 23. Milk yield was recorded when the ewes were mixed and moved, and before and after each mixing and moving procedure. Individual milk samples were analyzed for composition, renneting parameters, and bacteriological characteristics; samples with more than 10(6) somatic cells/mL were cultured for mastitis-related pathogens. Control ewes spent more time lying than groups RG (P < 0.001) and RGRL (P < 0.01) and less time in ambulatory activities than RGRL sheep (P < 0.05). Moved and remaining ewes showed a higher number of aggressive interactions than control subjects (P < 0.001 and P < 0.01, respectively). Control sheep showed the highest cell-mediated immune response compared with both moved and mixed ewes (P < 0.001 and P < 0.01, respectively). The RGRL ewes gave lower yields of milk than did the control ewes on the days after the first (P < 0.05) and the second (P < 0.01) change of pen and peers. The RGRL ewes also had a lower fat content (P < 0.05) than control ewes in the milk yielded on the day of the first regrouping and relocation and a lower milk protein content (P < 0.05) on the following day. The RG treatment resulted in the ewes yielding milk with a lower fat content (P < 0.01) on the day of each mixing procedure as compared with controls and in a decreased milk protein content on the days after the first (P < 0.05) and the second regrouping (P < 0.01). One case of subclinical mastitis was recorded in both the RG and RGRL groups, whereas no cases were detected in control group. These findings suggest that regrouping and relocation may cause increased aggression, altered immune responses, and short-term effects on the production performance of lactating ewes. These practices should be performed by attempting to minimize their impact on animal welfare.  相似文献   

20.
The present study was undertaken to antigenically characterize the buffalopox virus (BPV). Six monoclonal antibodies (MAbs) against the BP4 strain of BPV have been produced and characterized. All six MAbs appeared to be specific to BPV, as none of them showed cross-reactivity with other poxviruses in antigen capture ELISA. Only two MAbs (20AB8 and 20CD11) bound significantly with different BPV isolates in antigen capture ELISA, whereas the remaining four MAbs bound weakly with the BPV. In Western blot analysis with purified BPV-BP4, the rabbit hyperimmune serum against purified BPV-BP4 reacted with 15 immunodominant polypeptides (100 kDa to 25 kDa), whereas two MAbs (21CB6, 21DB11) reacted with 42 kDa and 45 kDa polypeptides, respectively. However, three MAbs (20AB8, 20CD11, 21CB5) reacted with three degraded polypeptides (100 kDa, 40 kDa and 87 kDa) of BPV-BP4. In radioimmunoprecipitation assay (RIPA) with the rabbit hyperimmune serum to BPV-BP4, three virus specific polypeptides (69 kDa, 34 kDa, 32 kDa) were recognized in BPV-BP4, whereas two polypeptides (69 kDa, 34 kDa) were recognized in other BPV isolates (BPV-Bly, BPV-Vij96, BPV-Vij97). In virus neutralization test, none of the six MAbs tested showed any significant neutralizing ability to infection with different BPV isolates. However, the hyperimmune serum showed weak neutralizing ability to BPV infection.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号