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1.
1. Chronic administration of a glycoprotein fraction from chicken pituitary using an ALZET osmotic pump at 12.5 micrograms/h for 2 weeks induced growth of ovarian follicles to a mature size in the ovary and deposition of yolk in sexually immature 6-week-old Japanese quail females which were kept under 8L:16D short-day conditions. However, no ovulation was induced in these birds. 2. Injection of 500 micrograms of the glycoprotein into other immature short-day females was performed following the above chronic administration, 12 or 14 and 15 d after implantation of the osmotic pump. About 24 h after injection, 3 of 14 females laid one or two eggs. Ovulation was confirmed in 4 females by autopsy. A total of 5 of 14 females ovulated 6 eggs, and significant development of the oviduct and the cloacal opening were observed in all of the treated females. 3. Thus, complete ovarian function could be induced in sexually immature female Japanese quail by administration of avian gonadotrophin using a combination of an osmotic pump and an injection.  相似文献   

2.
In 72 (46%) of 155 gilts discarded for genetic reasons after performance testing and housed under fattening conditions no heat could have been detected during the first 30 days. The gilts were assigned alternatingly to a control group and four different treatments of delayed puberty. The induction of puberty was carried out by injections of 1000 iu PMSG, 400 iu HCG and 2 mg oestradiol benzoate, 400 iu PMSG and 200 iu HCG and 800 iu PMSG and 400 iu HCG. If there was no estrus gilts were slaughtered 12 days later for examination of the ovaries. Those coming into estrus were slaughtered 8 days after disappearance of estrus. Estrus could be induced in 69 to 94% of the gilts, whereas 40% of the untreated showed estrus signs. After treatment with PMSG and HCG in 40 and 87% of the gilts cysts were found whereas none of the untreated and 26 and 29% of those treated with PMSG und HCG + oestradiol benzoate revealed ovarian cysts. In addition, those gilts that had come into estrus during the first 30 days were given injections of either 1000 iu PMSG or 800 iu PMSG and 400 iu HCG. The injections were made either on the 5th, 10th or 15th day of cycle. In both latter groups significantly more gilts showed standing heat than after treatment at cycle day 5. The results of inspection of the ovaries at slaughter and steroid hormones could not be assigned to a defined stage of the physiological ovarian cycle.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

3.
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4.
Forty-four female ranch mink, maintained out-of-doors under standard conditions, were exposed to natural photoperiod supplemented with a period of artificial light from approximately 2300 hr to 0300 hr from early January to mid February. Breeding was initiated on March 1. After repeated attempts to breed the animals, it was determined that the likelihood of their breeding was very low, presumably due to the artificial and asynchronous long-day photoperiod. In an attempt to induce breeding, the mink were randomly assigned to one of four treatment groups: saline, 25 International Units (IU) PMSG, 37.5 IU PMSG and 50 IU PMSG. Significantly different (p<0.05) patterns of breeding success were observed following PMSG treatment. Approximately 90% of the 37.5 and 50 IU PMSG-treated females bred while only 30 to 50% of the females in the saline and 25 IU PMSG-treated groups bred. More importantly, there was a marked difference in successful pregnancies observed between the saline- and PMSG-treated animals. None of the saline-treated females bore offspring while 40% of the animals that were treated with PMSG gave birth, with litter size averaging between 4 and 5 kits per female. Histological evaluation of ovaries obtained from an additional 13 animals treated in a similar fashion demonstrated that PMSG treatment significantly increased the number of small follicles. These results demonstrate that the exogenous administration of PMSG has a potential application in increasing the reproductive efficiency of female mink with functional ovarian tissue yet rendered infertile due to other factors.  相似文献   

5.
In a previous study, we found that 3-methyl-4-nitrophenol (PNMC), a component of diesel exhaust particles and also a degradation product of the insecticide fenitrothion, exhibits reproductive toxicity in the adult male Japanese quail. The present study investigated the toxicity of PNMC in the female Japanese quail and its ability to influence reproduction in immature females. The quail (21-day-old) were injected intramuscularly (im) with PNMC at doses 0.1, 1 or 10 mg/kg body weight daily for 3 days. There was no significant difference in body growth between the PNMC-administered and control birds. However, the weights of the oviducts were significantly lower in the PNMC-treated birds at all doses. Furthermore, the plasma concentrations of luteinizing hormone (LH) and estradiol-17 beta were significantly decreased with 1 and 10 mg/kg of PNMC. These findings suggest that PNMC might influence the hypothalamo-pituitary-gonadal axis with decreasing in secretion of GnRH, LH and ovarian steroid hormones and subsequently disturb growth of the reproductive organs of immature female quail. This study indicates that PNMC induces reproductive toxicity at the central level and disrupts reproductive function in the immature female quail.  相似文献   

6.
1. In two experiments laying hens were treated with an agonist of gonadotrophin releasing hormone (GnRH) to induce a reduction in the secretion of luteinising hormone (LH) and a pause in egg production. 2. In experiment 1, 70-week-old laying hens were either given daily subcutaneous injections of saline for 7 d, offered whole oats for 7 d (nutrient restriction), given daily injections of the GnRH agonist [D-Trp6-Pro9 N-ethyl amide]GnRH for 7 d at 50 micrograms/kg or 100 micrograms/kg or administered 4 biocompatible implants each containing 120 micrograms of the GnRH agonist. 3. Weekly egg production was monitored for 7 weeks and blood samples were taken at weekly intervals and assayed for plasma LH and oestradiol. Egg production was reduced in the birds treated with the agonist (28 to 46% reduction) but not to the same extent as in the birds offered whole oats (92.3% reduction). 4. The treatments also reduced plasma LH and oestradiol in treated hens but again to a greater extent in the birds offered whole oats than the birds treated with the agonist. Egg production and plasma LH and oestradiol increased following the termination of the treatments. 5. The birds fed whole oats suffered a reduction in weight of 16.7% over the treatment period whereas there were increases in the weights of the birds treated with saline, 50 micrograms of GnRH agonist and the implants of GnRH agonist, but no change in birds treated with 100 micrograms of GnRH agonist. 6. The birds fed oats lost feathers over the treatment period but the birds in the other treatment groups suffered no loss. 7. In experiment 2 laying hens were either injected daily with saline or 200 micrograms GnRH agonist and weekly egg production and plasma LH and oestradiol were measured. As egg production was reduced by almost 60% in the birds treated with the agonist but did not completely cease. Reductions in plasma LH and oestradiol were also observed. All variables increased to pretreatment levels once treatment ceased. 8. These data confirm the effects of severely depriving hens of nutrients on egg production and the secretion of LH and oestradiol.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

7.
Two experiments were performed to examine the influence of exogenous growth hormone on the reproductive axis in gilts. Experiment one employed 26 Yorkshire × Landrace prepubertal gilts, which were selected at 150 d and 86.5 ± 1.5 kg bodyweight (BW) and assigned equally to two treatments. Gilts received injections of either porcine growth hormone at 90 μg/kg BW, or vehicle buffer, from 150 to 159 d. At 154 d gilts received 500 IU PMSG, followed 96 hr later by 250 IU hCG. Gilts were slaughtered at 163 days and their ovaries recovered to determine ovulatory status. In each treatment, gilts failed to show any ovarian response to PMSG/hCG. All remaining control gilts ovulated and their ovaries appeared morphologically normal. In gilts receiving exogenous growth hormone, fewer ovaries (4/11, P<.01) appeared morphologically normal. The ovaries of all other growth hormone injected gilts had very large (12–25 mm) non-luteinized follicles. In experiment two, 20 prepubertal Yorkshire × Landrace gilts were selected at 138 days and 85 kg BW. These gilts received injections of growth hormone at 90 μg/kg BW (n=9) or vehicle (n=11) from 138 to 147 days. At 143 days, all gilts were given an injection of estradiol benzoate (EB) at 15 μg/kg BW. Blood samples were taken at the time of EB injection, at 24 and 36 hr and then at 6 hr intervals until 78 hr. All samples were assayed for serum LH concentrations. The EB induced LH peak height was lower (P<.04) in gilts receiving exogenous growth hormone than in controls. The results presented indicate that the daily injection of growth hormone at 90 μg/kg BW reduced the estradiol-induced release of LH in addition to reducing the number of corpora lutea in gonadotrophin stimulated gilts.  相似文献   

8.
In 2 experiments involving 151 non-lactating and 107 lactating Brahman or Brahman-cross cows, the effects of progesterone treatments (PRID) of 2 durations (7 v 14 days) and injections of pregnant mare serum gonadotrophin (PMSG) at 3 doses (O v 375 v 750 IU) were examined. All cows were inseminated with frozen/thawed semen 54 to 58 and 70 to 74 hours after PRID removal. Calving rates of non-lactating cows (38%) were unaffected by breed or treatment but were higher in previously cyclic than acyclic cows (44% v 19%, P less than 0.025) and in cows which exhibited oestrus after treatment (52% v 23%, P less than 0.001). Calving rates of lactating cows were not affected by these factors but were affected by treatment; PMSG produced no significant effect after a 7-day PRID treatment (33% overall) but increased calving rates after 14-day PRID treatments (22% v 46% v 37% for 0, 375 and 750 IU respectively, P less than 0.10). Comparisons of calving rates of lactating cows treated with 14-day PRID and PMSG and artificially inseminated, and untreated naturally mated cows, showed that treatment significantly increased the proportion of cows conceiving in the first 35 days of the mating period (50% v 23%, P less than 0.025). The results show that treatment with PRID for 14 days and PMSG can overcome post-partum anoestrus in lactating Brahman and Brahman-cross cows leading to significant reductions in the calving to conception interval.  相似文献   

9.
A total of 88 thoroughbred mares were diagnosed with clinical ovarian quiescence and subjected to four treatment regimens. Using PMSG, hCG or combinations of both. A high dose combination of 5,000IU PMSG with 5,000IU hCG showed significantly higher rates of marked estrus and ovulation induction (P<0.01) as well as conception rates (P<0.05). In the present study, the administration of a high-dose combination of PMSG with hCG was shown to be an effective treatment of ovarian quiescence in light mares.  相似文献   

10.
Effects of photoperiod on growth, carcass composition and serum concentrations of prolactin, growth hormone and cortisol were determined in prepubertal and postpubertal Holstein heifers. Forty-two prepubertal (avg body wt 84 +/- 3.0 kg) and 42 postpubertal (avg body wt 303 +/- 7.1 kg) Holstein heifers were utilized. Ten prepubertal and 10 postpubertal heifers were slaughtered before treatment began to obtain initial carcass data. The remaining 32 prepubertal and 32 postpubertal heifers were paired by body weight and randomly assigned to short-day (8 h of light: 16 h of dark) or long-day (16 h of light: 8 h of dark) photoperiods. After exposure to treatments for an average of 139 d, 10 prepubertal and 10 postpubertal heifers from each photoperiod treatment were slaughtered. In prepubertal heifers, photoperiod did not affect (P greater than .10) average daily body weight gain, carcass weight, carcass composition, accretion of carcass fat and carcass protein, or serum concentrations of prolactin, growth hormone or cortisol. However, prepubertal heifers exposed to long-day photoperiods had reduced (P less than .01) urinary N tau-methylhistidine excretion compared with heifers given short-day photoperiods. Postpubertal heifers exposed to short-day photoperiods had greater average body weight daily gain than animals exposed to long-day photoperiods. Although there was no effect of photoperiod (P greater than .10) on carcass or fat depot weights, postpubertal heifers exposed to short days had greater (P = .06) percentages of fat and reduced (P = .07) percentages of protein in the soft tissue of the 9-10-11 rib sections. Fat accretion was greater (P less than .05) in carcasses of postpubertal heifers exposed to short days than heifers given long-day photoperiods, but there was no effect (P greater than .10) of photoperiod on protein accretion. Photoperiod did not affect serum concentrations of growth hormone and cortisol, but serum prolactin tended (P less than .10) to be greater in postpubertal heifers exposed to long days. Under the conditions of this experiment, we conclude that exposure to short-day photoperiods stimulated body weight gain and fat accretion in postpubertal but not prepubertal Holstein heifers.  相似文献   

11.
1. A 28-d experiment was conducted to evaluate the effects of fumonisin B1 (FB1) on egg production and egg quality of young laying Japanese quail fed on fumonisin-contaminated rations. 2. To this end, 128 7-week-old birds were randomly distributed into 4 experimental groups (32 birds per group) and given rations containing 0 (control), 10, 50 and 250mg FB1/kg feed. Each treatment consisted of 4 replicates of 8 quail. Egg production and egg weight were checked daily. Feed consumption and feed conversion were determined weekly. Eggs laid on the last day of each 7-d period were collected and subjected to individual analysis for specific gravity, Haugh units and percentage eggshell. 3. Compared with controls, quail given > or = 50 mg FB1/kg had reduced feed intake and lower body weight gain. Feed conversion was reduced only in birds given 250 mg FB1/kg. 4. Mean egg production and egg weight were lower in birds given 250mg FB1/kg. Eggshell weight was reduced in birds given > or =50mg FB1/kg. However, mean specific gravity, Haugh units and percentage eggshell were not affected by FB1. 5. No histopathological changes were observed in liver, kidney or heart samples from any treatment group. 6. The results indicated that exposure to FB1 at concentrations > or = 50 mg/kg could adversely affect quail performance, emphasising the importance of controlling fumonisin contamination of quail rations.  相似文献   

12.
1. Groups of ISA Brown pullets were transferred from 8- to 16-h photoperiods at 34, 44 or 54 d. In each group, 12 birds were injected on alternate days over a 12-d period starting 6 d before the change in photoperiod with beta-oestradiol-3-benzoate (1 mg/kg body weight) or with arachis oil vehicle (controls). Short-day controls were similarly injected from 28 to 40 d. Long-day (16 h) controls were also included in the trial but were not injected. Age at first egg (AFE) was recorded and plasma luteinising hormone (LH) concentrations were measured around the time of oestradiol treatment. 2. Mean AFE for birds photostimulated at 34 d was not significantly different from short-day controls. Birds photostimulated at 44 and 54 d matured at similar ages but 3 weeks earlier than short-day controls (P<0.05). 3. There was a tendency for oestradiol to advance AFE for birds photostimulated at 34 d (P=0.15) but to delay AFE following photostimulation at 44 d (P=0.23). Oestradiol significantly delayed AFE for the birds photostimulated at 54 d (P=0.01). 4. Plasma LH levels during 6 d of oestradiol injection but before transfer from 8- to 16-h photoperiods tended to fall between 28 and 34 d, were relatively constant between 38 and 44 d, but declined significantly between 48 and 54 d. Following photostimulation at 34 d, increases in plasma LH levels for oestradiol-injected birds were significantly greater than for controls. Oestradiol treatment had no significant effect on changes in plasma LH concentrations after photostimulation at 44 or 54 d. 5. This trial confirms previous work showing that pullets are unresponsive to photostimulation before 6 weeks of age. It also demonstrates that raising circulating oestrogen levels by injecting 0.5 mg/kg oestradiol benzoate on alternate days enhances the LH response to photostimulation at 34-d, but only very slightly sensitises a 34-d old bird to an increase in photoperiod which, 10 d later, is capable of advancing AFE in control birds by 24 d. Increased circulating oestrogen might be a factor which allows pullets to advance AFE in response to an increase in daylength.  相似文献   

13.
Contents Three experiments were conducted to determine whether follicular fluid (FF) enters the oviduct and plays any role in the transport of oocytes into the oviduct. Experiment 1: Oestrus and ovulation were synchronized in cycling gilts (n = 21) over a 15 day period of feeding Regumate® and injections of 1000 IU pregnant mare’s serum gonadotrophin (PMSG) 24 h after the last Regumate® feed and 500 IU human chorionic gonadotrophin (hCG) 80 h after PMSG. Ipsi-lateral aspiration of FF and salpingectomy (group 1, n = 7), aspiration of FF without salpingectomy (group 2, n = 7) or ligation of the oviduct between the ampulla and infundibulum (group 3, n = 7) was performed endoscopically prior to ovulation (34–36 h after hCG). Ipsi-lateral (group 2 and 3) and contra-lateral salpingectomy was carried out in all gilts post ovulation, 42–44 h after hCG. The oviducts were flushed with 1 ml saline and the samples as well as the aspirated FF were analysed for progesterone and estradiol by RIA methods. In group 1 both progesterone and estradiol concentrations did not differ before and after ovulation. Withdrawal of FF from the ipsi-lateral ovary by aspiration (group 2) or ligation of the oviduct (group 3) did not influence the steroid content within the oviducts. Similarly low progesterone concentrations were measured in ipsi- and contra-lateral oviducts after ovulation (group 2: 0.29 ± 0.17 versus 0.24 ± 0.35 ng/ml and group 3: 0.22 ± 0.19 versus 0.21 ± 0.22 ng/ml). The high content of progesterone of FF (269.7 ± 67.9 and 389.6 ± 226.5 ng/ml in group 1 and 2, respectively) was not reflected in the oviductal fluid. Experiment 2: In five gilts 0.06 ml 3H-progesterone (30 000 dpm) were applied via a fine 27 G injection needle into the largest three follicles of the ipsi-lateral ovary prior to ovulation (34–36 h after hCG). The oviducts were flushed following ovario-salpingectomy 42–44 h after hCG. All follicles had ovulated. The oviductal flushings and oviductal and ovarian tissue were analysed for labelled progesterone. No differences were measured in the content of 3H-progesterone of oviductal flushings and of both oviductal and ovarian tissues between the ipsi-lateral injection and contra-lateral control sides. The main part of the counts detected was within the range of background dpm values. Only 2.4% of the initial counts were recovered from fluid and tissue samples. Experiment 3: In a subsequent study FF was cautiously aspirated by endoscopy from follicles of the ipsi-lateral ovary 34–36 h after hCG (n = 12 gilts). Postovulatory (58 h after hCG), both oviducts were flushed and the oocytes were recovered. To test the influence of follicle puncture alone on the process of ovulation (n = 8 gilts), the aspiration needle alone was pricked into the follicles of the ipsi-lateral ovary, without any fluid aspiration. Despite the cautious aspiration of FF from 89 follicles, 26 oocytes were recovered together with the FF. Eighty-six postovulatory follicles were observed on the ipsi-lateral ovary. Out of 57 oocytes able to reach the oviduct, 29 oocytes were flushed from the oviduct (50.4 ± 28.1%). From the contra-lateral control oviduct 71 oocytes out of 91 ovulations (69.0 ± 33.9%) were recaptured. Puncture of follicles without aspiration did not influence ovulation compared with the control (recovery rate 68.2 and 79.6%, respectively). Results indicate (1) on the basis of the low progesterone level within the oviductal fluid that only a small amount of FF seems to reach the oviduct at ovulation, and (2) FF does not appear to be a compulsory carrier of the porcine oocyte at ovulation.  相似文献   

14.
Poultry diets are formulated with additional animal fat or vegetable oils to improve growth rate and feed conversion efficiency. High‐fat diet feeding in rats and fish has been shown to result in alterations in the phospholipid composition and cholesterol content of the erythrocyte membrane, in turn affecting erythrocyte osmotic fragility. In contrast, the few studies performed using high‐fat diet feeding in avian species show no changes in erythrocyte osmotic fragility. This study made use of the Japanese quail as no data exists on investigation of this species with respect to high‐fat diet feeding and erythrocyte osmotic fragility. Fifty‐seven male quail were randomly divided into six groups and fed either a standard diet (commercial poultry feed) or one of five high‐fat diets (commercial poultry feed with 22% of either coconut oil, lard, palm oil, soya bean oil or sunflower oil on a weight/weight basis) for 12 weeks. All birds on the high‐fat diets were significantly heavier (p < 0.05) after the 12‐week feeding period, than when commencing the dietary intervention. Serum triglyceride concentrations of birds in all high‐fat diet groups were significantly lower (p < 0.05) than birds in the standard diet group, whereas only birds in the palm oil group had significantly lower (p < 0.05) serum cholesterol concentrations compared to the standard diet group. Fragiligrams of erythrocytes from birds in the various dietary groups were similar. High‐fat diet feeding with different types of additional fat did not affect the osmotic fragility of the quail erythrocytes. Feeding quail high‐energy diets of varying degrees of fatty acid saturation was well tolerated and did not seem to affect the overall health status of the birds. Resistance of avian erythrocytes to modification by excess dietary fat may be a general characteristic of avian erythrocytes.  相似文献   

15.
This study describes the distribution of vimentin, desmin, smooth muscle actin (SMA) and laminin in the oviduct of the immature and mature Japanese quail. The cytoskeletal proteins vimentin, desmin and SMA have been shown to be involved in cellular support, differentiation, migration and contractility. Laminin is a major component of basement membranes. Luminal epithelia in the infundibular and magnal regions of immature and mature birds exhibited strong vimentin immunoreactivity. Luminal epithelial cells exhibiting strong vimentin immunoreactivity were present in the isthmus and shell gland regions of only mature quails. Infundibular glandular grooves displayed strong vimentin immunostaining. In contrast, the glandular epithelia of the magnum, isthmus and shell gland were vimentin immunonegative. Fibroblasts and vascular endothelial cells in the lamina propria of the oviductal regions studied exhibited strong vimentin immunostaining. Smooth muscle cells forming the tunica muscularis and vascular tunica media displayed strong desmin and SMA immunostaining. Strong laminin immunostaining was demonstrated in the basement membranes associated with smooth muscle cells, as well as in the basement membranes underlying the luminal and glandular epithelia. In conclusion, this study has shown that the immunolocalization of desmin, SMA and laminin in the oviduct of the Japanese quail is similar to that in the domestic fowl. However, differences in the immunoexpression of vimentin in the LE of the two avian species were shown to exist. In addition, the study has shown that the immunolocalization of vimentin in the Japanese quail varies depending on the oviductal region, as well as the developmental stage of the oviduct.  相似文献   

16.
Twelve Yorkshire x Landrace prepubertal gilts were assigned equally to treatments involving daily injections of either porcine growth hormone (GH, 90 micrograms/kg) or vehicle buffer from 150 to 159 d of age. Blood samples were obtained every hour from 0600 hr at 153 d until 0500 hr at 154 d of age, inclusively. At 0800 hr on 154 d, gilts received an injection of 500 IU PMSG, followed 96 hr later by 250 IU hCG. Gilts were slaughtered at 163 d and the ovaries recovered for an assessment of the ovarian response to the gonadotrophic stimulation. Five control gilts (83%) exhibited a normal ovulatory response but only one GH gilt (17%) was so designated (P less than 0.05). There was no apparent effect of treatment on serum concentrations of LH, FSH or cortisol. Growth hormone treatment reduced serum concentrations of T4 (P less than 0.001) and prolactin (P less than 0.02), but increased serum GH (P less than 0.001), T3 (P less than 0.06), insulin (P less than 0.001) and glucose (P less than 0.001). Serum concentrations of free fatty acids (FFA) were not significantly altered by exogenous GH. The concomitant elevation of serum insulin and glucose suggests that an insulin-resistant state was induced which, if evident at the ovarian level, may be a factor mediating the adverse effects of exogenous GH on ovarian function. The data presented also suggests that circulating concentrations of thyroid originating hormones are altered by exogenous GH.  相似文献   

17.
In experiment 1, nine prepuberal crossbred gilts 145 +/- 2 days of age and 90.3 +/- 1.6 kg body weight (BW) were hypophysial stalk-transected (HST) or sham-HST. Starting at 0800 on Day 1 (35 +/- 2 days after surgery), three sham-HST and two HST gilts received 3.5% sodium citrate vehicle (V) while two HST gilts and two sham-HST gilts received pulses of 2.5 micrograms GnRH every 45 min for 9 days via a jugular vein cannula. At 0800 on day 7, all gilts received 1,000 IU of pregnant mare serum gonadotropin (PMSG) im. Blood was sampled every 15 min from 0800 to 0845 on Days 1 through 6. On Day 10, ovarian morphology and ovarian and follicular fluid weights were recorded. In experiment 2, eight prepuberal crossbred gilts, 146 +/- 6 days of age and 79.5 +/- 1.5 kg BW, were HST or sham-HST. Starting at 0800 on Day 1 (7 +/- 4 days after surgery), two sham-HST and three HST gilts received V, while three HST gilts received pulses of 2.5 micrograms GnRH every 45 min for 8 days. At 1200 on Day 5, all gilts, including three unoperated controls (UC), received 1,000 IU of PMSG im. Blood was sampled from all but UC gilts every 15 min from 0800 to 0845 on Days 1 through 5. Ovarian data were obtained on Day 9. The HST + V gilts failed to respond to PMSG, whereas growth of ovulatory follicles was stimulated in the other groups in both experiments.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

18.
Maiden heifers and lactating cows of known ovarian status and of several breeds were treated with a synthetic prostaglandin, cloprostenol, or a synthetic progestagen, norgestomet, at the start of an artificial insemination (AI) program. Animals in the cloprostenol treatment received 2 injections 10 days apart. Over the next 26 days those animals that showed oestrous behaviour were inseminated. Synchronisation rates and calving rates to insemination over the first 7 days were calculated. Those in the norgestomet treatment received an implant of norgestomet plus an injection of norgestomet and oestradiol valerate. The implant was removed 10 days later and the animals were given an injection of pregnant mare serum gonadotrophin (PMSG). They were inseminated at 48 h (maiden heifers) or 56 h (lactating cows) after implant removal. Calving rates to fixed-time insemination were recorded. After completion of the AI program the animals in both treatments were joined with bulls. Overall calving rates (AI plus bulls) were calculated. By day 7 of the program, 82% of the maiden heifers and 76% of the lactating cows in the cloprostenol treatment had been detected in oestrus. By day 21 the respective figures were 99% and 81% Norgestomet treatment had an immediate and a prolonged effect on ovarian activity in those females classified as having inactive ovaries at the start of the AI program. Calving rates of those females to fixed-time AI and overall were similar to those of the females with active ovaries in both treatments. Their calving rates to fixed-time insemination, and overall calving rates for the lactating females, were significantly higher than the corresponding values of their contemporaries treated with cloprostenol and inseminated on observed oestrus over 7 days. For those females classified as having active ovaries at the start of the AI program, calving rates to first insemination and overall were similar for both treatments. Overall calving rates of lactating cows of each breed were, with one exception, higher in the norgestomet treatment than in the cloprostenol treatment. Although norgestomet treatment was more expensive than cloprostenol treatment, the advantage in calf crop resulted in an overall monetary advantage to the norgestomet treatment.  相似文献   

19.
The amelioration of aflatoxicosis in Japanese quails was examined by the dietary addition of live yeast (Saccharomyces cerevisiae; SCE). Yeast incorporated into the diet at 1 g kg−1was evaluated for its ability to reduce the deleterious effects of 2·5 mg total aflatoxin ( ; 82·30 per cent 1 , 2·06 per cent 2, 7·68 per cent 1and 7·96 per cent 2) kg−1diet on growing Japanese quail chicks from 10 days to 45 days of age. Forty 10-day-old Japanese quail chicks were assigned to 2×2 factorial arrangement of treatments (control, , , plus ) each consisting of 10 quails. The performances of birds were evaluated. The treatment significantly and dramatically decreased food consumption and body-weight gain from the first week onwards. The significant adverse effect of on the food conversion ratio was also determined from week 1 to the end of the experiments. The addition of to the -containing diet significantly reduced these deleterious effects of on food consumption, body-weight gain and food conversion ratio. Compared to controls, the cumulative body weight gain was reduced by 37 per cent among the quails consuming without , but increased 15 per cent for the birds fed plus . Interestingly, the single inclusion of to the -free diet provided significant improvements in all the investigated growth performances of birds (approximately 40 per cent) compared to controls.  相似文献   

20.
Two artificial lighting regimens were studied in a commercial unit of 800 sows. The aim was to develop a simplified lighting regimen to overdrive the effects of season on reproduction. A long-day group had a constant 16 hours light and eight hours dark photoperiod in all units during a production cycle. A short-day group had eight hours of light and 16 hours darkness in a farrowing unit for four weeks and in a mating unit for four weeks. After one month of pregnancy the short-day group was transferred to 16 hours light and eight hours dark for the rest of the dry-sow period. Production data were collected for eight months, and the farrowing rate, weaning to oestrus interval, culling rate for fertility problems and the number of live-born piglets were analysed. Seasonal infertility, which had previously affected the herd, was not detected in either group during the follow-up period. The farrowing rate was 90 per cent for both groups. The median weaning to oestrus interval was five days in both lighting regimens with ranges from four to 74 days in the short-day group and three to 55 days in the long-day group. The long-day programme had a positive effect on the weaning to oestrus interval. When the sows were classified as either "normal", with a weaning to oestrus interval of up to 10 days, or "problem" animals, with a weaning to oestrus interval of over 10 days, the short-day programme also had a positive effect. The culling rate for fertility problems was 2.4 per cent for the short-day group and 3.2 per cent for the long-day group (P=0.027). The only significant predictor for the number of live-born piglets was parity (P=0.027).  相似文献   

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