Reproductive Performance of Doe Rabbits as Affect by GNRH Analogue Injection at Different Post-partum Days

2017 ◽  
Vol 12 (2) ◽  
pp. 103-108 ◽  
Author(s):  
I.T. El-Ratel ◽  
Tork M. Dorra ◽  
M.A. Sheteifa ◽  
Amira M. Mansour
2006 ◽  
Vol 18 (5) ◽  
pp. 545 ◽  
Author(s):  
A. A. Ramoun ◽  
S. A. Darweish ◽  
H. A. Abou El-Ghait ◽  
El-S. M. Fattouh

The aim of the present work was to study the effect of either gonadotrophin-releasing hormone (GnRH)–prostaglandin PGF2α–GnRH (G–P–G) or equine chorionic gonadotrophin (eCG)–PGF2α–GnRH (eCG–P–G) regimes with or without intramuscular injection of ergometrine maleate (Methergin) within 24 h post partum on the uterine involution, initiation of post partum cyclicity and subsequent reproductive performance of buffalo. A total of 60 parturient Egyptian buffalos (2–4 lactations) were used to conduct this study. The involved animals were allotted into two main groups (A and B), each with 30 animals, on the basis of whether buffalo cows received an i.m. injection of 3 mg of Methergin within the first 24 h post partum (A, Meth. T) or not (B, Meth. NT). Each main group was subdivided into three subgroups: A1, A2 and A3 in case of A and B1, B2 and B3 in case of B. The G–P–G regime was applied on both A1 (Meth. T) and B1 (Meth. NT) buffalos, where each individual received two i.m. injections of 0.020 mg GnRH analogue (buserelin) at Days 18 and 33 post partum with i.m. injection of 25 mg PGF2α (Dinoprost) in between at Day 25. The eCG–P–G regime was applied on both A2 (Meth. T) and B2 (Meth. NT) buffalos, where each individual received i.m. injection of 1000 IU eCG, 25 mg of PGF2α (Dinoprost) and 0.020 mg of GnRH analogue (buserelin) at Days 8, 18 and 25 post partum, respectively. The A3 subgroup (Meth. T, alone) was control for A1 and A2 subgroups and the B3 subgroup was the non-treated control for all subgroups. There was a significant (P < 0.01) decrease in the days required for complete uterine involution in subgroups A1, B1 and A3, indicating the enhancement of uterine involution. The post partum cyclicity was initiated earlier in all of the treatment regimes applied in the present study, as was indicated by significant (P < 0.01) decrease in the days to first ovulation in these subgroups compared with the non-treated control subgroup. The reproductive performance of treated buffalos improved as was shown by the significant (P < 0.01) decrease in days to first service, days open and calving interval. It is concluded that enhancement of uterine involution and/or earlier initiation of post-partum cyclicity improve the reproductive performance of buffalos.


1980 ◽  
Vol 14 (2) ◽  
pp. 129-131 ◽  
Author(s):  
Maria Susana Merani ◽  
Marta Susana Lizarralde

Akodon molinae, a vole mouse widely distributed in central Argentina, shows remarkable chromosome polymorphisms. It is one of the natural reservoirs of the actiologic agent of haemorrhagic fever, and a laboratory colony could be of great help in investigating this disease. Pregnancy lasted 23 (range 21-25) days. Litters of 4-5 young were born to monogamous breeding pairs about every 30 days, with weaning at 26 days post partum. The sex ratio at birth was 505 males to 500 females: at weaning it was 460 to 440. Sexual maturity was attained at about 16 weeks of age in males and 12-20 weeks in females. Akodon molinae is easy to handle, but fighting and killing or neglect of young are problems.


2001 ◽  
Vol 26 (2) ◽  
pp. 313-321 ◽  
Author(s):  
N. H. Gardner ◽  
C. K. Reynolds ◽  
R.H. Phipps ◽  
A.K. Jones ◽  
D.E. Beever

AbstractThe study compared the impact of feeding different energy supplements (barley, molassed sugar beet and fat) prior to calving and the effects of feeding supplemental fat post-partum, on subsequent production and reproductive efficiency of dairy cows. Forty-eight multiparous Holstein-Friesian dairy cows were assigned to one of two groups, six weeks prior to expected calving date and fed a grass based total mixed ration according to ME requirements for late gestation. Group 1 was supplemented with barley (B) or molassed sugar beet feed (SB) prior to calving and was then given a high starch lactation ration. Group 2 was supplemented with either fat (F) or no supplement (C) pre partum, and was then given a similar lactation ration as Group 1 but supplemented with fat. Lactation rations were fed through to week-20 post partum and the cows were monitored during this period. Milk yield (P<0.002) and milkfat (P<0.02) production were higher and milk protein concentration (P<0.001) was lower in Group 2. The number of days to first rise in progesterone following parturition was greater (P<0.01) in Group 2. Due to the design of the study, effects of prepartum supplementation were only evaluated within each lactation ration group. Conception rate to first service was higher (P<0.001) for B than SB supplemented cows in Group 1 and higher (P<0.02) for F than C supplemented cows in Group 2. Services per conception were lower (P=0.06) for B than SB supplemented cows in Group 1 and lower (P<0.05) for F than C supplemented cows in Group 2. Overall pregnancy rates and days open were not significantly different between the groups. The data shows that pre-partum nutrition had an important role in determining subsequent fertility. Despite having negative effects early post partum, supplementing with fat did not affect overall reproductive performance but it did improve milk production.


Reproduction ◽  
2002 ◽  
pp. 419-427 ◽  
Author(s):  
JG Gong ◽  
WJ Lee ◽  
PC Garnsworthy ◽  
R Webb

Although it has become increasingly clear that fertility in modern dairy cattle is declining in association with increased milk yields, the underlying mechanism is poorly understood. The first ovulation post partum is delayed in dairy cows undergoing selection for genetic merit for milk yield in association with lower circulating insulin concentrations. The aim of this study was to investigate whether feeding a diet to increase circulating insulin concentrations can overcome this delay in the first ovulation post partum. The experiment was a 2 x 2 factorial design (n = 10 per group) involving diet and genetic merit for milk yield. The dietary treatment started on the day of calving and lasted for 50 days. Plasma samples were collected each day and ovarian ultra-sonography was performed three times a week during the experimental feeding period. Milk yield was recorded each day, and body weight and body condition score were determined each week. Milk samples were collected three times a week from day 50 to day 105 post partum, and reproductive performance data were recorded for all the cows as part of the routine farm practice. The dietary treatment induced significant differences in plasma insulin concentrations in both high and low genetic merit cows. Although high genetic merit cows produced more milk, lost more body weight and had lower body condition scores during the experiment, no significant effect of diet was observed on these measurements. The high insulin inducing diet increased the proportion of cows ovulating within 50 days of calving and reduced the intervals from calving to first ovulation, and tended to reduce the intervals from calving to first service and to conception. These fertility parameters were also more favourable in low than in high genetic merit cows, but no interaction between diet and genetic merit was observed for any of these parameters. Genetic merit, but not diet, also affected the number of services required per conception and the conception rate. In conclusion, these results have confirmed that genetic selection for high milk yield is associated with a decrease in reproductive performance in dairy cows. More importantly, this study has demonstrated that it is possible to alleviate this problem by nutritional manipulation.


2011 ◽  
Vol 23 (1) ◽  
pp. 113
Author(s):  
I. H. Kim ◽  
H. C. Lee ◽  
H. G. Kang

Earlier postpartum cyclicity based on hormonal analysis was related to the subsequent fertility, although it has not been clarified under field conditions. This field study examined the relationship between the detection of corpus luteum (CL) at the first post partum month and subsequent reproductive performance in dairy cows. Holstein dairy cows underwent ultrasonography (Sonoace 600 with 7.5 MHz linear-array transducer; Medison Co. Ltd., Korea) at 30 (±7) days postpartum to determine the existence of CL in ovaries and then divided into 2 groups based on the existence of CL; the CL group (n = 156) or the non-CL group (n = 281). At the same time of ultrasonography, all cows were scored for body condition. Cows received the normal herd reproductive management program including oestrous detection or synchronization, or synchronization of ovulation in the breeding period. Pregnancy was determined per rectum 60 days after artificial insemination by both ultrasonography and palpation. Reproductive performance data were collected for a minimum of 210 days postpartum. Reproduction data between the CL and non-CL groups were evaluated by t-test, chi-square test, or logistic regression using an SAS program (Version 9.1: SAS Institute, Inc., Cary, NC, USA). The proportion of cows with CL in ovaries at 30 (±7) days postpartum was 35.7% of all cows. The number of days to first insemination after calving was more delayed (P < 0.0001) in the non-CL group (100.1 ± 2.7 days) than in the CL group (80.9 ± 2.9 days), while the pregnancy rate to first insemination did not differ (P > 0.05) between the CL group (44.2%) and the non-CL group (45.9%). The CL group had higher pregnancy proportions (PP) within 60 (odds ratio, OR = 2.3; P = 0.0063), 90 (OR = 1.6; P = 0.04), and 120 days (OR = 1.5; P = 0.05) postpartum than the non-CL group; however, the PP within 150 or 210 days postpartum did not differ between the 2 groups (P > 0.05). Besides, logistic analysis revealed that cows with body condition score (BCS) ≥3.00 were more likely to have CL (OR = 1.8; P = 0.015) compared with cows with BCS ≤ 2.75, while primiparous cows were less likely to have CL (OR = 0.6; P = 0.0085) compared with multiparous cows. In addition, cows that underwent ultrasonography later than 30 days postpartum were more likely to have CL (OR = 1.6; P = 0.0192) compared with cows that underwent ultrasonography earlier. In conclusion, the earlier cyclicity based on the detection of CL using ultrasonography at the first postpartum month, which might be in part due to a higher BCS, predicts an enhanced reproductive performance in dairy cows, particularly during the early and early-mid lactations. This work was supported by the research grant of the Chungbuk National University in 2010.


1970 ◽  
Vol 18 (2) ◽  
pp. 171 ◽  
Author(s):  
JM Taylor ◽  
BE Horner

The mosaic-tailed rat, M. cervinipes, is usually an abundant murid where it occurs in the northern regions of Australia. It is an inhabitant of the forests and their fringe associations and is semi-arboreal. Although the annual reproductive performance is unknown, breeding occurs at least in late spring and summer in more southern areas of its distribution and extends into autumn and winter farther north. Litter size ranges from two to four. The nipple-clinging behaviour of the young appears to be of selective advantage as an escape mechanism. Description of the histology of the gonads and accessory sex glands is given for juveniles, breeding adults, and sexually quiescent adults. M. cervinipes is polyoestrous and a spontaneous ovulator and may experience a post-partum oestrus. Melomys is not known to occur in plague proportions in its native habitat; its mode of reproduction favours a prolonged and modest contribution of young within a breeding period.


Pathogens ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 54 ◽  
Author(s):  
Katerina S. Ioannidi ◽  
Natalia G. C. Vasileiou ◽  
Marianna S. Barbagianni ◽  
Denise C. Orfanou ◽  
George Mantziaras ◽  
...  

The objectives of the study were (a) to study the characteristics of uterine involution in ewes that had developed subclinical uterine infection in the immediately post-partum period and (b) to evaluate effects of the infection in the subsequent reproductive performance of ewes. Uterine infection was induced in ewes (I, n = 10) by intrauterine inoculation of Escherichia coli; uninoculated controls were included (C, n = 12). Animals were examined at regular intervals before and post-inoculation. Clinical and ultrasonographic examinations were performed. Vaginal swab samples and biopsy uterine tissue samples were collected for bacteriological, cytological and histological examination. Finally, ewes were put to rams and reproductive performance was monitored. After challenge, it was ultrasonographically found that caruncular dimensions, myometrial thickness and diameter of uterine lumen were greater in I ewes. In these ewes, particular reduction of dimensions occurred during the second week post-partum, whilst in C ewes during the first week. The uterine artery diameter and the blood flow into the uterus were also greater in I than in C ewes. E. coli infection was more frequent and of longer duration in I than in C ewes: in 68.1% and 50.0% of ewes and 19.5 and 14 days, respectively. There was lower proportion of neutrophils and higher of lymphocytes in group I than in C. In inoculated ewes, there was histological evidence of uterine epithelial destruction, increased cellular infiltration, hyperaemia and extracasation, which persisted up to 42 days post-partum. During the subsequent reproductive season, all ewes in group I lambed normally and produced healthy and viable lambs. No significant difference in reproductive performance parameters were seen in I comparison to C ewes. It is concluded that the innate immunity of the uterus sufficed to counteract the bacterial infection, although the process of involution took longer than in healthy animals; moreover, the ultrasonographic examination is a useful means for assessment of the genital tract of ewes post-partum; finally, no adverse effects were noted in the subsequent reproductive performance of ewes.


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