Oestrous Cycle Length Research Articles

OESTRUS RESPONSES USING DOUBLE TREATMENTS OF PGF2a (LUTALYSE AND SYNCHROMATE) IN NIGERIAN JENNIES

This study was carried out to evaluate oestrus responses using double treatments of pgf2a (Lutalyse and Synchromate) in Nigerian jennies. Eight (8) cycling jennies aged 3.8 ± 2.0 years were used for this study. The jennies were randomly assigned to 2 groups of 4 jennies each; Group 1 (n=4): jennies treated with a double injection of 10mg of Lutalyse; Group 2 (n=4): jennies treated with double injection of 375μg of Synchroniate. Blood was collected from the jennies for extraction of serum, for progesterone and oestradiol estimation using Enzyme-Linked Immunosorbent Assays (ELISA). Groups 1 and 2, had time to onset of oestrus of 3.98 ± 0.95 and 1.78 ± 0.29 hours (P>0.05), duration of oestrus of 78.0 ± 22.7 and 120 16.97 hours (P<0.05), oestrus response rate of 75 and 100% and intensity of synchronization within 48 hours was 75 and 100% (P<0.01), respectively. From this study it was established that the oestrus period and oestrus cycle length of groups 1 and 2 was 8 and 15 days and also 17 and 21 days, respectively, in Nigerian indigenous jennies. In conclusion, Synchronization of jennies is possible using exogenous PGF2a, however, double treatment of Cloprostenol Sodium (Synchromate) had a better response, therefore, it is more efficient than double treatment of Dinoprost tromethamine (Lutalyse) in oestrus synchronization of jennies.

Efficacy of Supplementary Feeding of Bypass Fat and Area Specific Mineral Mixture on the Production and Reproductive Performance in Milch Buffaloes

Background: Bypass fat, also called rumen-protected fat, boosts dairy animals¢energy for better milk production and health. Mineral deficiency is a leading cause of poor growth, weakened immunity, lower milk yield and reproductive issues in dairy animals. Considering the aforementioned details, an on farm trial was undertaken at farmer’s field to assess the effectiveness of bypass fat and mineral mixture on overall performance of milch buffalo. Methods: Twenty lactating Murrah buffaloes reared under farmer's field were selected and distributed equally in two groups of ten buffaloes in each group, i.e. T1 (control) and T2 (supplementation bypass fat @ 100 g and minerals mixture @ 50 g/day/ buffalo beside the farmer practices). Result: The outcome of study revealed that the additional of bypass fat and a mineral mixture had no effect on the weights of the buffaloes undergoing the experiment. Supplementation of bypass fat and mineral mixture did not influence the DM intake (in terms of kg/d and DMI %) in lactating buffalo. The mean milk yield during supplementation period was determined 10.19 ±0.36 and 12.13±0.43 l/day in group T1 and T2, respectively; which was 19.04 per cent higher in group T2 than the control. The average length of the postpartum estrus cycle (62.20±5.86 days) and service period (82.49±7.46 days) was significantly (P less than 0.05) reduced in supplemented group than control (86.40±11.57 days and 131.00±12.33 days, respectively) at farmer¢s field. AI per conception was also observed to be significantly (P less than 0.05) higher in non-supplemented group than the supplemented group. AI per conceptions in supplemented group and control group was recorded 1.39±0.33 and 2.71±0.44, respectively. It could be inferred from the observations that the feeding of bypass fat and area-specific mineral mixture in the diet significantly (P less than 0.05) improved the yield of milk and its composition as well as postpartum reproductive performance in milch buffalo at farmer’s field.

Reproductive Performance of Estrus Pattern in Bachaur Cows of Bihar

Background: The Bachaur is a medium sized draft purpose breed mostly present in Madhubani, Darbhanga and Sitamarhi districts of Bihar and presently the breed is at the verge of extinction. Since no data is presently available regarding the estrus pattern in these cows therefore, present study was designed to document the oestrus intensity, estrus cycle length, estrus behaviour and duration of estrus in these animals. Methods: The total of nine healthy breeding Bachaur cows aged 3 to 5 years were maintained under identical managemental conditions.The estrous cycles of nine animals was synchronized using Cloprostenol Sodium @ 500 mg I/M (Pragma®, Intas, India) in cycling Bachaur cows. Estrus was detected in the morning and evening for external signs of estrus, estrus behavior, intensity of estrus, estrus duration and estrous cycle length. Result: In the present study, mounting or mounted by other animals was observed in more than 70% and sniffing, tried to lick and Flehmen’s reaction was observed in about 66.67% of treated cows. The other parameters like bellowing, restlessness, milk yield reduction, frequent micturition and Flehmen’s reaction were recorded in 44.44%, 55.56%, 44.44%, 55.56% and 66.67%, of animals, respectively. The most appreciable physical sign of estrus recorded was intense swelling of vulva (in 88.89%) however hyperaemia of vulva, copious estrual mucous discharge, pronounced tonicity of uterus, completely dilated os cervix and presence of large palpable follicle on the ovary was observed in 44.44%, 55.56%, 66.67%, 77.78% and 66.67%, of cows respectively.

Gayo horse reproduction performance as local animal genetic resources in Southeast Aceh, Aceh Province

The objective of this research was to analyze the reproductive performance of the Gayo horse as an animal genetic resources in Southeast Aceh. This research has conducted in Southeast Aceh. The study used a survey method. The choice of research location has done intentionally (purposive sampling). The total population of Gayo horses scattered in Southeast Aceh currently is 102 tails and the number of samples taken in this study is 24 individuals with the minimum requirement that respondents keep horses that have at least given birth 2 times. The required data in this study were the reproductive performance characteristics of Gayo horses including (1) estrus cycle, (2) length of time in estrus, (3) first mating age, (4) gestation period, (5) foaling interval and (6) postpartum mating. The data obtained from this research that the average length of estrus cycle in the range of 21-25 days with an average of 22.58±1.18 days, the length of time in estrus varied in the range of 4-17 days with an average 8.92±3.35 days, while age at first mating ranged from 24-36 months with an average of 30.25±5.15 months, furthermore gestational age had an average of 333.63±4.83 days with a range of 326-345 days, foaling interval is 470,25±11.86 days with a range of 458-480 days and postpartum mating an average of 136.63±7.03 days with a range of 122-150 days. The data obtained identified that the reproductive performance of Gayo horses in Southeast Aceh Regency is in normal condition.

Basic reproductive parameters of Kathiawari horses reared under arid zone region

The current study was undertaken with an aim to record and analyse the data related to basic reproductive parameters such as length of estrus cycle, estrus duration, pre-ovulatory follicle size at ovulation, day of ovulation, length of gestation and days of occurrence of foal heat in respect of Kathiawari mares for a period of thirteen consecutive breeding seasons (2010-2023). The mares were monitored closely for their estrus signs, examined with transrectal ultrasonography for the size of the follicle variation and to determine the size of the follicle at ovulation. The mares were inseminated with the frozen thawed semen collected from Kathiawari stallions at appropriate time. This is the first time ever report that live foals have been obtained using frozen semen via artificial insemination in kathiawari horses. The data on reproductive indices of the mares of Kathiawari breed in India are scanty and there are no available reports on reproductive characteristics of Kathiawari breed until today in the literature. The results of the present findings are of much useful and may serve as a ready reckoner for the reproductive traits of Kathiawari breed reared under arid region. The differences in the reproductive parameters observed in relation to other breeds of Indian horses may be attributed to breed differences and other environmental factors.

Endocrine correlates of female reproductive activity in the roan antelope (Hippotragus equinus)

AbstractAlthough ovarian endocrine activity has been described in most members of the tribe Hippotragini, little is known about the reproductive endocrine correlates of the roan antelope (Hippotragus equinus), an endangered antelope species of southern Africa. This study characterised the endocrine pattern of the reproductive activity (oestrous cycle, pregnancy and post‐partum period) in the female roan antelope by monitoring faecal progestogen metabolite (fPM) concentrations and oestrogen metabolite (fEM) concentrations for cyclicity and observing reproductive behaviours. The study was carried out over the course of 12 months. At the beginning of this study, all 18 focal females (nulliparous, primiparous and multiparous) were monitored for cyclicity (for between 3 and 4 months). Following observed copulation, pregnancy in multiparous females (n = 10) was subsequently monitored until parturition and 21 days post‐partum. Individual faecal samples were collected three times per week during the presumed period of cyclicity, twice per week during pregnancy and daily for 21 days post‐partum. Mating births, courtship events, and copulations were recorded when observed. In eight of the 18 females monitored, the patterns of fPM and fEM concentrations indicated oestrous cycle lengths (n = 10) of approximately 30.8 ± 2.1 days. The determined lengths of luteal and follicular phases were approximately 15.8 ± 1.5 days and 14.6 ± 2.1 respectively. Pregnancy was marked by a pronounced increase in fPM concentrations until parturition, and lasted approximately 280.4 ± 4.8 days; whereas the intercalving period ranged between 306 and 380 days (n = 9; mean: 333.2 ± 7.4 days). Twenty‐one day after parturition, 78% of the focal females (n = 5) did not show a resumption of the ovarian activity. This study demonstrated that monitoring faecal reproductive hormone metabolite patterns is a valuable approach for estimating ovarian activity in roan antelope and may be used to assist respective conservation breeding programmes by improving management practices.

GIVING ETHANOL EXTRACT OF KETIP BANANA STEM COULD RELIEVE POLYCYSTIC OVARY SYNDROME IN WHITE RAT MODEL

Polycystic ovary syndrome is a condition that affects the fertility of female reproductive organs. ketip banana pseudostem extract contains flavonoids, saponins, alkaloids, and vitamin C. It is known that ketip banana pseudostem extract can trigger cell proliferation and contain phytoestrogen compound. The purpose of this study was to determine the ability of ketip banana pseudostem extract on length of estrus cycle, histology structure and wight of reproductive organ, and estrogen hormone levels in white rats of PCOS model. White rats female Wistar strain aged 54 days used a total of 25 animals in this study. The treatment was given for 21 days by 1 ml/tail/day with the gavage method. Vaginal smear was began on 5th day of treatment every 12 hours/day for three estrus cycles (15 days). At the end of the study (21th day), the rats were dissected to take their ovaries and blood. The ovaries were weighed and then histological preparation with paraffin method and hematoxylin-Eosin staining. The parameters observed were length of estrus cycle, weight of ovary, number of ovary follicles, as well as estrogen hormone levels. The result of this study showed that ketip banana pseudostem extract can extend proestrus phases and estrus phases, increase estrogen hormone levels, increase corpus luteum number as significantly (p<0.05) on 150 mg/kgBW dosage.

The timing of the maternal recognition of pregnancy signal is specific to individual mares

Over several breeding seasons, eighteen inseminated mares were examined at 8(±1)h intervals from late oestrus until after ovulation. The time of ovulation was determined as 4h before the first detection of ovulation. Examinations for pregnancy began at 8h intervals between 236 to 260h (late Day 9 to 10) post ovulation. When present an embryo was reduced by compression with a total of 132 reductions on Days 10 (n=15), 11 (n=47), 12 (n=36), 13 (n=27), 14 (n=5) and 15 (n=2). Ten mares were used on multiple occasions, undergoing between 3 and 16 embryo reductions each. Mares were subsequently examined, first to determine non-pregnancy, and then to determine whether luteolysis or luteostasis occurred. Luteostatic mares maintained an ultrasonically identifiable corpus luteum, and between Days 22 and 25 were returned to oestrus by administration of PGF2α. Increasing numbers of mares became luteostatic following embryo reduction as the number of days post ovulation increased. The earliest initiation of luteostasis occurred when an embryo was reduced at 252h (10.5 days). Between the 8h examinations on Days 10 to 12 there was an increase in the proportion of mares undergoing luteostasis. When mares were used on multiple occasions, individual animals had aset time point within a ±8h window post ovulation when they responded to the MRP signal and after which, but not before, embryo reduction resulted in luteostasis. For the eight mares which had embryos reduced ≥6 occasions, the time when luteostasis occurred was consistent in an individual but varied between mares between Day 10 (244–252h) and Day 14 (348h). For example, one mare which did not recognise the presence of an embryo until Day 14 (348h), had 10 reductions undertaken between Days 11 to 13 (268–332h) and all resulted in luteolysis, but all 3 reductions at or after Day 14 (348h) resulted in luteostasis. Despite the late timing of when the MRP signal in this animal was recognised, no spontaneous embryo loss had been seen in three previous pregnancies. These results suggest that the timing of the luteolytic cascade is variable between mares but relatively constant in its timing in an individual animal. This would imply a consistent set of physiological processes that program the endometrium for the luteolytic cascade in any given animal. Further data is needed to investigate whether oestrous cycle length and variation in the oestrous and dioestrous phases of the mare play a role in initiating the mechanisms that enable the uterus to respond to the MRP signal.

Follicular Dynamics during Estrous Cycle of Pubertal, Mature and Postpartum Crossbred (Nili Ravi × Jianghan) Buffaloes.

Simple SummaryThe objective of this study was to observe the follicle dynamics and its relationship with different physiological (pubertal, sexual mature and postpartum) conditions of buffaloes. These data could be beneficial in establishing best reproductive model for future studies and enhancing the efficiency of advanced reproductive technologies (ARTs) in buffalo industry. The present study describes the estrous cycle characteristics (follicular wave pattern, ovulation, follicle growth, regression or atresia) in Chinese crossbred buffaloes during pubertal, sexual maturity and postpartum stages. This study would be helpful to provide the theoretical insight to overcome the poor reproductive performance by employing the ARTs to enhance fertility in crossbred buffaloes.The follicular dynamics is used as a reliable indicator for reproductive management in livestock. However, the follicular dynamics (follicle wave emergence, estrus cycle length, diameter of dominant follicle, follicular growth and atretic phases) during the estrous cycle of crossbred (Nili Ravi-Jianghan) buffalo is still unexplored. Therefore, the present study aimed to observe the follicular dynamics in estrous cycle of crossbred buffaloes at different physiological stages (pubertal; n = 28, sexual mature; n = 22 and postpartum; n = 18). In the present study, the follicular dynamics were ultrasonically examined at 12 h intervals throughout an estrous cycle during the breeding season. The results indicate that about 86.76% (59/68) crossbred buffaloes, irrespective of physiological stage, exhibited two follicular waves in estrous cycle with an average estrus cycle length was 20.7 ± 0.4 days. The estrus cycle length was significantly shorter (p < 0.05) in pubertal buffaloes (19.4 ± 0.4 days) compared with sexual mature (21.5 ± 0.3 days) and postpartum (21.9 ± 0.4 days) buffaloes. The first follicular wave emerged on same day during one- (pubertal vs. postpartum), two- (pubertal vs. mature vs. postpartum) or three-wave (mature vs. postpartum) estrous cycle buffaloes. The maximum diameter of dominant follicle (DF) in pubertal, sexually mature and postpartum crossbred buffaloes was 9.6 ± 2.0 mm, 10.6 ± 0.5 mm and 12.6 ± 0.7 mm with growth rate of 1.08 ± 0.04 mm/day, 0.92 ± 0.04 mm/day, and 0.9 ± 0.07 mm/day, respectively. In conclusion, similar to other buffalo breeds, Nili Ravi-Jianghan crossbred buffaloes showed the two-wave follicular pattern dominantly with an average duration of ~20 days estrous cycle. The observed follicular dynamics can be used as a reliable indicator for synchronization and fixed-time artificial insemination (FTAI) programs to improve the fertility of crossbred buffaloes.

Ovarian follicular dynamics in peripubertal Malabari goats

The aim of this study was to characterise the follicular dynamics in first two oestrous cycles of peripubertal Malabari goats. Transrectal ultrasonography was carried out on alternate days of oestrous cycles after first observed oestrus. Follicular studies revealed presence of two to five wave cycles with predominant three and four wave patterns. The interwave interval for ovulatory wave was longer than preceding waves in three and five wave cycles. The diameter of largest follicles in wave 1 was larger than follicles of subsequent waves of three, four and five wave cycles. The largest follicles in each wave could be observed from day 3 to day 13 of oestrous cycle. Majority of ovulations occurred on day 20 of oestrous cycles and short cycles were more in first oestrous cycle. The overall mean per cent of single and double ovulations were 56.3 and 43.8 and mean ovulatory follicle size was 6.59 ± 0.11 mm in peripubertal goats. The mean length of first and second oestrous cycle was observed as 17.72± 0.79 and 20.19± 0.43 days, respectively and mean duration of first and second oestrus was 36.88 ± 2.44 and 40.13 ± 1.84 h, respectively. The study revealed that predominant wave pattern was three and four waves in peripubertal Malabari breeds. The first oestrous cycle length was shorter and characterised by higher percentage of single ovulations with smaller periovulatory follicle size. Larger ovulatory follicles and double ovulations were observed in second oestrous cycle.

Effect of exogenous administration of oxytocin on postpartum follicular dynamics, oestrous rate and ovulation in Nili-Ravi buffaloes.

Based on different surveys, dairy farmers are concerned about extensive use of exogenous oxytocin in buffaloes, which is being held responsible for reproductive problems including irregular oestrous cycle and delayed ovulation. For these concerns, effects of oxytocin injection on postpartum follicular dynamics, postpartum oestrous interval (PEI), oestrous length, the interval from onset of estrus to ovulation and blood progesterone (P4) were studied in Nili-Ravi buffaloes. For this purpose, 23 animals within 1week after calving were randomly divided into three groups: without oxytocin (CON; n=7), 10 i.u. oxytocin (LOW; n=8), 30 i.u. oxytocin - (HIGH; n=8) and used to record the PEI for the study period of 154days. At subsequent estrus, three buffaloes from each group (not served) were selected randomly to monitor two cycles for 6weeks. Transrectal ultrasonography was performed to evaluate follicular and corpus luteum (CL) development, and blood sampling was done for progesterone (P4) analysis. These results revealed that postpartum oestrous interval (PEI) decreased significantly in oxytocin-treated groups. The number of small, medium and total follicles on the left ovary was significantly higher in the HIGH group. However, an overall number of small and total follicles on both right and left ovaries was significantly higher in CON and HIGH groups. On the other hand, there was no difference in the number of follicles on the right ovary among all treatment groups. The same was true for the size of pre-ovulatory follicles, CL, P4 concentrations and oestrous cycle length. The intervals from onset of estrus to ovulation and from standing estrus to ovulation were increased considerably in the HIGH group. It is concluded that exogenous oxytocin administration resulted in the shortening of PEI but triggered a delay in ovulation. Moreover, a higher dose of oxytocin could stimulate the growth of small, medium, and total follicles in postpartum Nili-Ravi buffaloes.

Growth and Reproduction Performances of Chaugarkha Goat of Kumaon Region of Uttarakhand

Chaugarkha goats are small size meat purpose breed distributed in temperate Kumaon region of Uttarakhand, India and the breed is identified as a unique new breed since 1992. The breeding tract of Chaugarkha goat is spread across four mountainous districts Almora, Bageshwar, Champawat and Pithoragarh of Kumaon region. The growth performance was analyzed by least squares analysis and information on reproduction parameters of Chaugarkha goats was generated. Least squares means at birth, three months, six months, nine months and twelve months were 1.83±0.03, 7.67±0.13, 11.45±0.17, 14.89±0.27 and 18.98±0.26 kg, respectively. Age at first mating (days), age at first kidding (days), kidding interval (days), service period (days) and gestation period (days) were 439.65±23.93, 583.83±32.66, 267.46±10.23, 204.30±17.57, and 148.98±0.70, respectively. The litter size was 1.23±0.04. Oestrous cycle length (days) and estrus duration (hrs) were 21.31±0.32, and 52.0±1.36, respectively. In the cluster 4 higher performances were recorded and it was carried forward from three months through six and nine months upto twelve months. But, no definite trend was observed for the effects of year. The male had higher estimates than females at all ages, which is along the expected line. The generated reproduction parameters will be helpful in the formulation and implementation of breeding plans.

Effect of Intrauterine Infusion of Equine Fresh Platelets-Rich Plasma (PRP) or Lyophilized PRP (L-GFequina) on Ovarian Activity and Pregnancy Rate in Repeat Breeder Purebred Arabian Mares.

Simple SummaryPersistent endometritis is one of the major causes of infertility in mares and results in endometrium degeneration, namely, endometrosis. Platelets-rich plasma (PRP) is an emerging therapeutic application in tissue regeneration because of its high concentration of growth factors with a high mitogenic and anti-inflammatory potential, but reduced preservation time. L-GFequina is a freeze-dried, stabilized, platelet-rich plasma product (PP) that can be stored at 2 to 8 °C for several months. It can be easily used after reconstitution with sterile saline or water, eliminating the need for repeated blood product collection and special equipment. The intrauterine infusion of equine platelet-rich plasma or L-GFequina can be used indistinctly in repeat breeder mares, shortening the estrous cycle, with no significant effect on the follicular diameter, as well as increasing pregnancy rate in Arabian purebred mares.This study was designed to examine the effect of the intrauterine infusion of platelet-rich plasma (PRP) or equine lyophilized growth factor (L-GFequina) on the follicular growth, endometrial thickness, estrus cycle length, and pregnancy rate in purebred Arabian mares. A total of 73 purebred Arabian mares who experienced repeat breeding for three successive cycles were randomly divided into the following three groups: control group, without treatment; second Group (PRP group), in which mares were intrauterine infused with 20 mL of fresh PRP on the second day after the end of physic estrus phase; and the third group (L-GFequina Group), consisting of mares that were intrauterine infused with 20 mL of reconstituted lyophilized horse platelets growth factors (L-GFequina) on the second day after the estrus phase. The results showed no significant difference between control and treated groups in the diameter of the preovulatory follicles during the post treatment cycle. The endometrium thickness increased significantly in the L-GFequina and PRP groups ahead of the non-treated group. Intrauterine L-GFequina or PRP administration shortened the estrus cycle length. A higher pregnancy rate was recorded in the L-GFequina and PRP treated mares. In conclusion, the intrauterine infusion of L-GFequina or PRP increased the endometrial thickness and pregnancy rate and could be used to improve fertility in Arabian purebred mares who experienced from repeat breeding.

Reproductive indices of Manipuri horses reared under arid zone region

The current study was undertaken with an object to record and analyse the data related to reproductive indices such as estrus cycle length, duration of estrus, size of the follicle at ovulation, day of ovulation, gestation length and estrus after foaling (foal heat) in respect of Manipuri mares. The mares were closely monitored for their estrus exhibition, examined with transrectal ultrasonography for the size of the follicle variation and to determine the size of the follicle at ovulation. The mares were inseminated with the frozen thawed semen collected from Manipuri stallions at appropriate time. This is the first time ever report that Manipuri stallion semen was cryopreserved successfully and live foals have been obtained using frozen semen via artificial insemination. The data on reproductive characteristics of the mares of Manipuri breed in India are scanty and there are no available reports on reproductive parameters of Manipuri breed until today in the literature. The results of the present findings are of much useful as a ready reckoner for the reproductive parameters and traits of Manipuri breed as well as indigenous horses reared under arid region. The differences observed in various parameters in relation to other breeds of Indian horses may be caused by breed effect and other environmental factors.

Farming systems in sheep rearing: Impact on growth and reproductive performance, nutrient digestibility, disease incidence and heat stress indices.

The experiment was conducted with an intent to know the effect of different farming systems on the growth performance, nutrient digestibility coefficients, reproductive traits, disease incidence, heat stress indices, and cost economics of Nellore sheep. The study includes two parallel trials to prevent the influence of age on heat stress indices (panting score and erythrocyte osmotic fragility (EOF)). One hundred and twenty lambs (60 ram-lambs and 60 ewe-lambs) were allotted in a randomized block design under extensive, semi-intensive, and intensive systems for trial I, whereas trial II include eighteen rams assigned to the three respective farming systems in a completely randomised design. Both, season (summer) and grazing practice increased the panting score and EOF. The heat stress indices were positively correlated (P<0.01) with dry-bulb temperature and temperature-humidity index (THI) and inversely correlated (P<0.01) to relative humidity. Allotting the sheep to intensive system increased (P<0.001) weight gain and average daily gain with higher effect in males compared to females. The parameters of asymptotic weight (A), integration constant (B), and maturation rate were higher for intensive males. The male Nellore lambs had higher asymptotic weight and lower maturity rate than females, irrespective of the rearing system. Intensive sheep revealed a higher dry matter intake, digestibility coefficients, feed conversion ratio. The instantaneous bite mass (IBM) was higher for Commelina benghalensis, while instantaneous bite frequency (IBF), instantaneous intake rate (IIR) were higher for Cyanodon dactylon and amaranthus viridis, respectively. The proportion of intakes were highest for Stylo hemata followed by Cynodon dactylon and Tridax procumbens species. No differences were observed for the weight at puberty, oestrus cycle length, oestrus duration, conception percent, gestation period, and lambing percent in three rearing systems; however, the age at puberty was lower (P<0.001) and the birth weight was higher (P<0.001) for sheep reared under intensive farming system. Highest disease incidence was observed in rainy and winter seasons, particularly in sheep reared under extensive system. The capital expenditure was same for the three rearing systems, while the recurring expenditure was higher for Intensive farming system. The gross income and net income were higher for intensive system on account of higher weight gains. However, the higher returns per rupee of expenditure project the extensive farming as an ideal rearing system for small farmers and entrepreneurs with a low initial capital.

THE REPRODUCTIVE PERFORMANCE OF N’DAMA AND MUTURU CATTLE IN NIGERIA. 1. OESTROUS CYCLE LENGTH, DURATION OF OESTRUS AND OESTROUS BEHAVIOR PATTERNS

Twelve primiparous cycling N’dama and Muturu cows comprising 8 Ndama and 4 Muturu Cows, were subjected to three hour continuous observations twice daily at 0630 – 0930hrs and 1500 -1800 hrs for a period of 9 months during which oestrous behavior and oestrous cycle characteristics of the cows were monitored. Results indicated that oestrous cycle length in the two breeds averaged 20.09±0.56 day and 20.56±0.87 day for N’dama and Muturu cows, respectively. Durations of standing oestrus were 12.55±2.93hr in the N’dama and 11.31±4.29hr in the Muturu. There were no significant breed effects (P &gt;0.05) on these parameters. Mounting activities in the herd were signification higher (P &lt; 0.05) in the morning hours than in the evening hours. The practical implication of these result in relation to controlled animal breeding were discussed.

Reproductive performance and superovulatory endangered Cameroonian Namshi breed (Bos taurus)

This study was undertaken to determine the reproductive performance of the endangered Bos-taurus Namshi breed of Cameroon. Ovarian response to superovulatory treatment was also evaluated. The following observations were recorded. The average calf mortality rate was 25.71% while the average birth weight was 12.22±0.82kg. The percentage of animals in oestrus during the wet and dry season was respectively 60% and 33.4%. The oestrus cycle length and the oestrus duration were respectively 20.80±1.20d and 7.00±0.80h: corresponding dry season figures for those parameters were 19.00±0.94d and 6.00±0.7h respectively. In the dry season the manifestation of oestrus was 80º during the day and 20º at night while in the wet season it was 55.55% and 44.5% respectively. Postpartum oestrus was at 18 months. The ovarian response to superovulatory treatment was about 6.40±2.50 ovulations per cow. Results indicate that the scarcity of Bos-taurus Namshi breed in Camerron could be attributed to high calf mortality rate, low calving rate and long postpartum periods. Embryo transfer could be a way to rapidly multiply this breed.

SEASONAL EFFECTS ON OESTRUS PATTERNS AND PROGESTERONE PROFILES OF YANKASA EWES OF DIFFERENT AGE-GROUPS IN THE SUB-HUMID TROPICS

Oestrus patterns and serum progesterone profiles of 10 adult and 10 yearling Yankasa ewes were investigated in the late hot-dry and late-wet seasons in the subhumid tropical climate of Zaria, Nigeria. The proportions of ewes which came on heat once, twice or thrice within the experimental periods in the late hot-dry and late-wet seasons were 25, 15 and 0%, and 5, 10 and 85% respectively, while mean oestrous cycle length was significantly longer (P&lt;0.001) in the hot-dry season than in the late-wet season (30.9 vs 18.4 days) due to the higher incidence of anoestrus in the former. However, the mean duration of oestrus was not affected by season. Mean serum progesterone levels were significantly (P&lt;0.05) higher in the late-wet season than in the late hot-dry season (1.57 vs 0.52 ng/ml). However, there was a highly significant (P&lt;0.001) interaction between season and age group in mean serum progesterone levels due to a relatively greater depression in progesterone levels in yearling ewes during the hot-dry season compared with adult ewes. The observed disruptions in the oestrus cycle and serum progesterone levels of the ewes in the hot-dry season confirm the adverse effect of heat stress on the reproductive behaviour of ewes.

Protective role of Allium cepa Linn (onion) juice on maternal dexamethasone induced alterations in reproductive functions of female offspring of Wistar rats

Maternal treatment with dexamethasone induces oxidative stress in the reproductive structures of offspring. Consumption of Allium cepa Linn improves antioxidant status. This study was designed to evaluate the protective role of Allium cepa Linn juice on maternal dexamethasone induced alterations in reproductive functions of the female offspring of Wistar rats.Twenty lactating dams (180–200 ​g) were randomly assigned into four groups (n ​= ​5) on the day of parturition and treated as follows during lactation for 21 days: Control (5 ​ml/kg BW distilled water); Dexamethasone (60 ​μg/kg BW); Allium cepa (5 ​ml/kg BW); Dexamethasone ​+ ​Allium cepa (60 ​μg/kg BW ​+ ​5 ​ml/kg BW). The female offspring were separated at birth. Days of vaginal opening and first oestrus cycle, length and frequency of estrous cycle as well as serum hormonal profiles were assessed as measure of reproductive functions. Ovarian superoxide dismutase (SOD) activity, catalase activity and malondialdehyde (MDA) level were measured as indices of oxidative stress.Oestrous cycle length, frequencies of diestrus as well as the Ovarian MDA were significantly increased (p ​< ​0.05) in dexamethasone (DEX) group relative to control group. Serum 17β-oestradiol and corticosterone level in addition to SOD and catalase activities were significantly reduced (p ​< ​0.05) in DEX group relative to control. Co-administration of Dex with Allium cepa Linn juice reduced the oestrous length, frequency of diestrous as well as ovarian MDA. There was also a significant increase in serum 17β-oestradiol, ovarian SOD and catalase activity.The results suggest that Allium cepa could protect against alterations in reproductive functions of offspring induced by maternal treatment with dexamethasone during lactation in Wistar rats. The flavonoid constituent of onion may also help in reducing oxidative stress in the offspring.

Effect of Photoperiod on Estrus Cycle and Reproductive Organs in Female African Giant Rat (Cricetomys Gambianus: Waterhouse)

African giant rat is a prolific animal in its wild condition. Therefore, in captivity, the decrease in productive performances may be due to photoperiod under which they are submitted. This research was carried out to evaluate whether photoperiod affects estrus cycle and reproductive organs in female African giant rat (AGR). Twenty-eight matured female AGR were randomly assigned to four lighting conditions (Light / Dark): 0 L/ 24 D, 12 L/ 12 D, 18 L/ 06 D and 24 L/ 0 D. Animals were individually housed and had free access to food and water. Daily, vaginal smears were taken and observed under a microscope to determine estrus cycle length. After four weeks, twelve animals were sacrificed and sexual organs were collected and weighted. Results showed that in AGR, the length of estrus cycle ranged between 5.5 and 6.4 days. However, this estrus cycle duration showed an upward (p&gt;0.05) trend with a decreasing photoperiod. The weight of ovary and uterus was significantly (p&lt;0.05) low in animals continuous enlightened compared to other treatment groups. Uterus length have dropped by 13.94%, 17.81 % and 9.50 % in animals exposed to 12 h, 18 h and 24 h of light per day respectively compared to those bred in dark condition. Regarding above results, AGR has a regular estrus cycle and the variation of photoperiod does not have effect on the duration of estrus cycle but it is detrimental for reproductive organs.