Reproductive performance of the largest captive Asian elephant (Elephas maximus) population in Sri Lanka.

The Pinnawela Elephant Orphanage (PEO) in Sri Lanka maintains one of the largest captive Asian elephant (Elephas maximus maximus) populations in the world, with a total of 79 animals (45 females and 34 males) at present. It was established in 1975 as an orphanage for rescued wild calves, and commenced natural breeding under controlled conditions when they reached breeding age. This study summarizes reproductive data of 65 live births from 38 years of records at PEO. The age at first calving (n=31) was 14.6±0.7years, and the numbers of females giving birth two, three, four and five times were 21, 8, 4 and 2, with corresponding inter-birth intervals (IBI) of 4.9±0.3, 4.8±0.5, 7.9±1.9 and 5.7±0.5years, respectively. Females giving birth to males (5.7±2.2years) had longer IBIs compared to birthing female calves (4.7±1.1years). The average gestation for 18 pregnancies with known conception dates was 667±11days. The average birth weight was similar for male (83.1±4.6kg; n=14) and female (82.8±8.4kg; n=6) calves. Sex ratio for live births was 36 male:29 female and not different from 1:1; however, more males (10/14) were born after a second parity. Calf mortality and stillbirth rates were low: 7.6% and 4.4%, respectively. This study highlights the successful breeding program at the PEO, providing baseline reproductive data that can aid in improving breeding of other elephants managed under captive conditions.

Effect of cow parity and synchronization method with PGF2α on conception rates of Bos indicus cows in Cameroon.

The objective of this work was to evaluate the effect of two synchronization methods with prostaglandins F2α (PGF2α) on heifers and multiparous cows. Fourty-three Bos indicus cows (white and Red Fulani) were divided into four groups in a two-by-two factorial structure, parity x method of synchronization. The synchronization methods consisted of a two-dose regime which involved injection of animals on day 0 with PGF2α (Lutalyse) at 5 ml per cow intramuscularly. On day 11, the injection was repeated at the same dosage. On day 14 (72 h after the second injection), a fixed-time artificial insemination (AI) was done. On day 15 (96 h after the second injection), a second insemination was done. The one-and-a-half-dose regime consisted of an injection similar to the first treatment mentioned above on day 0. Thereafter, cows were observed for heat, and anyone showing heat was inseminated. A second dose was given on day 11 to all animals not having shown any heat. A fixed-time AI was done on days 14 and 15. Blood samples were collected on the day 0 of insemination for each cow while day 11 and day 21 after insemination. Progesterone was analysed by means of standard ELISA progesterone kits to determine its profiles after insemination. Results show no evidence of the effect of treatments on conception rates (P > 0.05). Similarly, heifers and multiparous cows had similar conception rates (P > 0.05). Between 3 weeks and 3 months of pregnancy, there was a loss of embryos of 28% in heifers and 20% in multiparous cows, but the difference between the two groups was not significant (P > 0.05). It recommended that farmers do not synchronize animals with poor body condition score (BCS). They should also monitor weight gains of heifers, remove them from the herd when they have been mixed with young growing bulls and put them in a breeding herd. The two-dose regime is better to be used in areas where the inseminator cannot easily be available.

Reproductive cycles of buffalo.

The domestic water buffalo (Bubalus bubalis) has an important role in the agricultural economy of many developing countries in Asia, providing milk, meat and draught power. It is also used in some Mediterranean and Latin American countries as a source of milk and meat for specialized markets. Although the buffalo can adapt to harsh environments and live on poor quality forage, reproductive efficiency is often compromised by such conditions, resulting in late sexual maturity, long postpartum anoestrus, poor expression of oestrus, poor conception rates and long calving intervals. The age at puberty is influenced by genotype, nutrition, management and climate, and under favourable conditions occurs at 15-18 months in river buffalo and 21-24 months in swamp buffalo. The ovaries are smaller than in cattle and contain fewer primordial follicles. Buffalo are capable of breeding throughout the year, but in many countries a seasonal pattern of ovarian activity occurs. This is attributed in tropical regions to changes in rainfall resulting in feed availability or to temperature stress resulting in elevated prolactin secretion, and in temperate regions to changes in photoperiod and melatonin secretion. The mean length of the oestrous cycle is 21 days, with greater variation than observed in cattle. The signs of oestrus in buffalo are less overt than in cattle and homosexual behaviour between females is rare. The duration of oestrus is 5-27 h, with ovulation occurring 24-48 h (mean 34 h) after the onset of oestrus. The hormonal changes occurring in peripheral circulation are similar to those observed in cattle, but the peak concentrations of progesterone and oestradiol-17ß are less. The number of follicular waves during an oestrous cycle varies from one to three and influences the length of the luteal phase as well as the inter-ovulatory interval. Under optimal conditions, dairy types managed with limited or no suckling resume oestrus cyclicity by 30-60 days after calving, while swamp types with free suckling do so at 60-90 days. However, in many farming systems prolonged postpartum anoestrus is a major problem, and the causes include poor nutrition and body condition, and stress due to harsh climates and improper management. Synchronization of time or induction of oestrus can be done using the same regimens as applied in cattle, using various combinations of prostaglandins, progesterone releasing devices, GnRH and eCG, but success rate is poor when treatment is done during the periods of marginal breeding activity or seasonal anoestrus.

Brain targeted transcranial administration of diazepam and shortening of sleep latency in healthy human volunteers.

Application of medicated oils on scalp had been practiced for centuries in the Ayurvedic system of medicine in diseases associated with the central nervous system. It is possible that the effectiveness of the therapy may be a result of targeted delivery of active compounds to the brain transcranially. Evidence also comes from two previous studies with positive results on brain targeted transcranial delivery of methadone base and diazepam on rat models. Possibility of transcranial drug delivery was investigated in healthy human volunteers using electroencephalography techniques by assessing the ability of transcranially administered diazepam in bringing about ß activity in the electroencephalographic wave patterns and shortening of the sleep latency period. Non polar drug molecules dissolved in a non-aqueous sesame oil based vehicle is a significant feature in the transcranial dosage design. The study was under taken in two phases. In the Phase-I study scalp application of a single dose of 2 mg/3 ml of the oil was employed and in the Phase-II study repeat application of three doses 24 h apart were employed. Sleep latency changes were monitored with Multiple Sleep Latency Tests with 5 naps employing the standard electroencephalography, electroocculography and electromyography electrodes. Sleep onset was identified with the first epoch of any sleep stage non rapid eye movement 1, 2, 3, 4 or rapid eye movement using electroencephalography, electroocculography and electromyography criteria. In both phases of the study there was significant reduction in the sleep latencies. It was much more pronounced in the Phase-II study. None of the subjects however displayed beta activity in the electroencephalography. Sleep latency reduction following scalp application in both the phases are suggestive of transcranial migration of diazepam molecules to the receptor sites of the nerve tissue of the brain eliciting its pharmacological effect of sedation. Transcranial brain targeted dosage design is therefore feasible.

Reproduction in domestic buffalo.

The domestic buffalo is an indispensable livestock resource to millions of smallholder farmers in developing countries, particularly in Asia. Although its reproductive biology is basically similar to that of cattle, there are important differences and unique characteristics that need to be considered in order to apply modern reproductive technologies to improve its productivity. Under most smallholder production systems, the reproductive efficiency of buffalo is compromised by factors related to climate, management, nutrition and diseases. However, when managed and fed properly, buffalo can have good fertility and provide milk, calves and draught power over a long productive life. The basic technical problems associated with artificial insemination in buffalo were largely overcome two decades ago, but the technology has not had the expected impact in some developing countries, because largely of infrastructural and logistic problems. Approaches involving the use of hormones for treating anoestrus and for synchronizing oestrus have had varying rates of success, depending on the protocols used and the incidence of underlying problems that cause infertility. Embryo technologies such as multiple ovulation embryo transfer, in vitro embryo production, cryopreservation and cloning are being intensively studied but have had far lower success rates than in cattle. Improving the productivity of buffalo requires an understanding of their potential and limitations under each farming system, development of simple intervention strategies to ameliorate deficiencies in management, nutrition and healthcare, followed by judicious application of reproductive technologies that are sustainable with the resources available to buffalo farmers.

Validation of a human progesterone enzyme immunoassay (EIA) kit for use on serum of cattle in Cameroon.

A study aimed at validating a human progesterone enzyme immunoassay kit was carried out on cattle at Bambui, Cameroon. Progesterone ELISA Kits (EH-511) were obtained from Clinpro International. Forty-one cows were selected, of which 19 were pregnant and 22 within 14 days post partum. Blood samples were analysed and progesterone levels were deduced from a curve obtained from standard absorbance values (A450). Results show that 95.5% of postpartum cows had progesterone levels below 1 ng/ ml, with the highest level being 0.75 ng/ml. The mean level was 0.5 +/- 0.26 ng/ml. The cows in the 'pregnant group' had progesterone levels ranging from 3.5 to 17.5 ng/ml. This kit can be used for measuring progesterone levels in cattle. Levels of 1 ng/ml for two consecutive samples or one sample at or above 3 ng/ml are an indication of the presence of corpus luteum, while cows below 1 ng/ml will be in anoestrus.

A coordinated research programme to develop methodologies for an integrated approach to improve small scale market oriented dairy systems in developing countries.

A five-year Coordinated Research Project (CRP) entitled 'Integrated approach for improving small scale market oriented dairy systems' is currently being implemented by the Food and Agriculture Organization and the International Atomic Energy Agency, through their Joint Programme on 'Nuclear Techniques in Food and Agriculture'. The objectives are to (a) identify and prioritize the constraints and opportunities in the selected dairy farms; (b) determine the most important limiting factors; (c) develop intervention strategies; (c) assess the economic impact of the interventions; (d) develop methodologies for recording and demonstrating the economic impact; and (e) promote the adoption and dissemination of proven strategies and methodologies. Fifteen institutes in developing as well as developed countries are participating in the project, through ten research contracts (Bangladesh, Cameroon, Pakistan, Paraguay, Peru, South Africa, Sri Lanka, Tanzania, Tunisia and Venezuela), one technical contract (Peru) and four research agreements (Malaysia, U.K., U.S.A. and Uruguay). The initial phase of the project, which focused on the conduct of Participatory Rural Appraisals and Economic Opportunity Surveys in the countries of the research contract holders, has now been completed. This paper describes the background to the CRP approach and the procedures used for developing, initiating and implementing this project.

Use of metabolic profiles in dairy cattle in tropical and subtropical countries on smallholder dairy farms.

Metabolic profile testing has generally been used as part of a multidisciplinary approach for dairy herds in temperate climates. Our goal was to evaluate the effectiveness of the technique for identifying constraints on productivity in small herds in environments less favorable for milk production. Metabolites tested were chosen for stability in the sample after collection of blood, ease of analysis and practical knowledge of the meaning of the results. Blood levels of five different metabolites in low-producing dairy cows belonging to smallholders in tropical and subtropical environments were measured. The study involved 13 projects with 80 cows in each, carried out in six Latin American, six Asian, and one southern European countries. Data were also collected on feeding, body condition score (BCS) and weight change, parasitism, and reproduction. In Chile, Mexico, Paraguay, Philippines, Uruguay, and Venezuela, globulin levels were high in > 17% of cows sampled on each occasion. Globulin levels were also high in Turkey and Vietnam on one or more occasions. In Paraguay, 49% of cows had high globulin levels at two to three months after calving. These results suggest that inflammatory disease was present to a potentially important degree, although this was not always investigated and not always taken into account. In all countries except Mexico and Venezuela, high beta-hydroxybutyrate (BHB) levels before calving in many cows highlighted the presence of condition loss in late pregnancy, an important potential constraint on productivity and fertility. Fewer cows showed high BHB levels in lactation, whereas change in BCS and weight was more sensitive for measuring negative energy balance. Urea concentrations were low in only small numbers of cows suggesting that dietary protein shortages were not common. Albumin values were low mainly in cows where globulin values were high and, hence, did not generally provide additional information. The exception was in China where pregnant yaks over winter had high BHB and low albumin values, suggesting that they were seriously underfed. This observation stimulated a successful nutritional intervention in the following winter. Inorganic phosphate values were within the reference range in most countries a majority of the time suggesting, contrary to expectation, that this mineral was not commonly a constraint. The use of metabolic profile testing proved valuable in drawing attention to important potential constraints on productivity in dairy cows in tropical and subtropical environments and in confirming those which were not.

Reproduction in water buffalo: comparative aspects and implications for management.

The domestic buffalo occupies an important niche in many ecologically disadvantaged agricultural systems, providing milk, meat and draught power. Although buffalo can adapt to harsh environments and live on low quality forage, their reproductive efficiency is often compromised by such conditions. Climatic stress depresses ovarian cyclicity, oestrous expression and conception rates. Poor nutrition, usually related to seasonal fluctuations in availability and quality of feed, delays puberty and increases the duration of postpartum anoestrus. Management factors such as the system of grazing (free, tethered or none) and sucking by calves (restricted or ad libitum) also modulate reproductive functions. Finally, the skills and capabilities of farmers as well as the quality of support services such as artificial insemination and disease control also influence fertility. The relative importance of these factors vary greatly depending on ecological conditions and production systems. Improvement of reproductive efficiency therefore requires the identification of specific limiting factors under a given situation and the development and field testing of strategies for improvements and interventions that are sustainable with available local resources. The application of modern reproductive technologies in buffaloes requires an appreciation of their biology and reproductive physiology as well as the potentials and limitations under each specific production system.

Relative importance of larval and adult Mecistocirrus digitatus in inducing resistance to a reinfection in calves.

Calves immunized with adult Mecistocirrus digitatus implanted directly into the abomasum did not develop a substantial degree of immunity to a subsequent large oral (challenge) dose of larvae, which developed to maturity. In contrast animals immunized by oral infection developed strong resistance. The calves implanted with adult worms appeared to show a greater degree of susceptibility to maturation of the challenge infection than controls which received a challenge of the same magnitude without any previous immunization. The implanted female adult worms established in the hosts and continued to produce more eggs for a longer time than those which developed to maturity from the oral immunizing infection with third-stage larvae. Passive haemagglutination studies revealed that the implanted adult worms stimulated little or no antibody response in the hosts. In the calves which did not show a response to the adult worm implant the subsequent challenge with an oral infective dose of third-stage larvae also failed to stimulate a response. Likewise the two calves from the group which showed a weak antibody response to the adult worm implant did not show an increased response when challenged. In contrast, calves immunized with an oral infection of third-stage larvae had an antibody response which showed a vigorous rise on challenge in four of the five calves. Thus a direct relationship between resistance to challenge infection and the antibody response determined by the passive haemagglutination and gel-diffusion tests was observed in the calves immunized orally.

Peripartal changes of estrone, progesterone and prostaglandin in the water buffalo.

The peripheral blood plasma concentration of estrone, progesterone and 15-keto-13, 14-dihydroprostaglandin F2alpha (PGF2alpha metabolite) were determined by radioimmunoassay techniques during the peripartal period in 5 buffalo cows belonging to a river type breed. Estrone levels started to increase from below 200 pg/ml about 15 days prior to parturition, and reached high concentrations (400-750 pg/ml) during the last 5 days of pregnancy. The estrone concentration decreased to baseline levels after delivery. The concentration of progesterone fluctuated between 800 and 2000 pg/ml until 15 days before calving and showed a gradual increase during the last 15 days of pregnancy. The progesterone levels declined abruptly on the day of calving and remained below 100 pg/ml for up to 60 days post-partum. Increased levels of the prostaglandin metabolite were recorded from 15 days prior to parturition with further increases occurring during the last 3 days of pregnancy. PGF2alpha metabolite levels declined gradually after parturition, reaching base line levels 15-20 days after calving.

Early pregnancy diagnosis in buffaloes from plasma progesterone concentration.

Blood samples were collected from 84 buffalo cows 21 days after fixed time artificial insemination following oestrus synchronisation and cloprostenol. Progesterone concentration in plasma was determined by radioimmunoassay. The animals were examined for pregnancy by rectal palpation 60 to 90 days after insemination. Forty-two animals were predicted pregnant on the basis of progesterone concentration (more than 1.0 ng per ml), and 28 (66.7 per cent) of them were subsequently confirmed pregnant by rectal palpation. Thirty-five animals were predicted non-pregnant (progesterone less than 0.7 ng per ml), in 34 (97.1 per cent) this proved to be so. Of the total number, seven (8.3 per cent) were classified as doubtful because their progesterone concentrations were within the range 0.7 to 1.0 ng per ml: two of them were confirmed pregnant and the other five non-pregnant. Out of 31 animals diagnosed pregnant by rectal palpation, 28 (90.3 per cent) had been correctly detected by assay at 21 days. Thirty-four (64.2 per cent) of the 53 animals found non-pregnant had been correctly detected by assay. It was concluded that the determination of plasma progesterone concentration 21 days after insemination was an accurate method of predicting non-pregnancy in buffaloes.

Seasonal differences in plasma testosterone profiles in buffalo bulls.

Testosterone was measured by radioimmunoassay in blood samples collected hourly over 10 h from two adult buffalo bulls in April, May, August and December. The basal concentrations were below 0.2 ng/ml while peak concentrations ranged from 0.35 to 1.65 ng/ml, with not more than one complete peak occurring during a 10 h period. Both bulls had similar testosterone profiles within each sampling period but differences were evident between periods, the mean concentration being highest in August and falling through December and April to the lowest levels in May. Testosterone concentrations in buffaloes are therefore lower than those in other domestic species, and appear to vary during different times of the year.

Fertility in buffaloes after oestrus synchronisation with cloprostenol and fixed time insemination.

Fifty-seven cycling buffalo cows of the river type were treated with two doses of 0.5 mg cloprostenol intramuscularly given 11 days apart. Each animal was inseminated twice at 72 and 96 hours after the second injection of cloprostenol. The first service conception rate diagnosed by rectal palpation at 90 days was 38.6 per cent. At the time of insemination the cervix was easily penetrable on both days in only 39 (68.4 per cent) of the animals. They were inseminated at or beyond the internal cervical os, while the others were inseminated in the cervical canal. There was a marked difference in conception rate between those receiving deep inseminations (48.7 per cent) and the others (16.7 per cent). In relation to the interval from calving to insemination the conception rates for those which had calved 60 to 90, 90 to 120 and 120 to 150 days earlier were 16.6, 36.4 and 55.5 per cent respectively. The use of cloprostenol treatment and fixed-time insemination is a useful method of overcoming the problem of oestrus detection in buffaloes. Acceptable levels of fertility can be obtained in those animals which have a sufficiently relaxed cervix to permit semen deposition at the internal os, provided the interval from calving to insemination is more than 90 days.

Changes in the structure and function of the testes and epididymides in vasectomized rams.

Vasectomized rams were studied with regard to the structure and function of their testes and epididymides at different periods up to 3 years and 9 months after the operation, and compared with intact control rams. Control rams showed a marked seasonal pattern with higher values for size and weight of testes, diameter of seminiferous tubules, Sertoli cell ratios for germ cells, and size of cauda epididymidis immediately prior to and during the breeding season than at other times of the year. In vasectomized animals the seasonal pattern was ill-defined, the testicular parameters were lower, and the cauda epididymidis was larger than in intact rams. Spermatogenesis was qualitatively and quantitatively affected after vasectomy, with a sequential ebb-and-flow pattern of spermatogenic arrest and hypospermatogenesis. Epididymal changes included the development of multiple spermatoceles surrounded by a granulomatous reaction, and disturbances in the process of sperm maturation.

Synchronisation of oestrus in buffaloes (Bubalus bubalis) using prostaglandin F2alpha.

Prostaglandin F2alpha (PGF2alpha) was used intramuscularly in two preliminary trials to determine its effect in cycling buffalo cows. In the first trial, animals with corpora lutea in their ovaries responded to either two doses of 15 mg on two consecutive days, or to a single dose of 30 mg, by showing signs of oestrus commencing 31 to 55h after the initial injection. In the second trial two doses of 30 mg PGF2alpha given 11 days apart resulted in oestrus on the third day after the second injection.

Androgen levels in intact and vasectomized rams during the breeding and nonbreeding seasons.

Plasma androgen profiles were studied in two intact and two vasectomized rams in October (over a 12-hour period) and in a similar number in February (over a 25-hour period). No significant differences were found between intact animals and those vasectomized 4, 6, and 7 months previously. All intact and vasectomized animals showed a marked difference in profiles between October and February. The response to an intravenous injection of 4500 IU of human chorionic gonadotropin was also studied in February and no significant difference was observed in the subsequent pattern of plasma androgens.