Copper status in breeding and racing camels (<Emphasis Type="Italic">Camelus dromedarius</Emphasis>) and response to cupric oxide needle capsules

Copper was determined in the blood of breeding camels, camel calves and racing camels to evaluate copper status in these animals in UAE. Low blood copper concentrations were reported in newly born camel calves (100%) and calves 2–4 months old (68%), breeding camels at early (55.6%) and at mid lactation (48%) and at late pregnancy (69%). This is attributed to the low copper and high sulfate in the Rhodes grass which is the only diet offered to the breeding camels. On the other hand only 9.7% of racing camels showed low copper levels. This is because copper is routinely offered to racing camels when their blood copper is low. Cupric oxide needle capsules orally administered at the rate of 8 g per adult camel was effective in elevating blood copper from 7.083 μmol/L at day zero to 10.074 μmol/L at day 28 after dosing.     

Comparative efficacy of bromocriptine,cabergoline and thyroxine in inducing oestrus in bitches

Forty bitches in anoestrus for more than six months from the last heat, with a serum progesterone level less than 1 ng/ml were subjected to oestrus induction trials using anti-prolactin drugs and levothyroxine, once daily orally for 20 consecutive days. The mean serum progesterone level among them was found to be 0.57 ± 0.03 ng/ml. Out of 10 animals treated in each group, five (50%) in Group I (bromocriptine @ 50 μg/kg body weight), nine (90%) in Group II (cabergoline @ 5 μg/kg body weight), eight (80%) in Group III (thyroxine @10 μg/kg body weight) and seven (70%) in Group IV (thyroxine @ 5 μg/kg body weight) responded by evincing proestrual bleeding. The mean (±SEM) time taken from initiation of treatment to onset of proestrual bleeding in Groups I, II, III and IV was 28 ± 3.39, 13.44 ± 3.12 (P < 0.05), 24.50 ± 3.18 and 33 ± 2.21 days respectively. The mean (±SEM) duration of proestrus and oestrus in the treatment groups was 9.80 ± 0.86, 10.11 ± 0.68, 11.25 ± 0.88 and 10.71 ± 0.68 days and 7.60 ± 0.24, 8 ± 0.29, 8.5 ± 0.63 and 7.85 ± 0.46 days respectively. The conception rate in relation to the number of animals responding to oestrus induction in the treatment groups was 80%, 78%, 63% and 57%, respectively. The mean (±SEM) gestation length calculated from the last breeding date and litter size in the treatment groups varied from 60.50 ± 1.55 to 64.00 ± 0.82 days and 5.14 ± 0.34 to 6.40 ± 0.40 respectively.     

Pharmacokinetics,urinary excretion and plasma protein binding of danofloxacin following intravenous administration in buffalo calves (Bubalus bubalis)

Pharmacokinetics, urinary excretion and plasma protein binding of danofloxacin was investigated in buffalo calves following intravenous administration at the dose rate of 1.25 mg/kg to select the optimal dosage regimen of danofloxacin. Drug concentrations in plasma and urine were measured by microbiological assaying. In vitro plasma protein binding was determined employing the equilibrium dialysis technique. The distribution and elimination of danofloxacin were rapid, as indicated by values (mean ±SD) of distribution half-life (t_1/2α = 0.16 ± 0.07 h) and elimination half-life (t_1/2β = 4.24 ± 1.78 h), respectively. Volume of distribution at steady state (Vss) = 3.98 ± 1.69 L/kg indicated large distribution of drug. The area under plasma drug concentration versus time curve (AUC) was 1.79 ± 0.28 μg/mlxh and MRT was 8.64 ± 0.61 h. Urinary excretion of danofloxacin was 23% within 48 h of its administration. Mean plasma protein binding was 36% at concentrations ranging from 0.0125 μg/ml to 1 μg/ml. On the basis of pharmacokinetic parameters obtained, it is concluded that the revision of danofloxacin dosage regimen in buffalo calves is needed because the current dosage schedule (1.25 mg/kg) is likely to promote resistance.     

Influence of <Emphasis Type="Italic">E. coli</Emphasis> lipopolysaccharide induced fever on the plasma kinetics of cefepime in cross-bred calves

The pharmacokinetic behavior of cefepime was studied in healthy and febrile cross-bred calves after single intravenous administration (10 mg/kg). The fever was induced with E. coli lipopolysaccharide (1 μg/kg, IV). The drug concentration in plasma was detected by microbiological assay method using E. coli (MTCC 739) test organism. Pharmacokinetic analysis of disposition data indicated that intravenous administration data were best described by 2 compartment open model. At 1 min the concentration of cefepime in healthy and febrile animals were 55.3 ± 0.54 μg/ml and 50.0 ± 0.48 μg/ml, respectively and drug was detected up to 12 h. The elimination half-life of cefepime was increased from 1.26 ± 0.01 h in healthy animals to 1.62 ± 0.09 h in febrile animals. Drug distribution was altered by fever as febrile animals showed volume of distribution (0.27 ± 0.02 L/kg) higher than normal animal (0.19 ± 0.01 L/kg). Total body clearances in healthy and febrile animals were 104.4 ± 2.70 and 114.2 ± 1.20 ml/kg/h, respectively. To maintain minimum therapeutic concentration of 1 μg/ml, a satisfactory dosage regimen of cefepime in healthy and febrile cross-bred calves would be 15.5 mg/kg and 8.2 mg/kg body weight, respectively, to be repeated at 8 h intervals. The T>MIC values (8 h) of cefepime suggested that this agent is clinically effective in the treatment of various infections.     

Plasma pharmacokinetics and milk levels of ceftriaxone following single intravenous administration in healthy and endometritic cows

Pharmacokinetics and milk levels of ceftriaxone were studied in healthy and endometritic cows following single intravenous administration. The drug was detected up to 8 h of dosing in plasma of healthy and endometritic cows and the drug disposition followed three-compartment open model. The values of Vd_area, AUC, t_1/2β, Cl_B, MRT and P/C ratio were 0.50 ± 0.19 L.kg⁻¹, 62.2 ± 23.3 μg.ml⁻¹.h, 1.02 ± 0.07 h, 0.30 ± 0.09 L.kg⁻¹.h⁻¹, 1.55 ± 0.25 h and 0.52 ± 0.27, respectively, in healthy and 1.55 ± 0.52 L.kg⁻¹, 37.0 ± 17.1 μg.ml⁻¹.h, 1.56 ± 0.25 h, 0.56 ± 0.14 L.kg⁻¹.h⁻¹, 2.14 ± 0.34 h and 1.44 ± 0.60, respectively, in endometritic cows. The drug was detected in milk for 36 h after administration. For MIC₉₀ of 0.5 μg.ml⁻¹ the most appropriate dosage for ceftriaxone, would be 9.0 mg.kg⁻¹ repeated at 6 h intervals for the treatment of endometritis in cows.     

Estrus cycle effect on muscle tyrosine kinase activity in bitches

Estrus cycle is a well recognized cause of insulin resistance in bitches. The insulin receptor (IR) as well as the insulin-like growth factor-I receptor belong to the same subfamily of tyrosine kinase (TK) receptors. The objective of this study was to evaluate basal TK activity in muscle tissue of bitches during the estrus cycle. Twenty-four bitches were used in the study (7 in anestrus, 7 in estrus, and 10 in diestrus). Muscle samples, taken after spaying surgery to determine TK activity, were immediately frozen in liquid nitrogen and then stored at −80°C until the membranes were prepared by sequential centrifugation after being homogenized. TK activity was determined by Poly (Glu 4:Tyr 1) phosphorylation and expressed in cpm/μg of protein. TK activity was significantly lower (P < 0.001) in the animals in estrus (104.5 ± 11.9 cpm/μg of protein) and diestrus (94.5 ± 16.9 cpm/μg of protein) when compared with bitches in anestrus (183.2 ± 39.2 cpm/μg of protein). These results demonstrate, for the first time, lower basal TK activity in the muscle tissue of female dogs during estrus and diestrus, which may represent lower insulin signaling capacity, opening a new field of investigation into the molecular mechanisms of insulin resistance in dogs.     

Equine placenta expresses glutamine synthetase

In most mammalian species the developing fetus utilizes large amounts of glutamine derived both from the maternal circulation and synthesized de novo in the placenta. The present study was designed to determine the role of the placenta in glutamine synthesis in the horse. The placentae from eight Standardbred mares were sampled immediately after parturition together with additional tissues obtained at necropsy from three Standbred mares during diestrous. Glutamine synthetase protein was detectable in the non-pregnant horn of the placenta in amounts similar to those seen in gluteus muscle, but the amount in the pregnant horn was two times greater than in the non-pregnant horn. Glutamine was the second most abundant amino acid in amniotic fluid at a concentration of 310 ± 26 μmole/L with that of glycine being 535 ± 48 μmole/L. The most abundant amino acids in placental tissue were glycine (3,732 ± 194 μmole/Kg), glutamate (3,500 ± 343 μmole/Kg) and glutamine (2,836 ± 208 μmole/Kg). The results illustrate the importance of glutamine to the equine fetus and establish that the placenta, particularly the pregnant horn, has considerable capacity for glutamine synthesis.     

Bacteria flora and heavy metals in cultivated oysters <Emphasis Type="Italic">Crassostrea iredalei</Emphasis> of Setiu Wetland,East Coast Peninsular Malaysia

Slipper oyster Crassostrea iredalei is a species of good demand for its sweet flavor and white coloured flesh. The filter feeding nature predisposes oysters to accumulation of pathogenic and heavy metals in waters impacted by sewage pollutions and may thus render the oysters unfit for human consumption. A study was undertaken to investigate the presence of bacteria flora and heavy metal concentrations in cultivated oysters Crassostrea iredalei at Setiu Wetland, Terengganu, the only source of cultivated oysters in East Coast of Malaysia. A total of 200 slipper oyster samples were analyzed. The bacteria were isolated using non selective agar such as TSA agar and selective agars before they were then identified using conventional methods in combination with BBL Crystal identification kit. Heavy metals such as zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb) concentrations were determined using atomic absorption spectrophotometry. Results showed that the oysters harbor predominantly Shewanella putrifaciens followed by Vibrio parahaemolyticus, Vibrio vulnificus, Vibrio cholerae, Enterobacter cloacae, Escherichia coli and Chromobacterium violaceum. They also contain high concentration of Zn (785.68 ± 285.88 μg/g) with the lowest heavy metal was Pb (0.17 ± 0.15 μg/g), whilst the concentrations of other heavy metals were Cu (38.9 ± 13.2 μg/g) and Cd (1.60 ± 0.28 μg/g). The study is very useful to evaluate the type of bacteria and heavy metal present in oyster meat for human consumption.     

Bioequivalence Study of Two Long-acting Oxytetracycline Formulations in Sheep

Two commercially available long-acting oxytetracycline hydrochloride formulations (Primamycin LA (Pfizer) and Terralent 20% LA (İ.E. Ulagay)) were administered by the intramuscular route to 20 clinically healthy sheep at a dose of 20 mg/kg. The study was performed in a two-period crossover design. Plasma samples were analysed by high-pressure liquid chromatography. The mean maximum concentrations (C _max) was 8.00 ± 2.05 μg/mland 8.61 ± 1.42 μg/ml, respectively. The mean area under the concentration time curve (AUC) values were 154.95 ± 50.37(μg h)/ml and 161.70 ± 47.02(μg h)/ml, respectively. The 90%confidence intervals for the ratio of C _max and AUC values for the test and reference product are with in the interval 70−143% for C _max and interval 80-−125% for AUC proposed by EMEA. It was concluded that Primamycin LA and Terralent 20% LA formulations are bioequivalent in their rate and extent of drug absorbtion. Ozdemir N. and Yıldırım, M., 2006. Bioequivalence study of two long-acting oxytetracycline formulations in sheep. Veterinary Research Communications, 30(8), 929–934     

Effect of varying dietary energy levels during the last trimester of pregnancy on subsequent first lactation performance in Sahiwal heifers

The aim of the study was to determine optimum dietary energy level during the last trimester of pregnancy for Sahiwal heifers in subtropical Pakistan. Sixteen Sahiwal heifers, 5–6 months pregnant, were assigned to four dietary treatments with four heifers on each treatment. Isonitrogenous (CP = 14.1%) diets having varying energy, namely, ME 88%, ME 100% (Control), ME 112% and ME 124% of NRC recommended level for pregnant heifers, were fed until calving. All were fed a similar diet after calving. Precalving weight gain was highest (P < 0.05) in heifers fed ME 112 and 124% (486 ± 13 and 497 ± 5 g/day, respectively) followed by ME 100% (444 ± 7 g/day), and the lowest weight gain was recorded for ME 88% (397 ± 8 g/day). A similar trend was observed for feed efficiency. Body condition score at calving in groups ME 124% and ME 112% was higher than ME 88% and ME 100%. Nutrient digestibility, birth weight of calves and milk composition except fat content were not influenced by energy levels. The highest daily milk yield was observed in heifers fed ME 100% followed by ME 112, 124, and 88%. We conclude that the NRC recommendation is applicable to the subtropical region.     

Milk production and calf rearing practices in the smallholder areas in the Eastern Cape Province of South Africa

Farmer perceptions on milk production and calf rearing practices on communal rangelands in the smallholder areas of the Eastern Cape Province, South Africa were evaluated on a total of 218 cattle farmers using structured questionnaires, semi-structured interviews with key informants and personal observations. Nearly 70% of the households in the small-scale areas milked twice a day compared to 60% in the communal areas. About 62% of the interviewees weaned calves between 6 and 12 months of age. Milk yield/cow/day (7.5 ± 0.5 litres), fresh milk consumption/household/day (3.2 ± 0.5 litres) and sales/household/day (3.1 ± 1.1 litres) were highest in the sour-veld, small-scale farms (P < 0.05). Sour milk consumption/household/day (2.6 ± 0.2 litres) and sales/household/day (0.8 ± 0.2 litres) were significantly high in communal farms with a sour-veld. It was concluded that, calf rearing practices were poor and milk yield, consumption and sales were generally low and varied with production system and rangeland type. Further research is required to improve calf management practices, cow nutrition, milk yield and quality and how milk production can be used as a toll for rural development in the smallholder areas of South Africa.     

Phytoestrogen treatment induces testis alterations in dogs. Potential use in population control

Dog overpopulation is considered a human health risk; they are the terrestrial vector of rabies and reservoirs for other human diseases. Surgical neutering and intratesticular injections have been used in male dogs. Physiological and morphological alterations in reproductive organs can be induced by phytoestrogens. Our goal was to evaluate the effect of oral coumestrol on dog ejaculates and testis histology. Two groups of 5 healthy adult dogs were used. One coumestrolcontaining biscuit was given once a week for a 4 week period to the experimental group. Ejaculates were obtained and evaluated. After treatment, testis were obtained and processed for histology. Compared to controls, treated dogs have reduced tubules (462 ± 1.4 vs 336 ± 2 μ²), spermatogenic epithelium (49.1 ± 0.01 vs 13.3 ± 0.01 μ²), and lumen opening (891 ± 1.4 vs 530 ± 26.9 μ). Ejaculates from treated animals have increased numbers of abnormal spermatozoa and reduced sperm concentration.     

Investigation of Immunmodulatory effects of levamisole and vitamin E on Immunity and some blood parameters in newborn Jersey calves

The immunmodulatory effects of dl-α tocopherol (vitamin E) and levamisole on the immune system and some blood parameters of newborn Jersey calves were investigated with the present study. Treatment groups 1, 2 and 3 were injected 13,3 ml isotonic saline solution (0,9% NaCl), 3 mg/kg levamisole HCl and 2000 IU vitamin E weekly, starting at birth until the age of two weeks. Average serum IgM levels of the control, levamisole and vitamin E calves were 111,7 ± 9,3 mg/100 ml, 251,9 ± 27,6 mg/100 ml, 202,2 ± 43,3 mg/100 ml respectively on day 22. Average serum IgG levels of the levamisole and vitamin E groups elevated, compared to the control group on days 1, 8, 15 and 22. However, there were stastistically differences in treatment and control groups for serum total cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL), triglyceride and cortisol values and whole blood counts. All differences were in the reference ranges. Levamisole and vitamin E could be used as an alternative way for their beneficial effects such as improving the humoral immune responses of calves and their safety and practical use against the neonatal period infections in the field.     

Relationship of age to body weight,scrotal circumference,testicular ultrasonograms,and semen quality in Sahiwal bulls

The objective of the present study was to determine the relationship of age to body weight (BW), scrotal circumference (SC), number of pixels of testicular ultrasonograms (NP), and semen quality in Sahiwal bulls. The study was based on 128 Sahiwal bulls of different age groups (from 0 to >100 months of age). Bulls were evaluated for SC, BW, and NP. Semen was evaluated once a week for five consecutive weeks from regularly collected donor bulls (n = 86) ranging in age from 25–30 to >100 months. Ejaculate volume, sperm motility, sperm concentration, sperm morphology, percent live sperms, sperm plasma membrane integrity, and normal acrosome were compared among different age groups. Mean SC and BW increased (P < 0.05) in a curvilinear manner from birth to >100 months of age. Mean NP of testicular ultrasonograms increased (P < 0.05) from 0 to 24 months and then plateaued until >100 months of age. Body weight, SC, and NP were positively correlated with age from birth until >100 months (r = 0.91, 0.87, and 0.40, respectively). Ejaculate volume (5.7 ± 0.2 vs. 4.6 ± 0.09 ml) and sperm concentration (1,281.6 ± 17.7 vs. 1,115.8 ± 55.9 × 10⁶/ml) increased (P < 0.05) in mature bulls compared to younger ones. However, motility (68.6 ± 0.3%), plasma membrane integrity (50.8 ± 1.0%), and normal acrosome (74.8 ± 0.5%) remained insignificant due to age. In six of eight age groups studied, morphological abnormalities were well within the range (18.1 ± 0.3%). In conclusion, the BW, SC, and NP of testicular ultrasonograms, ejaculate volume, and concentration increased with age. Moreover, semen quality is fairly independent of age except volume and concentration in Sahiwal bulls.     

Pharmacokinetics and pharmacodynamics of chlorpyrifos in male and female cattle after topical administration

The aim of this work was to study the pharmacokinetic behaviour and the inhibitory effect on acetylcholinesterase and butyrylcholinesterase activities of chlorpyrifos in male and female cattle after pour-on administration. Determination of cholinesterase activity in plasma and erythrocyte was carried out according to Ellman kinetic method. The mean baseline activities were 9338.39 ± 1331.61 and 13220.69 ± 2274.18 to acetylcholinesterase and 624.65 ± 39.32 and 641.68 ± 88.08 IU/L to butyrylcholinesterase in females and males, respectively. Acetylcholinesterase was the predominant form of cholinesterase analyzed, with low levels of butyrylcholinesterase. The basal acetylcholinesterase activities of the bulls were significantly greater than those of cows. The inhibitory effect of topical chlorpyrifos administration was lower on butyrylcholinesterase than on acetylcholinesterase. Chlorpyrifos peak plasma concentration (male:10.920 ± 4.18; female:12.12 ± 3.88 μg/L) were reached at 11.92 ± 9.19 and 8.17 ± 7.67 h in male and female, respectively. The values of area under curve were 185.96 ± 168.45 and 278.89 ± 270.00 μg·h/L and mean residence time were 13.95 ± 8.10 and 14.90 ± 9.80 h in male and female, respectively.     

Studies on the development of omasum in west african dwarf goats (<Emphasis Type="Italic">Capra hircus</Emphasis>)

This work studied the sequential morphological changes of omasum in foetuses, neonates and adult West African Dwarf (WAD) goats by gross and light microscopic methods. The mean omasal volume was 1.37 ± 0.36, 4.2 ± 0.4, 8.7 ± 6.9 and 60.1 ± 8.6 ml for gestation day 87 and 146 foetuses, neonates and adults respectively. Grossly the mucosa exhibited longitudinally oriented primary, secondary, tertiary and quartnery laminae with smooth surface in foetuses and numerous papillae in the adults. Microscopically it was lined by stratified squamous epithelium which was divided into larger lighter luminal and smaller darker basal zones in gestation day 60 foetuses. The core of the laminae contained extension of the inner muscular tunic. The basal zone developed lateral evaginations (corial papillae) into the lighter zone of the laminae in gestation day 106 foetuses. By term these corial papillae approached the luminal surface. The papillae emerged above the luminal surface in 4 week old neonates. The papillae were fully developed in adult goats. The mean papillary height and width were -205.1 ± 34.0, 67.0 ± 9.6; 235.0 ± 86.5, 185.0 ± 42.3 and 570.3 ± 60.0, 290.1 ± 66.3 μm for foetuses, neonates and adult goats. The inner circular layer was thicker than the outer longitudinal layer of the muscular tunic. The central muscular layer of the laminae originated from the inner circular layer with attachment to the outer muscular layer in adults. This attachment could be adaptation for better anchorage and muscular contraction of the laminae in WAD goats.     

Changes in endogenous estrogens and expression of behaviors associated with estrus during the periovulatory period in Heatsynch treated Murrah buffaloes (Bubalus bubalis)

The objective of this study was (1) to establish the duration of behavioral estrus signs and timing of ovulation in Murrah buffaloes (n = 10) and (2) to determine relationship between behavioral estrus signs with change in plasma estrogen concentrations in animals treated with Heatsynch protocol. Estrus and its behavioral signs were detected at hourly intervals by visual observations per rectal examination of genitalia and bull parading four times in a day for 30 min each. Among the behavioral signs of estrus, swollen vulva was the best indicator of estrus followed by excitement and chasing by bull (90%). Among the duration of behavioral estrus signs, the first and longest duration of estrus signs was swollen vulva, which was seen up to 21.6 ± 1.1 h after onset of estrus. The mean total duration of estrus symptoms from appearance to disappearance of all the behavioral estrus symptoms was 40.2 ± 1.8 h. Endocrine profile during the periestrus period showed that the mean peak concentrations of total estrogen 330.9 ± 108.3 pg/ml occurred at 9.6 ± 1.0 h after estradiol benzoate injection. The average number of estrus symptoms observed per animal during Heatsynch treatment was 7.1. Ovulation occurred after 50.0 ± 2.0 h after estradiol benzoate treatment and 26.7 ± 2.0 h after end of total estrogen surge, respectively. In conclusion, our results suggest that all signs of behavioral estrus occurred after the preovulatory rise in estrogens. The first sign of estrus was swollen vulva, and this symptom persisted the longest.     

Wool characteristics in the third generation of Arkharmerino × Ghezel and Arkharmerino × Moghani crossbreed sheep

This investigation was conducted to evaluate the comparative productive performances and effect of some environmental factors on wool characteristics of Arkharmerino × Ghezel (Ar × Gh) and Arkharmerino × Moghani (Ar × Mo) crossbreed sheep. The mid-side fleece samples taken from animals during 2 years (2007–2008) were analyzed. Each sample was measured for average fiber diameter, fiber diameter variability, staple length, proportion of medullated fiber, proportion of kemp, and comfort factor. The comparative values for these fleece characteristics in F₃ generation Ar × Gh were 28.78 ± 0.48 μm, 36.84 ± 1.16%, 11.94 ± 0.35 cm, 7.07 ± 0.93%, 1.02 ± 0.23%, and 68.93%, respectively; while those traits were 29.79 ± 0.43 μm, 41.86 ± 1.16%, 11.96 ± 0.37 cm, 8.13 ± 1.06%, 2.71 ± 0.45%, and 63.33 ± 3.66% for Ar × Mo, respectively. The effects of genotype, sex, birth type, and year of birth were analyzed. Genotype had a significant (P < 0.01) effect on average fiber diameter and proportion of kemp, and Ar × Gh crossbreeds had lower diameter with less proportion of kemp. The two differences in fiber characteristics that were attributable to sex were fiber diameter variability and proportion of medullated fiber, and females had higher measure than males for both traits. Statistical analysis showed that crossbreeding with Arkharmerino generally had positive effects on the fleece favored to be used in the hand woven authentic carpet production.     

A study on the effect of GnRH administration on the ovarian response and laparoscopic intrauterine insemination of Awassi ewes treated with eCG to induce superovulation

The effect of GnRH administration on superovulatory response of ewes treated with equine chorionic gonadotrophin (eCG) in breeding and nonbreeding seasons and the contribution of laparoscopic insemination to the improvement of fertilization and embryo recovery were investigated. Twenty-four nonpregnant Awassi ewes of 3–4 years of age were randomly allocated into two groups (n = 12). Each ewe was treated with a progesterone impregnated intravaginal sponge for 12 days. The following superovulation treatment was used: ewes of group 1 received 1,200 IU of eCG once as an intramuscular injection 48 h prior to sponge withdrawal; ewes of group 2 also received 1,200 IU of eCG once as an intramuscular injection, 48 h prior to sponge withdrawal and after 24 h of sponge removal. Ewes were injected with 80 μg of GnRH. Ewes of groups 1 and 2 were further subdivided into four equal groups (n = 6). Subgroups A and C (superovulated with eCG and eCG plus GnRH, respectively) were mated naturally at least two times with Awassi rams of proven fertility at 8-h intervals. Subgroups B and D (same as A and C) had intrauterine insemination at 44–46 h after sponge removal, under laparoscopic visualization of uterine horns, depositing 1 ml of diluted semen containing 100 × 10⁶ motile sperm in the distal portion of each uterine horn. Ovarian response was assessed by determining the number of corpora lutea by laparoscopy at day 6 after mating. Embryo recovery was performed by using a semi-laparoscopic flushing procedure in both uterine horns. Results of the present study showed that ewes treated in breeding season with eCG plus GnRH has a higher number (P < 0.05) of corpora lutea than eCG alone as 7.33 ± 0.54 and 4.33 ± 0.39, respectively. There was no significant difference in the number of corpora lutea in nonbreeding season when ewes treated with eCG and eCG plus GnRH. The number of unovulated follicles was significantly higher (P < 0.05) in eCG treated ewes than in ewes treated with eCG plus GnRH, both in the breeding and nonbreeding seasons. The number of recovered embryos from ewes treated with eCG plus GnRH and eCG differ significantly (P < 0.05) as 4.32 ± 0.56 and 1.06 ± 0.26, respectively, in the breeding seasons. No significant difference was observed when these hormones used for superovulation in the nonbreeding season. A higher number of unfertilized ova (P < 0.05) was observed in ewes when naturally inseminated than in ewes inseminated using the intrauterine laparoscopic technique. Higher rate of embryo recovery (P < 0.05) was achieved when ewes were inseminated via intrauterine (4.66 ± 0.66) compared with ewes naturally mated (2.16 ± 0.74). The fertilization rate in ewes inseminated intrauterine using laparoscopic techniques and naturally mated were 91.5% and 44.8%, respectively. Fertilization failure in ewes inseminated intrauterine using laparoscopic techniques and naturally mated were 8.4% and 55.2%, respectively. It could be concluded that administration of GnRH 24 h after sponge removal increased ovulation rate of Awassi ewes treated with eCG for superovulation in the breeding season. The use of eCG to induce superovulation in Awassi ewes combined with laparoscopic intrauterine insemination increases the fertilization rate.     

Temporal changes in endogenous estrogens and expression of behaviors associated with estrus during the periovulaory period in Murrah buffaloes (<Emphasis Type="Italic">Bubalus bubalis</Emphasis>)

The objective of this study were (1) to establish the duration of behavioral estrus signs and timing of ovulation in Murrah buffaloes (n = 10) and (2) to determine relationship between behavioral estrus signs with change in plasma estrogen concentrations. Estrus and its behavioral signs were detected at hourly intervals by visual observations, per recta examination of genitalia and bull parading four times in a day for 30 minutes each. Among the behavioral signs of estrus, swollen vulva (80%) was the best indicator of estrus followed by excitement (70%). Among the duration of behavioral estrus signs the first and longest duration of estrus signs was swollen vulva which was seen upto 19.8 ± 0.8 h after onset of estrus. The mean total duration of estrus symptoms from appearance to disappearance of all the behavioral estrus symptoms was 23.5 ± 1.7 h. All the behavioral estrus symptoms were observed during the period of estrogen surge. Endocrine profile during the periestrus period showed that the mean peak concentrations of total estrogen 23.9 ± 3.9 pg/ml occurred at 8.8 ± 1.7 h after onset of estrus. The average number of estrus symptoms observed per animal during onset of spontaneous estrus was 5.7. Ovulation occurred after 37.4 ± 1.7 h after onset of estrus and 13.4 ± 1.0 h after end of total estrogen surge respectively. In conclusion, our results suggest that all signs of behavioral estrus occurred during the preovulatory rise in estrogens. The first sign of estrus to be observed was a swollen vulva and this symptom persisted the longest.