| Abstract: |
The present study was carried out in Physiology Laboratory, Department of Animal Production, Faculty of Agriculture, Zagazig University in cooperation with Animal Production Research Institute, Dokki, Giza, Egypt, during the period from December, 2004 till November, 2005. The total number of the non- pregnant she-camels (Camelus dromedarius) at 5 to 10 years of age and 500- 600 kg body weight during breeding (n=24) and non- breeding seasons at the hot-humid (n=20) and hot-dry (n=23) months, were used in the present study .A total number of 134 ovaries (left and right) were collected from Belbies Abattoir, Belbies City, Sharkiya Province, located in the north eastern part of the Nil Delta (30ºN), Egypt.The present work aimed to investigate the effect of breeding (December , January , February, March, April and May) and non- breeding seasons either the hot-humid (June, July and August) or hot-dry (September, October and November) months on body physiological parameters (rectal temperature, respiration rate and pulse rate), blood components (total proteins, albumin, globulin, aspartate-aminotransferase : AST, alanine- aminotransferase :ALT, alkaline phosphatase: ALP enzymes, cholesterol, sodium, potassium, calcium, total phosphorus, zinc and oestradiol -17β hormone concentrations), ovarian activity (ovary weight, number of follicles, number of corpora lutea, number of oocytes, number of follicles and oocytes recovery rate and oocytes status) in the left and right ovaries, and follicular fluid components (sodium, potassium, calcium, total phosphorus, AST, ALT, ALP enzymes and oestradial – 17β hormone concentrations) in the left and right ovaries of the dromedary she-camels. Histopathological status of the right and left ovaries were also recorded, during breeding and non-breeding seasons either the hot-humid or hot dry months.The obtained results were as follow:1. Physiological parameters:1.1. Rectal temperature (°C) and respiration rate (r.p.m.) in the dromedary she-camels increased significantly (P<0.01) in the non-breeding season at the hot-humid months as compared with the hot-dry months and the breeding season.1.2. Pulse rate (p.p.m.) in the dromedary she-camels increased significantly (P<0.01) in the non-breeding season at the hot-humid and hot-dry months as compared with the breeding season.2.Blood serum components:2.1.Total proteins concentration (mg/dl) in the blood serum she-camels increased significantly (P<0.01) in the non-breeding season at the hot-humid months and breeding season as compared with the hot-dry months, while the differences between hot-dry or breeding season on the total proteins concentration were insignificant.2.2.Albumin and globulin concentrations (mg/dl) in the blood serum she-camels decreased insignificantly in the breeding season as compared to the non-breeding season either the hot-humid or hot-dry months2.3.Cholesterol (mg/dl) and oestradiol -17β hormone (pg/dl) concentrations in the blood serum of the dromedary she-camels increased significantly (P<0.01) during breeding season as compared with the non-breeding season either the hot humid or hot-dry months. While, cholesterol and oestradiol 17β hormone concentrations decreased significantly (P<0.01) in the hot-humid months as compared with the hot-dry months.2.4.Sodium concentration (mg/dl) in the blood serum she-camels decreased insignificantly, while calcium, potassium, total phosphorus and zinc concentrations (mg/dl) increased significantly (P<0.01) during breeding season as compared with the non- breeding season either the hot-humid or hot –dry months.2.5.Aspartate – aminotransferase (AST) enzyme activity (U/L) in the blood serum of the dromedary she-camels increased significantly (P<0.01) in the non-breeding season at the hot-humid months as compared with the hot-dry months or breeding season. Alanine–aminotransferase (ALT) and alkaline phosphatase (ALP) enzymes activities (U/L) in the blood serum of the dromedary she-camels increased significantly (P<0.01) in the non-breeding season either the hot-humid or hot-dry months as compared with breeding season.3. Ovarian activity:3.1. Effect of breeding and non-breeding seasons:3.1.1. Ovary weight (gm) of the dromedary she-camels increased significantly (P<0.01) during breeding season and the hot-dry months as compared with the hot-humid months , while the number of corpora lutea increased significantly (P<0.01) during breeding season as compared with the non-breeding season either the hot-humid or hot-dry months.3.1.2.The number of normal follicles of the dromedary she-camels significantly (P<0.01) increased, while the number of atretic follicles significantly (P<0.01) decreased during breeding season as compared with the non- breeding season either the hot-humid or hot-dry months.3.1.3. The total number of follicles of the dromedary she-camels increased significantly (P<0.01) during breeding season and the hot-dry months as compared with the hot –humid months.3.1.4.The cumulus oocytes complex (COC’s), partially denuded cumulus oocytes (PDCO), expanded cumulus oocytes (ECO) and oocytes recovery rate of the dromedary she-camels increased significantly (P<0.01) during breeding season as compared with the non-breeding season either the hot-humid or hot-dry months, while denuded cumulus oocytes (DCO) during of breeding and non-breeding seasons were insignificant.3.1.5 Follicular fluid components:3.1.5.1.Follicular fluid sodium concentration (mg/dl) in the dromedary she-camels decreased significantly (P<0.05), while potassium, calcium , total phosphorus (mg/dl) and oestradiol-17β (pg/ml) hormone concentrations increased significantly (P<0.05 or 0.01) during breeding season as compared with the non-breeding season either the hot-humid or hot-dry months.3.1.5.2. Follicular fluid AST, ALT and ALP enzymes activities (U/L) in the dromedary she-camels increased significantly (P<0.05) during breeding season as compared with the non-breeding season either the hot-humid or hot-dry months.3.1.6.Histopathological status:3.1.6.1. The dromedary she-camels ovary showed higher in the breeding season in comparison with the non-breeding season either the hot-humid or hot-dry months. She-camels ovary showed also less activity, lower follicles number and interstitial tissues in the non – breeding season. So, she-camels ovary in the non-breeding season is considered in dormant phase.3.2.Effect of ovary side:3.2.1. The left ovary weight (gm) of the dromedary she-camels was significantly (P<0.01) higher than the right one, while the number of corpora lutea in the left ovary was insignificantly higher than the right ovary.3.2.2. The number of normal follicles of the in left ovary dromedary she- camels was significantly (P<0.01) higher, while the number of atretic follicles was significantly (P<0.01) lower than the right ovary.3.2.3. The total number of follicles of the dromedary she- camels in the left ovary was significantly (P<0.01) higher than the right one.3.2.4. The cumulus oocytes complex (COC’s), partially denuded cumulus oocytes (PDCO) and oocytes recovery rate of the dromedary she-camels were significantly (P<0.01) higher, while expanded cumulus oocytes (ECO) and denuded cumulus oocytes (DCO) were significantly (P<0.01) lower in the left ovary than the right one.3.2.5. Follicular fluid components:3.2.5.1.Follicular fluid sodium concentration (mg/dl) in the dromedary she camels was significantly (P<0.01) lower ,while potassium, calcium, total phosphorus (mg/dl) and oestradiol-17β hormone concentrations (pg/ml) were significantly (P<0.05 or 0.01) higher in the left ovary than the right one.3.2.5.2.Follicular fluid AST, ALT and ALP enzymes activities (U/L) in the dromedary she- camels were significantly (P<0.05) higher in the left ovary than the right one.3.2.6. Histopathological status:3.2.6.1. The left ovary of the dromedary she-camels showed more growing and mature follicles and higher activity than the right ovary.In conclusion, the female dromedary camels (Camelus dromedarius) showed better body temperature, blood components, hormonal patterns, histological state in the ovary, ovarian activity, follicular activity, oocytes status and oocytes recovery rate in the breeding season (short daylight) than the non- breeding season either the hot-humid or hot-dry months (long daylight). In addition, the left ovary appears more active than the right one. The ovarian activity in the breeding season and the non- breeding season at th hot –dry months were nearly similar. Female dromedary camels display follicular activity during the non-breeding season either the hot-humid or the hot-dry months. Therefore, it could be concluded that neither the nature of the follicular fluid, nor the size of the ovarian follicles in she-camels , histopathological status, enzymatic activities and hormonal alterations in the follicular fluid could be used for the differentiation between the atretic and normal follicles. If the she-camel is hot and subjected to a high environmental heat load, it will require a very high minute ventilation to regulate cerebral blood temperature adequately. So, the environmental temperature, relative humidity and daylight length seemed to play the major role in the regulation of seasonal reproductive activity in the female dromedary camels. The camel can be described as a seasonal breeder with a marked peak in sexual activity. Occasionally and particularly in specific climatic zones, a lesser peak also occur. The female camels show low level, at least physiological of breeding activity throughout the year. The variation in the timing and length of season clearly demonstrate that local environmental factors trigger off the start of increased sexual activity . Seasonality of reproduction for the female camel is based mainly on the status of ovarian activity in slaughtered females. However, endocrinological and physiological bases of seasonality in the female camel. Further detailed studies are required to establish the reproductive efficiency of the female dromedary camels throughout the non-breeding season in both the hot-humid and hot-dry months, under Egyptian environmental conditions.
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