Daily rhythms of behavioral and hormonal patterns in male dromedary camels housed in boxes

Background. Daily rhythmicity has been observed for a number of hormonal and behavioral variables in mammals. It can be entrained by several external factors, such as light-dark cycle and scheduled feeding. In dromedary camels, daily rhythmicity has been documented only for melatonin secretion and body temperature. In this study, the daily rhythmicity of behavioral repertoire, cortisol and testosterone levels was investigated in captive male camels. Methods. Six clinically healthy male dromedary camels (Camelus dromedarius) were used. The animals were housed in single boxes for 24 h daily and fed twice a day. Over a period of 48 h, behavioral observations were made and blood samples taken every two hours. The data were analyzed using diurnality index, conisor analysis and PROC mixed procedure. Results. The diurnality index for rumination and lying down was close to 0 (respectively, 0.09 and 0.19), while the indices for stereotypy, standing, feeding and walking were close to 1 (respectively, 0.74, 0.84, 0.92 and 0.85). Cosinor analysis revealed daily rhythmicity for all behaviors and for cortisol levels (acrophase at 12:57) but not for testosterone. Rumination and lying down (inactive behaviors) reached a peak during the scotophase, whereas feeding, walking and stereotypy (active behaviors) reached a peak during the photophase around midday. Cortisol level and expression of stereotypies peaked before and after food distribution and were negatively correlated (r =-0.287, P = 0.005). Testosterone levels and expression of sexual behaviors were stimulated by the visual and olfactory contacts with the females and were positively correlated (r =0.164, P =0.040). Testosterone was also negatively correlated with cortisol (r =-0.297; P =0.003). Discussion. These preliminary results provided new knowledge about the daily rhythm of behaviors in camels housed in boxes, suggesting that camels exhibit diurnal behavior pattern in the maintenance conditions outlined in the study. Daily rhythmicity seemed to be entrained not only by the light-dark cycle but also by scheduled feeding. The rise in stereotypy after food distribution could be due to the persistence of feeding motivation and frustration after the ingestion of food. Therefore, feeding practices should be improved to satisfy the foraging and feeding motivation of these camels. Behavioral and hormonal daily patterns in camels should be taken in consideration to adapt the management system, giving the animals more freedom during the light period and a diet richer in fiber, so as to improve reproductive performance, health and welfare

Identification of ß-nerve growth factor in dromedary camel seminal plasma and its role in induction of ovulation in females

The main objective of this study was to demonstrate the effect of seminal plasma ovulation inducing factor (OIF) on ovulation in female camels. Seminal plasma was fractionated using gel filtration chromatography, and two protein peaks were obtained and analysed by western blotting. The effect of the bioactive protein fraction (OIF/ß-NGF) was tested by intramuscular injection (1 ml) in synchronized females with the following treatments: PBS (negative control group, n=3); 20 /jg Buserelin (GnRH analogue, positive control group; n=3); and purified OIF with doses of 1 and 2 mg (n = 5, each treatment). Blood samples were collected every two days from day 0 until 14 days post-treatment, and the progesterone concentration was assessed. The obtained results showed that the OIF is highly present in the seminal plasma of dromedary camels as a protein with a molecular mass of approximately 14 kDa. It was detected as a betaNerve Growth Factor, named Cam-ß-NGF. The effect of this molecule on ovulation was clearly demonstrated by the significant increase of the plasma progesterone concentration in the treated female groups (1 and 2 mg of Cam-ß-NGF) as observed in Buserelin group. In summary, intramuscular injection of ß-NGF isolated from dromedary camel seminal plasma induces ovulation in females with similar rate to Buserelin treatment

Mating behaviour and semen parameters in dromedary camel bulls (Camelus dromedarius): A comparison between two types of artificial vagina

Semen collection in the dromedary camel (Camelus dromedarius) is performed using different types of artificial vagina (AV) (long, short, with cervix imitation, with plastic or silicone inner liner) either held by an operator or fitted inside a camel dummy. However, systematic studies about the acceptance of such modifications by bulls, and their effects on sperm parameters, have yet to be investigated. This study was conducted to test the hypothesis that a silicone inner liner inserted into a standard cow AV could cause discomfort to camel bulls during mating, but at the same time could improve the quality of the ejaculates collected. Five bulls underwent semen collection sessions, with (n=3) and without (n=3) the silicone liner fitted in the AV, for a total of 30 semen collection sessions. A standard methodology and data-recording system were used for evaluating mating behavior, in addition to evaluation of semen parameters. There was no difference between an AV with or without silicone inner liner used during our standardized semen collection procedure. The use of such an AV modification hence still remains debatable, until further studies are able to identify any potential benefits of using this or other AV types or modifications. Such studies, however, should be performed by applying a standardized semen collection methodology and a proper evaluation of mating behaviour and semen parameters

Effect of continuous female exposure on behavioral repertoire and stereotypical behaviors in restrained male dromedary camels during the onset of the breeding season

This study aimed to test the effects of the three management systems on the behavioral repertoire and particularly on the incidence of stereotypical behavior in restrained camels. Five male camels were tested under the following management systems: (i) unexposed, housing in a single box (Unexpo); (ii) continuous exposure, exposed continuously to females (ConExpoF); and (iii) re-unexposed, housing again in a single box (Re-Unexpo). Every day, bulls were filmed for 30 min and videos were analyzed using a focal animal sampling ethogram. Under the ConExpoF system, camels spent the majority of time in standing with opened legs (490.0 \ub1 94.3 s), looking (925.0 \ub1 93.7 s), and walking toward the females (206.0 \ub1 73.4 s) and they ate and ruminated less compared to Unexpo and Re-Unexpo systems. Rumination and standing durations were significantly longer in Re-Unexpo than in Unexpo and ConExpoF management systems. When camels were continuously exposed to females, they showed few stereotypical behaviors compared to Unexpo (490.0 \ub1 146.1 s) and Re-Unexpo (624.0 \ub1 146.1 s) systems. The frequency of both total and oral stereotypes was significantly higher in Unexpo and Re-Unexpo systems compared to ConExpoF; however, no significant difference was observed among the three management systems in the frequency of locomotor stereotypes. Overall, it appears that the continuous female exposure system might be a suitable management practice for male camels used for intensive reproduction, as it decreases the manifestation of stereotypical behavior in comparison with housing for 24 h in a single box

Effect of α-amylase, papain, and spermfluid® treatments on viscosity and semen parameters of dromedary camel ejaculates

Ejaculates fromfive clinically healthy dromedary camels (Camelus dromedarius)were used to evaluate the effects of different enzymatic treatments (Amylase, Papain, Spermfluid®) on liquefaction and seminal parameters. After collection, ejaculates were divided into 5 aliquots: (1) kept undiluted (control); or diluted 1:1 with: (2) Tris- Citrate-Fructose (TCF), (3) TCF containing Amylase, (4) TCF containing Papain or (5) Spermfluid® containing Bromelain. At 120 min after dilution, each aliquot was evaluated, at 20-min intervals, for viscosity, motility, viability and agglutination. Only the aliquots diluted with TCF containing Papain underwent complete liquefaction. Sperm motility decreased significantly during the observation times, except for the samples diluted with Spermfluid® (P = 0.005). Diluted samples showed different levels of agglutination, with the lowest being observed in the control and the highest in the Papain-treated samples. The viscosity of dromedary camel ejaculates could be effectively reduced by using the proteolytic enzyme Papain

Effects of a GnRH administration on testosterone profile, libido and semen parameters of dromedary camel bulls

GnRH treatment has been suggested to increase testosterone levels temporarily and to stimulate libido in stallions, but its use has not fully ascertained in dromedary camels. The aim of this work was to study the effects of administering 100. μg of GnRH on testosterone profile, libido and semen parameters in dromedary camels. The same bulls were used as self-controls and experimental group. Blood samples were collected every 20. min (T0-T12) for 4. h, and semen collections were performed over a 2-hour period after T12. GnRH was administered immediately after T0. In GnRH-treated bulls, testosterone levels showed an upward trend, peaking after 140. min, and then slowly decreasing. GnRH administration also led to a decrease in mating time and an increase in spermatozoa concentration. Overall, it seems that administration of 100. μg GnRH might increase testosterone levels temporarily and enhance camel reproduction performance

Could dromedary camels develop stereotypy? The first description of stereotypical behaviour in housed male dromedary camels and how it is affected by different management systems

International audienceDromedary camel husbandry has recently been evolving towards a semi-intensive system, due to the changes in use of the animal and the settlement of nomadic populations. Captivity could restrict its social activities, limiting the expression of various behavioural needs and causing the manifestation of stereotypy. The aims of this trial were, firstly, to identify and describe some stereotypical behaviours in captive male dromedary camels used for artificial insemination and, secondly, to study the effects on them of the following husbandry management systems: i) housing in single boxes for 24 hours (H24), ii) housing in single boxes for 23 hours with one hour free in the paddock (H23), and iii) housing in single boxes for 22 hours 30 min with 1 h of paddock time and 30 min exposure to a female camel herd (ExF). Every day, the camels were filmed in their single box in the morning for 30 minutes to record their behavioural activities and a focal animal sampling ethogram was filled in. In this study, male camels showed both oral and locomotor stereotypy most frequently when the bulls were reared in H24. Overall, this preliminary study is a starting point in the identification of stereotypies in male camels, reporting the positive effects of spending one hour outdoor and of social interaction with females

Mating behaviour and semen parameters in dromedary camel bulls (Camelus dromedarius): A comparison between two types of artificial vagina

Semen collection in the dromedary camel (Camelus dromedarius) is performed using different types of artificial vagina (AV) (long, short, with cervix imitation, with plastic or silicone inner liner) either held by an operator or fitted inside a camel dummy. However, systematic studies about the acceptance of such modifications by bulls, and their effects on sperm parameters, have yet to be investigated. This study was conducted to test the hypothesis that a silicone inner liner inserted into a standard cow AV could cause discomfort to camel bulls during mating, but at the same time could improve the quality of the ejaculates collected. Five bulls underwent semen collection sessions, with (n=3) and without (n=3) the silicone liner fitted in the AV, for a total of 30 semen collection sessions. A standard methodology and data-recording system were used for evaluating mating behavior, in addition to evaluation of semen parameters. There was no difference between an AV with or without silicone inner liner used during our standardized semen collection procedure. The use of such an AV modification hence still remains debatable, until further studies are able to identify any potential benefits of using this or other AV types or modifications. Such studies, however, should be performed by applying a standardized semen collection methodology and a proper evaluation of mating behaviour and semen parameters

Mating behaviour and semen parameters in dromedary camel bulls (Camelus dromedarius): a comparison between two types of artificial vagina

Semen collection in the dromedary camel (Camelus dromedarius) is performed using different types of artificial vagina (AV) (long, short, with cervix imitation, with plastic or silicone inner liner) either held by an operator or fitted inside a camel dummy. However, systematic studies about the acceptance of such modifications by bulls, and their effects on sperm parameters, have yet to be investigated. This study was conducted to test the hypothesis that a silicone inner liner inserted into a standard cow AV could cause discomfort to camel bulls during mating, but at the same time could improve the quality of the ejaculates collected. Five bulls underwent semen collection sessions, with (n=3) and without (n=3) the silicone liner fitted in the AV, for a total of 30 semen collection sessions. A standard methodology and data-recording system were used for evaluating mating behavior, in addition to evaluation of semen parameters. There was no difference between an AV with or without silicone inner liner used during our standardized semen collection procedure. The use of such an AV modification hence still remains debatable, until further studies are able to identify any potential benefits of using this or other AV types or modifications. Such studies, however, should be performed by applying a standardized semen collection methodology and a proper evaluation of mating behaviour and semen parameters