Behavioral Indicators of Ovarian Phase in the Dromedary She-camel

In beef and dairy cattle the estrus cycle affects endocrine, ovarian, and behavioral events and detection of estrus by behavioral parameters is well assessed (Roelofs et al 2010). Female dromedary camels are seasonal breeders and induced ovulators, in which four follicular phases have been distinguished: recruitment, growth, mature and regressing (Skidmore 2011). Currently, little data has been published about estrus behavior in the she- camel. Recent rapid development in using assisted reproductive techniques to enhance dromedary reproduction makes urgent the detection of estrus in this species. The aim of this study was to relate different reproductive phases with observed behaviors which she-camels showed in presence of a male, and to identify behavioral indicators for the mature phase of estrus. Twenty-four healthy adult non-pregnant and non-lactating females were used. Two days prior to initiating the study, all received 789 µg Cloprostenol (Estrumate®, Agro-pharm Inc., Canada) intramuscularly (i.m.). Each animal was examined once a week over a three week period and was checked by manual gynecological examination, and its reproductive system was ultrasonographically scanned. Camels bearing mature preovulatory follicles (diameter >13 mm, Ismail et al 2007) were treated i.m. with 20 µg gonadorelin (Fertagyl®, Intervet, Germany) to induce ovulation, and ensure the presence of corpora lutea in the subsequent week. Immediately following examination sessions, each female was freely exposed to a restrained bull, and its behaviors recorded using a video camera. The videos were analyzed though a scan sampling ethogram (States: looking at the male; looking outside; standing; walking; searching; male interaction; lying down; Events: sniffing; interaction with the male; urination; defecation; sound emission). A score for tail position ("tail score": 1= close to the vulva, 2= horizontal, 3= vertical) and for interest in the bull ("male time score": from 1 to 5; 1=less than 20% of observation period spent near the bull; 5= more than 80%), were recorded. Dromedary females were considered "in estrus" when there was at least one >13 mm pre-ovulatory follicle, and "not in estrus" when growing follicles or corpora lutea were detected (Basioni 2007). All data were analyzed using a General Linear Model procedure (SAS 2007) where the independent variable was the physiological status (estrus/not in estrus) and the behavioral data were dependant variables. The main significant effect of “estrus” reproductive status (Table 1) was the increased curiosity in the male, particularly, increased duration (P = 0.009) and frequency (P = 0.0004) in male interaction, and spending more time close to the male (P < 0.0001). From this data, it seems that the interest in the male may be a good behavioral indicator of mature phase in the she-camel: the dam looks for and interacts with the male, sniffs around more, spends more time in standing quite near the male and increases tendency to lie down in front of him. Increased curiosity, searching out, looking at, and standing close to the male are reported as estrus behavioral indicators in sheep (Banks 1964). Detection of mature ovarian phase by behavioral indicators to improve timing to perform mating or artificial insemination may have profound implication for enhanced fertility in the dromedary camel (Manjunatha et al 2012), thus our data is a first step in this new and emergent research area. Table 1. Effect of reproductive status (estrus/not estrus) on the duration (sec) and the frequency (n/15 min) of the studied behavioral states and events. Data are expressed as square mean ± SE Duration (sec) Looking at the male Looking outside Standing Walking Searching Male interaction Lying down Estrus 184.2±26.4 247.6±40.7A 204.5±25.8a 48.3±9.6 204.3±41.7 2.7±0.33A 13.0±6.9 Not Estrus 143.1±24.1 380.8±37.1B 118.7±22.9b 61.0±8.7 181.5±38.0 1.5±0.3B 2.4±0.5 Frequency (n/15min) Sniffing Interaction with male Urination Defecation Sound Emission Tail Score Male Time Score Estrus 3.6±0.53 12.4±1.5A 0.2±01 0.2±0.0 21.4±3.6 1.4±0.1 3.6±0.1A Not Estrus 2.4±0.4 4.6±1.3B 0.3±0.1 0.1±0.0 25.9±3.3 1.5±0.1 2.4±0.1B Means followed by different letters differ statistically: A,B; P < 0.01 and a,b; P < 0.05 Bank, E.M. (1964). Behaviour 23, 249. Basioni, G.F. (2007). J. Biol. Sci. 7, 1038. Ismail, S.T., Al-Eknah, M-M., Hemeida N.A. (2007). J King Saud Uni 8, 51. Roelofs, J., López-Gatiusc, F., Hunterd, R.H.F., van Eerdenburge, F.J.C.M. et al. (2010). Theriogenology 74, 327. Manjunatha, B.M., Pratap, N., Al-Bulushi, S., Hago, B.E. (2012) Theriogenology 78, 965. Skidmore, J.A. (2011). Anim. Reprod. Sci. 124,148. This work was funded by European Union, PROCAMED Project