Housing systems that guarantee social interaction and physical activity are the most suitable housing management systems for captive male dromedaries during the rutting season.
1. Introduction
Global climate changes, which are characterized by increasing desertification, high temperatures and drought, provide a driver to reconsider animal species that are bred in the livestock sector
[1]. Animal species that can genetically adapt to such environmental conditions should be given more attentions. Dromedary camel (
Camelus dromedarius) is one of the most adapted animals to harsh environmental conditions
[2]. In many drought- prone arid and semi-arid regions, dromedaries play a great role in the livelihood as breeding of other animals under such conditions face several obstacles. Camel breeding in intensive farming systems has been increasingly established, since reconstitution of animal species used for meat and milk production has become a crucial demand under current drastic environmental changes. Compared to other livestock species, dromedaries have received less attention by the scientific community. Thus, understanding the physiological and behavioral properties of dromedaries facilitates ideal harness of their natural advantages under intensive farming systems.
Dromedaries are classified as seasonal breeders, with a restricted breeding season that varies from two to six months
[3]. The breeding season extends from December to March in Egypt
[4], Tunisia
[5], Somaliland
[6], Pakistan
[7], India
[8] and Sudan
[9]. In Saudi Arabia and United Arab Emirates, the breeding season extends from October to April
[10,11][10][11]. This relatively short breeding season limits reproductive performance and is considered one of the most constraints facing camel breeding
[12,13,14][12][13][14]. Moreover, during the breeding season, male dromedaries exhibit aggressive behavior and substantial physiological, morphologic and behavioral changes negatively affecting animal performance
[15]. In intensive farming systems, dromedaries are kept in captive conditions. Moreover, during the rutting season, male dromedaries are conventionally kept tied with ropes in small pens and/or kept in single stalls to avoid aggression toward other males and humans
[16]. This breeding system may negatively affect animal welfare and increases negative effects of sexual activity-related peculiarities on animal performance. Padalino et al.
[17] stated that male dromedaries showed both oral and locomotor stereotypy most frequently when the bulls were housed in single boxes for 24 h, indicating poorer animal welfare. In context, Fatnassi et al.
[15] found that male dromedaries housed in a single stall for 22 h and 30 min, with one hour of paddock time and 30 min of exposure to a female camel herd had significantly higher sexual behavior scores, behavioral repertoires and decreased cortisol levels than those housed in a single stall for 24 h and those housed in a single stall for two to three hours with one hour free in the paddock. Skidmore
[18] reports that male dromedaries kept in herds tended to start breeding earlier with longer rutting periods than that of confined males, confirming the relationship between housing system and sexual behavior. Farsi et al.
[19] developed a highly reliable and sufficiently accurate scoring method to assess conveniently the locomotor activity rhythm and specific behaviors in camels. Accordingly, achieving the ideal housing system of male dromedaries during the rutting season can contribute to maximizing animal reproductive performance and reducing sexual–associated aggressiveness, thus improving animal welfare.
2. Effect on Behavioral Patterns
The effects of social contact (single or group), movement control (tied, fenced or exercised) and their interaction on frequency and duration of maintenance and posture behaviors of male dromedaries during the rutting season are presented in
Table 1. Social contact with other animals significantly affected maintenance and posture behaviors. Group-housed male dromedaries expressed higher (
p < 0.001) frequencies of maintenance (ruminating) and posture (lying, standing and walking) behaviors than single-housed male dromedaries. Group-housed male dromedaries devoted longer times (
p < 0.001) for ruminating and walking than single-housed male dromedaries, whereas single-housed male dromedaries devoted longer times (
p < 0.001) for lying and standing behaviors. Movement-control method significantly affected maintenance and posture behaviors. Compared to tied and fenced male dromedaries, exercised male dromedaries expressed higher frequencies and longer durations (
p < 0.001) of ruminating, standing and walking behaviors. On the other hand, tied male dromedaries gave preference (
p < 0.001) to lying behavior compared to fenced and exercised male dromedaries. Analysis of animal social contact by movement control showed that, regardless of social contact, male dromedaries that group housed in contact with other dromedaries, expressed higher frequencies and longer durations (
p < 0.001) of ruminating than male dromedaries in other housing systems. Male dromedaries in the tied housing system expressed higher frequencies and longer durations (
p < 0.001) of lying behavior than male dromedaries in other housing systems. Male dromedaries that were fenced or were exercised (single-fenced, single-exercised, group-fenced and group-exercised) expressed higher frequencies and longer durations (
p < 0.001) of standing and walking behaviors than male dromedaries in other housing systems.
Table 1. Effects of social contact, movement control and their interaction on frequency (n/20 min) and duration (sec/20 min) of maintenance and posture behaviors of male dromedaries during the rutting season.
Factors |
Variable |
Factors |
Sexual Behavior Parameters |
Maintenance |
Posture |
Teeth Grinding |
Factor |
Variables |
Leg Opening |
Hormones |
Minerals | Tail Flapping |
Dulla Extruding |
Blathering |
Urinating |
Ruminating |
Lying |
Standing |
Walking |
Cortisol (nmol/L) |
Testosterone (ng/mL) |
Triiodothyronine (ng/mL) |
Calcium (mg/dL) |
|
Frequency |
Duration |
Frequency |
Duration |
Frequency |
Duration |
Frequency |
Duration |
Social contact |
Single |
Social contact |
Single |
5.33 b |
3.56 b |
6.97 | b |
78.50 b |
2.44 b |
139.08 a |
5.89 b |
118.75 a |
3.33 b |
54.89 b |
Group |
12.86 a |
91.11 a |
5.55 a |
114.66 b |
8.00 a |
101.42 b |
6.67 a |
75.83 a |
SEM |
0.463 |
0.979 |
0.270 |
1.39 |
0.412 |
1.60 |
0.435 |
1.17 |
p value |
<0.001 |
<0.001 |
<0.001 |
<0.001 |
<0.001 |
<0.001 |
<0.001 |
<0.001 |
Movement control |
Tied |
7.83 b |
6.20 |
a |
6.00 |
4.67 |
8.67 |
a |
SEM |
0.68 |
0.58 |
0.60 |
0.54 |
0.50 |
0.57 |
p value |
0.029 |
0.023 |
0.033 |
0.255 |
0.603 |
0.039 |