The study was conducted on five adult clinically healthy Kachchhi camels (B.W. 450-550kg) to assess the effect of different payloads (L1-1500kg, L2-2000kg and L3-2500kg), seasons (S1- summer, S2-Hot humid and S3- winter) and work rest cycles (WR1:2h (W) - 1h (R) + 2h (W) - 1h (R) + 2h (W) - 1h (R) and WR2: 1h (W) - 15 min (R) - 1h (W) - 15 min (R) - 1h (W) - 1h (R) - 1h (W) - 15 min (R) - 1h (W) - 15 min (R) - 1h (W)) on physiological responses like rectal temperature (℉), respiration rate (No./min), pulse rate (No./min). The rectal temperature (℉) increased by 3.00 (3.04%) and 3.24 (3.30%), 7.64 (7.88%) and 6.50 (7.88%), 4.24 (4.37%) and 3.52 (3.60%) during S1, S2 and S3, respectively in WR1 and WR2 at end of work. The percentage rise in respiration rate (No. /min) in WR1 and WR2 was 58.71 and 59.03, 122.37 and 89.12 and 43.71 and 48.70 during S1, S2 and S3, respectively. The percentage rise in pulse rate was the lowest in S3 season (43.60 and 50.34) followed by S1 (47.53 and 50.47) and S2 season (64.22 and 76.9) respectively in WR1 and WR2. This indicated that camel can work comfortably under WR1 compared to WR2.
Though camels have been used as draught animals for years, not much information is available of their physiological responses before and after work under different work rest cycles at various combinations of draught, speed and work rest cycle in different environmental condition in India (Anonymous, 1999 and Verma and Mathur, 2002).
Camel can withstand a high degree of temperature and dehydration and can control excretion rates to work on limited supply of water for long periods (Tiwari et al., 2005). Optimum draft of 18% of body weight of camel can be achieved with associated increase of 14 to 16 beats/min in pulse rate, 5 to 6 breaths/min in respiration rate and 1.5 to 1.8°C in rectal temperature (Anonymous, 1990). The increase in body temperature of camels exposed to high heat load, especially following a 2oC reduction below the normal minimum, is advantageous because it allows a considerable amount of heat to be stored during the day and dissipated at night (by radiation) without the expenditure of water (Grigg et al., 2009). The camel’s exceptional performance in the hot desert climate results from unique behavioral, anatomical and physiological features to economize water by reducing the metabolic rate and regulating body temperature. The so-called “adaptive heterothermy” in the dromedary camel was discovered more than 50 years ago (Schmidt-Nielsen et al., 1957). In the absence of heat stress and with free access to water, the daily rhythm (controlled by circadian processes; see (El Allali et al., 2013) in rectal temperature presents an amplitude of about 2°C (the animal being then a perfect thermoregulatory or homeotherm).The physiological responses such as pulse rate, respiration rate and rectal temperature in field conditions during the tillage operations provide suitable data for assessment of work capacity of animal. This is essential for proper task design and in order to avoid accumulation of work stress in animal (Pathak, 1985). The increased demand of oxygen for work performance and thermo-regulatory mechanism in operation were reflected by increase in the respiratory frequency, pulse rate and rectal temperature on carting in camels (Rai and Khanna, 1990b)
Materials and Methods
Experimental Location and Climate
The present experiment was conducted at Instructional farm, Department of Livestock Production Management, College of Veterinary Science & Animal Husbandry, Anand Agricultural University, Anand during hot dry, hot humid and winter season. Anand town is situated at 22°35’ North latitude and 72°55’ East longitude at an elevation of 45 meter above the mean sea level. Anand, a mid-Gujarat Zone has a subtropical climate. The climatic condition of Anand based on observation during last 50 years (1956 to 2005) is cold and dry (Max. temp-27.81°C to 32.40°C and THI-73.45 to78.16) in winter (mid October to mid February). Summer commences form middle of February and ends in middle of June (Max temp-34.64°C to 40.08°C and THI-77.98 to 87.08), remains quite hot and dry. Monsoon is hot and humid, prevails from about mid-June to mid-October (Max temp – 31.13°C to 35.08°C and THI – 82.05 to 84.73).
Experimental Animals and Management
This study was conducted on five adult clinically healthy Kachchhi camels of 450-550 kg body weight and 7-8 years of age. The camel was acclimatized for route of transport. The camels were given the feed as per the ICAR guideline (1985).
Duration of Experiment
The present experiment was conducted in three seasons namely S1 – hot dry (15th May -30th June), S2 – hot humid (1st Sept – 15th Oct) and S3 – winter (1st Dec – 15thJan).
Workrest Cycle and Total Loads
The camels worked for 6 hrs daily from morning 08.00 hrs to 16.00 hrs in two work rest cycles viz. WR1: 2h (W) – 1h (R) + 2h (W) – 1h (R) + 2h (W) – 1h (R) (Singh, 1996) and WR2: 1h (W) – 15 min (R) – 1h (W) – 15 min (R) – 1h (W) – 1h (R) – 1h (W) – 15 min (R) – 1h (W) – 15 min (R) – 1h (W) (traditional) on straight tar road of about 5.2 km/round. Three loads (L1 – 1500 kg, L2 – 2000 kg and L3 – 2500 kg) were placed on the camel cart. The total load was the sum of payload + weight of cart + weight of driver. The camel worked with three pay loads in two work rest cycles for six days (two days for each pay load)
Measurement of Physiological Responses
Physiological responses like rectal temperature of all the experimental animals was recorded by using clinical thermometer, pulse rate was measured by putting index and middle finger on Coccygeal artery below the tail and respiration rate was measured by filling the hot guises on the back side of the palm before the start of the work and end of the each session of the work as per the work rest cycle.
The data were presented as mean ± standard error (SE). All means and SE were estimated as per the procedure outlined in SPSS® 11.00 statistical packages (SPSS). The level of significance was set at 95% confidence interval at P < 0.05. The significance between means and their combined interaction effect of different treatment effect individually season (S), Payload (L), Session of work (Se), and Work Rest Cycle (WR) were assessed using the multi-factorial completely randomized design (CRD) procedures (Snedecor and Cochran, 1980).
Result and Discussion
The rectal temperature was observed to be (97.61±0.54) significantly lower (p < 0.05) at the start of work as compared at the end of work (101.91±0.60). The rectal temperature recorded during S3 was significantly (p < 0.05) lower as compared to S1 and S2 in both the work rest cycles. The rectal temperature was observed to be significantly (p < 0.05) lower under WR2 (99.54±0.47) as compared to WR1 (99.98±0.54). The rectal temperature increased by 3.00 (3.04%), 7.64 (7.88%) and 4.24 (4.37%) during S1, S2 and S3, respectively in WR1 at the end of work (Table 1).
Table1: Effect of work rest cycle, season and session of work on physiological responses
|Parameter||Work rest cycle||Seasons||Session|
|Rectal Temperature (oF)||WR1||100.20b±0.33||100.52b±0.66||99.24a±0.38||97.78A±0.45||102.19B±0.53|
|Respiration rate (no./min.)||WR1||16.7b±0.83||17.2b±1.70||12.6a±0.52||11.60A±0.05||19.42B±1.01|
|Pulse rate (no./min.)||WR1||44.53a±2.07||43.40a±2.58||47.66b±2.03||35.73A±1.87||54.66B±2.56|
Season mean with different superscripts (a, b) in row differ at p < 0.05; Session mean with different superscript (A, B) in row differ at p < 0.05; Abbreviations used: BW = Before Work, AW = After Work
The corresponding values for WR2 were 3.24 (3.30%), 6.50 (7.88%) and 3.52 (3.60%). The interaction effect of S × Se affected significantly (p < 0.05) to the rectal temperature shown in Table 2. Bouaouda et al. (2014) remarked the average daily body temperature rhythm for camels maintained under a 12L/12D cycle show robust daily rhythmicity. The lowest body temperature was observed in the morning, and the highest in the late afternoon. During the hydration period, the amplitude of average body temperature rhythm was 2.39 ± 0.11°C with a minimum of 35.37 ± 0.13°C noted in the morning and a maximum of 37.76 ± 0.10°C recorded in the evening.
The respiration rate exhibited at the start of work (11.42±0.40) was significantly (p < 0.05) lower than exhibited at the end of work (19.04±1.45) in Kachchhi camel during S1, S2 and S3 in both work rest cycles. The percentage rise in respiration rate (No/min) in WR1 was 58.71, 122.37 and 43.71 during S1, S2 and S3, respectively than the initial values. The corresponding values for WR2 were 59.03, 89.12 and 48.70. The respiration rate increased to the tune of 58.82, 94.85 and 44.80% in S1, S2 and S3 at the end of work. There was increase in respiration rate by 33 % during S2 in WR1 as compared to WR2 and simultaneously, there was no much variation in respiration rate during S1 and S3 according to table 1.
The pulse rate recorded in Table 1 at start of work was significantly (p < 0.05) lower (35.20±3.48) as compared to end of work (54.66±2.56). The increase in pulse rate in both the work rest cycles followed the same pattern. The percentage rise in pulse rate was the lowest in S3 (43.60) followed by S1 (47.53) and S2 (64.22). The corresponding value was 50.34, 50.47 and 76.9. The percentage rise in Pulse rate was 20.62 and 12.68 in S2 season in WR1 and WR2 respectively as compared to S3 season. Table 2 shown an interaction effect between S × Se significantly (p < 0.05) in S1 and S2 and non significant effect in S3 for respiration rate.
Table2: Interaction effect of S × Se of rectal temperature (F°) on Kachchhi camel
|Se1||98.41A ± 0.30||97.02A ± 0.38||97.41A ± 0.32|
|Se2||101.40B ± 0.46||103.38B ± 0.45||100.94B ± 0.37|
Interaction effect of S x Se with different superscript (A, B) in column differ at p < 0.05
Table3: Interaction effect of S × Se of respiration rate (no/m) on Kachchhi camel
|Se1||12.80m ± 0.70||11.46m ± 0.55||10.00m ± 0.51|
|Se2||20.33n ± 0.98 n||22.33n ± 0.80||14.46m ± 0.78|
Interaction effect of S x Se with different superscript (m, n) in column differ at p < 0.05
The rectal temperature recorded at the end of each session of work showed that the rectal temperature shoot up sharply between first two session of work in WR1 in all three season. Whereas it increased gradually in WR2. This indicated irrespective of seasons and loads WR1 is more comfortable for Kachchhi camel under middle Gujarat agroclimatic condition. The values of rectal temperature, respiration rate (No/m) and pulse rate (No/m) observed under present investigation are well supported by Khan and Rai (1989), Rai and Khanna (1984), Anonymus (1995), Patel et al. (1995), Verma and Mathur (1995), Tiwari et al. (2003 and 2006), Pradeep et al. (2006). El-Harairy et al. (2010) studied the effect of different seasons of the year on rectal temperature and respiration rate was significant (P<0.05), being higher during summer than in winter, spring and autumn seasons. The highest (P<0.05) value of the rectal temperature was recorded during summer and the lowest (P<0.05) value during winter season. However, the effects of different seasons of the year on pulse rate was also significant (P<0.05), being lower during winter than summer, autumn and spring seasons. The highest (P<0.05) value of the pulse rate was recorded during summer and the lowest (P<0.05) value during winter season. The overall mean of pulse rate was 51.66.