Identifying potential thermal drivers of sudomotor in camels (Camelus dromedarius).

The mechanism of sudomotor regulation in the family Camelidae, as in other mammals, is poorly understood. Five healthy dromedary bulls (400 kg and 4 years-old) were used to examine the interrelationship of sweating rate (SR) with ten thermal parameters measured (and/or estimated) every 3-hr for a 24-hr time period under natural and shaded environmental conditions, in order to subsequently identify the potential thermal drivers of sudomotor in this species. Results revealed that all parameters, including SR, had clearly (P < 0·001) exhibited monophasic circadian rhythms. Moreover, the obtained findings pointed out that strong/moderate positive correlations were existed between SR and eight parameters [i.e. ambient (Ta), rectal (Tr), body (Tb), skin (Tsk), coat (Tct) temperatures as well as total (ambient-to-body, BTGt), external (ambient-to-skin, BTGex), and internal (skin-to-body, BTGin) body thermal gradients] suggesting that they may all be good indicators of sweating activity. Nonetheless, out of those highly-correlated parameters, merely six (i.e. Ta, Tb, Tsk, Tct, BTGt, and BTGex) showed superior coefficients of determination (R2 ≥ 0·90; P < 0·000) when interrelated with SR; thereby, implying that they have the potential to drive sudomotor. Notably, however, results were more probably allude that sudomotor is regulated through BTGt. Accordingly, the onset of sweating (i.e. threshold) and its effective level was determined using BTGt. A method of how SR can be regulated through BTGt was proposed according to Webb's theory of controlling body-heat content. Some shortcomings prevent confirming that BTGt is the best thermal driver of sudomotor in this species were noted. Research dealing with this interesting physiological process requires further experimentation to fully elucidate the basic functional mechanisms of Camelidae's thermoregulatory system .

Daily rhythms of physiological parameters in the dromedary camel under natural and laboratory conditions.

Camels are well adapted to hot arid environments and can contribute significantly to the economy of developing countries in arid regions of the world. Full understanding of the physiology of camels requires understanding of the internal temporal order of the body, as reflected in daily or circadian rhythms. In the current study, we investigated the daily rhythmicity of 20 physiological variables in camels exposed to natural oscillations of ambient temperature in a desert environment and compared the daily temporal courses of the variables. We also studied the rhythm of core body temperature under experimental conditions with constant ambient temperature in the presence and absence of a light-dark cycle. The obtained results indicated that different physiological variables exhibit different degrees of daily rhythmicity and reach their daily peaks at different times of the day, starting with plasma cholesterol, which peaks 24min after midnight, and ending with plasma calcium, which peaks 3h before midnight. Furthermore, the rhythm of core body temperature persisted in the absence of environmental rhythmicity, thus confirming its endogenous nature. The observed delay in the acrophase of core body temperature rhythm under constant conditions suggests that the circadian period is longer than 24h. Further studies with more refined experimental manipulation of different variables are needed to fully elucidate the causal network of circadian rhythms in dromedary camels.

Regional and circadian variations of sweating rate and body surface temperature in camels (Camelus dromedarius).

It was the aim of this study to investigate the regional variations in surface temperature and sweating rate and to visualize body thermal windows responsible for the dissipation of excess body heat in dromedary camels. This study was conducted on five dromedary camels with mean body weight of 450 ± 20.5 kg and 2 years of age. Sweating rate, skin and body surface temperature showed significant (P < 0.001) circadian variation together with the variation in ambient temperature. However, daily mean values of sweating rate, skin and body surface temperature measured on seven regions of the camel body did not significantly differ. The variation in body surface temperature compared to the variation in skin temperature was higher in the hump compared to the axillary and flank regions, indicating the significance of camel's fur in protecting the skin from daily variation in ambient temperature. Infrared thermography revealed that flank and axillary regions had lower thermal gradients at higher ambient temperature (T(a) ) and higher thermal gradients at lower T(a) , which might indicate the working of flank and axillary regions as thermal windows dissipating heat during the night. Sweating rate showed moderate correlation to skin and body surface temperatures, which might indicate their working as potential thermal drivers of sweating in camels.

Improvement of growth and nitrogen utilization in sheep using sugar beet pulp treated with Trichoderma reesei or urea.

Twenty-five intact Barki lambs with mean body weight of 24.81 ± 0.16 kg were used to investigate the effect of including in the diet sugar beet pulp (SBP) treated biologically with Trichoderma reesei or chemically with urea 4 % on nutrients digestibility, growth performance, nitrogen (N) utilization, and hematological and biochemical parameters. Two experiments were conducted. In the growth experiment, five lambs were randomly assigned to one of five dietary treatments. Lambs were offered isonitrogenous and isoenergetic concentrate feed mixture containing on dry matter basis 0 % SBP (D0), 50 % SBP (D1), 50 % SBP treated with 4 % urea (D2), 50 % SBP treated with T. reesei (D3), and 25 % SPB treated with 4 % urea plus 25 % SPB treated with T. reesei (D4). In the metabolism experiment, five rams were used in a 5 × 5 Latin square design and housed in metabolism crates for 21 days. The present study showed that inclusion of SBP at the level of 50 % (D1) negatively affected diet digestibility coefficients of crude protein, crude fiber, and ether extract, in addition to average daily gain, feed conversion, and N utilization. However, treatment of SBP with urea (D2), T. reesei (D3), or the combination (D4) of both had improved (P < 0.05) these parameters with superiority of D3. Despite the significant differences in the tested hematological and biochemical parameters of lambs fed on biologically or chemically treated SBP diets, their levels remained within the physiological ranges which could indicate that treated SBP did not have any adverse effect on lambs' health.

In vitro gossypol induced spermatozoa motility alterations in rabbits.

The objectives of the present study were to: (i) examine the in vitro dose response of rabbit spermatozoa motility to the antifertility agent gossypol (GOS) and (ii) determine whether filtered (FIL) and unfiltered (UNFIL) GOS differ in their magnitude of effect. Rabbit semen belonging to adult males (n = 5; 12-14 months) were cultured with UNFIL GOS and FIL GOS (5% solution) and subsequently diluted (1:1-7) for analysis using a Computer Assisted Semen Analyzer (CASA) system in 5 time periods (0, 60, 120, 180 and 360 minutes). At Time 0, no significant change in rabbit spermatozoa motility (MOT) and progressive motility (PROG) with GOS FIL was noted, while increases were observed with GOS UNFIL. At Time 60, weak changes were noted for MOT and PROG. After 120 minutes of culture with both GOS FIL and GOS UNFIL, MOT and PROG decreased significantly in some experimental groups. However, no differences were recorded for both the parameters at Times 180 and 360, with the exception of PROG in the GOS UNFIL category (groups A, B, E, F and G), where a significant decrease was noticed. Detailed evaluation of the distance and velocity parameters revealed reduction in all these studied markers after 60 and 120 minutes of in vitro culture with both GOS FIL and GOS UNFIL, indirectly confirming the PROG decrease. Straightness (STR), linearity (LIN), wobble (WOB), amplitude of lateral head displacement (ALH) and beat cross frequency (BCF) mostly remained unaltered at all time periods for GOS FIL, where as some minor alterations were noticed in GOS UNFIL category for STR, LIN, WOB, ALH and BCF parameters at Time 0, 60 and 120. The present study confirms the dose and time dependent alterations of rabbit spermatozoa motility parameters by GOS. The GOS dynamics in our experiment shows that rabbit spermatozoa as a biological material can indicate a GOS inhibition of motility. Obtained data for the first time indicates a higher immobilizing potential of unfiltered GOS in comparison to filtered GOS in its inhibitory action of spermatozoa motility parameters in rabbits.

Diazinon toxicity affects histophysiological and biochemical parameters in rabbits.

Diazinon is a widely used pesticide in agriculture. So, the current work aimed to investigate the effects of diazinon exposure on some physiological and biochemical parameters, as well as, histopathological changes and histochemical acetyl-cholinesterase activity (AChE). The red Baladi rabbits were dipped into water (Control Group), diazinon at low concentrations of 0.6 mg diazinon low concentration (DLC) or high concentration of 3mg diazinon high concentration (DHC) dissolved in 1l of water for 10s. Treatment was repeated after 10 days and animals were sacrificed between 0 and 21 days after the second treatment. Blood analysis revealed that Red blood cells (RBC's), hemoglobin (Hb) and plasma total protein (TP) were significantly decreased in both diazinon concentrations (P<0.01), (P<0.05), (P<0.01) respectively. Cholesterol and microsomal protein were increased (P<0.01), while, liver/ body weight and cytochrome P-450 were decreased in both concentrations (P<0.01). Also there was a highly significant effect of concentration X day interaction on all parameters (P<0.01). Histopathological changes of liver, kidney and brain were observed after DHC dipping. Glycogen content was decreased in liver and increased in kidney Bowman's capsule. Furthermore, AChE activity was inhibited in brain tissue, decreased in liver cells, but gradually increased in kidney glomerular cells. Therefore, kidney and brain were highly affected by diazinon exposure compared with the liver. Exposure of animals to diazinon caused extensive changes in physiological, biochemical, and histopathological parameters as well as histochemical AChE. So, contact exposure of diazinon leads to negative response on animal health.