Applicability of thermography as a potential non-invasive technique to assess the body-thermal status of heat-stressed and water-deprived goats (Capra hircus).

To evaluate the use of infrared thermography to assess the thermal status of heat-stressed and water-deprived Capra hircus, full-body surface temperature (TS) and six other body-thermal variables [core, rectal (TR), and skin (TSK) temperatures, respiratory and heart rates, and total body-thermal gradient (core-to-ambient, BTG)] were measured after three days of euhydration (EU), dehydration (DE), and rehydration (RE). Results revealed that the combined effect of heat stress and water deprivation had affected all tested variables including the TS, and once these animals gained access to water in the RE stage variables returned to their EU levels. Moreover, there were positive correlations between TS and all variables with the exception of BTG. From these six variables, only three variables (i.e. the TR, TSK, and BTG) during the DE stage and two variables (i.e. the TSK and BTG) throughout the experimental stages showed higher constancy (R2 ≥ 0 75, P < 0 001; agreement intervals ±1 96 95 % CI) with TS. However, BTG appeared more closely correlated with TS, representing the body-thermal status more realistically than other variables. In effect, the mean and thresholds of the BTG were predicted using the recorded TS and were within 0.02 °C of original estimates. Collectively, these findings show that infrared thermography is appropriate for assessing body-thermal status, and thus the welfare, of these animals under the three conditions studied, and conclude that full-body TS can be a surrogate proxy for BTG in these animals. Further experiments are needed to adequately examine the reproducibility of these results under biometeorologically-simulated environments and natural habitats.

Using chrono-physiological management in form of shifting the feeding time has no advantage in goat kids exposed to experimentally induced heat stress.

Despite the proven outcomes of implementing chrono-physiological management (CPM) in several animals to promote their production performance, studies on its usefulness in goats are lacking. Twelve healthy Aardi male goat kids (22.60±1.10kg body weight; 6 months of age) were randomly allocated into two groups (morning-fed at 09:00 h and evening-fed at 21:00 h). The physiological and productive advantage of CPM (in form of shifting feeding time) was investigated in both groups while exposed to experimentally induced heat stress for 42 days (daily ambient temperature was cycling from 25 to 45°C). Thermophysiological (rectal, skin, and coat temperatures as well as respiratory rate), blood biochemical (plasma level of albumin, glucose, triacylglycerol, and urea), and production performance (daily feed intake, average daily gain, and feed conversion ratio) measurements were all obtained throughout this period. Current findings collectively revealed that shifting feeding time from 09:00 to 21:00 h had no (P > 0.05) impact on the thermophysiological status and blood metabolites of heat stressed kids. Above all, evidences have indicated that shifting feeding time had failed (P > 0.05) to demonstrate any consequence on promoting growth in these kids, thereby suggesting that shifting feeding time under hot climatic conditions has no advantage in goats. In fact, implementation of such an approach might not to be encouraged for heat-adapted animals. Experiments using other CPM methods (such as simultaneous shift of both feeding time and lighting program) can be however of further interest.

Generation and Characterization of Nanobodies Against Tomato Leaf Curl Sudan Virus.

Begomoviruses infect food, fiber, and vegetable crop plants, including tomato, potato, bean, cotton, cucumber, and pumpkin, and damage many economically important crop plants worldwide. Tomato leaf curl Sudan virus (ToLCSDV) is the most widespread tomato-infecting begomovirus in Saudi Arabia. Using phage display technology, this study isolated two camel-derived nanobodies against purified ToLCSDV virions from a library of antigen-binding fragments (VHH or nanobody) of heavy-chain antibodies built from an immunized camel. The isolated nanobodies also cross-reacted with purified tomato yellow leaf curl virus virions and showed significant enzyme-linked immunosorbent assay reactivity with extracts from plants with typical begomovirus infection symptoms. The results can pave the way to developing diagnostics for begomovirus detection, design, and characterization of novel nanomaterials based on virus-like particles, in addition to nanobody-mediated begomovirus resistance in economically important crops, such as tomato, potato, and cucumber.

Resilience of Lambs to Limited Water Availability without Compromising Their Production Performance.

Water scarcity is a common phenomenon in arid and semi-arid regions, which could have tremendous effects on livestock production. This study aimed to determine the level of water restriction that lambs fed on a pelleted diet can tolerate without compromising their production performance. A total of 24 male Najdi lambs were housed individually and randomly allocated into three equal groups, namely ad libitum water intake, 33% water-intake restriction, and 67% water-intake restriction. Dry-matter intake, feed conversion ratio, and average daily gain were decreased (p < 0.05) with the increasing level of water restriction. Water restriction had also reduced (p < 0.05) nutrient digestibility. The water-conserving ability of the water-restricted lambs was manifested by the production of concentrated and lower (p < 0.05) quantities of urine and feces. Meanwhile, serum osmolality and concentrations of albumin, total protein, urea-N, glucose, and non-esterified fatty acids were increased (p < 0.05) with the increasing levels of water restriction. It is surprising that lambs subjected to 67% water restriction retained more (p < 0.05) nitrogen relative to intake and had better (p < 0.05) efficiency of nitrogen utilization. It was strongly evident that lambs could tolerate water-intake restriction of up to 33% without compromising their production performance.

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 .

Unraveling the relationship between the topographic distribution patterns of skin temperature and perspiration response in dromedary camels.

The question of how skin temperature (Tsk), measured at different regions of the skin, can affect sudomotor activity and thus show a pattern in topographic distribution for the perspiration response (PR) rate in dromedary camels was approached and examined in this experiment. Under natural summer conditions, four healthy dromedary bulls, with a mean body mass of 420 kg and age of three years, were measured for Tsk and PR in seven skin regions (i.e. head, neck, shoulder, axillary, hump, flank, and hip) twice daily [between 04:00-05:00 h with a mean ambient temperature (Ta) of 26·78 °C and relative humidity (RH) of 18·25% as well as between 13:00-14:00 h with Ta of 44·78 °C and RH of 5·90%] for two successive days. The experiment has clearly demonstrated some novel findings. In fact, results pointed out that Tsk (P < 0·05) exhibited a distinct topographic pattern that faded almost completely at a higher Ta. Meanwhile, PR unexpectedly manifested a uniform (P ≥ 0·05) distribution throughout the experiment, which appears to serve an eco-teleological purpose in dromedaries. Moreover, the obtained findings indicated that the hump and hip regions in particular can work as thermal windows, yet all seven skin regions can predict whole-skin PR fairly accurately (R2 ≥ 0·90; P < 0·000). Above all, analysis indicated that Tsk in many regions can affect perspiration in camels (R2 < 0·82; P < 0·000), but it failed to demonstrate a topographic pattern in perspiration response at higher or lower Ta; therefore, the data attests that no specific relationship may exist between the topography of a perspiration pattern and the level of regional Tsk. Some shortcomings were noted herein, but research dealing with this subject may very well improve our understanding of the basic functional mechanisms of the thermoregulatory system in this species.

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.

Feasibility of utilising an infrared-thermographic technique for early detection of subclinical mastitis in dairy camels (Camelus dromedarius).

Despite the proven ability of infrared thermography (IRT) technology for early detection of subclinical mastitis in dairy cows/sheep/goats, studies on its diagnostic feasibility in dairy camels are lacking. Sixty-five lactating camels in mid lactation, machine milked twice-daily and managed under intensive conditions were screened to evaluate the feasibility of utilising IRT compared with other routine indicators in detecting subclinical mastitis. Immediately before the morning milking, a portable infrared camera was used to obtain thermograms in duplicate for the front and rear left quarters to determine the udder surface temperature (UST). Thereafter, milk samples from quarters were collected, and processed for California mastitis test (CMT) score and somatic cell count (SCC). In the present study, CMT score was used to define subclinical mastitis and the feasibility of IRT to detect subclinical mastitis was compared with CMT and SCC. According to CMT score, subclinical mastitic udders had an average UST of 1·42 °C greater (P<0·0001) than healthy udders. The relationship between UST and CMT was found to be highly correlated (r=0·77; P<0·001), and UST was linearly increased as the CMT increased [UST (°C)=34·86+0·66×CMT score; R 2=0·65; P<0·001]. Additionally, high correlations were obtained between UST and SCC score (r=0·75; P<0·001) and the relationship between UST and SCC was fitted best to a logarithmic equation [UST, °C=33·39+0·88×Log (SCC, ×103 cells/ml), R 2=0·61, P<0·001]. The cut-off value, sensitivity, specificity and area under the receiver operating characteristics (ROC) curve for UST were 35·15 °C, 0·90, 0·98, and 0·95, respectively, when subclinical mastitis was defined according to CMT score, and were 35·70 °C, 0·89, 0·96 and 0·94, respectively, when categorised according to the obtained SCC threshold (SCC=432 000 cells/ml). In conclusion, IRT, as an indirect non-invasive screening method, was highly feasible for distinguishing subclinical mastitic udders in dairy camels, which is crucial to treat mastitis early and efficiently.

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.