The influence of high dietary protein, energy and mineral intake on deficient young camel (Camelus dromedarius)--I. Changes in metabolic profiles and growth performance

Pregnancy status and thyroid function in semi-intensive-kept Marecha she-camels (Camelus dromedarius): managerial implications

Pakistani Marecha dromedaries, a distinctive breed not covered in the empirical data of the literature reviewed existing for thyroidal physiology in camels, are subjected to investigate thyroid function in pregnant multiparous (n = 22) and non-pregnant nor lactating (n = 22) females. The function of the thyroid gland in pubescent she-camels has evoked discrepancies among researchers exploring this topic in different breeds evolving in divergent environments. Despite season, age, sex, reproductive status, health disorders, and stress are reported as potential modulating factors, these research studies failed to find statistically significant results supporting their hypothesis. For the current research, serum samples were obtained twice a week during one month from semi-intensive-kept Marecha she-camels and analyzed for triiodothyronine (T3) and thyroxine (T4) concentrations. Feed ingredients and additives were quality assessed to examine their nutrient profile, with special attention to protein content and exogenous calcium administration. Statistical differences in serum thyroid hormone levels were found between gravid and non-gravid females, being pregnant she-camels the subgroup with higher levels (P < 0.05). The genetic background of such phenotypic variability in thyroid metabolism in camels has to be further addressed to adapt husbandry practices for breed-specific requirements. Meanwhile, local management strategies are susceptible of accurate routines for sustainable farming.

Effects of a long-acting trace mineral rumen bolus supplement on growth performance, metabolic profiles, and trace mineral status of growing camels

A study was conducted to evaluate the effects of a long-acting trace mineral rumen bolus (TMB) supplement on the productive performance, metabolic profiles, and trace mineral status of growing camels under natural grazing conditions. Fifteen 6-month-old growing male camels (average bodyweight 139.51 ± 26.49 kg) were used in a 150-day trial. Animals were individually housed in a shaded pen and randomly assigned to receive zero (control group, CON), one (TMB1), or two (TMB2) long-acting TMBs. Feed intake was measured weekly, and camels were weighed monthly. Blood samples were collected from all camels on days 1, 30, 60, 90, 120, and 150 to obtain metabolic profiles. Zinc, selenium, copper, cobalt, and manganese concentrations were determined in the diet, serum, and liver. In comparison with controls, giving camels one TMB increased the average daily gain (14.38%; P < 0.04) and feed efficiency (13.68%; P < 0.01). Additionally, the serum and liver concentrations of zinc, copper, selenium, cobalt, and manganese were greater (P < 0.01) in camels in the TMB2 group. These data indicate that TMB supplementation has positive effects on the growth performance and trace mineral profiles of camels. Different levels, sources, and synergistic combinations of trace minerals can be used in further studies to elucidate their abilities to increase productive variables as well as their availability and cost to the camel industry.

Studies on rickets and osteomalacia in Bactrian camels (Camelus bactrianus)

Epidemiological studies have indicated incidences of 32.9% and 27.8% for rickets and osteomalacia, respectively, in Bactrian camels (Camelus bactrianus), but there is an increased incidence under drought conditions, sometimes reaching 75%. We have found that concentrations of phosphorus and copper in forage and soil samples in a drought affected area were significantly lower than in a control area or normal reference values (P < 0.01) ; the mean Ca:P ratio in the forages was 50:1. The phosphorus content of blood and hair from affected camels was significantly less than that in controls (P < 0.01) and concentrations of copper in the liver and kidney were significantly lower in affected camels than control animals (P < 0.01); the concentrations of triiodothyronine (T(3)), thyroxine (T(4)) and parathyroid hormone (PTH) in the serum from affected animals were significantly higher than those from healthy controls (P < 0.01); serum inorganic phosphorus and ceruloplasmin levels were lower than those in the controls (P < 0.01 or P < 0.05); the concentrations of serum alpha-globulin and beta-globulin were significantly higher in the affected camels than in the healthy controls (P < 0.01). The pathological changes seen in camels affected with rickets included porous, brittle, light, osteoporotic bones that were susceptible to fractures and had less resistance to cutting and sawing. Wrist joints were enlarged with an apparent bowing of the long bones in forelimb and with typical broadening of the epiphyses. In adult female camels, many enlarged scars were often seen in ribs indicating earlier fractures. The disease could be cured with supplementary bone meal, phosphate or mineral mixtures and in field investigations clinical signs disappeared within 15 days. Over the same period, the concentrations of phosphorus and alkaline phosphatase in blood returned to normal. The disease may be effectively prevented by use of mineral blocks (block salt licks) or dosing orally with copper, selenium and cobalt soluble glass boluses. We conclude that rickets and osteomalacia are mainly caused by phosphorus and copper deficiencies in the pasture.

Comparative study of copper and zinc metabolism in cattle and camel

At an experimental farm, five camels and five cows were fed a similar basal diet for 6 mo. They received oral trace element supplementation for 3 mo (day 22-112). This supplementation included zinc, copper, selenium, manganese, iodine, and cobalt, and corresponded to twice the requirements generally recommended for cows. Plasma copper and zinc concentrations were significantly lower in the camels (61 micrograms/100 mL for copper and 38 micrograms/100 mL for zinc) than in the cows (111 and 83, respectively). The supplementation had no effect on plasma zinc concentration in the camels in spite of the low observed values in this species. Liver copper concentration at the beginning of the trial was lower in the camels (9 ppm) than in the cows (35 ppm), and stayed at lower levels during the entire supplementation period. There was no clear difference in fecal excretion of copper and zinc between the camels and the cows. The results suggested that trace element requirements are lower in camels than in cows and that camels regulate their plasma zinc concentration at a very low level (< 40 micrograms/100 mL).

Trace-elements status in camels. A review

Data relating to trace-elements status in camels is scarce, from both a clinical and biochemical point of view. Clinical deficiency or toxicity has rarely been described in this species. However, there is a some evidence that camels are sensitive to trace element disorders in the same way as other ruminants. For example, copper deficiency in camels has been reported in East Africa. Normal plasma level is comparable to cattle (70-120 mg/100 mL). Camels appear to maintain zinc levels at a lower value than other domestic ruminants (< 60 micrograms/100 mL). Iron metabolism is more active in the liver than in the spleen. Data concerning manganese levels are possibly unreliable. Some cases of selenium deficiency (white muscle disease) have been reported. No data are available for cobalt status in camels. Finally, camels appear to be more sensitive to iodine deficiency than the other domestic ruminants.

The influence of high dietary protein, energy and mineral intake on deficient young camel (Camelus dromedarius)—II. Changes in mineral status

1. Mangrove Avicennia marina is poor in some trace elements such as copper, zinc and manganese. In a trial we used 32 young camels divided into four groups. 2. Groups 1 and 3 were supplemented with copper and zinc in drinking water after 1 month of mangrove feeding. 3. Groups 2 and 3 received concentrate rich in protein and energy. The supplementation was stopped after 2 months. 4. All the camels were deficient in trace elements at the beginning of mineral supplementation. 5. The plasma concentration of copper increased significantly up to normal levels (less than 70 micrograms/100 ml) in energy protein supplemented groups, but the quantity supplied (100 mg of copper sulphate/day) was not sufficient to maintain this level after the end of supplementation. 6. The original zinc deficiency was too severe to observe a significant effect of the mineral supplementation. 7. Calcium, magnesium and phosphorus levels were improved during the supplementation period in protein-energy supplemented groups. 8. A high interaction between mineral absorption and quality of the diet was observed. A well-balanced diet seems essential to avoid deficient mineral status.