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1.
The daily requirement for calcium and phosphorus by giraffes to sustain the growth and maintenance of their skeletons is large. The source of sufficient calcium is browse. The source of necessary phosphorus is obscure, but it could be osteophagia, a frequently observed behaviour in giraffes. We have assessed whether bone ingested as a result of osteophagia can be digested in the rumen. Bone samples from cancellous (cervical vertebrae) and dense bones (metacarpal shaft) were immersed in the rumens of five sheep, for a period of up to 30 days, and the effect compared to immersion in distilled water and in artificial saliva for 30 days. Distilled water had no effect on the bones. Dense bone samples were softened by exposure to the saliva and rumen fluid, but did not lose either calcium or phosphorus. In saliva and rumen fluid the cancellous bone samples also softened, and their mass and volume decreased as a result of exposure to saliva, but in neither fluid did they lose significant amounts of calcium and phosphorus. We conclude that although saliva and rumen fluid can soften ingested bones, there is an insignificant digestion of bones in the rumen. 相似文献
2.
The objective of this study was to investigate how well cows drink the Propeller calcium drink, and it's effect on blood calcium concentration. Drinking was tested in 120 cows right after calving, before cows drank anything else. 60 cows each were offered 20 liters of Propeller calcium drink or 20 liters of water. Cows drank the Propeller as good as water. 72% of all cows drank all 20 liters, 18% drank on average 8.2 liters and 10% drank less than 1 liter. Blood calcium concentration was studied in 16 cows right after calving. Eight cows each were offered 20 liters of Propeller calcium drink or no calcium drink. Blood calcium significantly increased ten minutes after Propeller intake and stayed significantly elevated for 24 hours. Without calcium drink blood calcium levels decreased significantly. Advantages of the new Propeller calcium drink over calcium gels or boli could be that cows now drink calcium themselves and that the Propeller increases blood calcium concentration rapidly and long lasting. 相似文献
3.
The study was undertaken to find out the effects of over supplementation of dietary calcium and vitamin D3 on the mineralization
of growing skeleton, taking rabbit as an animal model; further to study the effects of Nandrolone deconoate and TGF-β1 on
the mineralization of osteopenic bones. Twenty four New Zealand White rabbits of either sex, 60 day old, were randomly divided
in 4 equal groups, A, B, C and D. The animals of groups B, C and D were administered with oral supplementation of calcium
(2000 mg/kg of standard rabbit feed) and vit-D3 (1000 IU/kg of standard feed) for 60 days. The animals of group A were given
standard ration without any supplementation. After 60 days, the Ca-vit.D3 supplementation was discontinued; and the animals
of group C were administered with TGF-β1 (10 ng, i.m.) once in every three days and animals of group D were given Nandrolone
deconoate (10 mg, i.m.) once every week for 30 days, whereas in animals of group B, no treatment was given. All the animals
were evaluated based on different observations like body weight, radiographic observations, circulating biochemical and hormone
profile (plasma Ca, IP, AP, OC and iPTH) every 15 days up to 60 days after initiation of treatment. The results indicated
that the body weight of rabbits in different groups increased gradually and steadily at different intervals till the end of
observation period, however, the increase was non-significantly more in group D. The CI in group A increased gradually at
different intervals; whereas in groups B, C and D, there was no appreciable increase in the CI during the period of Ca-vit.D3
supplementation, suggesting development of osteopenia. Treatment with TGF-β1 did not increase the CI significantly, whereas
Nandrolone treatment resulted in significant increase in the CI on days 45 and 60. The plasma Ca levels showed slight but
gradual increase from day 0 to 60 in almost all groups. Subsequently also, there was no marked change at different intervals
in groups A and B; however, significant reduction in plasma Ca was noticed in group C on 15 th day and in group D on 60 th day after initiation of treatment. Plasma IP levels in groups B and C showed a decreasing trend up to day 60. After discontinuation
of Ca-vit.D3 supplementation, in group B, it further decreased to remain significantly lower on 15 th day, and in groups C and D, it increased significantly on 60 th post-treatment day. There was no significant change in the AP activity during the entire period of study in group A; whereas
significant reduction in AP activity was measured on 30 th and 60 th days of treatment in groups B and C, and on 15 th day of treatment in group D. Plasma iPTH values did not show any significant change at any interval during the first 60 days
in all groups. On 30 th and 60 th days of treatment, the mean iPTH level remained significantly lesser in group B. In all groups treated with over supplementation
of Ca and vit.D3, there was a non-significant increase in the plasma OC levels up to day 60; however, there was no significant
difference between the groups. It can be concluded that additional supplementation of Ca and vit.D3 results in osteopenia
in growing rabbits. Administration of Nandrolone helps to increase the mineral density in osteopenic bones, whereas TGF-β1
does not seem to have positive effect on the skeletal mineralization. 相似文献
4.
1. Two experiments were performed to compare the relative effectiveness of feeding 1,25‐dihydroxycholecalciferol (1,25‐DHCG) in minimising leg abnormalities in broilers with other methods and to investigate interactions between dietary 1,25‐DHCC and calcium. 2. Adding 5 μg 1,25‐DHCC/kg to a diet containing 12 g calcium/kg was more effective than early food restriction or meal feeding in preventing leg abnormalities but was found to cause a growth depression. 3. The second experiment, which had a factorial design, with diets containing 7.5, 100 and 12.5 g calcium and 0, 2.0, 3.5 and 5.0 μg 1,25‐DHCC/kg, showed linear and quadratic interactions between these dietary factors. Diets with higher concentrations of both 1,25‐DHCC and calcium resulted in growth depression associated with hypercalcaemia. 4. The incidence of tibial dyschondroplasia (TD) at 3 weeks of age was highest with the basal diet containing 7.5 g calcium/kg and was markedly reduced by addition of 1,25‐DHCC and/or calcium. The incidence was very low or non‐existent when 1,25‐DHCC was fed at 3–5 μg/kg or greater. 5. Feeding 5 μg/kg 1,25‐DHCC had no effect on plasma 1,25‐DHCC concentrations, although at the higher dietary calcium contents plasma concentrations of 25‐hydroxy‐ and 24,25‐dihydroxy‐cholecalciferol were lower in those birds fed 1,25‐DHCC. 6. It is concluded that 1,25‐DHCC is most effective in preventing TD without accompanying growth depression when it is fed in conjunction with diets containing less than 10 g calcium/kg. 相似文献
6.
1. Susceptibility to calcium‐induced urolithiasis was assessed in pullets of two commercial SCWL strains (A and B) reared together from 5 to 18 weeks of age on diets containing 10 g/kg calcium (normal calcium: NC) or 35 g/kg calcium (high calcium: HC). 2. Kidney damage was not observed in pullets reared on NC diets. For pullets fed on HC diets, strain A developed significantly greater kidney asymmetry, a higher incidence of gross kidney damage and a higher incidence of uroliths than strain B. 3. Supplementing the HC diet with 6 g/kg DL‐methionine significantly reduced the incidence of calcium‐induced gross kidney damage and urolith formation in both strains. Ammonium sulphate (5.3 g/kg) was significantly more effective than dl‐methionine in reducing calcium‐induced kidney damage. 4. Neither dl‐methionine nor ammonium sulphate caused a measurable metabolic acidosis. Neither supplement consistently affected water consumption or manure moisture. 相似文献
7.
1. Eight diets (1 to 8) containing respectively 36.8, 30.9, 19.6, 9.7, 5.5, 1.9, 0.96 and 0.48 g of calcium/kg food were each fed for 11 weeks to 24 individually‐caged laying hens (Gallus domesticus) aged 24 weeks. After the experimental period, all birds were returned to a normal diet (34.9 g calcium/kg). 2. Food consumption and egg production decreased as dietary calcium decreased. Shell weight was unaffected on diets 1 and 2; on diet 3 there was slight reduction of shell weight and on diets 4 to 8 the reduction was marked. The proportion of calcium in the shell was affected particularly on diets 7 and 8, though those from diet 5 also showed a decreased shell calcium. 3. The values for calcium intake and calcium loss in the egg showed that, generally, birds restricted calcium loss to less than intake. Only on the very low concentrations of calcium (diets 6, 7 and 8) did output appear to exceed input. 4. The main mechanism for controlling calcium loss involves the regulation of the number of eggs produced, i.e. the number of ovulations. Alterations in shell quality are of less importance with respect to calcium balance, although shell strength was impaired on the more restrictive diets (5 to 8). 相似文献
8.
1. Withdrawal of cholecalciferol (D 3) supplement from a layers diet drastically reduced blood 25‐hydroxycholecalciferol (25‐OH‐D 3), 1α ,25‐dihydroxycholecalciferol (calcitriol) and egg specific gravity (SG) within two weeks, followed by a decrease in blood total calcium (Ca). 2. Doubling the D3 supplement in the control diet (27.5 μg or 1100 IU/kg) almost linearly increased the circulating concentration of 25‐OH‐D3 without raising the concentration of calcitriol, Ca, or egg SG. 3. Replacing D3 by the optimal concentration of calcitriol (5 μg/kg diet) improved egg SG after 21 weeks of treatment without increasing blood calcitriol or total Ca. 4. By itself, 24,25‐dihydroxycholecalciferol [24,25‐(OH)2D3] was unable to maintain normal blood levels of calcitriol, Ca or egg SG and, when added together with calcitriol in the diet, tended to elevate blood Ca but suppress the beneficial effect of calcitriol on shell quality, with little or no effect on blood calcitriol. 相似文献
9.
The purpose of this study was to investigate the impact of eggshell calcium (Biomin H ® dietary supplement) and its combinations with alfacalcidol (1α-hydroxyvitamin D 3) and menaquinone-7 (vitamin K 2) on ovariectomy-induced bone loss in rats. Adult female rats ( n = 48) were divided into 6 groups of 8 individuals each: sham-operated rats (SHAM); ovariectomized (OVX) rats untreated; OVX rats treated with Biomin H ® (BIO); OVX rats simultaneously receiving Biomin H ®, vitamin D 3 (BIO + D 3); OVX rats simultaneously treated with Biomin H ®, vitamin K 2 (BIO + K 2) and OVX rats treated with Biomin H ®, vitamin D 3, vitamin K 2 (BIO + D 3 + K 2) during 8 weeks. Biochemical parameters, bone mineral density (BMD), bone mineral content (BMC) and femoral bone microstructure were determined. Plasma calcium and phosphate were increased in BIO + D 3 and BIO + D 3 + K 2 groups as compared to OVX. Alkaline phosphatase was elevated in OVX, BIO versus SHAM, BIO + D 3 + K2 groups. When compared to OVX group, decreased urine deoxypyridinoline was observed in all treated groups and femoral BMD, BMC were higher in BIO, BIO + D 3, BIO + D 3 + K 2 groups. The BIO + K 2 rats had similar densitometrical values than OVX individuals. Microcomputed tomography revealed increased trabecular relative bone volume (due to an increase in trabecular number) in BIO + D 3, BIO + D 3 + K 2 as compared to OVX. The higher relative bone volume in BIO + D 3, BIO + D 3 + K 2 groups was also accompanied by an increase in bone surface. In the cortical bone, an enhanced periosteal bone apposition was identified in BIO, BIO + D 3, BIO + K 2, BIO + D 3 + K 2 groups. The rats from BIO + D 3 + K 2 group had a higher area of primary osteon's vascular canals. In BIO + D 3, BIO + K 2, BIO + D 3 + K 2 groups, an increased area of secondary osteons was determined in comparison with OVX. Our results indicate the beneficial effect of triple application of Biomin H ®, vitamin D 3, vitamin K 2, as well as simultaneous administration of Biomin H ®, vitamin D 3 on the inhibition of ovariectomy-induced bone loss in a rat model of osteoporosis. 相似文献
10.
1. Hens fed on a diet containing 0–05% calcium virtually ceased egg laying (production <4%) whereas those fed on a diet containing 0–5% Ca maintained production at between 20 and 30%. 2. After a return to a normal diet (3% Ca) egg weight, shell weight, ovarian characteristics and oviduct size were of a similar nature in the two groups, though the differences in egg weight, shell weight and shell calcium were significant at the 1 % level. 3. Bone weight and bone ash did not differ significantly between the groups but after a return to normal rations, bone weight and bone ash became higher in the group that had received the 0.05% Ca diet. 4. There were no clinical signs of bone demineralisation during the experiments. 相似文献
11.
Overliming and excessive application of superphosphate caused a zinc deficiency in the soil and so reduced the uptake of zinc by fodder plants. Bucks reared on such fodder had significantly (p<0.01) less zinc in their hair compared with controls and suffered from conditioned zinc deficiency syndrome with a significant (p<0.01) loss of body weight, stunted growth, alopecia, lethargy, abnormal (kyphotic) gait, anorexia, digestive and respiratory problems. Oral supplementation with zinc sulphate very rapidly improved these conditions to near normality. Histological examination of samples of skin and testis from the zinc-deficient bucks revealed formation of excessive keratin, retention of nuclei in the stratum corneum and reduction in the width of the stratum granulosum in the skin, while samples of testis indicated degenerative changes, including atrophy of the seminiferous tubules, hyperplasia of the germinal epithelium and thickening of the walls of blood ve ssels. 相似文献
12.
1. Four experiments were carried out with Warren laying hens to elucidate the changes in plasma inorganic phosphorus (P i) concentration during egg formation. 2. In hens receiving a normal diet containing a calcium supplement in a powdery form Pi increased from 25 to 42 mg/1 during an entire shell formation cycle (from 10 to 22 h after oviposition of the previous egg), while in cockerels Pi decreased slightly during the night. 3. This increase in Pi in hens, was not related to cessation of feeding at the onset of darkness but was specifically connected with the beginning of shell secretion. 4. When hens received calcium as crushed sea‐shells separately from the diet, the nocturnal peak in Pi virtually disappeared and only a temporary increase of 4 mg/1 between 10 and 14 h after oviposition remained. 5. These results indicate that the beginning of shell secretion is always accompanied by an increase in Pi and that a separate presentation of dietary calcium reduces the bone mobilisation at night. 相似文献
14.
1. A low‐calcium diet (0.5 g calcium/kg) was used to prevent the onset of laying in young pullets. 2. It was fed at 16 weeks of age to five separate groups (groups 2 to 6) each of 50 to 60 birds. 3. Group 2 was fed on a normal layers’ diet at 23 weeks of age, group 3 at 27 weeks, group 4 at 31 weeks, group 5 at 35 weeks and group 6 at 55 weeks while the control group (group 1) of similar size to groups 2 to 6 was subjected to a normal commercial treatment for laying stock. 4. In all the experimental groups the onset of sexual maturity occurred normally, but only one or two eggs were laid before laying ceased under the influence of the treatment. 5. Laying re‐started when the hens were fed on a normal diet and production rapidly rose to a high level. 6. Groups 1, 2 and 3 differed little in the total number of eggs produced up to 72 weeks of age. 7. In all experimental groups there were fewer very small, small and medium eggs than in the control group. 8. It is suggested that the use of a low‐calcium diet before the onset of lay may have advantages which could be exploited on a commercial scale. 相似文献
15.
Summary The effect of molecular structure on the drug disposition and protein binding in plasma, the urinary recovery, and the renal clearance of sulphamerazine (SMR), sulphadiazine (SDZ), and sulphadimidine (SDM) and their N 4‐acetyl and hydroxy derivatives were studied in pigs. Following IV administration of SDM, SMR and SDZ, their mean elimination half‐lives were 12.4 h, 4.3 h and 4.9 h respectively. The plasma concentrations of parent sulphonamide were higher than those of the metabolites, and ran parallel. The acetylated derivatives were the main metabolites; traces of 6‐hydroxymethylsulphamerazine and 4‐hydroxysulphadiazine were detected in plasma. The urine recovery data showed that in pigs acetylation is the major elimination pathway of SDM, SMR and SDZ; hydroxylation became more important in case of SMR (6‐hydroxymethyl and 4‐hydroxy derivatives) and SDZ (4‐hydroxy derivatives) than in SDM. In pigs methyl substitution of the pyrimidine side chain decreased the renal clearance of the parent drug and made the parent compound less accessible for hydroxylation. Acetylation and hydroxylation speeded up drug elimentation, because their renal clearance values were higher than those of the parent drug. 相似文献
16.
Avian influenza outbreaks have occurred during winter months, and effective disinfection of poultry premises at freezing temperatures is needed. The commercial disinfectants Virkon and Accel, supplemented with an antifreeze agent [propylene glycol (PG), methanol (MeOH), or calcium chloride (CaCl 2)], were evaluated for their effectiveness in killing avian influenza virus (AIV) at −20°C or 21°C. An AIV suspension was applied to stainless steel disks, air-dried, and covered with a disinfectant or antifreeze agent for 5 to 30 min. Virkon (2%) and Accel (6.25%) with 30% PG, 20% MeOH, or 20% CaCl 2 inactivated 6 log 10 AIV within 5 min at −20°C and 21°C. At these temperatures PG and MeOH alone did not kill AIV, but the 20% CaCl 2 solution alone inactivated 5 log 10 AIV within 10 min. The results suggested that CaCl 2 is potentially useful to enhance the effectiveness of disinfection of poultry facilities after outbreaks of AIV infection in warm and cold seasons. 相似文献
17.
Insects are a poor source of dietary calcium and since they are seasonally abundant, it has been suggested that calcium availability may play a significant role in controlling the timing of reproduction in insectivorous bats. To assess the possible role of dietary calcium, we have measured bone calcium concentrations in female and male long-fingered bats (Miniopterus schreibersii) through a full reproductive cycle. The results indicate that winter was not a period of calcium stress and, therefore, that seasonal changes in insect abundance and dietary calcium availability are not a satisfactory explanation for the occurrence of delayed implantation in the long-fingered bat. Bone calcium concentrations of females did not differ significantly throughout pregnancy, indicating that the insects available in winter and early summer were sufficient to meet the calcium demands of pregnancy. Lactating females had the lowest bone calcium concentrations of all specimens, supporting the suggestion that lactation is indeed a period of severe calcium stress in aerial insectivores. We conclude that parturition is probably timed so that lactation coincides with the period of maximal insect abundance and corresponding dietary calcium availability. 相似文献
19.
ObjectiveTo verify the efficacy of citral in inducing sedation and anesthesia in silver catfish ( Rhamdia quelen) and grass carp ( Ctenopharyngodon idella) and to assess the safety of essential oil (EO) of Aloysia citriodora and citral in inducing and maintaining anesthesia in silver catfish. Study designClinical study, randomized, parallel, multi-arm with control group in target species. AnimalsA total of 96 juvenile and 72 adult silver catfish and 80 juvenile grass carp were used. MethodsSilver catfish and grass carp were exposed to different concentrations of citral, 15–675 and 15–600 μL L –1, respectively, during the maximum period of 30 minutes to verify sedation and anesthesia induction and recovery times. In addition, for anesthetic induction, silver catfish were exposed to the EO of A. citriodora and citral at 225 μL L –1 for 3.5 minutes. Then, fish were transferred to an anesthesia maintenance solution at 50 μL L –1 for 10 minutes to assess hematologic and biochemical variables at 60 minutes, 2 and 6 days after treatment. ResultsCitral only induced sedation from 15, 25 and 40 μLL –1 in both species. Anesthesia without mortality was induced in silver catfish at 50–600 μL L –1 and grass carp at 75–450 μL L –1. At 675 and 600 μL L –1, mortality was recorded in silver catfish and grass carp, respectively. The EO of A. citriodora and citral were safe in inducing and maintaining anesthesia in silver catfish, with mean corpuscular hemoglobin concentration being the only variable that varied in relation to time and treatments. Conclusions and clinical relevanceCitral was effective in inducing sedation and anesthesia in both species. In addition, A. citriodora EO and citral were safe in inducing and maintaining anesthesia in silver catfish. Both agents are promising substances for the development of new drugs for fish. 相似文献
20.
Zoonotic diseases, transmitted from animals to humans, are a public health challenge in developing countries. Livestock value chain actors have an important role to play as the first line of defence in safeguarding public health. However, although the livelihood and economic impacts of zoonoses are widely known, adoption of biosecurity measures aimed at preventing zoonoses is low, particularly among actors in informal livestock value chains in low and middle-income countries. The main objective of this study was to investigate knowledge of zoonoses and adoption of biosecurity measures by livestock and milk value chain actors in Bura, Tana River County, in Kenya, where cattle, camels, sheep and goats are the main livestock kept. The study utilised a mixed methods approach, with a questionnaire survey administered to 154 value chain actors. Additional information was elicited through key informant interviews and participatory methods with relevant stakeholders outside the value chain. Our results found low levels of knowledge of zoonoses and low levels of adherence to food safety standards, with only 37% of milk traders knowing about brucellosis, in spite of a sero-prevalence of 9% in the small ruminants tested in this study, and no slaughterhouse worker knew about Q fever. Actors had little formal education (between 0 and 10%) and lacked training in food safety and biosecurity measures. Adoption of biosecurity measures by value chain actors was very low or non-existent, with only 11% of butchers wearing gloves. There was a gendered dimension, evidenced by markedly different participation in value chains and lower adoption rates and knowledge levels among female actors. Finally, cultural and religious practices were shown to play an important role in exposure and transmission of diseases, influencing perceptions and attitudes to risks and adoption of biosecurity measures. 相似文献
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