Claudia Preda - Academia.edu (original) (raw)
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Papers by Claudia Preda
Scientific Works. Series C. Veterinary Medicine, 2013
Two hen breeds, White Cornish (COR) and White Leghorn (LEG) 34-week-aged were used in this experi... more Two hen breeds, White Cornish (COR) and White Leghorn (LEG) 34-week-aged were used in this experiment. The basic diet of these hens contained 3.8% Ca. This diet was supplemented for an experimental period of 8 days with 0.0, 1.0 and 2.0 and, respectively, 3.0% calcium. During the experimental period the plasma blood levels of Ca, phosphorus, parathormone, calcitonin, vitamin D and estradiol were monitored. The results relive a significant increase of the blood plasma levels of Ca and phosphorus in both COR and LEG hens beginning form the 2% calcium dietary supplementation. Phosphorus levels increased too, but the Ca/P ratio indicated an imbalance for the calcium. In the same time it was found a significant decrease of the plasma level of parathormone in both 2% and 3% Ca supplemented CRG and LEG hens. Blood plasma level of calcitonin doesn't follow a clear increasing in any experimental group, neither for CRH nor for LEG hens: statistical analyses between day one and day 8 th of the experimental periods didn't relive any statistical significant difference in any experimental group for this hormone. Plasma vitamin D concentrations followed a statistical significant (P<0.05) increase for both 2% and 3% calcium supplemented diets in both CRN and LEG hens. Estrogen levels were found significantly elevated in LEG hens vs. CRH hens, but the differences were not in relation to the blood calcium concentrations. In conclusion, blood calcium levels in hens influences the parathormone and vitamin D secretions but its influence on the calcitonin and estrogens is not clear. Further experiments are recommended to find the exact mechanisms of blood calcium regulation in birds.
The paper presents the results of the researches carried out in the SCDA Drăgănești Vlașca experi... more The paper presents the results of the researches carried out in the SCDA Drăgănești Vlașca experimental field, in two agriculture systems, conservative and conventional. Soil samples, taken in two phases, were analyzed in the laboratory to determine physical and chemical parameters: organic matter content, soil structure, bulk density, soil reaction, nutrients (N, P, K, and S) contents, total porosity, and resistance to penetration. Micro biological analyses were also performed: total number of bacteria (TNB10/g dry soil), total number of micro fungi (TNF10/g soil), and soil respiration (mg CO2/100 g sol). Soil arrangement state assessed through BD, TP, and RP is more favorable in the case of the conservative system as compared to the conventional one. The analyzed indicators highlight a soil looser arrangement in the conservative system and a certain improvement of the air condition. The slightly positive effects determined by the conservative system application reflect upon the ...
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj Napoca Veterinary Medicine, Nov 28, 2014
Scientific Works. Series C. Veterinary Medicine, 2013
Two hen breeds, White Cornish (COR) and White Leghorn (LEG) 34-week-aged were used in this experi... more Two hen breeds, White Cornish (COR) and White Leghorn (LEG) 34-week-aged were used in this experiment. The basic diet of these hens contained 3.8% Ca. This diet was supplemented for an experimental period of 8 days with 0.0, 1.0 and 2.0 and, respectively, 3.0% calcium. During the experimental period the plasma blood levels of Ca, phosphorus, parathormone, calcitonin, vitamin D and estradiol were monitored. The results relive a significant increase of the blood plasma levels of Ca and phosphorus in both COR and LEG hens beginning form the 2% calcium dietary supplementation. Phosphorus levels increased too, but the Ca/P ratio indicated an imbalance for the calcium. In the same time it was found a significant decrease of the plasma level of parathormone in both 2% and 3% Ca supplemented CRG and LEG hens. Blood plasma level of calcitonin doesn't follow a clear increasing in any experimental group, neither for CRH nor for LEG hens: statistical analyses between day one and day 8 th of the experimental periods didn't relive any statistical significant difference in any experimental group for this hormone. Plasma vitamin D concentrations followed a statistical significant (P<0.05) increase for both 2% and 3% calcium supplemented diets in both CRN and LEG hens. Estrogen levels were found significantly elevated in LEG hens vs. CRH hens, but the differences were not in relation to the blood calcium concentrations. In conclusion, blood calcium levels in hens influences the parathormone and vitamin D secretions but its influence on the calcitonin and estrogens is not clear. Further experiments are recommended to find the exact mechanisms of blood calcium regulation in birds.
The paper presents the results of the researches carried out in the SCDA Drăgănești Vlașca experi... more The paper presents the results of the researches carried out in the SCDA Drăgănești Vlașca experimental field, in two agriculture systems, conservative and conventional. Soil samples, taken in two phases, were analyzed in the laboratory to determine physical and chemical parameters: organic matter content, soil structure, bulk density, soil reaction, nutrients (N, P, K, and S) contents, total porosity, and resistance to penetration. Micro biological analyses were also performed: total number of bacteria (TNB10/g dry soil), total number of micro fungi (TNF10/g soil), and soil respiration (mg CO2/100 g sol). Soil arrangement state assessed through BD, TP, and RP is more favorable in the case of the conservative system as compared to the conventional one. The analyzed indicators highlight a soil looser arrangement in the conservative system and a certain improvement of the air condition. The slightly positive effects determined by the conservative system application reflect upon the ...
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj Napoca Veterinary Medicine, Nov 28, 2014