572 research outputs found
Phenotypic Relation Growth Rate in Performance Test and Litter Size of Sows
In this study we investigated influence of weight gain level of gilts reached during performance test on the expression of important reproductive traits. For the purpose of research, data on the litter size from 2nd to 9th parity of 700 tested gilts were monitored. Characteristics that were examined are: growth at the end of the test, the number of piglets born alive, stillborn and weaned piglets per parity and a total from 2nd to 9th parity, and the percentage of sows entering the next farrowing. Results obtained in this study indicate that gilts with a lower weight gain in performance test have smaller number of live born (8.8:9.23 p<0.01) and reared piglets (8.46:8.55, p<0.01) in regard to the higher weight gain gilts, but a larger number of stillborn piglets (0.35:0.29). Also, gilts with the lowest weight gain during the performance test had smaller average litter size from 2nd to 9th parity. Even greater difference is determined if the average litter size from 3rd to 7th parity (9.8:10.0 and 10.4) is observed. The largest percentage of sows farrowing for the second time was in gilts with the highest weight gain during the performance test (39.5%: 14.8% and 15.5%) which expressed statistically significant difference (p<0.01). Gilts with a lower gain weight in performance test had a higher percentage of sows included in the next farrowing. Data showed a large drop in the number of sows with the second and third parity in the total sample, where the percentages of earned second and third litters were 16.5 and 45.3%, while the percentages of actual parity from the 4th to 7th parity were: 79.2; 94.7; 83.3; 96.7; 72.4 and 90.5%
Estrus Induction in Sexually Mature Gilts with Different Hormonal Treatments
The aim of this study was to determine the effectiveness of the synchronized estrus induction in sexually mature gilts, after treatment with different hormonal treatments, given in the unknown phase of a spontaneous estrus cycle. Sexually mature gilts were used, with at least one spontaneous estrous cycle. A total of 90 gilts were treated with single i/m injection of 1,000 IU eCG (Folligon®), 40 gilts were treated with two separate i/m injection of 1 ml PGF2α (Dinolytic®), at an interval of 11 days, and 40 gilts were treated orally (within diet) with 20 mg of synthetic progestagen preparation Altrenogest (Regumate®), during 18 days. Estrus was detected twice daily, in the 10h to 12h intervals, by direct contact with the teaser boar. The best induction of synchronized estrus (in 90% of gilts), which appeared within the first 7 days (mean 5.3 days) after treatment, was found in gilts treated with progestagen preparations. In the three repetitions of treatment with eCG, within the first 7 days (mean 4.2 days) after the treatment, estrus was detected in 65%, 40% or 33% of the treated gilts. After treatment with luteolytic preparation PGF2α (Dynolitic®), estrus was detected in 40% of gilts, on average 5.5 days after treatment. The obtained results clearly show that the successful induction of synchronized estrus in sexually mature gilts can be done only by the method for prolongation of the luteal phase of the spontaneous estrous cycles, using progestagen preparations
Litters Health Status and Growth Parameters in the Sows Feeding Diets Supplemented with Probiotic Actisaf Sc 47® within Pregnancy Or Lactation
The aim of this study was to investigate the effect of supplementing standard diets for pregnant and lactating sows with live yeast culture (Saccharomyces cerevisiae) on their health status, as well as the health status and growth parameters of their litters during lactation. A total of 120 sows were divided into three groups: the first group was fed diets supplemented with probiotics during pregnancy (G+P, n=40), the second group was fed these diets during lactation (L+P, n=40), and the third group was the control group which was not fed diets supplemented with probiotics (C, n = 40). During the lactation period, a significantly (p<0.01) smaller proportion of probiotic treated sows (G+P=7.5%, L+P=12.5%) manifested clinical signs of the uterus and/or the udder disease in comparison with the control sows (22.5%). The incidence of infectious diarrhea in the nursing piglets was significantly (p<0.05) lower in the treated sows (12.5%) compared to the control sows (27.5 %). The average number of weaned piglets per litter (p/l) and average litter weight at weaning (lw) (G+P=11.6 p/l and 103.6 kg lw, L+P=11.1 p/l and 102.8 kg lw, C=10 p/l and 79 kg lw) were significantly higher (p<0.01 or p<0.05) in sows treated with probiotic compared to the control sows. These results clearly show that the use of probiotic significantly improves the health status of sows and nursing piglets, as well as the piglets growth parameters
Metabolic acclimation to heat stress in farm housed Holstein cows with different body condition scores
The aim of this study was to determine the effects of body condition score to metabolic acclimation in heat stressed Holstein cows. Body condition of cows had no effect on any of the tested parameters during the thermal neutral period, except for the percentage of protein in milk. Heat stress has been demonstrated to have an impact on all the selected parameters, and has been found to be the cause of decreased milk production and quality, increased rectal temperature and respiration rate, decreased glucose, non esterified fatty acids (NEFA) and cholesterol concentration, increased urea and bilirubin concentration, and loss of subcutaneous fat. Obese cows (BCS>4) had less ability of acclimation to heat stress as compared to normal and thin cows (significantly lower production and milk quality, and significantly higher rectal temperature and respiration level in relation to the other groups of cows). Obese cows showed a significantly higher concentration of NEFA and significantly lower glucose during exposure to heat stress. The steady increase in NEFA concentrations and decrease of backfat thickness suggested that fat was used for energy purposes, which significantly increased the heat balance and led to poor acclimation to heat stress in obese cows. Cows with high body condition were at higher risk of developing liver failure and lipidosis (reduced cholesterol and elevated bilirubin concentration) during heat stress, which could be linked with increased concentrations of fatty acids in the blood. This was found with an increased concentration of urea during exposure to heat stress, with significantly higher concentration in obese cows. Using the fat for energy purposes depends on the sensitivity to insulin, which increases during heat stress. Obese cows are naturally less sensitive to insulin and more prone to lipolysis. However, these signs should be the focus of future research.Key words: Body condition score, heat stress, metabolic status, cow
Cryptoferromagnetic state in superconductor-ferromagnet multilayers
We study a possibility of a non-homogeneous magnetic order
(cryptoferromagnetic state) in heterostructures consisting of a bulk
superconductor and a ferromagnetic thin layer that can be due to the influence
of the superconductor. The exchange field in the ferromagnet may be strong and
exceed the inverse mean free time. A new approach based on solving the
Eilenberger equations in the ferromagnet and the Usadel equations in the
superconductor is developed. We derive a phase diagram between the
cryptoferromagnetic and ferromagnetic states and discuss the possibility of an
experimental observation of the CF state in different materials.Comment: 4 pages, 1 figur
Photodoping and in-gap interface states across the metal-insulator transition in LaAlO3/SrTiO3 heterostructures
By using scanning tunneling microscopy/spectroscopy we show that the interface between LaAlO3 and SrTiO3 band insulators is characterized by in-gap interface states. These features were observed in insulating as well as conducting LaAlO3/SrTiO3 bilayers. The data show how the interface density of states evolves across the insulating to metal transition, demonstrating that nanoscale electronic inhomogeneities in the system are induced by spatially localized electrons
Superconductor-Ferromagnet Bi-Layers: a Comparison of s-Wave and d-Wave Order Parameters
We study superconductor-ferromagnet bi-layers, not only for s-wave but also
for d-wave superconductors. We observe oscillations of the critical temperature
when varying the thickness of the ferromagnetic layer for both s-wave and
d-wave superconductors. However, for a rotated d-wave order parameter the
critical temperature differs considerably from that for the unrotated case. In
addition we calculate the density of states for different thicknesses of the
ferromagnetic layer; the results reflect the oscillatory behaviour of the
superconducting correlations.Comment: 11 pages, 5 figures, accepted for publication in J. Phys.: Condens.
Matte
Adsorptive Behavior of an Activated Carbon for Bisphenol A Removal in Single and Binary (Bisphenol A—Heavy Metal) Solutions
Authors thank M.I. Bautista-Toledo for the activated carbon donation.Bisphenol A (BPA) is an extensively produced and consumed chemical in the world. Due to its widespread use, contamination by this pollutant has increased in recent years, reaching a critical environmental point. This work investigates the feasibility of bisphenol A adsorption from industrial wastewater solutions, testing the reduction of bisphenol A in synthetic solutions by a commercial activated carbon, AC-40, in batch mode. Besides, mixtures of bisphenol A and different heavy metal cations were also studied. So far, no works have reported a complete study about bisphenol A removal by this activated carbon including the use of this material to remove BPA in the presence of metal cations. First, adsorption experiments were performed in batch changing pH, dose of adsorbent, initial bisphenol A concentration and contact time. Results showed greater retention of bisphenol A by increasing the acidity of the medium. Further, the percentage of bisphenol A adsorbed increased with increasing contact time. The selected conditions for the rest of the experiments were pH 5 and a contact time of 48 h. In addition, an increase in retention of bisphenol A when the dose of adsorbent increased was observed. Then, specific experiments were carried out to define the kinetics and the adsorption isotherm. Equilibrium data were adequately fitted to a Langmuir isotherm and the kinetics data fitted well to the pseudo-second-order model. The maximum adsorption capacity provided by Langmuir model was 94.34 mg/g. Finally, the effect of the presence of other heavy metals in water solution on the adsorption of bisphenol A was analyzed. Binary tests revealed competition between the adsorbates and a significant selectivity toward bisphenol A. Finally, the study of the adsorption performance in three consecutive adsorption–desorption cycles showed efficiencies higher than 90% in all cycles, indicating that the activated carbon has good reusability
Josephson current in superconductor-ferromagnet structures with a nonhomogeneous magnetization
We calculate the dc Josephson current for two types of
superconductor-ferromagnet (S/F) Josephson junctions. The junction of the first
type is a S/F/S junction. On the basis of the Eilenberger equation, the
Josephson current is calculated for an arbitrary impurity concentration. If the expression for the Josephson critical current is reduced
to that which can be obtained from the Usadel equation ( is the exchange
energy, is the momentum relaxation time). In the opposite limit
the superconducting condensate oscillates with period and
penetrates into the F region over distances of the order of the mean free path
. For this kind of junctions we also calculate in the case when the F
layer presents a nonhomogeneous (spiral) magnetic structure with the period
. It is shown that for not too low temperatures, the -state which
occurs in the case of a homogeneous magnetization (Q=0) may disappear even at
small values of . In this nonhomogeneous case, the superconducting
condensate has a nonzero triplet component and can penetrate into the F layer
over a long distance of the order of . The junction
of the second type consists of two S/F bilayers separated by a thin insulating
film. It is shown that the critical Josephson current depends on the
relative orientation of the effective exchange field of the bilayers. In
the case of an antiparallel orientation, increases with increasing .
We establish also that in the F film deposited on a superconductor, the
Meissner current created by the internal magnetic field may be both diamagnetic
or paramagnetic.Comment: 13 pages, 11 figures. To be published in Phys. Rev.
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