62 research outputs found
Effect of breed and age on beef carcass quality, fatness and fatty acid composition
The aim of this research was to determine differences in beef carcass fatness and in the fatty acid composition of muscle and adipose tissue of three different breeds slaughtered at the age of 14 months and 19 months. The breed significantly affected the muscle fat content, carcass subcutaneous fat tissue thickness and fatty acid composition of the muscle and subcutaneous fat tissue. Different age at slaughter had no significant effect on analysed traits. The muscle tissue of the Herefords contained a higher (P < 0.05) percentage of C14 : 0 and C16 : 0 fatty acids and fewer long-chain fatty acids than the Simmentals and Charolais. The subcutaneous fat tissue of the Simmentals contained a higher (P < 0.05) percentage of PUFA, PUFA/SFA ratio and n-6 fatty acids. When fed with a high-energy diet, the Herefords proved to have the most fattened carcasses and the highest content of saturated fatty acids in the muscle. Changes in the diet of feedlot cattle should result in a more favourable fatty acid composition
UTJECAJ DUŽINE TRANSPORTA I MIJEŠANJA GRUPA NA KAKVOĆU JUNEĆIH TRUPOVA SIMENTALSKIH BIKOVA
In the last few years, beef producers have had great problems with beef distribution, related primarily to the frequent incidence of dark, firm, dry meat. Consumers are unlikely to buy and consume such meat. The aim of this study was to examine the effect of transport period and mixing of groups during rest period in lairage on the quality of beef carcasses. The study included 40 Simmental bulls aged from 18 to 20 months. Ultimate pH value and meat colour were measured 24 hours post mortem in m. longissimus dorsi and m. gracilis. Only 45% of carcasses were within the standard pHu range. Results of transport period did not show significant effect on beef quality. In contrast to transport period, mixing of groups during rest period in lairage had highly significant adverse effect on beef quality (p<0.001). The effect of mixing of bulls during the resting period of 18 hours, could however be regarded of being the main stress factor.Proizvođači junećega mesa proteklih godina imaju značajne probleme u plasmanu junetine, prvenstveno zbog učestalije pojave tamnog suhog i tvrdog mesa (DFD). Potrošači takvo meso nerado kupuju i konzumiraju. Cilj ovog istraživanja je utvrditi značajnost utjecaja dužine transporta i miješanja grupa bikova tijekom odmora u stočnom depou na kakvoću junećih trupova. Istraživanje je uključilo 40 simentalske junadi u dobi od 18 do 20 mjeseci. Mjerenje konačne pH vrijednosti i boje mesa vršena su 24 sata post mortem na m. longissimus dorsi i m. gracilis. Samo je 45% trupova imalo vrijednost kpH u poželjnom intervalu. Istraživanjem nije utvrđen značajan utjecaj dužine transporta na pokazatelje kakvoće junećih trupova. Miješanje grupa bikova tijekom odmora u stočnom depou ima značajan utjecaj na kakvoću junećih trupova (p<0.001). Utjecaj miješanja grupa bikova tijekom odmora u stočnom može se smatrati jednim od glavnih uzročnika stresa odgovornog za pojavu DFD junećega mesa
Potential of Endangered Local Donkey Breeds in Meat and Milk Production
The problem of the erosion of animal genetic resources is evident in certain local donkey breeds, and their long-term sustainability can be achieved by economically repositioning them. To develop alternative and sustainable commercial programs, the meat and milk production characteristics of Istrian donkey and Littoral Dinaric donkey breeds were investigated. The meat production characteristics were examined in mature males, whose carcasses were dissected, and meat composition was determined using NIT spectrophotometry and gas chromatography. Milk yield and milk composition were determined in jennies in second or subsequent lactations by measuring milk volume and using infrared spectrometry and gas chromatography. Compared to the Littoral Dinaric donkey, the Istrian donkey has a higher carcass weight and dressing percentage (p < 0.001). The share of boneless meat in relation to live weight was 28.27% in the Istrian donkey and 26.18% in the Littoral Dinaric donkey. The absolute masses of primal cuts of meat in E, I, and II classes were significantly greater in Istrian donkeys than in Littoral Dinaric donkeys (p < 0.01), although the differences in the proportions of primal cuts were not significant. The breed did not have a significant impact on the color, pH, or meat composition. A significant influence of breed on milk yield, lactose, protein, and the fat content of milk was observed (p < 0.01). A significant influence of breed on the ratio of n-6/n-3 PUFA fatty acids in donkey milk was observed (p = 0.002). The values of the atherogenic and thrombogenic indexes were favorable, considering potential beneficial effects of donkey milk and meat on consumer health. The findings of this research suggest that local donkey breeds hold significant potential for meat and milk production, focusing on the uniqueness and quality of their products rather than the quantity of meat and milk they can produce
EFFECTS DIFFERENT TRANSPORT PERIOD AND MIXING OF GROUPS ON MEAT QUALITY OF SIMMENTAL BULLS
Summary In the last few years, beef producers have had great problems with beef distribution, related primarily to the frequent incidence of dark, firm, dry meat. Consumers are unlikely to buy and consume such meat. The aim of this study was to examine the effect of transport period and mixing of groups during rest period in lairage on the quality of beef carcasses. The study included 40 Simmental bulls aged from 18 to 20 months. Ultimate pH value and meat colour were measured 24 hours post mortem in m. longissimus dorsi and m. gracilis. Only 45% of carcasses were within the standard pHu range. Results of transport period did not show significant effect on beef quality. In contrast to transport period, mixing of groups during rest period in lairage had highly significant adverse effect on beef quality (p<0.001). The effect of mixing of bulls during the resting period of 18 hours, could however be regarded of being the main stress factor
Generating transgenic reporter lines for studying nervous system development in the cnidarian nematostella vectensis
Neurons often display complex morphologies with long and fine processes that can be difficult to visualize, in particular in living animals. Transgenic reporter lines in which fluorescent proteins are expressed in defined populations of neurons are important tools that can overcome these difficulties. By using membrane-attached fluorescent proteins, such reporter transgenes can identify the complete outline of subsets of neurons or they can highlight the subcellular localization of fusion proteins, for example at pre- or postsynaptic sites. The relative stability of fluorescent proteins furthermore allows the tracing of the progeny of cells over time and can therefore provide information about potential roles of the gene whose regulatory elements are controlling the expression of the fluorescent protein. Here we describe the generation of transgenic reporter lines in the sea anemone Nematostella vectensis, a cnidarian model organism for studying the evolution of developmental processes. We also provide an overview of existing transgenic Nematostella lines that have been used to study conserved and derived aspects of nervous system development.acceptedVersio
Comparative Analysis of the Subventricular Zone in Rat, Ferret and Macaque: Evidence for an Outer Subventricular Zone in Rodents
The mammalian cerebral cortex arises from precursor cells that reside in a proliferative region surrounding the lateral ventricles of the developing brain. Recent work has shown that precursor cells in the subventricular zone (SVZ) provide a major contribution to prenatal cortical neurogenesis, and that the SVZ is significantly thicker in gyrencephalic mammals such as primates than it is in lissencephalic mammals including rodents. Identifying characteristics that are shared by or that distinguish cortical precursor cells across mammalian species will shed light on factors that regulate cortical neurogenesis and may point toward mechanisms that underlie the evolutionary expansion of the neocortex in gyrencephalic mammals. We immunostained sections of the developing cerebral cortex from lissencephalic rats, and from gyrencephalic ferrets and macaques to compare the distribution of precursor cell types in each species. We also performed time-lapse imaging of precursor cells in the developing rat neocortex. We show that the distribution of Pax6+ and Tbr2+ precursor cells is similar in lissencephalic rat and gyrencephalic ferret, and different in the gyrencephalic cortex of macaque. We show that mitotic Pax6+ translocating radial glial cells (tRG) are present in the cerebral cortex of each species during and after neurogenesis, demonstrating that the function of Pax6+ tRG cells is not restricted to neurogenesis. Furthermore, we show that Olig2 expression distinguishes two distinct subtypes of Pax6+ tRG cells. Finally we present a novel method for discriminating the inner and outer SVZ across mammalian species and show that the key cytoarchitectural features and cell types that define the outer SVZ in developing primates are present in the developing rat neocortex. Our data demonstrate that the developing rat cerebral cortex possesses an outer subventricular zone during late stages of cortical neurogenesis and that the developing rodent cortex shares important features with that of primates
Mutations in Eml1 lead to ectopic progenitors and neuronal heterotopia in mouse and human.
Neuronal migration disorders such as lissencephaly and subcortical band heterotopia are associated with epilepsy and intellectual disability. DCX, PAFAH1B1 and TUBA1A are mutated in these disorders; however, corresponding mouse mutants do not show heterotopic neurons in the neocortex. In contrast, spontaneously arisen HeCo mice display this phenotype, and our study revealed that misplaced apical progenitors contribute to heterotopia formation. While HeCo neurons migrated at the same speed as wild type, abnormally distributed dividing progenitors were found throughout the cortical wall from embryonic day 13. We identified Eml1, encoding a microtubule-associated protein, as the gene mutated in HeCo mice. Full-length transcripts were lacking as a result of a retrotransposon insertion in an intron. Eml1 knockdown mimicked the HeCo progenitor phenotype and reexpression rescued it. We further found EML1 to be mutated in ribbon-like heterotopia in humans. Our data link abnormal spindle orientations, ectopic progenitors and severe heterotopia in mouse and human
Presbyopia:Effectiveness of correction strategies
Presbyopia is a global problem affecting over a billion people worldwide. The prevalence of unmanaged presbyopia is as high as 50% of those over 50 years of age in developing world populations due to a lack of awareness and accessibility to affordable treatment, and is even as high as 34% in developed countries. Definitions of presbyopia are inconsistent and varied, so we propose a redefinition that states “presbyopia occurs when the physiologically normal age-related reduction in the eye's focusing range reaches a point, when optimally corrected for distance vision, that the clarity of vision at near is insufficient to satisfy an individual's requirements”. Presbyopia is inevitable if one lives long enough, but intrinsic and extrinsic risk factors including cigarette smoking, pregnancy history, hyperopic or astigmatic refractive error, ultraviolet radiation, female sex (although accommodation is similar to males), hotter climates and some medical conditions such as diabetes can accelerate the onset of presbyopic symptoms. Whilst clinicians can ameliorate the symptoms of presbyopia with near vision spectacle correction, bifocal and progressive spectacle lenses, monovision, translating or multifocal contact lenses, monovision, extended depth of focus, multifocal (refractive, diffractive and asymmetric designs) or ‘accommodating’ intraocular lenses, corneal inlays, scleral expansion, laser refractive surgery (corneal monovision, corneal shrinkage, corneal multifocal profiles and lenticular softening), pharmacologic agents, and electro-stimulation of the ciliary muscle, none fully overcome presbyopia in all patients. While the restoration of natural accommodation or an equivalent remains elusive, guidance is gives on presbyopic correction evaluation techniques
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