The aim of this study was to determine among nine temperature-humidity index (THI) equations, the one that best represents the effects of heat stress on crossbred dairy calves reared in a tropical environment. Twelve male and female calves, aged 20 to 60 days, and raised in a tropical pen were evaluated. Respiratory (RR) and heart rates (HR), rectal (RT), body surface (BST), dry bulb (Tdb) and wet bulb (Tbw) temperatures, partial vapor pressure (Pv), relative humidity (RH) and dew point temperature (Tpo) were quantified in the morning and afternoon. Nine THI equations were calculated. The highest correlation between physiological variables and this was used to select the best THI equation. Averages for nine THI equations, Tdb, Twb, Pv, Tdp, RR, HR, RT, and BST were higher in the afternoon than in the morning, whereas that for RH was the opposite. The highest values for RT occurred at temperatures above 26.4°C and when humidity was below 55.5%. The Tdb and Pv correlations with RR (0.697 and 0.707), RT (0.703 and 0.706) and BST (0.818 and 0.817) were significant and positive, whereas the RH correlations with the same physiological variables were significant and negative (-0.622, -0.590 and -0.638, respectively). The best index was the THI sensible heat-based ( T H I = 3.43 + 1.058 x T d b - 0.293 x R H + 0.0164 x T d b x R H + 35.7), which was significantly correlated with RR (r=0.668 and r²=0.446), HR (r=0.259 and r²=0.067), RT (r=0.693 and r²=0.479) and BST (r=0.807 and r²=0.650). In conclusion, the THI sensible heat-based equation best represents the effects of heat stress on crossbred dairy calves reared in a tropical environment.
Background: The growth of fish farming in Brazil has been noticeable over the past few years, and the Nile tilapia (Oreochromis niloticus) is the most bred species in the country. Studies on the physiology of these animals are necessary so that the production continues to grow and to improve its rates. However, very discrepant data are still found in the area of blood biochemistry. The aim of this study was to evaluate the physiological variations in serum concentrations of proteins, metabolites, electrolytes and serum enzymes in Nile tilapias bred in net cages in Cachoeira Dourada, state of Minas Gerais, Brazil, during summer and winter.Materials, Methods & Results: During the year of 2016, samples from 100 Nile tilapias were collected during summer (January and February) and samples from 100 Nile tilapias were also collected during winter (July and August). Only one blood sample was collected by caudal venipuncture of each fish, just before the slaughter, always in the morning. The serum samples obtained were then analyzed for serum concentrations of proteins, metabolites, electrolytes, lipids and serum enzymes. Serum concentrations of total proteins, globulins, triglycerides, high density lipoprotein (HDL), alkaline phosphatase, sodium and chloride were significantly higher during winter in comparison to summer, while the serum concentration of uric acid was significantly lower during winter in comparison to summer.Discussion: Due to the lower temperature of water during winter, tilapias reduced food intake and became more susceptible to diseases, which led to an increase in circulating globulins. In that same season, there was an increase in serum concentrations of sodium and chloride as a result of adding sodium chloride to the water in order to stimulate mucus secretion on the fishes’ skin and gills to prevent pathologies. Triglycerides, HDL, and uric acid are considered indicators of nutritional status of animals. The increase in serum concentrations of triglycerides and HDL indicates that tilapias are mobilizing energy reserves, however, when the increase in serum concentrations of uric acid is observed, it is fair to assume there has been an increase in food intake, raising protein catabolism. The increase of serum concentration in alkaline phosphatase is caused by the presence of multiple forms of enzymes that are induced by the action of endogenous corticosteroids, which are produced as a result of the stress suffered by tilapias during the fishing process and during winter, when the water temperature is lower than the ideal for this species. It can be concluded that the season has influence on some serum biochemical constituents of Nile tilapias bred in net cages, and that the predominant variations happen during winter due to immunity decline and during summer due to the increase in food intake and, consequently, in the metabolism of tilapias.
Platinosomosis affects felines and it is caused by a trematode of the genus Platynosomum sp. The parasitized animals can be symptomatic or asymptomatic and the disease can evolve severely, killing the animal. Due to the similarity between clinical signs and changes of platinosomosis and those of other pathologies caused by the parasite and having in mind that the parasite occasionally appears on the stool, the search for trematodes and eggs in material coming from bile aspirate is a more efficient way to diagnose the parasitic disease, what helps to distinguish it from other liver diseases. Thus, the clinical veterinarian is able to perform the treatment correctly. The aim was to report a case of cystic liver disease related to platinosomosis in a domestic feline which has been undergoing treatment of liver disease for over a year. During the clinical evaluation, the animal was apathetic and with hepatomegaly. A complete blood count (CBC) revealed a discreet lymphopenia. The enzymes alkaline phosphatase and alanine transaminase were above the normal range for the species. The parasitological examination of the biliary material indicated eggs from the trematode Platynosomum sp. whereas the histopathology examination of liver masses indicated cystic structures covered by connective tissue and multifocal mononuclear inflammatory infiltrate. In conclusion, liver cysts in felines with chronic liver disease can be associated with cases of diseases caused by the trematode helminths.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.