Indeks termalnog komfora (THI) krava u letnjim mesecima od 2005 do 2016 godine na teritoriji AP Vojvodine

One of the most important factors of comfort and well-being of animals is a constant ambient temperature. A stressful environment temperature is estimated comparative measurement of air temperature and humidity (eng. Temperature-Humidity Index, THI). The aim of this study was to determine the mean peak value of THI index in Vojvodina in the period 2005-2016 years. The research results show that the mean value of THI index measured at 14 o'clock in the warmest part of the day exceeds the value of 72, which is considered the upper limit of the thermal comfort of the cows. The linear regression equation shows that from 2005 to 2016 there is a trend increase in mean maximum THI index in all three summer months in June, an increase of 0.17; in July to 0.29 in August, and by about 0.51 units per year. The number of days in which the THI indexed outside the thermal comfort of the cows more than 12 hours per day has increased from 2005 to the present. In 2007 and 2012 there were extremely negative conditions in which the THI index was above the optimum for more than 12 hours a day. During the summer thermal comfort of cows in Vojvodina was significantly compromised, with further growth.Jedan od najvažnijih činilaca komfora i dobrobiti životinja je stalna ambijentalna temperatura. Stresogenost temperature ambijenta se procenjuje uporednim merenjem temperature vazduha i vlažnosti vazduha (eng. Temperature-Humidity Index, THI). Cilj ovog rada je da se utvrde srednje maksimalne vrednosti THI indeksa na teritoriji AP Vojvodine u periodu 2005-2016 godina. Rezultati istraživanja pokazuju da srednja vrednost THI indeksa izmerena u 14 časova u najtoplijem delu dana prevazilazi vrednost 72, koja se smatra gornjom granicom termalnog komfora kod krava. Linearna regresiona jednačina pokazuje da od 2005 do 2016 godine postoji trend porasta srednjeg maksimalnog THI indeksa u sva tri letnja meseca: u junu porast za 0,17; u julu za 0,29 i u avgustu za oko 0,51 jedinica godišnje. Broj dana u kojima je THI indek izvan termalnog komfora krava duže od 12 časova dnevno je u porastu od 2005 godine do danas. U 2007. i 2012 godini postojali su ekstremno negativni uslovi u kojima je THI indeks bio iznad optimuma više od 12 sati dnevno. Tokom letnjih meseci termalni komfor krava na teritoriji AP Vojvodine je značajno ugrožen, sa daljom tendencijom porasta

Population-genetical characteristics of the bee population of Vojvodina

In 1893. Jovan Zivanovic notes that based on the color of the abdomen of bees, two varieties of bees are present in Vojvodina, one dark and the other with two yellow rings on abdomen. Up to the present time there are mixed opinions about the presence of one or more populations of bees in Vojvodina, especially about the presence of the yellow variety in Banat. The aim of this paper is to establish the existence of one or more populations of bees, using genetic analysis of bees. Evaluation of genetic connections, diversity within the population and structure of the bee population in Vojvodina, were calculated on the basis of allele variation of 25 microsatellite loci. A genetic typification of the following microsatellites was performed: A8, A14, A24, A29, A43, A79, A88, A113, Ac11, Ac88, Ac139, Ac306, Ap15, Ap68, Ap85, Ap90, Ap223, Ap224, Ap226, Ap249, Ap273, Ap274, Ap288, At168, At188. 92% or 23 loci proved to be polymorphic in samples of bees from Srem and Backa, and 88% or 22 loci proved to be polymorphic in samples of bees from Banat. Heterozygosity calculated for the whole population is not significantly different from the expected heterozygosity. It was found that the obtained genetic differences between bees of Srem and Backa, and Banat region are not sufficient for these two populations to be considered separate

Variations in milk production based on the temperature-humidity index and blood metabolic parameters in cows during exposure to heat stress

The temperature-humidity index (THI) is conventionally used to measure heat stress. The aim of this paper is to determine the influence of THI and THI+metabolic parameters in prediction of milk production. A total of thirty Holstein-Friesian cows were exposed to heat stress and the THI values, milk production and metabolite concentrations were measured on days 0 (in the thermoneutral period), 7 and 14 after the exposure. The average daily THI values obtained were 65 +/- 1.05 (day 0), 75 +/- 1.1 (day 7) and 77 +/- 1.4 (day 14). Heat-stressed cows were found to exhibit a decrease in milk production, contents of glucose and non-esterified fatty acids (NEFA) and the glucose-to-insulin ratio (G:I), whereas the levels of insulin, tumor necrosis factor-alpha (TNF-alpha) and the revised quantitative insulin sensitivity check index (RQUICKI) turned out to be elevated. THI can explain 37% of the milk production variance. The percent variance explained is significantly higher after the addition of metabolic parameters in the THI+glucose (58%) and THI+glucose+TNF-alpha (65%) models and non-significantly higher after the addition of other metabolic parameters. Partial correlation analysis showed that a correlation between milk production and THI is significantly dependent on glucose. TNF-alpha showed a tendency to regulate the above-mentioned correlation, while other metabolic parameters showed a non-significant effect on the correlation between THI and milk production. It was concluded that variation in milk production during heat stress could be better predicted when THI is used in combination with glucose and TNF-alpha as a metabolic predictor. The effect of glucose and TNF-alpha in milk production during heat stress would be investigated in the next stage of our research