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Heat stress of cattle from embryonic phase until culling
11-22Views:322Heat stress becomes a serious problem in the livestock sector as it affects cows' performance negatively. The objective of this paper review is to investigate the effects of heat stress during the different phases of the life cycle of cows; embryos, calves, heifers, and cows. Heat stress during early maternal gestation affects the ability of embryos to develop increasing the risk of abortion and early embryonic death. Heat stress during late maternal gestation affects the performance of calves and heifers later in their life, as it reduces growth performance, conducts physiological changes, impaired immunity, changes the behavior, and reduces the length and intensity of the estrus in heifers with decreasing in milk production in the first lactation. On the level of cows, milk quality and production, meat quality, and the final body weight decrease under hot temperatures. Heat stress decreases the conception rate, alters follicle growth, and estrous symptoms. Hormones secretion and physiological changes because of the heat stress conduct to impair the immunity system, and in oxidative stress and death in some cases. Same as for calves and heifers a change in the behavior of cows was detected in order to decrease their temperature.
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Impact of chronic heat stress on digestibility of nutrients and performance of meat type ducks
51-55Views:215The aim of the study is to determine the effect of vitamin and mineral supplement under permanently high environmental temperature (30±1 °C) on the digestibility of nutrients, performance and furthermore the composition of duck meat in the growing period. A total of four hundred mixed sex 14 days old Cherry Valley type hybrid ducks were used for the study. Two experimental diets were formulated in the study (control and vitamin E, C and zinc supplemented diet). Based on the results the following conclusions were drown: the antioxidant defence system plays an important role in the reduction of heat stress generated lipid peroxidation process. Feed additives which have direct or indirect antioxidant effects can reduce the negative effects of heat stress on the ducks performance and meat composition. Digestibility of nutrients (Dry Matter, Crude Protein, Crude Fat) was not affected by antioxidant supplementation under chronic heat stress (30±1 °C). The performance was affected significantly by Vitamin C and E and zinc supplementation under heat stress (P<0.05). In the treated group the daily weight gain (dWG) increased and the feed conversion ratio (FCR) was improved significantly (P<0.05). The energy and protein conversion was decreased also significantly (P<0.05).
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Study of animal welfare status and heat stress measures applied in dairy cow herds in Hungary
79-82Views:121The following material focuses on dairy production and climate related issues in Hungary. All the data was gathered during PhD
project: Study of animal welfare status in dairy cow herds in Hungary. Relations between animal welfare and climate changes expressed by
increase in temperature are described. Extremely hot weather creates hard conditions for milking cows when animal welfare is highly
compromised. From the preliminary results obtained one might formulate hypothesis that there are still areas on the farms where immediate
actions should be taken to give a relief to cows in hot seasons. There was found significant number of farms with too many animals per one
water trough, dirty water troughs, limited access to water troughs and hazardous surface for cows in critical places where many animals are
gathered. Calves with not sufficient amount of water in hot days and other parts of the year were reported. Silage exposure to the sun and
mouldy food in a silage clump was also found to be an important factor in monitoring impact of warm weather. Half of the farms letting
animals to spend time on the pasture or paddock did not provide shade for animals. Low conception rate of first insemination was predicted
to be influenced by heat stress, what is proved by lack of heat decreasing measures taken on the farms. -
How have thermal conditions changed in different phenological stages of apple (Malus domestica) in Northeastern Hungary?
137-142Views:71In temperate climates, most fruit trees need cold weather, low temperatures in winter, and a certain amount of heat during the growing season until harvest. One of the most apparent effects of climate change is the elevated temperature in all seasons of the year. In our study, the changes in thermal conditions have been calculated in Hungary's most significant growing region of apples using the Chill Unit for winters and the Growing Degree Days for summers. The meteorological data were obtained from the gridded dataset of the Hungarian Meteorological Service on a 10 km × 10 km grid, so the whole studied area is well-covered over the last 50 years. The results show that the trees are more exposed to early budding than a few decades ago. Furthermore, the accumulated heat amount in summers has increased drastically, which may increase the heat stress and lead to higher yield losses.
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Examination of the vegetative and generative accomplishment of new apple varieties
29-34Views:133Our research focuses on apple varieties, what are planted expansively in the development apple orchards of Western-Europe, but about the production characteristics of these varieties we don't have or just few practical experiences in Hungary. These varieties can be described with regular and high yields, aesthetic and alluring appearance in their origin places, what ensure profitable producing for the growers. In our climate what tends to be often extreme (hard cold winters, late spring frosts, summer drought, heat stress) these varieties may behave differently, so before the substantial planting it is expedient to carry out variety evaluations to avoid the later failures. The place of our experimental is located in the Nyírség, what presents adequately the ecological conditions of the surrounding areas, so the gained results can be easily adapted in the biggest apple production site of Hungary. Regarding the vegetative and the generative parameters of the 14 examined varieties ('Schniga', 'Jugala', 'Fendeca', 'Galaval', 'Fengal', 'Red Cap', 'Early Red One', 'Jeromine', 'Crimson Crisp', 'Red Topaz', 'Red Jonaprince', 'Red Idared', 'Fuji SW', club variety) we found significant differences, which is the result of the genetically coded characteristics of the varieties, the effects of the vintage, the different training methods and the correlations of these factors.
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Scientific background of precision animal nutrition
95-99Views:126Precision animal nutrition consists of meeting the nutrient requirements of animals as accurately as possible in the interest of a safe, high-quality and efficient production, besides ensuring the lowest possible load on the environment. This is facilitated by electronic feeding based on IT technology, an important but by far not the only tool of precision nutrition. In the present paper the following most important elements of precision nutrition are discussed: diet formulation, quality control of ingredients and compound feeds, reduction of the harmful effects of heat stress in pigs with different nutritional tools, application of the recent findings of the molecular genetics in animal nutrition, the relationship between genetics and animal nutrition and reduction of the N and P excretion by nutritional tools.
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The effect of season on the microbiological status of raw milk
95-99Views:181Many factors can influence the microbiological quality of raw cow’s milk. In this study, our aim was to determine whether there was any difference between the microbiological statuses of milk produced in different seasons. Samples were collected and analysed from five dairy farms in Hajdú-Bihar County, from February to November in 2019. During our studies, total plate count (TPC), coliform count and Staphylococcus aureus count of raw cow’s milk samples were determined.
There was no significant difference (P>0.05) between the mean TPC values detected in the milk collected in winter and autumn, but that values were significantly (P<0.05) lower than in the milk samples collected in spring and summer. Similarly to the TPC, in the case of coliform bacteria the lowest mean colony count was detected in the samples collected in winter. The difference was significant (P<0.05), compared to the values observed in the samples collected in summer. S. aureus was detected in bulk milk of only two farms in excess of 1.0 log10 cfu/ml. Also in case of S. aureus, there was a significant difference (P<0.05) between the values observed in the samples collected in winter and in summer. Samples from spring and summer contained the highest amount of S. aureus.
Based on the results of our studies, in the case of almost all farms the mean TPC, coliform and S. aureus counts were lower in the samples collected in winter, than in the samples collected in summer. The fact that the samples collected in winter contained the lowest amount of colonies could be attributed to the inhibition of growth of mesophilic microorganisms below 8 °C. Furthermore, the fact that we observed the highest colony counts in samples collected in summer, can be related to the heat stress of cows during the summer due to unfavorable weather conditions (high temperature and humidity).