Nirgends sonst in Deutschland sind die Hühnerhaltungen so konzentriert wie in Sachsen. Einige Betriebe dominieren den Markt, für die kleineren bleiben nur kleine Anteile – neufeudale Zustände haben sich herausgebildet. Redaktionsschluss: Mai 2015

The landfill leachate is commonly treated for non-biodegradable organic matters, ammonia and colour. Experimental investigations using polyaluminium chlorite (PAC) and UV/O3 have been conducted for the determination of optimal pH value, reaction time and PAC concentration for the removal of chemical oxygen demand (COD) and colour. In pre-treatment coagulation stages, the highest COD and colour removal efficiencies were observed at the concentration of PAC ≥ 3,000 mglG1 and pH values between 7 and 8. However, these experiments also indicated significant removal efficiency for PAC starting with concentrations of 1,500 mglG1. The efficiency of COD and colour removal were approximately 30% and 70%, respectively. Similar efficiencies have been observed also during the second treatment stage where UV/O3 processes were used to treat coagulated leachate. After UV/O3 application, the pH of leachate reached the optimum value of 7.5 whereas the highest COD and colour removal efficiency was 55% and 72%, respectively, and the optimal reaction time was achieved after 80 min. / Nước rỉ rác sinh ra từ bãi chôn lấp chất thải rắn cần được xử lý các thành phần chất hữu cơ khó phân hủy sinh học, xử lí amoni và độ màu. Một số kết quả thử nghiệm về xử lý COD và màu của nước rỉ rác bằng việc sử dụng phương pháp keo tụ với PAC và quá trình UV/O3 đã được thực hiện cùng với việc xác định các giá trị pH tối ưu, thời gian phản ứng và nồng độ PAC tối ưu. Hiệu suất xử lý cao nhất đạt được khi nồng độ của PAC ≥ 3.000 mg/l, pH trong khoảng từ 7 đển 8 trong giai đoạn tiền xử lý. Tuy nhiên, hiệu quả loại bỏ COD và màu bắt đầu tăng rõ khi nồng độ PAC từ 1.500 mg/l trở lên. Hiệu quả loại bỏ COD và màu tương ứng là khoảng 30% và 70%. Các giá trị pH này phù hợp cho quá trình phản ứng UV/O3 được sử dụng sau giai đoạn keo tụ. Sau quá trình xử lý bằng hệ UV/O3, pH của nước rỉ rác tối ưu được xác định là 7,5 (hiệu suất xử lý COD và màu cao nhất tương ứng là 55% và 72%), thời gian phản ứng tối ưu là 80 phút.

Plumage damage (PD) as a result of severe feather pecking (SFP) and skin lesions (SL) due to cannibalism (CA) is serious welfare, performance, and economic problems in commercial layer farms. Genetics, nutrition, and housing conditions are central complexes that contribute to the multifactorial causes of these behavioral disorders. Practical recommendations consider the quality of litter as an important criterion for the prevention of SFP, although systematic longitudinal studies providing evidence-based findings are lacking. Therefore, the aim of this study was to investigate the effects of litter condition on the occurrence of PD and SL in the field using a longitudinal design. Integument scoring (PD and SL; 7 times), litter scoring (structure, cake formation, litter quality, and litter height; 12 times), and laboratory litter analysis (dry matter (DM), nitrogen (N), phosphorus (P) and pH value; 12 times) were performed in 28 laying hen flocks with a median flock size of 12,357 birds, in barn (n = 21) or free-range systems (n = 7), during the first laying period. Binary logistic regression (BLR) models showed the association of housing type and animal age on PD and SL (P < 0.001), and of the hybrid type on PD (P < 0.001). Furthermore, a significant association with PD and SL was observed for several litter traits. An increase in litter height, DM, and P was associated with lower PD (P ≤ 0.022) and SL (P < 0.001). In contrast, a higher N content of the litter was associated with an increase in SL (P = 0.007). Cake formation (P < 0.001) and a low structure (P = 0.025) of the litter showed an association with higher PD. In conclusion, this study identified caked litter with less structure, low height, and low contents of DM and P as risk factors for behavioral disorders in commercial laying flocks.

The aim of this work was to study the interaction of melatonin and prolactin in the control of seasonal breeding and coat development in goats. British Saanen goats (n=5) were maintained for 8 weeks in long days (20L: 40) followed by 8 weeks exogenous melatonin. Group treatment was staggered over the year in an attempt to dissociate breeding season advance from advanced coat growth. To assess the effect of prolactin suppression, the 20L:4D treatment from January was repeated in consecutive years but followed in March by melatonin (Year 1) or bromocriptine (Year 2). To study further the interaction of melatonin and prolactin on coat development and reproductive advance, goats (n=5) were maintained as follows: 1) natural photoperiod and temperature, Jul-Juni 2) 16L: 8D, natural temperature, Jul-Deci 3) 16L:8D, 17°C, Jul-Decj 4) 8L:16D, 8°C, Dec-Jun. To study melatonin suppression of prolactin, the secretagogues arginine vasopressin, serotonin and thyrotropin releasing hormone were given to goats (n=6) maintained in sequence under 8L:16D, 20L:4D and simulated short days (20L:4D+melatonin). Depending on long-day Imelatonin treatment onset, the breeding season was advanced from November to May, August or September. With 20L:4D followed by melatonin or bromocriptine the spring prolactin rise was delayed. A corresponding delay in winter coat moulting was observed only under melatonin. However, a winter secondary to primary (SIP) follicle ratio was retained with both treatments. Prolactin may determine coat structure, whilst melatonin influences the duration of fibre retention. Under conditions of summer or winter solstice hold, the seasonal prolactin variation was inhibited and initial SIP follicle ratios were retained. A tendency for a spontaneous change in prolactin secretion suggested existence of an endogenous rhythm. Maintained seasonal temperature did not influence melatonin secretion. Dusk and dawn prolactin peaks corresponded with the rise and fall in nocturnal melatonin. Basal prolactin concentrations and peak responses to the secretagogues altered with photoperiod, being low under 8L:16D and increased under 20L:4D. Exogenous melatonin under 20L:4D did not suppress prolactin to short-day concentrations. Invol vement of another factor mediating photoperiodic changes in prolactin secretion is suggested.

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Every year many thousands of newborn lambs die of cold exposure. This thesis is concerned with some of the physiological and genetic factors involved in the resistance of neonatal lambs of ten different breeds to hypothermia with particular reference to their heat production capabilities. The project was a development-of preliminary work carried out at the Animal Breeding Research Organisation, Edinburgh during the year immediately preceding this study. An attempt was made to reproduce in the laboratory, a standard cold stress comparable to that experienced by the newborn lamb born into cold, wet and windy conditions. A suitable test was evolved using water as the cooling medium to reduce body temperature and measuring heat production (in the form of oxygen consumption) using an indirect open-circuit calorimeter. 265 lambs of ten different breeds were tested. Significant breed differences were found for resistance to body cooling and base metabolic rate. Peak metabolic rate was significantly affected by weight. The results of the experimentation (1976-1979) give an insight and k4o into the variation existing, both within and between breeds, jit the traits likely to be useful in the selection of individuals and breeds most suited to survive severe environmental conditions during the neonatal period. An attempt was made to separate the effects of factors such as weight, skin thickness, age, sex and litter size. In particular, observations during cooling tests indicate the possible importance of tissue insulation, recorded in the form of skin thickness, in aiding the neonate to maintain body temperature in a cooling environment where fleece insulation is low. It was thought that the insulative properties of the birthcoat were unlikely to be expressed under waterbath conditions and no significant effects of birthcoat were found despite there being significant breed variation in this trait. To demonstrate birthcoat effects a wind tunnel procedure was used with artificial wind and rain providing a cold stress. Use of this equipment allowed separation of the effects of birthcoat extremes within the Welsh Mountain breed. The effect of fasting lambs from birth (4hrs) and pre-partum cold exposure of the dam were investigated for effects on the newborn's metabolic response to cold and cold resistance capabilities in the Scottish Blackface breed. The fasted lambs showed enhanced cold resistance possibly as a result of fat metabolism being initiated prior to the applied cold stress. Cold exposure of pre-partum ewes increased gestation length and the birth weight of their lambs. Base metabolic rate was lower for fasted lambs and peak metabolic rate enhanced in lambs from cold stressed ewes. The contribution of non-shivering thermogenesis was investigated and emphasis placed on fat metabolism in early post natal life when brown adipose tissue may be particularly relevant in cold thermogenesis. Metabolic responses to injected noradrenaline were investigated and a comparison made between maximum metabolic response to cold and catecholamine stimulation in the Cheviot breed. Some methods of rewarming were also studied with passive techniques showing possible field application. The possibilities for selection of more cold resistant types of sheep are discussed.

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