The importance of the gestation period for welfare of lambs: Maternal stressors and lamb vigour and wellbeing

The prenatal period is of critical importance in defining how individuals respond to their environment throughout life. Stress experienced by pregnant females has been shown to have detrimental effects on offspring behaviour, health and productivity. The sheep has been used extensively as a model species to inform human studies. However, in the farmed environment, the consequences for the lamb of the imposition of prenatal stresses upon the ewe have received much less attention. The stressors that pregnant ewes are most frequently exposed to include sub-optimal nutrition and those related to housing, husbandry and environment which may be either acute or chronic. A systematic review of the literature was adopted to identify material which had production-relevant maternal stressors and lamb outcomes. The current review focussed upon the lamb up to weaning around the age of 100 days and the results clearly demonstrate that stressors imposed upon the ewe have implications for offspring welfare and performance. Maternal under-nutrition (UN) in the last third of pregnancy consistently impaired lamb birth-weight and subsequent vigour and performance, while earlier UN had a variable effect on performance. Feeding the ewe above requirements did not have positive effects on lamb performance and welfare. Social and husbandry stressors such as transport, shearing, mixing and physiological treatments designed to mimic acute stress which would be considered disadvantageous for the ewe had positive or neutral effects for the lamb, highlighting a potential conflict between the welfare of the ewe and her lamb. This review also identified considerable gaps in knowledge, particularly in respect of the impact of disease upon the ewe during pregnancy and interactions between different stressors and the responses of ewe and lamb.

Hydrolysis characteristics and kinetics of waste hay biomass as a potential energy crop for fermentable sugars production using autoclave parr reactor system

The use of the organic fraction of municipal solid waste crops has received considerable attention as a sustainable feedstock that can replace fossil fuels for the production of renewable energy. Therefore, municipal bin-waste in the form of hay was investigated as a potential energy crop for fermentable sugars production. Hydrolysis of hay by dilute phosphoric acid was carried out in autoclave parr reactor, where reactor temperature (135-200 degrees c) and acid concentration (2.5-10% (w/w)) were examined. Analysis of the decomposition rate of hemicellulosic biomass was undertaken using HPLC of the reaction products. Xylose production reached a maximum value of 13.5 g/100 g dry mass corresponding to a yield of 67% at the best identified conditions of 2.5 wt% H3PO4, 175 degrees C, 10 min reaction time, and at 5 wt% H3PO4, 150 degrees C, and 5 min reaction time. For glucose, an average yield of 25% was obtained at 5 wt% H3PO4, 175 degrees C and 30 min. Glucose degradation to HMF was achieved at 10 wt% H3PO4 and 200 degrees C. The maximum yield for produced arabinose was an average of 3 g/100 g dry. mass corresponding to 100% of the total possible arabinose. The kinetic study of the acid hydrolysis was also carried out using the Saeman and the Two-fraction models. It was found for both models that the kinetic constants (k) depend on the acid concentration and temperature. For xylose and arabinose it was found that the rate of formation was more favoured than the rate of degradation. By contrast, for glucose it was found that glucose degradation was occurring faster than glucose formation. It can be concluded that dilute phosphoric acid hydrolysis of hay crop is feasible for the production of fermentable sugars which are essential for bioethanol synthesis.