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In relation to hill sheep, the perception is that they live to a high welfare standard with minimal labour input per ewe, and that there is little reason for concern.  This perception has however not been confirmed by science to date, chiefly due to a lack of research interest into the hill sheep sector.  Meanwhile, extensive sheep farming faces increasing economic pressures, with low returns and falling government subsidy that may compromise animal welfare.  Labour has been shown to be a key input factor for both productivity and welfare in extensive production systems. Despite this, little research has been done to try and optimise the labour input for productivity and welfare. This study is a first attempt to link labour input, productivity and welfare in extensive sheep systems through empirical observation and computer modelling.  The fieldwork was undertaken from 2007 to 2009 on three research farms and three commercial farms.  Labour use was analysed within a number of defined tasks.  Linear programming (LP) modelling was then used to explore eight different scenarios with regard to sheep welfare, labour and productivity, and the potential impacts of specific management changes. Data analysis and model results showed hill sheep live to a high welfare standard according to the low incidence of welfare problems with low risks to productivity, confirming public expectations.  Farmers, are however, aware their attention to an individual sheep’s welfare brings poor returns in terms of flock productivity.  With this in mind, there is some scope for welfare-beneficial or –neutral reductions in labour, particularly if within-farm movement, e.g. between grazing areas, can be reduced.  However, larger reductions of labour, even within legal guidelines, could seriously endanger the welfare of individual sheep, though without great risks to productivity at flock or farm level.  Thus considerable savings in labour might, in some circumstances, reduce costs and hence improve profitability.

The aim of this study was to evaluate the growth supporting value of DE derived from gut fermentation in growing pigs. Unmolassed sugar beet pulp (SBP) was selected as a model material for fermentation. For a reference material which would be digested in the small intestine by the endogenous enzymes, maize starch (MS) was selected. A cereal-based control diet was formulated to fulfil the needs of pigs for all essential nutrients apart from energy. To this control diet, either SBP (150 & 300 g/kg) or MS (100 & 200 g/kg) were added. The study consisted of two phases. The first phase (digestion trial and growth trial) was devoted to studying the digestion of these diets and to comparing the effects on growth of pigs of the two DE sources (SBP and MS). The second phase was to determine the production of VFA resulting from the fermentation of SBP. Methods used included stoichiometric calculations based on measurements of the molar proportions of VFA combined with CH4 production, and a direct assessment of the true fermented materials using antibiotics to suppress fermentation. The results of the first phase showed that the energy in SBP and MS had an apparent digestibility of 0.74 and 0.98. The DE from SBP was used for supporting carcass gain with an efficiency of 0.57 of the DE from MS. The results of the second phase indicated that measurements of methane production alone or even with inclusion of free hydrogen could underestimate the extent of fermentation in the gut of pigs. The results also suggest that with the cereal-based control diet, fermentation could supply up to 13.6% of the dietary DE in the form of VFA or 18.0% in the form of fermented energy. For this control diet incorporating 30% SBP, the respective values were 25.4% and 33.4%. The absorbed VFA resulting from the fermentation of SBP had a growth supporting value of 0.763 of that of absorbed glucose from MS.

Three experiments carried out in the southeast of Mexico (Yucatan) are reported. In the first, yield of P. purpureum increased from 3,760 to 14,526 kgDM/ha with age 6 weeks (young) and 28 weeks (mature). Maturity increased lignin from 43 to 108g/kgDM. Potential degradabilities of leaf and stem were 788g & 782g/kgDM with young, and 725 & 403g/kgDM with mature. Young yielded more potentially degradable DM (70 & 35kgDM/ha/d) than mature. In the second, molasses urea block (MUB) supplementation of bulls grazing during the dry season, did not improve the potential degradability of pasture (525g/kgDM). Estimated pasture intake was 68gDM/kgW0.75 /d, and measured rumen pool size of grazing bulls was 79 gDM/kgW 0.75. Intake of MUB was low (236gDM/d) and only increased rumen NH 3-N from 100 to 128mg/l. Availability of pasture was 255kg DM/animal. It is suggested that need of supplementation could be low if there is sufficient pasture to allow selective grazing. In the third, hay diets of young or mature P. purpureum were studied in six zebu (Bos indicus) bulls fed ad libitum. Intakes were, 91 and 44gDM/kgW0.75/d, digestibilities, 591 and 453g/kgDM, estimated energy intakes 768 and 307kJME/kgW0.75/d and Metabolizable Protein, 4.1 and 1.3g/kgW0.75/d with young and mature forages respectively. Forage maturity resulted in negative N balance (352 vs -113mgN/kgW0.75/d), decreased potential (756 vs 568g/kgDM) and fractional rate (0.07 vs 0.03%) of rumen DM degradation, but gave higher DM degradabilities of the non-soluble fraction (378 vs 283g/kgDM). Forage maturity reduced rumen outflow rates of liquid (0.09 vs 0.05%), and solid (0.038 vs 0.015%) phases, increasing mean retention times of digesta (22 vs 65h), and the rumen pool size (84 vs 120gDM/kgW0.75) and reduced the eating (380 vs 273min) and rumination daily times (433 vs 398min). The Purine Derivatives (PD) excretion in urine reflected differences between diets (651 vs 354mMol/kgW0.75/d). However, rumen Microbial N Supply estimated by the PD method was very low in comparison with estimates from digestibility and N balance measurements. It is suggested this effect could be explained by greater recycling of PD to the rumen and a lower endogenous excretion by zebu cattle.

Experiments were conducted to investigate the comparative effects of the nitrogen sources, poultry waste, urea or casein/fish meal on the microbial fermentation of carbohydrates in vitro and on in vivo glucose metabolism in sheep. In vitro studies An artificial rumen designed by Czerkawski and Breckenridge (1969) was used in the present study. A series of short term incubations were carried out in which starch or cellulose was incubated with casein, urea, poultry waste or casein + urea. These food combinations were isonitrogenous and had identical dry matter contents. An additional treatment containing grass cubes, hay and poultry waste was also studied. Control incubations were carried out in parallel with all treatment incubations. Nutrients used in control incubations were grass cubes and hay. The duration of each incubation was 61/2h. Fermentation parameters studied were, rate of gas production, pH, and concentrations of volatile fatty acids and ammonia. The fermentation of poultry waste with either of the carbohydrate sources gave rise to a higher volume of gas production than either casein or urea. Urea resulted in a reduction in the volume of gas in the incubation vessels and caused a much larger increase in pH of the incubation medium than did poultry waste. Using mixtures based on starch, the total gas produced in the medium containing poultry waste after 60 and 390 min. of incubation was 44% and 100% greater respectively than that produced from the medium containing casein. Similarly when poultry waste was fermented with cellulose, the total gas production after 60 and 390 min. was 59% and 108% greater respectively than that produced from the fermentation of cellulose + casein. The differences in gas production between urea and poultry waste or urea and casein were not quantified since urea resulted in a reduction in the volume of gas produced. From the starch and cellulose based diets, VFA production in the presence of poultry waste was greater than that from either casein or urea. At the end of incubation, production of VFA from the fermentation of starch + poultry waste was 1.5 or 3.5 times greater than that from starch + casein or starch + urea respectively. Similarly, for a mixture containing cellulose, VFA production in the presence of poultry waste was 2.3 or 6 times higher than that derived from casein or urea respectively. With both starch and cellulose, poultry waste maintained much lower concentrations of ammonia and much lower levels of pH than did urea but considerably higher than those observed with casein. Incubation of grass cubes and hay with poultry waste resulted in greater production of gas and VFA than that obtained from the controls (grass cubes and hay). In vivo studies The primed-continuous infusion technique of Steele et al. (1956) was used to study the comparative effects of poultry waste, urea or fish meal on glucose metabolism with 3 sheep using a 3 x 3 Latin square design. The animals were frequently fed during the experimental period and were maintained on medium quality high roughage diets. Although there were no significant changes in blood glucose level in sheep receiving different nitrogen supplements, the urea and poultry waste containing diets showed a tendency to give lower values than did the fish meal diet. Similarly overall mean insulin concentrations tended to be higher for the fish meal diet than those for the poultry waste or urea diet. Plasma levels of free fatty acid showed small differences between diets which were not significant. Irreversible loss of glucose, glucose pool size, glucose space were estimated. In three out of nine infusions plateau specific activity of glucose was achieved. Consequently, these parameters were calculated for two animals only on each of the dietary treatments. When a plateau glucose specific activity was not attained, the animals exhibited irregular feeding behaviour after about 3h. of infusion and blood analysis showed that they had unusually high levels of cortisol. Plasma glucose concentrations of these animals throughout the infusion period, varied considerably. It appears that uneven feeding behaviour resulted in large fluctuations in the plasma glucose concentrations and specific activity. The results of the in vitro study indicated that poultry waste is more efficient in promoting the utilization of both starch and cellulose than either urea or casein. Poultry waste also caused an improvement in the overall digestion of natural roughage feeds. It was not possible to draw firm conclusion on the results of in vivo experiments because, of the variable data. No significant differences were observed in the concentrations of plasma glucose, insulin, urea or free fatty acids between dietary treatments of fish meal, urea or poultry waste.

Three experiments were carried out to investigate dietary and genetic factors influencing the n-3 polyunsaturated fatty acid content of sheepmeat. In the first experiment, four isoenergetic and iso-nitrogenous diets, based on dried grass with similar fat levels (60 g/kg OM) from different sources; Megalac (control), linseed (a-linolenic acid, CI8:3n-3), fish oil (eicosapentaenoic, C20:5n-3 and docosahexaenoic, C22:6n-3 acids) and linseed plus fish oil were fed to four rumen and duodenal cannulated sheep in a 4x4 Latin square design. Biohydrogenation of C 18:3n-3 was, 80-92 % in all diets, while that of C20:5n-3 and C22:6n-3 was 58-74 %. Dietary n-3 PUFA decreased microbial efficiency (p < 0.05) measured using the total purine technique as a microbial marker, whilst fish oil depressed fibre digestion in the rumen (p < 0.01). In experiment two, the same four diets were randomly allocated to 72 lambs from three breeds; Suffolk, Soayand Friesland blocked on live weight. Muscle fatty acid content was 2.4-2.8 % of tissue weight. Compared to the control diet, linseed doubled the quantity of CI8:3n-3 in muscle and increased levels of C20:5n-3 and C22:6n-3 by 0.5 (p < 0.001). Fish oil alone increased C20:5n-3 and C22:6n-3 by 3-4 times (p < 0.001), whilst the mixed diet resulted in n-3 PUFA levels intermediate between the linseed and fish oil diets. Soay lambs deposited more PUF A on the control diet than Suffolk or Friesland lambs (p < 0.05). In the third experiment three iso-energetic and iso-nitrogenous diets, with different fat sources, Megalac or formaldehyde treated linseed (protected) with or without fish oil, and with two levels of vitamin E 100 (low) and 500 (high) mg/kg OM were randomly allocated to 96 lambs from two breeds; Suffolk and Scottish Blackface blocked on live weight. Muscle fatty acid content was 2.3-3.1 % of tissue weight but was lower in control fed lambs (p3 mg/kg muscle) in all lambs fed any of the diets. Overall, dietary modifications were more effective than genetic factors in increasing the n-3 PUF A in sheepmeat.