Farm Animal Welfare-From the Farmers' Perspective.

Improvements in the welfare of animals in the intensive production industries are increasingly being demanded by the public. Scientific methods of welfare improvement have been developed and are beginning to be used on farms, including those provided by precision livestock farming. The number of welfare challenges that animals are facing in the livestock production industries is growing rapidly, and farmers are a key component in attempts to improve welfare because their livelihood is at stake. The challenges include climate change, which not only exposes animals to heat stress but also potentially reduces forage and water availability for livestock production systems. Heat-stressed animals have reduced welfare, and it is important to farmers that they convert feed to products for human consumption less efficiently, their immune system is compromised, and both the quality of the products and the animals' reproduction are adversely affected. Livestock farmers are also facing escalating feed and fertiliser costs, both of which may jeopardise feed availability for the animals. The availability of skilled labour to work in livestock industries is increasingly limited, with rural migration to cities and the succession of older farmers uncertain. In future, high-energy and protein feeds are unlikely to be available in large quantities when required for the expanding human population. It is expected that livestock farming will increasingly be confined to marginal land offering low-quality pasture, which will favour ruminant livestock, at the expense of pigs and poultry unable to readily digest coarse fibre in plants. Farmers also face disease challenges to their animals' welfare, as the development of antibiotic resistance in microbes has heralded an era when we can no longer rely on antibiotics to control disease or improve the feed conversion efficiency of livestock. Farmers can use medicinal plants, pro-, pre- and synbiotics and good husbandry to help maintain a high standard of health in their animals. Loss of biodiversity in livestock breeds reduces the availability of less productive genotypes that survive better on nutrient-poor diets than animals selected for high productivity. Farmers have a range of options to help address these challenges, including changing to less intensive diets, diversification from livestock farming to other enterprises, such as cereal and pseudocereal crops, silvopastoral systems and using less highly selected breeds. These options may not always produce good animal welfare, but they will help to give farm animals a better life.

The effects of replacing wheat and soyabean meal with duckweed (Lemna minor) and including enzymes in the diet of laying hens on the yield and quality of eggs, biochemical parameters, and their antioxidant status.

Duckweed is a rapidly growing aquatic plant, which could be used in the diet of laying hens to enhance carbon capture and improve land use efficiency. Digestion may be improved by supplementation with exogenous enzymes. We replaced soyabean meal and wheat with duckweed in a 10-week study with 432, 60-week-old Hy-Line W-36 layers, divided into six isocaloric and isonitrogenous dietary treatments, each with eight replicates. Two factors were investigated: first, duckweed substituted for wheat gluten meal and soyabean meal at 0, 7.5 and 15% of the diet, and second, with and without a multi-enzyme supplement (500 mg/kg). Duckweed did not affect egg output or weight, but it improved yolk color (P = 0.01) and reduced the liver enzymes aspartate aminotransferase (P = 0.04) and alanine aminotransferase (P = 0.02) in serum, suggesting hepatoprotective effects. Enzyme addition did not alter the effects of including duckweed in the diet, but it increased feed intake (P = 0.03). It is concluded that, as well as offering the potential to increase land productivity, inclusion of duckweed in the diet of laying hens enhances egg yolk color and hepatoprotection, without detrimental effects on performance.

The effects of green tea in the diet of broilers challenged with coccidiosis on their performance, carcass characteristics, intestinal mucosal morphology, blood constituents and ceca microflora.

BACKGROUND: Coccidiosis is an endemic protozoal disease of chickens normally controlled by ionophores. However, coccidiostats are also antibiotics, and evidence of resistance in both coccidia and bacteria may develop and reduce antibacterial activity in humans. This has led to a search for natural coccidiostats, such as green tea. OBJECTIVES: To study the effects of supplementing broilers with various levels and types of green tea, in comparison to use of a conventional coccidiostat or a control, unsupplemented diet. METHODS: A total of 360 male, day-old Ross 308 broilers (days 1-42) were used to evaluate the gut morphology and performance when challenged with coccidiosis and fed varying dietary levels of green tea powder or extract. Treatments were Negative control (NC, unsupplemented control diet); positive control (PC, control diet + commercial coccidiostat); control diets with 0.2, 0.3 or 0.4 g/kg green tea extract (GTE 0.2, 0.3 and 0.4); and control diets with 1, 2 or 3 g/kg green tea powder (GTP 1, 2 and 3). RESULTS: Compared with NC, PC and all green tea treatments, but particularly GTE0.4, increased feed intake and growth rate, with the best feed conversion ratio at GTE0.4. As a proportion of carcase weight, higher inclusion rates increased intestine weight and decreased abdominal fat. The duodenum, jejunum and ileum of birds fed green tea, and particularly GTE0.4, had longer, wider villi, and shallower crypts. Epithelium thickness was reduced by green tea and PC, compared to NC. Clostridium perfringens and coliform populations decreased in proportion to green tea inclusion rate and decreased in PC. Lactobacilli increased with green tea and were more for NC than PC. Green tea at the highest concentrations reduced blood glucose and LDL and VLDL cholesterol. CONCLUSIONS: Green tea offers a possible replacement for conventional ionophores to control coccidiosis in broiler chickens. The best inclusion rate was 0.4 g/kg.

Nano-selenium Supplementation Increases Selenoprotein (Sel) Gene Expression Profiles and Milk Selenium Concentration in Lactating Dairy Cows.

Supplementation with selenium is common for dairy cows, but the importance of selenium source is not clear. This study aimed to compare nano-selenium (Nano-Se) and sodium selenite supplements for dairy cows on lactation performance, milk Se levels and selenoprotein (Sel) gene expression. Twelve multiparous Holstein cows were randomly divided into two groups: a control group fed a basal diet plus 0.30 mg Se/kg of DM as sodium selenite or Nano-Se for 30 days. Dry matter intake, milk yield and composition were not affected by dietary Se source (P > 0.05); however, the milk total Se levels and milk glutathione peroxidase (GSH-Px) activities were higher with Nano-Se supplementation than sodium selenite (P < 0.05). At the end of the experiment, Nano-Se supplementation significantly increased plasma Se levels and GSH-Px activity, compared with the sodium selenite supplement. The mRNA expression levels of glutathione peroxidase 1, 2 and 4; thioredoxin reductase 2 and 3; and selenoproteins W, T, K and F were markedly upregulated (P < 0.05) in the mammary gland of the Nano-Se group. Thus, the source of selenium plays an important role in the antioxidant status and in particular the Sel gene expression in the mammary glands of dairy cows, both being stimulated by nano sources.

Growth, Carcass Composition, Haematology and Immunity of Broilers Supplemented with Sumac Berries (Rhus coriaria L.) and Thyme (Thymus vulgaris).

Alternatives to antibiotics as growth promoters for broilers could reduce bacterial resistance to antibiotics, while at the same time maintaining growth and improving carcass composition. We investigated the benefits of adding the medicinal plants sumac and thyme at 1, 2 or 3% of the diet for male Ross broiler chicks, with four replicates of ten birds in each treatment group and a Control. Feed intake was reduced for chickens fed the sumac supplements, and, at the two higher doses, defeathered body weight was also reduced. Abdominal fat was reduced by 41% in chickens fed thyme and 62% in those fed sumac. This reflected reduced low density lipoproteins in their blood, and in higher dose thyme treatments and all sumac treatments, reduced high density lipoproteins in blood. Apart from this, there was little effect of the supplements on carcass composition. Blood glucose was reduced in the supplemented chickens. There was evidence of higher antibody titers to Newcastle disease and influenza in supplemented chickens. It is concluded that both thyme and sumac offer potential to reduce fat content and improve disease responsiveness in broiler production systems.

A comparison of the effects of antibiotics, probiotics, synbiotics and prebiotics on the performance and carcass characteristics of broilers.

Routine use of the antibiotic flavomycin in broiler production may lead to resistance, and alternative growth promoters are used to enhance performance. Two hundred day-old male Ross 308 broiler chicks were allocated to five dietary supplements included from d 1-42: flavomycin, three possible alternatives, a probiotic, prebiotic and a synbiotic, as well as a control treatment. There were four replicate cages of 10 birds each in each treatment. Compared with the control and antibiotics treatments, the probiotic, prebiotic and synbiotic treatments increased (p = 0.001) weight gain (64, 66, 73, 70 and 74 g/d, respectively). The synbiotic treatment reduced (p = 0.004) the feed conversion ratio, compared with the control and antibiotic treatments (1.70, 1.84, 1.83, respectively). Compared with the control and antibiotic treatments, the birds fed the synbiotic treatment had greater relative gizzard (+47%) and spleen weights (+115%), and lighter kidneys (-47%). The birds fed the symbiotic treatment also had thinner walls of the caudal gut segments. The prebiotic had the most beneficial effect on cecal microbiota, stimulating aerobic and lactic acid producing bacteria and reducing Escherichia coli bacteria. Enterococci were increased in the antibiotic treatment. We conclude that there were significant performance and health benefits of using prebiotics, probiotics and synbiotics for broilers, rather than antibiotics.

Responses to graded replacement of urea by maize steep liquor in diets for intensively fed lambs for meat production.

Urea is a common ingredient of the diets of intensively fed lambs, but is increasingly required for industrial processes. Maize steep liquor (MSL) is a by-product of maize grain degradation to produce starch that may be a suitable replacement. Fifty growing lambs were fed on equinitrogenous diets in which between 0% and 80% of the urea was replaced by MSL; their growth and metabolism were recorded over 70 days. Increasing replacement of urea by MSL increased feed intake and nutrient digestibilities, leading to increased growth rates, more efficient feed conversion, and increased nitrogen retention. Concentrations of triiodothyroxin, thyroxin, glucose, and methionine were increased by replacement of urea by liquor, and plasma urea was reduced. This study suggests that MSL is a suitable replacement for up to 80% of urea in the diet of rapidly growing lambs.