Copping out of novel feeds: HOW climate change pledgers and food summits overlooked insect protein.

The intention with this critical review is to appraise recent work done on insect proteins as animal feeds, and to discuss the possible factors which led to the ruling out of insect proteins by food and feed commissioners, as well as climate change pledgers. Of late, edible insect larvae have gained popularity as a promising protein source. On the basis of proximate analysis, insect species such as Tenebrio molitor, Musca domestica, Acheta domestica, Zophobas morio and Hermetia illucens have been reported to contain substantial amounts of protein, essential amino acids and minerals. Given these chemical properties, insects may be fruitfully utilized as a partial or sole protein source for monogastric rations. Although insect larvae hold immense potential as promising sustainable protein ingredients which are both ecologically and environmentally friendly, these unconventional feedstuffs are frequently overlooked and/or excluded from policies and legislation on feedstuff of animal origin, at local and international summits which pledge to develop sustainable food systems. Concerns about food insecurity, our expanding carbon footprint and deteriorating ecosystems, dictate that food and climate change summits bring to the mitigation table the concept of transitioning animal diets. A change must be effected from standard to sustainable diets, starting with a declaration on environmental impact and climate change concerns related to soybean cultivation and marine loss due to overfishing. The available literature on the chemical properties and environmental impact of fishmeal and soyabean meal production was scrutinized by accessing electronic databases and comparing these to insects' nutritional composition and the impact which insect rearing has on the environment. As the literature search results revealed, information on the specific laws dealing with insect proteins as feed ingredients is scant, while the existing laws vary greatly. This has implications for innovation, as well as the trade in insect protein at a global level.

Meta-analysis of blood indices and production physiology of broiler chickens on dietary fermented cassava intervention.

The effects of dietary fermented cassava on the blood constituents and production parameters of broiler chickens have been reported with variable outcomes. Therefore, this investigation aimed to explore the impacts of dietary fermented cassava on growth traits, blood constituents, visceral organ, and carcass characteristics of broiler chickens. Four databases were searched for studies that assessed responses of broiler chickens dietary fermented cassava. Eleven articles were used for the investigation, and data generated were analysed using OpenMEE software. A random effects model was used, and effect sizes were presented as standardised mean difference (SMD) at a 95 % confidence interval (CI). Sources of heterogeneity were evaluated using the following modifiers: broiler strain used, cassava form, feeding duration, type of microbes used for the fermentation, and inclusion level of cassava. Results indicate that fermented cassava-based diets increased feed intake (SMD = 0.38; 95 % CI: 0.11, 0.65; P = 0.006), feed conversion ratio (SMD = 1.26; 95 % CI: 0.91, 1.61; P < 0.001), white blood cells (SMD = 1.26; 95 % CI: 0.54, 1.98; P < 0.001), total serum protein (SMD = 1.23; 95 % CI: 0.41, 2.05; P = 0.003), serum cholesterol (SMD = 0.43; 95 % CI: 0.01, 0.85; P = 0.050), serum creatinine (SMD = 2.53; 95 % CI: 0.53, 4.53; P = 0.013), and serum uric acid (SMD = 4.33; 95 % CI: 6.25, 2.41; P < 0.001), but lowered average daily gain and carcass yield, taking heterogeneity into account. Results reveal that studied modifiers were responsible for the inconsistent results among authors. In conclusion, dietary fermented cassava negatively influenced carcass yield, growth performance, and aspects of blood indices of broiler chickens, but did not affect abdominal fat content, visceral organ weights, and cut-part weights. However, more innovative research is needed to improve the feeding quality of cassava using other biotechnological tools in order to maximise its potential as an energy source in broiler chickens.

Sex Does Not Affect the Colour, Shear Stress, and Lipid Oxidation of Pork Meat, but Feed-Added Plant-Derived Extracts, Storage Time and Packaging Type Do.

Essential plant oils added to products, packaging or animal feed are used as a method of preserving food quality because they extend the shelf-life of meat due their antioxidant and/or antimicrobial capacity. This action can be achieved with the correct packaging that preserves the meat's quality and safety. This study investigates the effects of plant-derived extracts (PDE) on the meat quality and shelf-life of pork packaged in vacuum or modified atmosphere packaging (MAP). Thirty-six barrows and thirty-six gilts were allocated into three experimental groups: the control, garlic extract (1 kg/ton of feed) and oregano-rosemary oil (2 kg/ton of feed) with the same base-diet. Two packaging were used: vacuum and a commercial MAP (70% O2, 30% CO2). The meat fat content, pH, colour, TBARS values and Warner-Bratzler shear stress were investigated. The sex of the animals did not affect any of the studied variables, whereas PDE affected some of the colour variables and the shear stress; both the packaging type and the storage time affected the colour variables, lipid oxidation and shear stress. Vacuum-packed meat was more stable in terms of colour, lipid oxidation and shear stress than MAP-packed meat.

Effect of dietary inclusion of tea residue and tea leaves on ruminal fermentation characteristics and methane production.

The aim of this study was to compare the differences of dietary tea leaves (TL) and tea residue (TR) inclusion on rumen fermentation characteristics and to explore whether TR could be an alternative feedstuff of ruminants. For these purposes, seven treatments consisted of two inclusion types (TL vs. TR) and three inclusion levels (g/g of dry matter basis) of 10% (TL10/TR10), 20% (TL20/TR20), and 30% (TL30/TR30) in each inclusion type, plus control group with inclusion of 0% (CON) were designed, with four replicates in each group, to conduct an in vitro ruminal fermentation test. Results showed that the contents of crude protein, neutral detergent fiber, and acid detergent fiber were higher in TR than TL, while TL contained more ether extract and crude ash than TR. Interaction effects between inclusion type and inclusion level were observed in concentrations of isobutyrate and microbial crude protein (MCP), as well as in gas production and digestibility of organic matter. Fermentation characteristics were significantly influenced by TL and TR depending on the inclusion level, except for the concentration of total branched-chain volatile fatty acid. These significant differences of fermentation characteristics due to inclusion level mainly focused on CON and tea inclusion, with higher values in CON than TR or TL groups. The total gas production during the 48-h incubation showed no differences among CON, TL10, and TR10. The inclusion of TR and TL decreased the production of methane. The concentration of MCP in CON, TR10 and TR30 was lower than TR20 and all TL groups. In conclusion, dietary inclusion of TR and TL possessed equivalent effect on rumen fermentation characteristics and methane production, substituting diet with TR or TL for over 10% would inhibit rumen fermentation despite positive effects in TR20 and all TL groups regarding more MCP and less methane production. This study indicates that special attention should be paid to the inclusion level of TR and TL when considering them as alternative feedstuffs of ruminants. Further in vivo study is needed to evaluate the applicability of tea residue as a feedstuff for production of ruminants.

Genetic engineering of complex feed enzymes into barley seed for direct utilization in animal feedstuff.

Currently, feed enzymes are primarily obtained through fermentation of fungi, bacteria, and other microorganisms. Although the manufacturing technology for feed enzymes has evolved rapidly, the activities of these enzymes decline during the granulating process and the cost of application has increased over time. An alternative approach is the use of genetically modified plants containing complex feed enzymes for direct utilization in animal feedstuff. We co-expressed three commonly used feed enzymes (phytase, ß-glucanase, and xylanase) in barley seeds using the Agrobacterium-mediated transformation method and generated a new barley germplasm. The results showed that these enzymes were stable and had no effect on the development of the seeds. Supplementation of the basal diet of laying hens with only 8% of enzyme-containing seeds decreased the quantities of indigestible carbohydrates, improved the availability of phosphorus, and reduced the impact of animal production on the environment to an extent similar to directly adding exogenous enzymes to the feed. Feeding enzyme-containing seeds to layers significantly increased the strength of the eggshell and the weight of the eggs by 10.0%-11.3% and 5.6%-7.7% respectively. The intestinal microbiota obtained from layers fed with enzyme-containing seeds was altered compared to controls and was dominated by Alispes and Rikenella. Therefore, the transgenic barley seeds produced in this study can be used as an ideal feedstuff for use in animal feed.

Sun-dried Azolla leaf meal at 10% dietary inclusion improved growth, meat quality, and increased skeletal muscle Ribosomal protein S6 kinase ß1 abundance in growing rabbit.

Rapidly growing human populations and the increased need for high nutritive value meat in terms of low fat, high protein, and low sodium content are the driving reasons for the increase in rabbit meat production. However, dietary protein alternatives to sustain rabbit meat production, without competing with humans for strategic crops are needed. Therefore, the current study was conducted to investigate the effect of Azolla leaf meal (ALM) as a dietary protein source on growth performance, meat quality, and abundance and activation of Ribosomal protein S6 kinase ß1 (p70S6K1), a downstream target of mammalian target of rapamycin signalling pathway and, thus, a key player in the regulation of protein synthesis and muscle mass. For this purpose, 60 weaned male V-Line rabbits were blocked for the initial BW and randomly allotted into four dietary treatments, with 15 replicate per treatment (n = 15/group) as follows: (1) CON group was fed on basal diet contains 0% of ALM, (2) AZ10 group fed on diet containing 10% ALM, (3) AZ20 group fed on diet containing 20% ALM, and (4) AZ30 group fed on diet containing 30% ALM. Rabbits were raised individually, and the experimental period was 42 days. At the end of the experiment, rabbits were euthanised and blood and skeletal muscle samples were collected. Body weight and BW gain were the highest in AZ10 group (P = 0.01), while feed intake was the highest in AZ30 (P = 0.01), feed conversion ratio was the lowest in AZ10 and highest in AZ30 (P = 0.01). Dressing % was the highest in AZ10 and lowest in AZ30 groups (P = 0.01). Muscle cross-sectional area was low in both AZ20 and AZ30 groups compared to CON (P = 0.01). The lysine concentration of Longissimus lumborum muscle increased (P = 0.03) while isoleucine tended to decrease in AZ10 vs CON (P = 0.09). The phosphorylation ratio of skeletal muscle p70S6K1 increased in AZ10 and AZ20 groups (P = 0.05). Therefore, ALM could be included in a growing rabbit diet, up to 10%, while higher doses negatively alter production performance, meat quality, and feed efficiency of growing rabbits.

Multi-criteria assessment of the viability of valorising vegetable by-products from the distribution as secondary raw material for animal feed.

Approximately 33% of food produced around the world is wasted. In the distribution sector, erroneous orders or demand predictions result in products that cannot be sold before the expiration date. Despite its enormous potential, a low percentage of this food wastage is valorised causing negative social, economic and environmental impacts. Vegetable food waste has potential as raw material for animal feed. However, the profitability of its valorisation depends on several key factors and there is a risk of underestimating any of them making this valorisation technically, economically or environmentally unfeasible. Moreover, the geographical dispersion requires selecting the appropriate location for the processing plant and optimising the logistics routes to collect and transport them from the origin points to the processing plant. GISWASTE tool, which combines Analytic Hierarchy Process (AHP) method with ArcGIS, has been used to simulate the viability of this valorisation alternative from a holistic point of view. In addition, a sensitivity analysis in the economic modelling has been carried out to determine the economic viability factors with more influence in the global profitability. The valorisation of vegetable food waste from distribution and retailing sector for animal feed has been considered feasible in the case study region: Basque Country (Spain). However, there are some economic uncertainties for the return of the investment. The variable with more influence over the profitability is by far the incomes from waste management (81.4%).

Dietary carbohydrate and lipid source affect cholesterol metabolism of European sea bass (Dicentrarchus labrax) juveniles.

Plant feedstuffs (PF) are rich in carbohydrates, which may interact with lipid metabolism. Thus, when considering dietary replacement of fishery by-products with PF, knowledge is needed on how dietary lipid source (LS) and carbohydrates affect lipid metabolism and other metabolic pathways. For that purpose, a 73-d growth trial was performed with European sea bass juveniles (IBW 74 g) fed four diets differing in LS (fish oil (FO) or a blend of vegetable oils (VO)) and carbohydrate content (0 % (CH-) or 20 % (CH+) gelatinised starch). At the end of the trial no differences among diets were observed on growth and feed utilisation. Protein efficiency ratio was, however, higher in the CH+ groups. Muscle and liver fatty acid profiles reflected the dietary LS. Dietary carbohydrate promoted higher plasma cholesterol and phospholipids (PL), whole-body and hepatic (mainly 16 : 0) lipids and increased muscular and hepatic glycogen. Except for PL, which were higher in the FO groups, no major alterations between FO and VO groups were observed on plasma metabolites (glucose, TAG, cholesterol, PL), liver and muscle glycogen, and lipid and cholesterol contents. Activities of glucose-6-phosphate dehydrogenase and malic enzyme - lipogenesis-related enzymes - increased with carbohydrate intake. Hepatic expression of genes involved in cholesterol metabolism was up-regulated with carbohydrate (HMGCR and CYP3A27) and VO (HMGCR and CYP51A1) intake. No dietary regulation of long-chain PUFA biosynthesis at the transcriptional level was observed. Overall, very few interactions between dietary carbohydrates and LS were observed. However, important insights on the direct relation between dietary carbohydrate and the cholesterol biosynthetic pathway in European sea bass were demonstrated.