Effect of Laminaria digitata dietary inclusion and CAZyme supplementation on blood cells, serum metabolites and hepatic lipids and minerals of weaned piglets.

Seaweeds, such as Laminaria digitata, are a sustainable alternative to conventional feedstuffs for weaned piglet diets, improving their health and mitigating environmental impacts. L. digitata has a complex cell wall that can be difficult for monogastrics to digest. However, carbohydrate-active enzymes (CAZymes) such as Rovabio® Excel AP and alginate lyase can help break down these polysaccharides and render intracellular nutrients more accessible. This study aimed to evaluate the impact of 10% L. digitata feed inclusion and CAZyme supplementation on piglet blood cells, serum metabolites, liver lipid and mineral profiles. Forty weaned piglets were randomly assigned to one of four diets (n = 10 each): a control diet, 10% L. digitata (LA), 10% L. digitata + 0.005% Rovabio® Excel AP (LAR), and 10% L. digitata + 0.01% alginate lyase (LAL). After two weeks of trial, animals were slaughtered and liver and blood serum samples taken for analysis. The results showed that the LA and LAL diets increased blood lymphocytes, IgG and IgM, and decreased serum lipids, improving both cellular and humoral immune response and cardiovascular health. Dietary CAZymes reversed the anti-inflammatory and hematopoietic effects. Additionally, cortisol levels were reduced with seaweed inclusion compared to the control diet (P < 0.001). In the liver, total n-3 PUFA and n-6/n-3 ratio were increased and decreased, respectively, due to eicosapentaenoic acid and α-linolenic acid accumulation (P < 0.001). However, total liver mineral content was incorporated to a lesser extent with the combined seaweed and enzyme diets (P < 0.001), potentially indicating a negative effect on mineral bioavailability. Overall, results suggest that a 10% L. digitata inclusion can effectively improve piglet health by reducing stress during weaning, without the need for dietary CAZymes.

Use of Grape By-Products to Enhance Meat Quality and Nutritional Value in Monogastrics.

Grape by-products could be used in monogastric animals' nutrition to reduce feeding costs with conventional crops (e.g., maize and soybean meal) and to improve meat quality. The main grape by-products with the largest expression worldwide, particularly in the Mediterranean region, are grape pomace, grape seed, grape seed oil and grape skins. These by-products are rich sources of bioactive polyphenols, dietary fiber and polyunsaturated fatty acids (PUFA), more specifically, the beneficial n-3 PUFA, that could be transferred to pork and poultry meat. The potential biological activities, mainly associated with antimicrobial and antioxidant properties, make them putative candidates as feed supplements and/or ingredients capable of enhancing meat quality traits, such as color, lipid oxidation and shelf life. However, grape by-products face several limitations, namely, the high level of lignified cell wall and tannin content, both antinutritional compounds that limit nutrients absorption. Therefore, it is imperative to improve grape by-products' bioavailability, taking advantage of enzyme supplementation or pretreatment processes, to use them as feed alternatives contributing to boost a circular agricultural economy. The present review summarizes the current applications and challenges of using grape by-products from the agro-industrial sector in pig and poultry diets aiming at improving meat quality and nutritional value.

Grape By-Products as Feedstuff for Pig and Poultry Production.

Grape by-products are exceptional options for replacement of conventional and unsustainable feed sources, since large amounts are generated every year from the winery industry. However, the majority is wasted with severe environmental and economic consequences. The present review aimed to evaluate the effects of grape by-products on pig and poultry growth performance. The most recent literature was reviewed using ScienceDirect and PubMed databases and the results of a total of 16 and 38 papers for pigs and poultry, respectively, were assessed. Fewer studies are documented for pig, but the incorporation of grape by-products up to 9% feed led to an improvement in growth performance with an increase in average daily gain. Conversely, lower levels (<3% feed) are needed to achieve these results in poultry. The beneficial effects of grape by-products on animal performance are mainly due to their antioxidant, antimicrobial, and gut morphology modulator properties, but their high level of cell wall lignification and content of polyphenolic compounds (e.g., tannin) limits nutrient digestion and absorption by monogastric animals. The use of exogenous enzymes or mechanical/chemical processes can provide additional nutritional value to these products by improving nutrient bioavailability. Overall, the valorization of grape by-products is imperative to use them as feed alternatives and intestinal health promoters, thereby contributing to boost circular agricultural economy.