The effect of Spirulina (Arthrospira platensis), individually or in combination with two commercial carbohydrases, in piglet diets was assessed on growth performance, nutrient digestibility and meat quality traits. Forty post‐weaned male piglets from Large White × Landrace sows crossed with Pietrain boars with an initial live weight of 12.0 ± 0.89 kg were used. Piglets were assigned to one of four dietary treatments (n = 10): cereal and soya bean meal base diet (control), base diet with 10% Spirulina (SP), SP diet supplemented with 0.005% Rovabio® Excel AP (SP + R) and SP diet supplemented with 0.01% lysozyme (SP + L). Animals were slaughtered after a 4‐week experimental period. Growth performance was negatively affected by the incorporation of Spirulina in the diets, with an average decrease of 9.1% on final weight, in comparison with control animals. Total tract apparent digestibility (TTAD) of crude protein was higher (p < .05) in the control group than in other groups. In addition, lysozyme increased TTAD of crude fat and acid detergent fibre, relative to the SP and control groups, respectively. In addition, the incorporation of Spirulina, individually and supplemented with enzymes, did not impair meat quality traits. Surprisingly, no protective effect against lipid oxidation was observed with the inclusion of Spirulina in pork after 7 days of storage. This study indicates that growth performance of post‐weaning piglets was impaired by the incorporation of 10% Spirulina in the diets, which is mediated by an increase in digesta viscosity and a lower protein digestibility, as a consequence of the resistance of microalga proteins to the action of endogenous peptidases. In addition, it also indicates that lysozyme, in contrast to Rovabio® Excel AP, is efficient in the degradation of Spirulina cell wall in piglet's intestine. However, the digestion of proteins liberated by Spirulina cell wall disruption is still a challenge.

No abstract

Seasonal weight loss (SWL) is a major constraint to extensive animal production systems. The Australian sheep production is based on merino sheep, a European breed not tolerant to SWL. Tolerant alternative breeds such as the fat-tailed Damara and the Dorper have been increasingly used in Australia and elsewhere, due to their robustness. The aim of this study was to understand the mineral profile of muscle and liver tissues of Australian Merino, Damara and Dorper, when subjected to SWL in order to understand SWL-tolerance physiology. Twenty-four lambs were divided randomly between growing (control) and nutritionally restricted groups for each breed.The trial lasted 42 days. Animals were weighed bi-weekly and at the end of the trial, lambs were slaughtered. Liver and muscle samples were taken immediately after slaughter. Mineral assessment was carried out using inductively coupled plasmaoptical emission spectrometry. Analysis of variance showed mineral concentrations were generally increased in the muscle of restricted animals, mainly because of fat tissue mobilization. An increase in Zn and Fe concentrations indicates an increase of enzymatic activity in the liver of restricted sheep as well as differential abundance of Fe-containing proteins. High concentrations of Cu in the liver of Dorper indicate higher ability to accumulate this element, even under SWL. K E Y W O R D Sliver, minerals, muscle, seasonal weight loss

Seaweeds have caught the attention of the scientific community in recent years. Their production can mitigate the negative impact of anthropogenic activity and their use in animal nutrition reduces the dependency on conventional crops such as maize and soybean meal. In the context of monogastric animals, novel approaches have made it possible to optimise their use in feed, namely polysaccharide extraction, biomass fermentation, enzymatic processing, and feed supplementation with carbohydrate-active enzymes (CAZymes). Their bioactive properties make them putative candidates as feed ingredients that enhance meat quality traits, such as lipid oxidation, shelf-life, and meat colour. Indeed, they are excellent sources of essential amino acids, polyunsaturated fatty acids, minerals, and pigments that can be transferred to the meat of monogastric animals. However, their nutritional composition is highly variable, depending on species, harvesting region, local pollution, and harvesting season, among other factors. In this review, we assess the current use and challenges of using seaweeds in pig and poultry diets, envisaging to improve meat quality and its nutritional value.

We hypothesized that dietary inclusion of 15% Laminaria digitata, supplemented or not with carbohydrases, could improve the nutritional value of poultry meat without impairing animal growth performance. A total of 120 22-day old broilers were fed the following dietary treatments (n = 10) for 14 days: cereal-based diet (control); control diet with 15% L. digitata (LA); LA diet with 0.005% Rovabio® Excel AP (LAR); LA diet with 0.01% alginate lyase (LAE). Final body weight was lower and feed conversion ratio higher with LA diet than with the control. The ileal viscosity increased with LA and LAR diets relative to control but without differences between LAE and control. The pH of thigh meat was higher, and the redness value of breast was lower with LA diet than with control. Meat overall acceptability was positively scored for all treatments. The γ-tocopherol decreased, whereas total chlorophylls and carotenoids increased in meat with alga diets relative to control. The percentage of n-3 polyunsaturated fatty acids (PUFA) and accumulation of bromine and iodine in meat increased with alga diets compared with control. Feeding 15% of L. digitata to broilers impaired growth performance but enhanced meat quality by increasing antioxidant pigments, with beneficial effects on n-3 PUFA and iodine.