The aim of this research has been to assess the effect of the dietary protein level on piglet growth and post-weaning diarrhea (PWD) incidence. Piglet fecal microbiota and feces composition were also assessed. The experiment was carried out on 144 weaned piglets (Duroc × Large White; 72 piglets per treatment) and lasted from weaning (at 25 days of age) until the end of the post-weaning phase (at 95 days). Two dietary protein levels were compared: high (HP; 17.5% crude protein on average, during the experiment) and low (LP; 15.5% on average). Lower (p < 0.01) average daily gain and feed conversion ratio were observed in LP piglets in the first growth phase. However, at the end of the post-weaning period, the growth parameters were not significantly different in the two diets. Diarrhea scores were lower in piglets fed LP diets than in piglets fed HP diets (28.6% of the total vs. 71.4% in the HP piglets). Fibrobacteres, Proteobacteria, and Spirochaetes were more abundant in the feces of the piglets fed LP diets. Feces nitrogen content was lower in piglets fed LP diets. In conclusion, low protein levels in the diet can reduce the incidence of PWD while only marginally affecting growth parameters.

This study evaluated the effects of adding oregano aqueous extract (OAE) to the diet of pig slaughtered at finisher stage. Study was performed to identify glycoconjugates and evaluate the oxidative stress levels in the duodenum and colon intestinal tracts. Glycohistochemistry was performed by staining with Periodic acid–Schiff (PAS), Alcian blue (AB) pH 2.5, AB-PAS, AB pH 1, AB pH 0.5, low iron diamine, and high iron diamine. Serial sections were pre-treated with sialidase V before staining with AB pH 2.5 (Sial-AB) preceded or not by saponification. To study oxidative stress, an immunohistochemical analysis was applied to investigate the presence of the oxidative stress target molecule Bcl-2 Associate X protein (BAX). Findings show that oregano aqueous extract supplementation improves the production of the secretion glycoconjugates involved in direct and indirect defense, thus enhancing the protection of the pig intestinal mucosa. Moreover, the reduced BAX protein immunostaining observed in both duodenum and colon of swine of the oregano-supplemented group respect to that observed in the control group suggests an enhanced antioxidant action by oregano adding. Findings could be useful for other studies aiming to reduce antibiotic use and prevent antimicrobial resistance.

Among oregano properties, its antioxidant and antibacterial effects are particularly interesting. Oregano is also able to induce a higher glycoconjugate production in gut, creating a physical barrier against microorganisms. This study evaluated the effects of adding an aqueous extract of oregano (OAE) to the diet of two homogenous groups of pigs during the finisher phase. The diets were as follows: control commercial diet (CTR group) and CTR diet supplemented (2 g/kg) with OAE (O group). Samples of ileum and caecum from the two groups were examined by conventional histochemistry to analyze complex carbohydrates and by immunohistochemistry to detect Bcl-2 Associate X protein (BAX), an indicator of oxidative stress. Glyco-histochemistry showed significant differences between the two groups. Immunohistochemistry revealed a lower presence of BAX in O group. The OAE supplementation improved the production of glycoconjugates, able to enhance in pig the protection of intestinal mucosa by means of direct and indirect defense actions. The reduced BAX immunostaining observed in O group may be an indicator of enhanced antioxidant action promoted by oregano. The results of this study can be used in further research to identify ways to improve endogenous defence ability, with the aim of reducing antibiotic use and preventing antimicrobial resistance.

Consumer demand for high-quality products, combined with expectations for more sustainable production systems and animal welfare, is driving major changes in livestock farming practices. It is known that space allowance plays a central role in pig welfare, promoting resting and reducing the incidence of injuries and stress-related behaviors; however, there is little scientific evidence on the effect that available space has on the carcass and meat quality. In this study, space allowances were compared, in both an indoor conventional system (1.15, 1.9 and 3 m²/pig) and an indoor organic system with outdoor access (1.4 + 1, 2.6 + 2 and 3.9 + 3 m²/pig). The increase in space available for pigs had no effect on pig performance, carcass and meat quality characteristics, such as pH, drip and cooking loss. However, lowering stocking density in the conventional indoor housing system improved meat tenderness, as assessed by the Slice Shear Force test, while no difference was found between meat tenderness in organic pigs raised with three different stocking densities. Increased space allowance per pig reduced n-3 fatty acids in pig loins from both housing systems and n-6 fatty acids and PUFAs in loins from pigs reared in the organic housing system with both indoor and outdoor space.

Italian pigs for slaughter weigh between 150 and 170 kg, and their breeding is strictly regulated by the Protected Designation of Origin. Intensive production raises environmental concerns, in particular, nitrogen (N) emissions. To address these issues, low-crude-protein diet strategies have been proposed. However, few experiments have tested the effects of very low crude protein levels on performance and nitrogen efficiency, above all, in heavy pigs. The aim of our study was to explore new feeding solutions, compared to traditional ones, in accordance with PDO regulations, from 50 kg live weight to slaughtering: (1) traditional diet based on soy and maize; (2) iso-protein diet protein that is pea-based; and (3) low-crude-protein (−24.5% vs. C and T1 diets) diet that is cereal-based. Our results show that the use of different protein sources and the very low crude protein levels did not influence the technical efficiency and quality parameters; instead, a highly significant difference (p < 0.01) was recorded in the nitrogen efficiency of the cereal-based diet both in terms of nitrogen excretion and efficiency, achieving −28% and +21%, respectively. These results open up very interesting scenarios regarding the future feeding of heavy pigs and the cropping systems on which this is based.

The trial explored innovative low-protein diets for weaning piglets, testing the elimination of fish meal and blood derivatives. The trial compared three treatments, each with two post-weaning feeds: control feed with blood plasma and fishmeal; T1: low-protein feed with seven amino acids, fishmeal, and blood plasma; T2: low-protein feed with seven amino acids without fishmeal and blood plasma. The trial tested 180 weaned piglets, 24 days of age, evenly distributed by weight, age, and litter of origin. At the end of the first phase, T1 and T2 recorded a significantly higher average weight, ADG, and FCR compared with the control feed. At the end of the second phase, the T2 group maintained a significantly better weight, ADG, and FCR than the control group. Considering the entire test period (phase 1 and phase 2), the T2 thesis appears to have a significantly higher average weight, ADG, with a lower FCR compared to the control group. The T2 thesis fixed a significantly (p < 0.01) greater quantity of nitrogen compared to the T1 thesis and control feed (T2 58.71% vs. T1 54.13% and control 54.02%). In conclusion, a low-protein diet without raw materials of animal origin proved more efficient in terms of performance and nitrogen retention.