Impact of Peas (Pisum Sativum L.) as a Sustainable Source of Protein in Growing Pigs’ Diets on Production Efficiency, Nitrogen Metabolism and Gastrointestinal Tract Health

This pilot study evaluated the effects of dietary pea inclusion as a sustainable and nutritional alternative protein source on growth performance, nitrogen balance, digestibility, and intestinal health on nine castrated male Topigs hybrid pigs (three pigs/group), with an initial average weight of 20 ± 2.5 kg, for 45 experimental days. To conduct this digestibility pilot study, the pigs were kept individually in metabolic cages. Three experimental groups were compared: T0 (control), T10 (10% pea inclusion), and T20 (20% pea inclusion). Growth performance parameters, such as the feed conversion ratio (FCR), daily feed intake (DFI), and dry matter intake (DMI), were significantly higher in the T10 and T20 groups compared to T0 (p < 0.05). Nitrogen retention was significantly higher in the T10 group (p = 0.042) compared to the T0 group only. Biochemical markers, such as the total bilirubin (T-Bil) and uric acid (UA) levels, were significantly higher in T20 compared to T0 (p < 0.05). The short-chain fatty acids (SCFAs) increased significantly in the ceca and ilea of the T10 and T20 groups compared to T0, with higher levels of acetic acid (C2) and butyric acid (C4). A positive effect on Lactobacillus populations was observed in both the ileum and cecum in the T10 and T20 groups (p < 0.05). Intestinal morphology analysis revealed that the villus width, villus area, and crypt depth were significantly increased in the jejuna and ilea of both pea-fed groups. The N retention, SCFA concentration, and Lactobacillus population from the ileal and cecal segments showed a strong correlation. These findings suggest that the dietary inclusion of peas positively impacts growth performance, nitrogen retention, and intestinal health, with enhanced microbial populations and improved gut morphology.