(1) Background: This study determined whether adding butyric acid and lauric acid glycerides in nursing pigs’ feed would improve growth performance, proteinogram, biochemical parameters, and antioxidant status. (2) Methods: Ninety male pigs were divided into five groups with six repetitions per group: NC, negative control (no additive); TRI-BUT, addition of tributyrin in the basal ration; MDT-BUT, addition of mono-, di-, and triglycerides of butyric acid in the basal feed; MDT-LAU, the addition of mono-, di-, and triglycerides of lauric acid in the basal feed; and PC, positive control (addition of gentamicin in the basal feed). (3) Results: PC, TRI-BUT, and MDT-LAU resulted in a high average daily WG from days 1 to 39 (p < 0.01). MDT-LAU, MDT-BUT, and PC resulted in a greater feed:gain from days 1 to 39 than the NC (p = 0.03). Great concentrations of the gamma globulin fraction in all groups were observed than in the NC (p = 0.01). Ceruloplasmin, haptoglobin, and C-reactive protein concentrations were lower in all groups than in the NC (p < 0.05). Higher serum glutathione S-transferase activity was observed in the TRI-BUT and MDT-BUT than in the PC (p = 0.04). (4) Conclusions: The addition of butyric acid and lauric acid glycerides in the diet of pigs in the nursery phase can replace growth promoters since the products improve the growth performance, reduce acute-phase proteins, and increase gamma globulin concentrations.

Wheat silage is an underexplored forage in ruminant nutrition that offers potential benefits due to its high crude protein content and capacity to mitigate methane emissions. However, little is known about its interaction with feed additives. This study evaluated the effects of monensin (25 ppm) and narasin (13 ppm) on the in vitro ruminal fermentation of wheat silage using a randomized complete block design with three treatments and seven replicates per incubation. Gas production was recorded over 48 h, and fermentation parameters, including pH, in vitro organic matter digestibility (IVOMD), metabolizable energy (ME), ammonia nitrogen (NH₃-N), and volatile fatty acid (VFA) profiles, were determined. Both ionophores maintained a higher ruminal pH compared to the control (p < 0.01) and reduced total gas production, ME, and IVOMD (p < 0.01), without significant differences between monensin and narasin. No effects were observed on total VFA production, acetate-to-propionate ratio, or ammonia concentration, although isobutyrate was reduced (p < 0.01). Fermentation kinetics revealed decreased gas production and digestion rates in the slowly degradable fraction, particularly with monensin. In conclusion, ionophores modulated fermentation but did not improve digestibility or energy availability, suggesting limited nutritional benefits when wheat silage is used as the sole forage source.