Abstract
Background: Studying how dietary imbalances affect blood serum metabolite (BSM) and faecal volatile fatty acids (VFA) profiles may help to understand whether pigs are fed adequate diets in commercial farms. The present study aimed to evaluate the effect of high and low net energy (NE) and crude protein (CP) diets on performance, BSM and VFA profiles on finishing pigs.Results: Twenty pens of 11 pigs (87.0 ± 4.10 kg; 18 weeks old) were assigned to 1 out of 5 dietary treatments (DT): control (C; 10.03 MJ/kg NE, 160.0 g/kg CP, and 9.5 g/kg SID Lys), low CP (LCP; 10.03 MJ/kg NE, 132.0 g/kg CP, 7.5 g/kg SID Lys), high CP (HCP; 10.03 MJ/kg NE, 188.0 g/kg CP, 11.5 g/kg SID Lys), low NE (LNE; 9.61 MJ/kg NE, 160.0 g/kg CP, 9.5 g/kg SID Lys) and high NE (HNE; 10.45 MJ/kg NE, 160.0 g/kg CP, 9.5 g/kg SID Lys). Pigs were followed for 10 days and blood and faecal samples were collected at the end of the trial. Performance was not affected by DT (P > 0.05). Albumin and glucose did not differ between DT (P > 0.05). HNE pigs had higher triglycerides (0.42 ± 0.03 mmol/L) and creatinine (133.8 ± 3.97 µmol/L) than LNE pigs (0.28 ± 0.03; 117.2 ± 3.97; P < 0.05); however, HNE pigs had lower total protein (60.9 ± 1.51 g/L) than C pigs (67.4 ± 1.51; P = 0.033). LCP pigs had higher cholesterol (2.4 ± 0.08 mmol/L) than LNE pigs (2.0 ± 0.08; P = 0.015); while HCP pigs had higher serum urea nitrogen (13.6 ± 0.95 mg/dL) than the other DT (7.5 ± 0.95; P < 0.001). Total VFA (mmol/kg) did not differ among DT (P > 0.05), but C and HNE pigs had higher branched-chain fatty acids (6.3 ± 0.38% of total VFA) than LNE pigs (4.4 ± 0.38; P < 0.05).Conclusions: Dietary imbalances in energy and protein affect BSM and VFA profile. BSM and VFA analysis may be good indicators to detect unbalanced diets in pig farms, especially serum urea nitrogen, to detect an excess of protein.
Blood Serum Metabolite and Volatile Fatty Acid Profiles of Finishing Pigs Fed Diets with High and Low Levels of Energy and Crude Protein
