EFECT OF PERIPARTAL PROPYLENE GLYCOL SUPPLEMENTATION ON SOME BIOCHEMICAL PARAMETERS IN DAIRY GOATS

摘要

The effect of peripartal supplementation with diet enriched with propylene glycol on some biochemical parameters was studied on 60 Maltese multiparous goats, from 10th day prepartum to 40th day postpartum. Goats were divided into two groups of 30, homogeneous for age (31 years), milk yield of the previous lactation (2±0.5kg/head/day) and body condition score (2.250.5) and raised in two multiple boxes. The groups, called "Glycol" and "Control", received concentrate (0.7kg/head/day) and vetch hay (1.5kg/head/day). The hay of the Glycol group was integrated with 100mL/kg of the propylene glycol (Liqui-Beef?, San Marco-Italy). Blood samples were collected from 10th to 1st day prepartum and from 1st to 40th day postpartum for the determination of Glucose, Non Esterified Fatty Acids (NEFA), ?-hydroxybutyrate (BHBA), Triglycerides, Total cholesterol, High Density Lipoprotein (HDL), Total protein, Urea and Creatinine, activities of Aspartate aminotransferase (AST), Alanine aminotransferase (ALT) and Creatine Kinase (CK). Data were analysed as a two-factor ANOVA with diet (Control and Glycol) and period (pre- and postpartum) as the main effects. As regards the energetic metabolism, "Glycol" group showed significant lower levels only during the prepartum period; specifically for BHBA (Glycol 0.28 mmol/l vs. Control 0.33 mmol/l; P=0.047), Triglycerides (Glycol 0.36 mmol/l vs. Control 0.50; P=0.043), Total cholesterol (Glycol 1.50 mmol/l vs. Control 1.66 mmol/l; P=0.07) and HDL (Glycol 0.79 mmol/l vs. Control 0.93 mmol/l; P=0.004). The parameters concerning hepatic functionality (AST and ALT) were significantly lower in the Glycol group during the prepartum (AST: Glycol 51.43 U/l vs. Control 62.00 U/l; P=0.006. ALT: Glycol 11.55 U/l vs. Control 14.21 U/l; P=0.005) as well as postpartum period (AST: Glycol 69.00 U/l vs. Control 74.28 U/l; P=0.008. ALT: Glycol 12.02 U/l vs. Control 15.05 U/l; P=0.005). The same trend was observed for the CK values (prepartum: Glycol 42.79 U/l vs. Control 62.63 U/l, P=0.004; postpartum: Glycol 77.70 U/l vs. Control 89.60 U/l, P=0.02). Peripartal use of propylene glycol enriched diet, improving the metabolic-nutritional status of the animals and consequently the productive performances (as previously observed), represents an interesting nutritional strategy for the economic benefits of dairy farms.