Effect of diets with different levels of guanidinoacetic acid on newly weaned piglets

Abstract

Ninety barrow piglets weaned at 21 days old were used to evaluate the effects of guanidinoacetic acid (GAA) supplementation on their performance and blood creatinine and creatine kinase (CK) levels during the nursery phase (21 to 63 days old). The piglets were distributed in a randomized block design with five treatments (0, 0.05, 0.10, 0.15, and 0.20% GAA inclusion), six repetitions, and three animals per repetition. The experimental rations were formulated to meet the nutritional requirements for the phases of 21 to 32, 33 to 42 and 43 to 63 days of age. The experimental diets and water were offered ad libitum throughout the experimental period. At 42 and 63 days old, blood was collected from one animal in each experimental unit for creatinine and creatine kinase analysis. The analysed variables were daily weight gain (DFG), daily feed intake (DFI), and feed conversion (FC) in the 21 to 42 days old and 21 to 63 days old of the nursery phase. All variables were subjected to analysis of variance and regression analysis. We adopted ? = 0.05, and considered a trend to be present when ? was between 0.05 and 0.10. In the pre-initial period (21 to 42 days old), there was an increasing trend in daily weight (P = 0.069), which increased to the level of 0.97% of GAA inclusion. The DFI and FC were not significantly affected by the addition of different GAA levels in the diet. Creatinine levels in the blood at 42 and 63 days old were not significantly influenced by the treatments. The level of CK at 42 days old showed an increasing trend (P = 0.077) that occurred quadratically to the level of 0.085% of GAA inclusion, with no significant difference for this variable at 63 days old. The use of GAA did not promote improvements in performance or blood creatinine and CK levels in piglets in the nursery phase.