Jason Perez

Simple Summary: The present study evaluates the effects of two dietary supplements (guanidinoacetic acid [GAA] and zilpaterol hydrochloride [ZLH]) on the productive performance of fattening lambs over a 60-day period. The inclusion of these additives did not result in significant differences in the parameters studied. However, serum glucose and creatinine levels in the GAA group were higher than those in the control group. These findings suggest that further research is needed to determine the optimal dosage and duration of GAA supplementation to enhance lamb growth and meat production. Abstract: This study evaluated the effects of dietary supplementation with guanidinoacetic acid (GAA) and zilpaterol hydrochloride (ZLH) on productive performance, carcass traits, and blood chemistry in non-castrated male lambs over 60 days. Twenty-four Pelibuey × Dorper crossbred lambs (16.3 ± 2.7 kg) were adapted to housing and diet for 14 days before being randomly assigned to one of three treatments: (1) Control: total mixed ration (TMR) without additives; (2) GAA: TMR with 0.2% GAA; and (3) ZLH: TMR with 6 mg/kg dry matter (DM) of ZLH for the last 30 days. No significant differences were observed in productive performance or carcass traits among treatments. However, lambs fed GAA showed higher serum glucose and creatinine levels than the control group (p < 0.05), suggesting a potential effect on energy metabolism. ZLH supplementation had no measurable impact on the parameters evaluated. These findings indicate that while GAA may influence certain metabolic indicators, further research with extended feeding periods or varying dosages is needed to clarify its effects on growth and carcass characteristics in lambs.

The objective of this research is to conduct a comparative analysis of the two models of growth and development that were applied in Peru over the past six decades (1961-2021). The objective is to conduct a comparative analysis of the Import Substitution Model (ISM) and the Liberal Model (LM), to determine which of these models has demonstrated superior performance in terms of economic growth and social welfare for the country. In this instance, the documentary and systematic review of the material obtained from both physical and virtual libraries was employed as a method. Consequently, a variety of economic indicators have been examined, including the primary indicator of economic growth, gross domestic product (GDP), to account for the effects of inflation and ensure the accuracy of the data. Furthermore, the principal social indicators have been examined and contrasted to gauge the nation's social well-being. The findings of the study demonstrate that the ML has demonstrably outstripped the MSI in terms of economic growth and the enhancement of social welfare for Peruvian society over the past three decades. However, it would be erroneous to assume that this model has entirely resolved the country's economic and social challenges.