Effect of dietary variation on indicators of metabolic energy, protein, and liver function in dairy cows during the transition period

Abstract

A metabolic profile is a useful tool for nutritional diagnosis and assessing health status, especially during the critical transition period in dairy cows. The objective of this study was to characterize blood metabolic indicators during the transition period, evaluating a diet based on pastures, corn silage, and soy in comparison to a conventional pasture and concentrate-based diet. The study was conducted in the Bijagual area, district of David, Province of Chiriquí, Republic of Panama, using 30 dairy cows. Body weight, body condition score, and the temperature-humidity index were assessed throughout the transition period (one month before and one month after calving). Additionally, blood samples were collected in the field on days -28, -21, -14, -7, 0, 3, 7, 14, 21, and 28 relative to calving to analyze energy indicators (glucose, triglycerides, beta-hydroxybutyrate, non-esterified fatty acids), protein indicators (total protein, blood urea nitrogen), and liver function indicators (globulin, albumin, albumin/globulin ratio, and bilirubin). Data were statistically analyzed using a repeated measures mixed model via the SAS statistical package. The results showed that diet based on pastures, corn silage, and soy yielded better performance in energy, protein, and liver function indicators, with the exception of cholesterol, which was higher in the conventional pasture and concentrate-based treatment. It was concluded that the metabolic biomarkers related to energy, protein, and liver function remained within normal ranges for dairy cows, indicating adequate nutritional management and resilience of the cows during the transition period in both treatments.