Nutrient digestibility, blood metabolites, and production performance of peripartal ewes fed dietary plant extract and monensin

Abstract

The influences of a blend of plant extracts (PE; broadleaf plantain and peppermint) and monensin (MON) on metabolite status, digestibility and performance of ewes during periparturient period were investigated. Thirty-two estrus-synchronized multiparous Afshari ewes (90 ± 3.1 kg body weight (BW); 3.0 ± 0.15 body condition score (BCS); mean ± standard deviation) were used in a completely randomized design with a 2 × 2 factorial arrangement and assigned to one of four dietary treatments with supplementation of 1) no additive (control, CON-PE), 2) 2 g/d of a commercial blend of PE (CON + PE), 3) 30 mg/d of MON (MON-PE) or 4) combination of 2 g/d of PE along with 30 mg/d of monensin (MON + PE). Ewes were individually fed to diets containing hay at 650 g/kg from −21 d relative to lambing and 600 g/kg until 21 d after lambing. Blood was collected weekly and at +1 day relative to lambing 3 h of morning feeding. The overall dry matter intake (DMI) was increased (P = 0.004) by PE and MON+PE inclusion. Although dietary additives did not influence BCS, BW and subcutaneous fat thickness (SFT) in pre- and postpartum, the MON+PE diet tended to increase BCS (P = 0.092), BW (P = 0.076) and SFT (P = 0.077) on d 21 postpartum. Plasma concentration of cholesterol and albumin was not significantly affected by dietary additives, whereas plasma glucose concentration was increased by feeding MON alone or MON+PE (P = 0.002). Apparent digestibility of dry matter and organic matter was similar among the treatments. Production of colostrum (P = 0.002) and milk (P = 0.01) increased when diets were supplemented with MON+PE. The MON-PE diet decreased milk fat content. Addition of PE alone increased milk fat (P = 0.001) and protein (P < 0.001) percentages. In conclusion, feeding PE and (or) MON+PE increased DMI and colostrum, milk and protein yield. Therefore, supplementation of MON+PE may be beneficial for improving production performance in transition ewes.