*2.1. Location*

The experiment was conducted at the Teaching and Research Unit of Small Ruminants located at the Experimental Farm of the Universidad Autónoma Chapingo, Mexico, which is located at 19◦22 north latitude and 98◦35 west longitude, with an altitude of 2250 m. The climate is temperate subhumid, with rain during the summer and dry during the winter, with average annual precipitation and temperatures of 665 mm and 15.2 ◦C, respectively [23]. The study was conducted during the summer, under hot and rainy conditions. The care and handling procedures for the lambs were carried out following the guidelines of the Official Mexican Standard (NOM-062-ZOO-1995).

## *2.2. Polyherbal Mixture Characteristics*

The HM used was Peptasan® (Nuproxa S. de RL. de CV. Querétaro, México), which is a commercial polyherbal formula labelled to contain 150 g kg−<sup>1</sup> of saponins. In addition, Peptasan® is composed of parts from the *Saccharum officinarum*, *Balanites roxburghi* and *Acacia concinna* plants. *S. officinarum* contains polysaccharides with immunostimulating effects [24]; *B. roxburghii* contains saponins and flavonoids with antioxidant, antiinflammatory, antimicrobial and antiviral properties [25]; and *A. concinna* contains saponins with immunomodulatory properties [26].
