This experiment was designed to evaluate the effects of Agave tequilana inulin and Lactobacillus casei (L. casei) on growth performace, hematological variables, serum metabolites, and total coliforms in nursing lambs. The experimental design was completely randomized; treatments were T1, control (pre-starter concentrate, PC), T2: T1+2% inulin, and T3: T1+2% inulin+L. casei; treatments were compared with Tukey test (p≤0.05); and 45 new born Kathadin×Dorset lambs (4.8±0.8 kg birth weight) were the experimental units (15 per treatment). The variables were daily weight gain (DWG), dry matter intake and diarrheas incidence (%) during 56 d. Twenty-four hours after birth and at the end of the experiment, blood samples were collected to evaluate hematological variables and serum metabolites. Besides, the populations of total coliforms and lactobacilli were estimated in fecal samples. Addition of agave inulin and L. casei increased (p≤0.05) DWG 356, 384, and 415 g/d, weaning weight 24.92, 26.18, and 28.07 kg, as well as lactobacilli population 5.79, 6.32, and 6.48 Log10 cfu/g, for T1, T2, and T3, respectively. Lambs fed L. casei had decreased (p≤0.05) populations of total coliforms (T1 = 6.18, T2 = 5.77, and T3 = 5.07 Log10 cfu/g), diarrheas incidence (T1 = 11.67%, T2 = 8.33%, and T3 = 5.0%), and serum cholesterol concentration (11% in T2 and 13% in T3, compared to control). The combination of Agave tequilana inulin and L. casei increases weight gain and improves intestinal health by reducing coliforms and diarrheas incidence in Katahdin× Dorset lambs during the pre-weaning period.

Las diarreas en especies pecuarias son controladas con antibióticos, pero su uso inadecuado causa problemas de resistencia bacteriana. Las bacterias ácido lácticas (BAL) en la microbiota intestinal ejercen exclusión competitiva contra patógenos causantes de diarreas, y la inulina es un sustrato para las BAL. Por lo tanto, el objetivo de este estudio fue determinar el efecto prebiótico de dos fuentes de inulina en el crecimiento in vitro de Lactobacillus salivarius (Ls) y Enterococcus faecium (Ef), con el uso de Lactobacillus casei (Lc) como control positivo. Las incubaciones in vitro se realizaron a 37 °C, con sustitución de glucosa por inulina de achicoria (IAc) o de agave (IAg) en el medio MRS. Los tratamientos (T) evaluados fueron T1: MRS-glucosa+Lc; T2: MRS-IAc+Lc, T3: MRS-IAc+Ls, T4: MRS-IAc+Ef, T5: MRS-IAg+Lc, T6: MRS-IAg+Ls y T7: MRS-IAg+Ef. La curva y la tasa de crecimiento se determinaron mediante densidad óptica (630 nm) a las 0, 3, 6, 12, 24, 30, 36, 48, 54 y 60 h. El diseño experimental fue completamente al azar, los datos se analizaron con PROC GLM (SAS) y la comparación de medias se realizó mediante la prueba de Tukey. Los tratamientos con MRS-IAg mostraron mayores (P<0.05) tasas de crecimiento (0.51a, 0.50a y 0.50a h-1, T5, T6 y T7, respectivamente) y resultaron similares al control positivo (T2) cuando creció en MRS-IAc (0.48a h-1). El pH durante el crecimiento fue diferente entre tratamientos (P<0.05). La inulina de agave favorece el crecimiento de bacterias probióticas como Lactobacillus salivarius y Enterococcus faecium, y su efecto prebiótico supera a la inulina de achicoria.

The Cervidae family has a wide distribution due to its adaptation to numerous ecological environments, which allows it to develop a diverse microbial community in its digestive tract. Recently, research has focused on the taxonomic composition and functionality of the intestinal and faecal microbiota of different cervid species worldwide, as well as their microbial diversity and variation under different associated factors such as age, sex, diet, distribution, and seasonal variation. In addition, there is special interest in knowing how cervids act as reservoirs of zoonotic pathogenic microorganisms, which represent a threat to public health. This review provides a synthesis of the growing field of microbiota determination in cervids worldwide, focusing on intestinal and faecal samples using 16S next-generation sequencing. It also documents factors influencing microbial diversity and composition, the microorganisms reported as pathogenic/zoonotic, and the perspectives regarding the conservation of these species. Knowing the interactions between bacteria and cervid health can drive management and conservation strategies for these species and help develop an understanding of their evolutionary history and the interaction with emerging disease-causing microorganisms.