Effect of Partial Replacement of Steam Rolled Corn With Soybean Hulls or Prickly Pear Cactus in the Horse's Diet in the Presence of Live Saccharomyces cerevisiae on In Vitro Fecal Gas Production

The Role of Yeast Saccharomyces cerevisiae in Supporting Gut Health in Horses: An Updated Review on Its Effects on Digestibility and Intestinal and Fecal Microbiota

To support the overall health of horses, it is essential to maintain an optimal gut health (GH) status, which encompasses several physiological and functional aspects, including the balance and functionality of intestinal microbial populations and, accordingly, the effective digestion and absorption of nutrients. Numerous biotic and abiotic stressors can lead to an imbalance of GH, such as the quality of forages and the composition of diet, e.g., the inclusion of high energy-dense feeds to meet the energy requirements of performance horses. To support the digestive function and the intestinal microbial populations, the diet can be supplemented with feed additives, such as probiotic yeasts, that promote the ability of cellulolytic bacteria in the hindgut to digest the available fiber fractions, finally increasing feed efficiency. Among the different yeasts available, S. cerevisiae is the most used in horses' nutrition; however, results of digestibility trials, as well as data on intestinal and fecal microbial populations, are sometimes contradictory. Therefore, the purpose of this review is to summarize the effects of S. cerevisiae on in vivo and in vitro digestibility, providing an updated overview of its effects on the intestinal and fecal microbial population.

Use of palm bran (Nopalea cochenillifera (L.) Salm-Dyck) in partial replacement of concentrate in maintenance equine diets - a pilot study

Forage palm is extremely suitable as animal fodder due to its high tolerance to the climatic rigors of the semiarid region and its ability to withstand the harsh physical–chemical limitations of poor soils. Thus, in this study, the effects of the partial replacement (0 %, 5 %, 10 % and 15 % replacement) of a molasses- or oat-based commercial concentrate with forage palm bran (FPB) on the acceptability, apparent digestibility and glycemic response of horses at maintenance were evaluated. The ratio of concentrate to roughage (Tifton 85 hay) was 30:70, and the dry matter (DM) intake was 2 % of body weight (BW). For the preference test, 10 barren Mangalarga Marchador mares were used. The experimental diets were offered simultaneously to determine the consumption preference and the intake ratio. For the digestibility test, four mixed-breed geldings were used and were distributed in a Latin square experimental design (4×4). For the glycemic response, blood samples were collected 30 min before and 30, 60, 90, 120, 180 and 240 min after supplying the feed. The preference test indicated that feed containing 0 % and 5 % FPB was preferred by the animals. Nutrient digestibility coefficients did not differ among the experimental diets. Blood glucose was lower at 180 min in the 7.42 % FPB inclusion diet (R2=0.97); this was estimated using the following equation: Y=115.05-2.75x+0.19x2. It is concluded that the incorporation of up to 15 % of forage palm bran as a substitute for concentrate in the maintenance diet tested did not negatively influence feed intake, nutrient digestibility or glycemic index; however, inclusion values above 5 % reduced diet acceptability.

Role of dose dependent Escherichia coli as ruminal anti-microflora agent to mitigate biogases production in prickly pear cactus flour based diet

The present investigation was conducted to evaluate the effects of Escherichia coli against the ruminal microflora fermentation activities in the mitigation of CH₄ and CO₂ production as well as ruminal fermentation kinetics by substituting dietary corn grain with prickly pear cactus (PC) flour. Three total mixed PC rations were prepared (/kg DM): 0 g (Control), 75 g (PC75), and 150 g (PC150). Besides, E. coli was supplemented at four different levels (dose): 0, 10, 20, and 40 mg/g DM of substrates. The in vitro rumen GP, CH₄, and CO₂ were estimated to be affected due to various doses of E. coli up to 72 h of incubation. Asymptotic GP, fractional rate of GP, and lag time were influenced significantly (P < .05) in the presence of ration. However, E. coli doses showed minor impact on the rate of GP as well as lag time. The asymptotic CH₄ production was decreased linearly (P = .005) at the ration PC150. E. coli doses reduced the asymptotic CH₄ production at 10 and 20 mg/g DM. The asymptotic CO₂ production was linearly (P < .001) decreased by different levels of PC. The cubic (P = .023) effect of E. coli doses as well as significant (P = .002) ration × E. coli doses impact were reported on asymptotic CO₂ production. The fractional rate of GP was quadratically (P < .05) influenced by PC and E. coli doses. The rations, dose, and rations × E. coli dose interaction had no influence (P > .05) on lag time. In a nutshell, PC flour inclusion in diet has the potentiality to replace the existing conventional feedstuffs for ruminant. Most importantly, revealing the first report, PC flours along with E. coli supplementation at varied doses mitigated the ruminal biogases production. This was as consequence to the antimicrobial impacts of E. coli against ruminal microflora, and that could certainly be a promising approach in order to improve ruminant's diet constituents.