Effect of different levels of Ipomoea batatas flour inclusion on the ruminal pH of sheep in metabolic cages

Abstract

The accumulation of industrial by-products increases the use of sweet potato waste for ruminants, but ruminal pH characteristics are still not well known. The objective was to assess the fluctuation of ruminal pH in sheep supplemented with different levels of sweet potato flour inclusion in their diet. Four rumen-fistulated sheep were used; they were fed a diet based on ryegrass haylage (Lolium multiflorum) and sweet potato flour (Ipomoea batatas), provided according to the level of inclusion in the total diet (0, 0.5, 1.0 and 1.5%). Approximately 80 ml of ruminal fluid was collected for reading on a bench pH meter. Statistical data analysis was run on Statistical Analysis System (SAS Institute INC. Cary, NC, USA), and statistical difference was considered for p < 0.05. The animals that received 1.5% of sweet potato flour in their diet presented acid rumen pH; the 1.0% group presented rumen pH acidification in the first 6 hours after feeding, and the 0.5% level of inclusion did not change the rumen environment. It is concluded that the inclusion of 0.5% sweet potato flour in sheep diet proved to be an efficient energy supplementation strategy.

Sweet potato (Ipomea batatas) feed affects intake, digestibility and nitrogen retention of ovine fed with ryegrass hay (Lolium multiflorum Lam)

“…The linear reduction of PB digestibility may have been caused by the reduction in pH since previous phases of this research showed pH reduction of 6.52, 6.38, 6.13 and 5.72 for supplementation with sweet potato at 0, 0.5, 1.0 1.5% the animal's body weight, respectively, characterizing a negative linear effect for ruminal pH (Malaguez et al, 2021). The pH is used to determine the concentration of H + in a solution, with physiologically accepted values for the rumen are between 6.0 and 7.0 (Malaguez et al, 2021).…”

“…Sweet potato starch is more fermentable due to the high amylopectin content. Amylopectin contains α-1.6 bonds which are highly ramified and, therefore, more susceptible to degradation by ruminal microorganisms (Malaguez et al, 2021). This increases the production of volatile fatty acids (VFA), mainly propionate, which becomes an ingestion regulator when it is oxidized in the liver (Allen, 2000).…”

“…For this reason, demand is high leading to significant variations in availability and market cost. Other starch sources can be used such as oat, wheat, sorghum, and barley, which are highly energetic cereals with varying solubility (Malaguez et al, 2021). Starch is the main energy source utilized for ruminants (Ortega and Mendonza, 2003).…”

“…Nevertheless, starch is also present in roots and tubers (Zeoula et al, 2006). The search for alternative ingredients to replace corn is important considering the variable price of this commodity (Malaguez et al, 2021).…”

“…Since sweet potato is mainly commercialized for humans, it goes through rigorous quality control to guarantee the product is suitable for consumption (Van Hal, 2000). Any product not meeting the quality standards of size and form is not harvested becoming susceptible to contamination by disease that spreads onto subsequent crops (Malaguez et al, 2021).…”