Effects of Mannan Oligosaccharides on Gas Emission, Protein and Energy Utilization, and Fasting Metabolism in Sheep

Abstract

Simple SummaryMannan oligosaccharides (MOS) are a promising feed additive to improve animal health, immune capacity, and antioxidation. Based on the previous studies, we carried out three experiments to investigate the effects of MOS on the gas emission, protein and energy utilization, and fasting metabolism of sheep. The results showed that 2.0% MOS supplementation led to the lowest in vitro CO2 production and lower CH4 production and decreased in vivo intake. However, it also decreased urine nitrogen excretion and energy released as CH4, and then improved the utilization of crude protein and energy of sheep. There were no differences in the parameters of respiration and energy metabolism of sheep under the fasting condition. The findings indicated that MOS slightly affected the gas emission and nutrients and energy utilization of sheep.AbstractThis study investigated the effects of mannan oligosaccharides (MOS) on in vitro and in vivo gas emission, utilization of crude protein (CP) and energy, and relative parameters of sheep under fasting metabolism conditions. In vitro gas productions were evaluated over 12 h in sheep diets containing different amounts of MOS (from 0% to 6.0%/kg, the increment was 0.5%). A control experiment was used to assess the gas emission, utilization of CP and energy, and fasting metabolism in control sheep and sheep treated with 2.0% MOS over 24 days (d). The results showed that 2.0% MOS supplementation led to the lowest in vitro CO2 production and less CH4 production, while also leading to decrease in vivo nutrients intake, CP and energy excretion, digested and retained CP, and energy released as CH4 (p < 0.05). Furthermore, 2.0% MOS supplementation appeared to decrease in vivo O2 consumption and CH4 production per metabolic body weight (BW0.75), and increase the CP retention rate of sheep (p < 0.074). MOS did not affect other parameters, along with the same parameters of sheep under fasting metabolism conditions (p > 0.05). The findings indicate MOS has only slight effects on the gas emission and nutrients and energy metabolism of sheep.

Effects of mannan oligosaccharides on growth performance, nutrient digestibility, ruminal fermentation and hematological parameters in sheep

“…Because supplementation dietary MOS brought long villi and shallow crypts which provided a larger surface area for nutrients absorption in small intestine of animals ( Chacher et al, 2017 ), and an our previous study also demonstrated that supplementation dietary MOS elongated the villus height and the muscular thickness, and decreased the villus width of lamb duodenum significantly ( Zheng et al, 2020 ), so, the monitoring results about supplementation dietary MOS improved nutrient digestion of sheep in the current study were observed. And some previous studies have reported similar results, with MOS increasing the digestion of NDF and ADF ( Zheng et al, 2018 ), and nitrogen retention in sheep ( Zheng et al, 2018 ; Zheng et al, 2019 ), as well as improving the nitrogen, zinc, and iron metabolism of calves and lambs ( Cole, Purdy & Hutcheson, 1992 ). However, another study reported that MOS did not affect nutrient digestibility in dairy cows ( Moallem et al, 2009 ).…”

“…In sheep, supplementation dietary MOS increased ruminal pH and total short chain fatty acids (SCFAs) concentration, decreased lipopolysaccharides (LPS) level in plasma, reduced ruminal ammonia concentration and ruminal stratum corneum thickness and total thickness of ruminal epithelium, as well as the incidence and severity of hepatic abscesses ( Diaz et al, 2018 ). In our previous studies, similarly, supplementation dietary MOS increased antioxidant capacity ( Zheng et al, 2018 ) and crude protein (CP) retention rate and decreased energy release as methane (CH 4 ) in sheep ( Zheng et al, 2019 ).…”

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“…A positive relationship between CO 2 and CH 4 in the current study agreed with those reported by Zheng et al 34 and Patra and Yu. 42 However, some studies have shown that there was a negative relationship, because CO 2 and H 2 are, in general, the precursors for CH 4 formation in the rumen.…”

“…It is possible that O 2 consumption was not affected due to the similarity of dry matter intake by the lambs. The unchanged RQ was expected as the sheep in the current study were fed ad libitum and feed intake was not affected 33,34 . An RQ greater than 1 is usually reported in trials with ruminants, as shown by Nichols et al 35 .…”

“…The unchanged RQ was expected as the sheep in the current study were fed ad libitum and feed intake was not affected. 33,34 An RQ greater than 1 is usually reported in trials with ruminants, as shown by Nichols et al 35 and Morris and Kononoff. 36 Although the oxidation of lipids, protein and carbohydrates results in an RQ of 0.71, 0.81 and 1.00, our results greater than 1 can be explained by lipid synthesis that results in an RQ greater than 1.…”