Effects of essential oils, yeast culture and malate on rumen fermentation, blood metabolites, growth performance and nutrient digestibility of Baluchi lambs fed high‐concentrate diets

Abstract

The experiment was conducted to evaluate the effects of dietary supplementation with a mixture of essential oils (MEO), yeast culture (YC) and malate on performance, nutrient digestion, rumen fermentation and blood metabolites of lambs fed high-concentrate growing diets. For this purpose, twenty Baluchi lambs (17.3 ± 0.5 kg body weight and 3 months old) were randomly assigned to four dietary treatments in a completely randomized design with five lambs per treatment. The treatment groups were as follows: (i) control: basal diet without any additive, (ii) basal diet plus 400 mg/day MEO (thymol, carvacrol, eugenol, limonene and cinnamaldehyde), (iii) basal diet with 4 g/day YC and (iv) basal diet plus 4 g/day malate. No differences between the dietary treatments were observed in dry matter intake, average daily gain or feed conversion ratio (p > 0.05). Compared with control and malate treatment, lambs fed MEO and YC had an improved crude protein digestibility (p < 0.05). Yeast culture significantly increased (p > 0.05) cell wall digestibility compared to the other treatments. No differences were observed between treatments with respect to nitrogen balance or ruminal pH and ammonia concentrations (p > 0.05). No differences were observed between treatments with respect to ruminal total volatile fatty acid concentration and molar proportions of acetate, butyrate and valerate. Molar proportion of propionate was higher (p < 0.05) for YC and malate compared to control and MEO. Plasma glucose concentration was higher (p < 0.05) in lambs fed YC and malate than in lambs fed the control or the MEO diet. Blood concentration of triglycerides significantly decreased when feeding the MEO and YC diets (p < 0.05). It was concluded that YC may be more useful as a feed additive for manipulation of rumen fermentation in lambs fed with high-concentrate diets than MEO and malate, because YC enhanced crude protein and cell wall digestibility, ruminal molar proportion of propionate and plasma glucose concentration.

Effects of yeast culture supplementation and the ratio of non‐structural carbohydrate to fat on growth performance, carcass traits and the fatty acid profile of the longissimus dorsi muscle in lambs

“…Gomes, Leme, Silva, Antunes, and Guedes () suggested that supplemental yeast in a high‐concentrate diet (80%) significantly increased the DP of steers, while an increase in CW with YC supplementation was observed in another study using steers (Salinas‐Chavira et al, ). These results were consistent with the current study and might be related to the increases in CP digestibility after YC supplementation (Malekkhahi et al, ). However, some findings reported that YC supplementation had no significant effect on CW or DP (Geng et al, ; Tripathi & Karim, ).…”

Effects of legume seeds and processing treatment on growth, carcass traits and blood constituents of fattening lambs

“…Such a hypothesis is consistent with the results of Masoero et al (2005) who observed increased starch digestibility in vitro of these extruded seeds (that is peas, faba beans, and lupins) compared with the untreated seeds. The higher degradability of starch in the rumen has been shown to change rumen fermentation patterns by increasing that production of short chain fatty acids, (particularly propionate), which has further been related to reduced synthesis of triglyceride and cholesterol in the liver cells, as well as to changes in the lipid profile of blood (Malekkhahi et al, 2015).…”

Review: Enhancing gastrointestinal health in dairy cows

“…As an adjunct to balanced diets, the risk of rumen acidosis can be reduced by the inclusion of rumen modifiers that include antibiotics, buffers and neutralising agents, yeasts, direct-fed microbials and enzymes, and, possibly, by essential oils (Khorrami et al, 2015;Malekkhahi et al, 2015).…”