Replacing soybean meal with flax seed meal: effects on nutrient digestibility, rumen microbial protein synthesis and growth performance in sheep

Abstract

Flax seed meal (FSM) is rich in various nutrients, especially CP and energy, and can be used as animal protein feed. In animal husbandry production, it is a long-term goal to replace soybean meal (SBM) in animal feed with other plant protein feed. However, studies on the effects of replacing SBM with FSM in fattening sheep are limited. The aim of this experiment was to study the effects of replacing a portion of SBM with FSM on nutrient digestibility, rumen microbial protein synthesis and growth performance in sheep. Thirty-six Dorper × Small Thin-Tailed crossbred rams (BW = 40.4 ± 1.73 kg, mean ± SD) were randomly assigned into four groups. The dietary treatments (forage/concentrate, 45 : 55) were isocaloric according to the nutrient requirements of rams. Soybean meal was replaced with FSM at different levels (DM basis): (1) 18% SBM (18SBM), (2) 12% SBM and 6% FSM (6FSM), (3) 6% SBM and 12% FSM (12FSM) and (4) 18% FSM (18FSM). The rams were fed in individual pens for 60 days, with the first 10 days for adaptation to diets, and then the digestibility of nutrients was determined. There was no significant difference in DM intake, but quadratic (P < 0.001) effects on the average daily gain and feed efficiency were detected, with the highest values in the 6FSM and 12FSM groups. For DM and NDF digestibility, quadratic effects were observed with the higher values in the 6FSM and 12FSM groups, but the digestibility of CP linearly decreased with the increase in FSM in the diet (P = 0.043). There was a quadratic (P < 0.001) effect of FSM inclusion rate on the estimated microbial CP yield. However, the values of intestinally absorbable dietary protein decreased linearly (P < 0.001). For the supply of metabolisable protein, both the linear (P = 0.001) and quadratic (P = 0.044) effects were observed with the lowest value in the 18FSM group. Overall, the results indicated that SBM can be effectively replaced by FSM in the diets of fattening sheep and the optimal proportion was 12.0% under the conditions of this experiment.

Fermented Rubber Seed Kernel with Yeast in the Diets of Tropical Lactating Dairy Cows: Effects on Feed Intake, Hematology, Microbial Protein Synthesis, Milk Yield and Milk Composition

“…Soybean meal (SBM) is a primary protein source in concentrate diets due to its protein-rich and favorable amino acid content [ 3 ]. Nevertheless, the cost of cattle feed has been affected by the high cost of SBM [ 4 ]. As a result, there is a need to seek alternative dietary protein sources that are less expensive and generated locally to replace SBM in animal diets [ 5 ].…”

In Vitro Fermentation Characteristics of Camelina Meal Comparison with Soybean Meal

“…Zagorakis et al (2015) and Sizmaz et al (2016) reported that CM has the potential to substitute SBM, with the protein having relatively low effective degradability compared with that of SBM. Therefore, Hao et al (2020) reported that the effectiveness of total diet degradation rate of CP was decreased linearly while DOM and gross energy degradation were increased in flax seed meal. On the contrary, in the trial conducted by Salas et al (2019) the in vitro OM degradation was decreased compared with SBM.…”

Exploring the effects of palm kernel meal feeding on the meat quality and rumen microorganisms of Qinghai Tibetan sheep

“…For example, cottonseed meal can be an important substitute for soybean meal, especially since it has no negative effects on the performance of lambs (Silva et al, 2016 ). Similarly, using peanut meal as a substitute in feeds can improve the fatty acid profile of sheep meat (Lima Valença et al, 2020 ), while flaxseed meal can effectively improve sheep performance as well as the efficiency of feed utilization (Hao et al, 2020 ). PKM can also be used instead of soybean meal due to its secondary effects on the growth performance of goats (Silva et al, 2020 ).…”