Barley, an Undervalued Cereal for Poultry Diets: Limitations and Opportunities

HvBGlu3, a GH1 β-glucosidase enzyme gene, negatively influences β-glucan content in barley grains

KEY MESSAGE

HvBGlu3, a β-glucosidase enzyme gene, negatively influences β-glucan content in barley grains by mediating starch and sucrose metabolism in developing grains. Barley grains are rich in β-glucan, an important factor affecting end-use quality. Previously, we identified several stable marker-trait associations (MTAs) and novel candidate genes associated with β-glucan content in barley grains using GWAS (Genome Wide Association Study) analysis. The gene HORVU3Hr1G096910, encoding β-glucosidase 3, named HvBGlu3, is found to be associated with β-glucan content in barley grains. In this study, conserved domain analysis suggested that HvBGlu3 belongs to glycoside hydrolase family 1 (GH1). Gene knockout assay revealed that HvBGlu3 negatively influenced β-glucan content in barley grains. Transcriptome analysis of developing grains of hvbglu3 mutant and the wild type indicated that the knockout of the gene led to the increased expression level of genes involved in starch and sucrose metabolism. Glucose metabolism analysis showed that the contents of many sugars in developing grains were significantly changed in hvbglu3 mutants. In conclusion, HvBGlu3 modulates β-glucan content in barley grains by mediating starch and sucrose metabolism in developing grains. The obtained results may be useful for breeders to breed elite barley cultivars for food use by screening barley lines with loss of function of HvBGlu3 in barley breeding.

Impacts of Solid-State Fermented Barley with Fibrolytic Exogenous Enzymes on Feed Utilization, and Antioxidant Status of Broiler Chickens

The present and future high demand of common cereals as corn and wheat encourage the development of feed processing technology that allows for the dietary inclusion of other cereals of low nutritional value in poultry feeding. Barley grains contain anti-nutritional factors that limit their dietary inclusion in the poultry industry. The treatment of barley with solid-state fermentation and exogenous enzymes (FBEs) provides a good alternative to common cereals. In this study, barley grains were subjected to solid-state microbial fermentation using Lactobacillus plantarum, Bacillus subtilis and exogenous fibrolytic enzymes. This study aimed to assess the impact of FBEs on growth, feed utilization efficiency, immune modulation, antioxidant status and the expression of intestinal barrier and nutrient transporter-related genes. One-day-old broiler chicks (Ross 308, n = 400) comprised four representative groups with ten replicates (10 chicks/replicate) and were fed corn-soybean meal basal diets with inclusions of FBEs at 0, 5, 10 and 15% for 38 days. Solid-state fermentation of barley grains with fibrolytic enzymes increased protein content, lowered crude fiber and reduced sugars compared to non-fermented barley gains. In consequence, the group fed FBEs10% had the superior feed utilization efficiency and body weight gain (increased by 4.7%) with higher levels of nutrient metabolizability, pancreatic digestive enzyme activities and low digesta viscosity. Notably, the group fed FBEs10% showed an increased villi height and a decreased crypt depth with a remarkable hyperactivity of duodenal glands. In addition, higher inclusion levels of FBEs boosted serum immune-related parameters and intestinal and breast muscle antioxidants status. Intestinal nutrient transporters encoding genes (GLUT-1, CAAT-1, LAT1 and PepT-1) and intestinal barriers encoding genes (MUC-2, JAM-2, occludin, claudins-1 and β-defensin 1) were upregulated with higher dietary FBEs levels. In conclusion, feeding on FBEs10% positively enhanced broiler chickens' performance, feed efficiency and antioxidant status, and boosted intestinal barrier nutrient transporters encoding genes.

Differences in Ratio of Carbon Stable Isotopes among Barley Grain Milling Fractions with Various Concentrations of Beta-Glucans

The grains of three barley varieties were milled and sieved to obtain respective milling fractions with a content of beta-glucans (b-G) from 1.4 to 10.7%. The enriched fraction obtained by the extraction and precipitation contained 24.7% of b-G. The differences between the ratio of stable C carbon isotopes were established. Milling fractions with coarse particles had more beta-glucans and a more negative ratio of δ13C isotope in comparison to the respective intact barley grain. However, the enriched fraction had a less negative isotope ratio. So, it is not expected that the deviation from the stable isotope ratio of grain in milling fractions is the result of the content of b-G, but it depends on other barley grain constituents. In different parts of barley grain, there are substances with different stable isotope ratios, and by milling and sieving, they are assorted to the same milling fraction with most of the b-G. The method for determining the ratio of a stable carbon isotope in diverse barley grain fractions, applied in this investigation, is potentially opening the possibility for an additional method of screening the concentration of bioactive constituents in barley grain.

Emmer wheat (Triticum dicoccum)-based intervention in Japanese quail's diet and its impact on performance, carcass yield, meat fatty acids, and fecal volatile fatty acids

The high nutritional and nutraceutical qualities of emmer wheat make it a valuable cereal grain. The present study was designed to quantify the contribution of emmer wheat inclusion into Japanese quail's rations in terms of their productive responses, alterations in the fatty acid profile of their meat, and changes in the composition of volatile fatty acids in their feces. For this purpose, a total of 160, 1-day-old Japanese quails (Coturnix coturnix japonica) were randomly allotted to four dietary treatments (4 replicates and 10 quails/replicate) with different levels of emmer wheat including 0% (control), 5% (T5), 10% (T10), and 15% (T15). These dietary treatments were administered for a period of 35 days. The results obtained from the study showed that dietary changes led by incorporation of increasing levels of emmer wheat into quail rations had no negative impact on quail's health and production. Moreover, supplemental emmer could promote better feed conversion ratio and higher carcass yield, while it did not affect the relative weights of internal organs including liver, gizzard, and heart. In addition, the incorporation of increasing levels of emmer wheat into quail rations was characterized by a reduction in total saturated and monounsaturated fatty acids, whereas an increase was observed in the levels of total unsaturated and polyunsaturated fatty acids in breast meat. Emmer wheat inclusion also increased the levels of omega-3 and omega-6 fatty acids in breast meat. Regarding volatile fatty acid profile, a lower percentage of propionic acid while a higher percentage of acetic acid were recorded in feces of quails fed emmer wheat-based diets when compared to those fed control diets. Overall, as confirmed by the present findings, the incorporation of emmer wheat into quail diets could be proposed as a valuable strategy for the promotion of animal health and performance. More research is needed to further investigate the promising roles of using emmer wheat in poultry nutrition.