Search Results (6)

Alfalfa silage has a high proportion of rumen-degradable protein content. Increasing dietary rumen-degradable starch (RDS) can enhance ruminal microbial protein synthesis. This study was conducted to investigate the influence of RDS levels in substrates with alfalfa silage on in vitro rumen fermentation and nitrogen (N) utilization. Rumen fluid was collected and dispensed into anaerobic fermentation bottles, each containing 1 g of substrate and 60 mL of rumen fluid–buffer mixture. The substrate was composed of 40% alfalfa silage and five different RDS levels: 14.85% RDS, 16.40% RDS, 18.67% RDS, 20.21% RDS, and 21.62% RDS. For each RDS level, three replicates were prepared. Each substrate was then incubated at 39 °C for 3, 6, 12, and 24 h. After incubation, the following parameters were measured: gas production, pH, α-amylase activity, ammonia nitrogen (NH₃-N), bacterial protein (BCP), and short-chain fatty acid (SCFA) concentrations were measured. Total gas production increased linearly with increasing RDS levels from 3 to 10 h of incubation (p < 0.01), with no difference observed among five levels after 11 h. At 3 h of incubation, pH decreased linearly with increasing RDS levels (p < 0.05). BCP concentrations and α-amylase activity increased linearly or quadratically with increasing RDS levels (p < 0.01), while the R4 group had the highest concentrations of BCP and the R5 group had the highest activity of α-amylase (p < 0.01). At 6 h of incubation, the NH₃-N concentration decreased linearly or quadratically with increasing RDS levels (p < 0.05), and the α-amylase activity, acetate, propionate, and total SCFA concentrations increased linearly (p < 0.01). The R4 group had the highest activity of α-amylase (p < 0.01), and the R5 group had the highest concentrations of acetate (p < 0.05) and propionate (p < 0.01). At 12 h of incubation, BCP, NH₃-N, and propionate concentrations, as well as α-amylase activity, increased linearly or quadratically with increasing RDS levels (p < 0.05). At 24 h of incubation, the α-amylase activity increased linearly with increasing RDS levels (p < 0.05). The highest multiple-factor associative effects index was observed in the 20.21% RDS substrate, indicating that an RDS level of 20.21% in the alfalfa silage substrate resulted in a desirable rumen N utilization. Full article

Diversifying feed with annual legumes could help to reduce reliance on imported sources of alfalfa hay, ensuring a consistent supply of forage throughout year, and potentially decreasing the cost of raising ruminants. This study evaluated the varietal variability in hay yield, chemical composition, carbohydrate and protein fractions, and in vitro digestibility of five common vetch varieties used in this experiment during the full-flowering period in Jianghuai region during the 2022 crop season. Results showed that improved varieties (Lanjian No. 1 and Lanjian No. 2, 6.30 and 6.11 t DM/ha) had significantly higher hay yields than the local variety (333A, Longjian No. 1), with Lanjian No. 3 showing intermediate yields. Variety Lanjian No. 1 had the highest non-protein nitrogen concentration and in vitro digestibility, while Lanjian No. 2 had the highest starch concentration, fraction of intermediately degradable pectin and starch, and fraction of neutral detergent-soluble protein and acid detergent-soluble protein. Pearson correlation showed that hay yield was not significantly correlated with quality parameters. Principal component analysis showed that Lanjian No. 1 and Lanjian No. 2 received higher nutritive value. In summary, Lanjian No. 1 and Lanjian No. 2 had better potential use as high-protein feedstuffs for dairy cattle and sheep in the Jianghuai region based on yield, protein fractions, and in vitro digestibility. Full article

The growing demand for gluten-free products requires the study of alternatives to produce nutritionally and technologically favorable foods. The aim was to evaluate the content and antioxidant capacity of gluten-free bread enriched with whole flour of purple maize (PM) and how starch and bioaccessibility of antioxidant compounds were modified during in vitro digestion. Gluten-free bread was prepared with the addition of 34%, 50%, and 70% PM, and white maize bread served as control. The content of total polyphenols, anthocyanins, and antioxidant capacity through FRAP and TEAC was measured. Specific volume, crumb texture, and starch digestibility were determined in the breads. Simultaneously, in vitro digestion and dialysis by membrane were performed to evaluate the bioaccessible and potentially bioavailable fraction. Bread with 34% PM had a similar specific volume and crumb texture to the control, but higher content of polyphenols (52.91 mg AG/100 g), anthocyanins (23.13 mg c3-GE/100 g), and antioxidant capacity (3.55 and 5.12 µmol tr/g for FRAP and TEAC, respectively). The PM breads had a higher antioxidant content and capacity and higher slowly digestible and resistant starch than the control. These parameters increased as the PM proportion rose. After digestion, anthocyanins were degraded, polyphenols and antioxidant capacity decreased, but they remained potentially bioavailable, although to a lesser extent. Bread with 34% shows acceptable technological parameters, lower starch digestibility, and contribution of bioactive compounds with antioxidant capacity. This indicates that purple maize flour represents a potential ingredient to produce gluten-free bread with an improved nutritional profile. Full article

The objective of this study was to evaluate the impact of the genotype on the chemical composition, feeding value and in vitro rumen degradability of fresh and ensiled forage of four native maize varieties (Amarillo, Olotillo, Tampiqueño and Tuxpeño) from Tamaulipas, Mexico, and a commercial hybrid, as well as the stability and aerobic deterioration of the silage. In all genotypes, fresh forage consisted of whole plants of maize that were harvested when the grain reached a milky-mass state, and silage was fresh forage chopped and ensiled in plastic bags, where it fermented for 120 days. The hybrid presented the highest content (p < 0.05) of dry matter (DM), organic matter (OM), ether extract, non-fibrous carbohydrates (NFCs) and starch, as well as the lowest content (p < 0.05) of fibers (NDF and ADF), acid detergent lignin and water-soluble carbohydrates (WSCs). Furthermore, the hybrid and Amarillo genotypes obtained the lowest pH and ammoniacal nitrogen content (p < 0.05), intermediate values (p < 0.05) of lactic and butyric acid, and the lowest and highest acetic acid content (p < 0.05), respectively. Although OM did not differ (p > 0.05) between states of the forage, the fresh forage presented a higher (p < 0.05) content of DM, crude protein, NDF, ADF, WSCs, pH and butyric acid in all genotypes, while the rest of the parameters were higher (p < 0.05) in the silage. However, Amarillo obtained the highest feeding value (p < 0.05) in terms of DM intake, relative forage value, digestible energy, metabolizable energy and rumen degradability (DM, NDF and ADF), and between states of the forage, ensiled obtained the highest feeding value (p < 0.05). During the aerobic exposure, the Amarillo and hybrid silage showed greater (p < 0.05) stability (>38 h), and less (p < 0.05) deterioration, pH increase and loss of DM and OM, while Tuxpeño obtained less stability and greater deterioration. In conclusion, the genotype did influence the chemical composition of fresh and ensiled forage, which affected the feeding value and in vitro rumen degradability, and the Amarillo and hybrid genotypes presented the best values in the evaluated parameters. Full article

The starch availability and nutritional value of corn (Zea mays L.) are affected by zein proteins. The aim of the study was to see whether the proposed reduction of γ-zeins during the fermentation of silages is a result of either the enzymatic proteolytic activity or of the acidic environment, and how this reduction affects starch availability and degradability in high-moisture corn. A mass spectrometry (MS) technique was used to quantify the 16- and 27-kDa γ-zeins. Briefly, two-dimensional gel electrophoresis (2-DE) was used for γ-zein separation, followed by densitometry for protein quantification and matrix-assisted laser desorption ionization time-of-flight MS (MALDI-TOF/TOF) for protein identification. The results show that the reduction in γ-zeins induced by the ensiling led to a more pronounced starch availability and in vitro degradation, and this reduction was dependent on the type of proteolysis. More specifically, the results indicate that the reduction of γ-zeins in the ensiled corn was primarily driven by the enzymatic proteolysis. Furthermore, we demonstrated that 2-DE followed by densitometric quantification and the mass spectrometry analysis for protein identification can be used as a state-of-the-art method for γ-zein evaluation both in fresh and fermented/ensiled corn samples. Full article

Faba bean is an important vegetable protein source for ruminant diets. This research aimed to compare the nutritional characteristics of four commercial and four local cultivars in order to better characterise the local ones and promote their use in animal nutrition. The seeds’ weight and the chemical composition, including starch and the energy, was evaluated. The in vitro fermentation characteristics were studied for 48 h using bull’s rumen fluid as inoculum. All the varieties showed the values’ weight corresponding to the specific botanical typology. The varieties significantly differed for protein, starch and lignin (p < 0.01) and structural carbohydrates (p < 0.05) concentration. No significant differences were observed for energy content. All the in vitro fermentation parameters resulted significantly different among the varieties. Organic matter degradability ranged between 89.9% and 85.1% and the potential gas production from 367 to 325 mL/g. The Pearson’s analysis showed significant correlation between morphological characteristics, chemical data and in vitro fermentation parameters. In conclusion, this investigation confirms the possibility of using local faba bean varieties (i.e., Aquino, Castrocielo, 13#5, 4#4) in ruminant nutrition with the advantage that, being local natural resources, they are better adapted to the climate and agronomic conditions and limit environmental impact. Full article