Faezeh Khani; Ali Assadi-Alamouti; Behzad Khorrami
Abstract
Objective: Livestock producers in Iran face increasing challenges with forage supply due to progressively detrimental climatic changes. Due to nutrient losses during drying, and spoilage and mold during storage of fresh forage, ensiling is used to preserve and utilize forage when fresh produce is unavailable. ...
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Objective: Livestock producers in Iran face increasing challenges with forage supply due to progressively detrimental climatic changes. Due to nutrient losses during drying, and spoilage and mold during storage of fresh forage, ensiling is used to preserve and utilize forage when fresh produce is unavailable. Intercropping barley crop (Hordeum vulgare) with forage pea (Pisum arvense L.) can provide a substantial portion of the protein requirements for growing livestock and dairy cows, given its acceptable protein yield per hectare. Considering the advantages of legume-cereal forage intercropping and the widespread adoption of winter cropping for forage production nationwide, particularly in the Varamin region of Iran, optimizing the legume-cereal ratio in forage crop mixtures is essential to maximize agronomic performance, water-use efficiency, nutritional value, and suitability of the mix for animal feeding. Therefore, this study aimed to investigate the effects of different ratios of whole-crop barley to forage pea on silage fermentation quality and digestibility, and to determine the optimal mixing ratio.
Method: Whole crop barley and forage pea were harvested at specific growth stages (early dough stage for barley and mid-flowering to late flowering/early pod formation for forage pea). The experiment consisted of four treatments: 1) 100% barley silage, 2) 80% barley + 20% forage pea silage, 3) 70% barley + 30% forage pea silage, and 4) 60% barley + 40% forage pea silage, with three replicates in a completely randomized design. Ensiling was carried out in 10-liter plastic mini-silos. After 60 days of ensiling, the silos were opened and sampled for analysis of crude ash, ether extract (EE), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent insoluble nitrogen (ADIN), lignin (ADL), water-soluble carbohydrates (WSC), ammonia N and volatile fatty acids. An in vitro gas production test was used to compare treatments for gas production kinetics, and estimated digestibility, metabolisable energy, and short-chain fatty acid concentrations.
Result: With the increase in the proportion of forage pea, the dry matter content decreased while pH increased. The inclusion of forage pea in the mixture tended to increase crude protein and crude ash contents (P < 0.10). However, the values of EE, ADF, NDF, ADL, and ADIN were not affected by the forage pea (P > 0.05). Furthermore, increasing the proportion of forage pea significantly elevated the concentration of ammonia-N in the silage (P<0.05). No significant differences were observed among silages in terms of acetic, propionic, and butyric acid concentrations, with the levels of these volatile fatty acids falling within the range typically found in well-fermented silages. The treated silage containing 20% forage pea exhibited higher gas production volume, organic matter digestibility, metabolizable energy, and short-chain fatty acids than forage barley silage as the sole crop (P < 0.05).
Conclusions: Overall, the results demonstrated that mixing forage pea with whole crop barley during ensiling improved its nutritional value by enhancing CP content and reducing fiber levels, while taking advantage of barley forage, such as higher dry matter and WSC. This approach could serve as a winter-cropping strategy in semi-arid climates, improving feed quality, reducing costs, and promoting environmental sustainability. The present study suggested a 20% forage pea inclusion level for mixing with barley forage in laboratory conditions. However, this proportion should be further studied in animal trials.
Behzad Khorrami; Seyed Alireza Vakili; mohsen danesh mesgaran
Abstract
Introduction: Today, the use of antimicrobial agents such as antibiotics in livestock diets is facing reduced social acceptance because of the appearance of residues in milk and meat, and therefore, ruminant nutritionists are seeking for appropriate alternatives for these feed additives. The study of ...
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Introduction: Today, the use of antimicrobial agents such as antibiotics in livestock diets is facing reduced social acceptance because of the appearance of residues in milk and meat, and therefore, ruminant nutritionists are seeking for appropriate alternatives for these feed additives. The study of essential oils (EOs) as natural feed additives capable of improving rumen microbial fermentation has taken into consideration by nutritionists. Among the EOs, thyme (THY) and cinnamon (CIN) oil have attracted significant attention due to their antimicrobial activity against ruminal microorganisms. Therefore, more research is required to understand their impacts on rumen microbial fermentation in ruminants. Moreover, to the best of our knowledge, few studies has synchronously compared the influences of THY and CIN on rumen fermentation and microorganisms. This study was conducted to evaluate the effect of THY and CIN on performance, and rumen microbial fermentation under in vitro and in vivo conditions.
Materials and methods: In the in vitro experiment, different concentrations (0, 125, 250, 500, and 1000 mg/l) of THY and CIN were incubated for 24-h in batch culture. In the in vivo study 18 growing Holstein calves were used in a completely randomized design to examine effects of supplementing a basal diet (CON) with thyme oil (THY, 5 g/d/calf) or cinnamon oil (CIN, 5 g/d/calf) on performance and rumen microbial fermentation. Calves were fed ad libitum diets consisting of 15% forage and 85% concentrate for 80 d.
Results and discussion: The high concentration of THY and CIN (1000 mg/l) inhibited rumen microbial fermentation thereby decreasing total gas production and DM disappearance at 24 of incubation, and total VFA concentration. Cinnamon oil at 1000 mg/l increased final pH of batch culture (P<0.05). The lower concentration of THY and CIN (125 and 250 mg/l) decreased the acetate to propionate ratio (P<0.05), without reducing VFA concentration. Supplementation of THY or CIN did not affect DMI and ADG. There were also no effects of EOs on ruminal pH, rumen concentrations of ammonia nitrogen and total VFA; whereas molar proportion of acetate and ratio of acetate to propionate decreased (P<0.05), and the molar proportion of propionate increased (P<0.05). Rumen molar proportion of butyrate was significantly increased (P<0.05) by adding CIN. The population of protozoa and methanogens bacteria decreased in the rumen of calves receiving EOs (P<0.05). Ruminal population of Fibrobacter succinogenes was not affected by treatments, but populations of Ruminococcus albus and flavefaciens decreased by THY and CIN (P<0.05).
Conclusion: Based on the results of the present study, although dietary addition of THY and CIN did not have a significant effect on the performance of feedlot calves, but it improved the rumen fermentation properties, which may be considered as potential alternatives for antibiotics in beef production systems.