nguyen linh

In the era of free antibiotics used in animal production, the application of feed additives should be prioritized to improve poultry health and production. This study was conducted to evaluate the influences of garlic fermented by Lactobacillus spp. on the growth rate, intestinal microorganisms, and immune response of turkey broilers. A completely randomised design was used, involving 90 turkey broilers aged 1–56 days, with five treatments and three replicates per treatment. The birds were given feed and water ad libitum for entire the experiment period. The treatments included the supplement of aqueous extract from fermented garlic (FG) to drinking water. The results showed that broilers supplemented with 0.8% FG exhibited the largest final body weight (1,158 g/bird), body weight gain (19.64 g/bird/day), and significantly improved feed conversion ratio (1.962) while decreased the feed intake of turkey broilers from to 1–56 days. The immune organ indices including the spleen, thymus, and bursa of Fabricius indices were increased in the treatment of 0.6% FG (P<0.05) while antibody titres (at 28 and 42 days of age) were improved in the 0.6% and 0.8% FG treatment (P<0.05). Clostridium perfringens and Salmonella spp. were not detected in the intestines of these birds, while the amount of Escherichia coli was reduced (P<0.05) and Lactobacillus spp. increased (P>0.05) without a significant effect. It can be concluded that supplementation with 0.8% FG improved growth performance, and 0.6% FG may enhance the immunity of turkeys. The use of 0.6 and 0.8% FG could be widely applied for poultry production.

This paper presents a new equivalent stiffness-based load transfer model for an open-ended pipe pile. The main idea of this model is to replace the sum of unit stiffnesses corresponding with external and internal unit skin frictions in the basic differential equation of load transfer by a weighted average of equivalent unit stiffnesses using a dual approach of equivalent replacement. The contribution of external and internal skin frictions to equivalent unit stiffnesses is evaluated by normalized dimensionless weighting coefficients in the form of average value with the penetration depth. Application of new load transfer model to a jacked open-ended pile concerning semi-empirical models of external and internal unit skin frictions leads to corresponding explicit expressions of weighting coefficient. A computational example of a jacked open-ended pile is carried out. It is shown that the proposed equivalent stiffness-based load transfer model is an effective tool for analyzing behaviors of the open-ended pile in considering the soil plugging effect.