13 research outputs found

    Effect of supplementation of oil palm (Eleis guineensis) frond asa substitute for concentrate feed on rumen fermentation, carcass characteristics and microbial populations in sheep

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    Thirty growing cross-bred sheep (20.4 ± 1.9 kg body weight (BW)) were used to determine the effects of dietary supplementation of oil palm (Eleis guineensis) frond (OPF) pellets on growth performance, microbial population and carcass characteristics of sheep. Experimental animals were allotted into three treatment groups fed varying levels of OPF pellets and commercial sheep pellets. Treatment diets were control diet (CON group, n=10), 25% OPF pellet in diet (% w/w) (HAF group, n=10) and 50% OPF pellet in diet (OPF group, n=10). After 100 days of feeding, all animals from each group were slaughtered, and carcass and rumen fluid were sampled. Both the HAF and CON groups had much more propionic acid and less acetic acid (P<0.05) compared to the OPF group at 8 h of sampling. Both HAF and CON had more marbling compared to OPF (P˂0.05). The HAF and CON groups had also more bacteria per milliliter (mL) of rumen fluid compared with the OPF group at 0 and 2 h of sampling. Therefore, the supplementation of OPF, which is an easily available oil palm by-product, could be used as a feed ingredient at 25% inclusion level to support sheep farming in tropical countries that lack grazing pasture

    Effects of season and age at first calving on genetic and phenotypic characteristics of lactation curve parameters in Holstein cows

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    Abstract In this research data representing 72,946 primiparous cows from 724 herds with 638,063 total test day records calved between 2001 and 2011. These data were analysed to determine the effect of age at first and season of calving on parameters of the Wood lactation curve. Also, genetic trend of the lactation curve parameters in different calving years were evaluated. The results indicate that the highest rate of atypical lactation curve was related to cows that calved in summer (28.05 %). The maximum phenotypic relationship between initial milk yield and total 305-d milk yield was observed in cows calved in spring (0.40). The role of peak yield is more than peak time on 305-d total milk yield in primiparous Holstein. One month increase in age at first calving from 18 to 26 month raised 305-d milk yield by around 138 kg and from 27 to 32 month decreased by 61 kg. The persistency of lactation between 101 and 200 days is higher than that of 201–305 days. Our results indicate that the shape of lactation curve is largely dependent on the season of calving (higher level of milk production in cows which calved in autumn and winter). The heritabilities of parameters of lactation curve and persistency measures were low. The genetic trends for peak time, peak yield and 305-d milk yields were positive and estimated to be 0.019, 0.021 and 8.13 kg/year respectively. So the range from 24 to 26.5 month of calving is the optimum calving time in primiparous Holstein for maximizing 305-d milk yield

    Application of the Response Surface Method in the Analysis of Ohmic Heating Process Performance in Sour Orange Juice Processing

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    Three voltage gradients (8.38, 10.83, and 13.33 V cm-1) and three weight loss percentages (10, 20, and 30 percent) were examined; also the system performance coefficient, input current, heating process duration, power consumption and electrical conductivity investigated. The response surface method was also used for modeling s and optimization. For the response surface method, weight loss percentage and voltage gradient were selected as independent variables; and factors  system performance coefficient, heating process duration, input current, power consumption and electrical conductivity were selected as responses. According to results, all obtained models were significant for responses factors, but the voltage gradient and weight loss percentage were insignificant for all factors except the electrical conductivity and power consumption. The best model was a quadratic model against interaction for the system performance coefficient, input current and power consumption; and the linear model against mean was the best model for electrical conductivity and heating time

    The role of alkyl chain length in the inhibitory effect n-alkyl xanthates on mushroom tyrosinase activities

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    Sodium salts of four n-alkyl xanthate compounds, C2H5OCS2Na (I), C3H7OCS2Na (II), C4H9OCS2Na (III), and C6H13OCS2Na (IV) were synthesized and examined for inhibition of both cresolase and catecholase activities of mushroom tyrosinase (MT) in 10 mM sodium phosphate buffer, pH 6.8, at 293 K using UV spectrophotemetry. 4-[(4-methylbenzo)azo]-1,2-benzendiol (MeBACat) and 4-[(4-methylphenyl)azo]-phenol (MePAPh) were used as synthetic substrates for the enzyme for catecholase and cresolase reactions, respectively. Lineweaver-Burk plots showed different patterns of mixed, competitive or uncompetitive inhibition for the four xanthates. For the cresolase activity, I and II showed uncompetitive inhibition but III and IV showed competitive inhibition pattern. For the catecholase activity, I and II showed mixed inhibition but III and IV showed competitive inhibition. The synthesized compounds can be classified as potent inhibitors of MT due to their Ki values of 13.8, 11, 8 and 5 µM for the cresolase activity, and 1.4, 5, 13 and 25 µM for the catecholase activity for I, II, III and IV, respectively. For the catecholase activity both substrate and inhibitor can be bound to the enzyme with negative cooperativity between the binding sites (α > 1) and this negative cooperativity increases with increasing length of the aliphatic tail of these compounds. The length of the hydrophobic tail of the xanthates has a stronger effect on the Ki values for catecholase inhibition than for cresolase inhibition. Increasing the length of the hydrophobic tail leads to a decrease of the Ki values for cresolase inhibition and an increase of the Ki values for catecholase inhibition

    Saffron extract feed improves the antioxidant status of laying hens and the inhibitory effect on cancer cells (PC3 and MCF7) Growth

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    Abstract Background There have been some reports regarding supplementation of saffron petal extract on performance and egg quality in laying hens. However, the effect of saffron petal extract fed diet at different amounts on antioxidant status of laying hens and the impact of the resulting egg yolk on growth/inhibitory activity of cancer cells has not been fully studied. Objectives The effect of dried saffron petal extract on the laying performance, egg qualitative traits, antioxidant status, and its inhibitory effect on cancer cells was studied. Methods A total of 200 39‐week‐old Hy‐line W36 Leghorn laying hens were selected based on a completely randomised design in four treatments with five replications (10 hens per replication). The four treatment diets consisted of a basal diet with no supplement (control), and three diet supplement groups containing 40, 60 and 80 ppm of saffron petal extract. Results Adding 80 ppm of saffron petal extract to layer diets increased egg production (p < 0.05). Malondialdehyde,1,1‐diphenyl‐2‐picrylhydrazyl value and Superoxide dismutase significantly improved by saffron petal dietary supplementation. The yolk weight and colour, Haugh unit and shell weight and thickness were also influenced (p < 0.05) with highest values achieved in the 60 ppm saffron extract supplemented diet. Results demonstrated a significant effect of saffron extract inclusion in the diet on the growth of Michigan Cancer Foundation‐7 and Prostate Cancer Cell in a positive dose‐dependent manner (p < 0.05) and the most intense inhibitory effect on cancer cells was observed with 60–80 ppm extract. Conclusions Saffron petal extract can be used to potentially modulate the antioxidant status of laying hens and the inhibitory effect on cancer cells, best achieved with 60–80 ppm extract

    A study on the energy and exergy of Ohmic heating (OH) process of sour orange juice using an artificial neural network (ANN) and response surface methodology (RSM)

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    The nonmodern statistical methods are often unusable for modeling complex and nonlinear calculations. Therefore, the present research modeled and investigated the energy and exergy of the ohmic heating process using an artificial neural network and response surface method (RSM). The radial basis function (RBF) and the multi-layer perceptron (MLP) networks were used for modeling using sigmoid, linear, and hyperbolic tangent activation functions. The input consisted of voltage gradient; weight loss percentage, duration ohmic, Input flow, Power consumption, electrical conductivity and system performance coefficient and the output included the energy efficiency, exergy efficiency, exergy loss, and improvement potential. The response surface method was also used to predict the data. According to the result, the best prediction amount for energy and exergy efficiencies, exergy loss and improvement potential were in RBF network by sigmoid activation function and after this network, RSM had the best amount for energy efficiency, Also for exergy efficiencies, exergy loss and improvement potential obtained acceptable results in MLP network by a linear activation function. The worst amount was at MLP network by tangent hyperbolic. In general, the neural network can have more ability than the response surface method

    Application of random regression models for genetic analysis of 305-d milk yield over different lactations of Iranian Holsteins

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    Objective During the last decade, genetic evaluation of dairy cows using longitudinal data (test day milk yield or 305- day milk yield) using random regression method has been officially adopted in several countries. The objectives of this study were to estimate covariance functions for genetic and permanent environmental effects and to obtain genetic parameters of 305-day milk yield over seven parities. Methods Data including 60,279 total 305–day milk yield of 17,309 Iranian Holstein dairy cows in 7 parities calved between 20 to 140 months between 2004 and 2011. Residual variances were modeled by homogeneous and step functions with 7 and 10 classes. Results The results showed that a third order polynomial for additive genetic and permanent environmental effects plus a step function with 10 classes for the residual variance was the most adequate and parsimonious model to describe the covariance structure of the data. Heritability estimates obtained by this model varied from 0.17 to 0.28. The performance of this model was better than repeatability model. Moreover, 10 classes of residual variance produce the more accurate result than 7 classes or homogeneous residual effect. Conclusion A quadratic Legendre polynomial for additive genetic and permanent environmental effects with 10 step function residual classes are sufficient to produce a parsimonious model that explained the change in 305-day milk yield over consecutive parities of Iranian Holstein cows
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