Search

A global increase in the demand for livestock products suggests that there will be a consequent rise in demand for feed, not only of cereals but of other feeds and particularly proteins. In the present study, oil industry by-products such as soybean meal, soybean cake and sunflower meal were analysed as sources of amino acids in animal nutrition. From among oilseed byproducts, the soybean meal content the most of crude protein up to 44% and the best of amino acid composition, while content of crude cellulose (about 6%) is lower in comparison to other oilseed meals. The results showed that the total amino acids in the examined samples ranged from 31.87 to 41.01%, and the total essential and nonessential amino acids varied from 13.41 to 17.38% and from 18.46 to 23.76%, respectively. Generally, the protein contained in soybean meal and cake was rich in essential amino acids. However, because of the lowest amino acid score, methionine was considered as a limiting amino acid in both soybean by-products. On the other hand, soya's meal contained higher level of lysine than other protein-based vegetable alternative to soya like sunflower meals examined in this study. Glutamic acid, aspartic acid, leucine and valine were the most abundant amino acids in all tested by-products of the oil industry. Therefore, partial substitution of protein sources in feeds with proteins from the oil industry by-products may improve feed quality.

Oxidative changes in fish feed during storage are a major problem in aquaculture nutrition. The current study aims to present fast and simple spectrometric method to measure thiobarbituric acid reactive substances (TBARS) in the commercial rainbow trout feeds without hydrolysis step, as a method for determination of lipid peroxidation. The proposed test was validated and relevant method characteristics which were evaluated within the validation protocol were: linearity (range), limit of detection, limit of quantification, precision (repeatability and intra-laboratory reproducibility), accuracy and method performance (Xand R-control charts). The obtained results indicated that presented TBARS test was linear in the range of 1.11-13.33 nmol/mL and precise under both repeatability and reproducibility test conditions. The method was characterized by acceptable accuracy considering low analyte concentration in the samples. The method also showed to be stable in terms of changes in the average level and variability. The results in the present work indicated that the proposed test could be successfully applied for TBARS quantification in rainbow trout feed for routine quality control in aquaculture sector, especially in case when need to analyse a great number of samples in a short time.

Sunflower meal, a by-product of oil extraction from sunflower seeds, is an important protein source in domestic as well as European feed industry. There is a common interest for the proper utilization of sunflower meal and for the development of an effective fractionation process in order to obtain a nutritionally improved sunflower meal. This paper proposes and compares two dry fractionation processes for the improvement of sunflower meal protein content on a laboratory scale. The first phase of both processes included two step milling using a hammer and roller mill. In the second phase, the ground sunflower meal was fractionated by sieving or by air classification. Results indicated that the implementation of any of the suggested processes improved protein content of the starting sunflower meal to a level sufficient to categorize it as "high-protein" according to current national regulation on animal feed quality, with the fraction yields over 50%. For the air classification process the most promising result was achieved for air flow of 7 m3 /h (12.8% relative protein enrichment, 56.42% fraction yield). For the fractionation process with sieving as a separation step, when fractions smaller than 350 µm were conjoined, relative protein enrichment of 28.5% and fraction yield of 51.17% were achieved. The high protein content (48.81% on dry basis) of the joined fraction enables enough space for optimizing the protein content - fraction yield ratio of obtained sunflower meal. By applying sieves with larger aperture, it is possible to obtain higher yields of sunflower meal categorized as high-protein on account of a slight decrease in protein content, which gives this process a certain flexibility and potential for application on a larger scale.

Table eggs can play an important role as functional food, especially if specially designed mixtures enriched with o-3 fatty acids, natural pigments and vitamins are used for their production. Thus, the aim of this study was to investigate the effects of inclusion of flax-corn meal co-extrudate (FCM) in combination with natural pigments in hens' diet on physical properties, yolk colour and fatty acid composition of eggs. One hundred and twenty Lohmann Brown laying hens were fed corn-soybean meal based diet with the addition of FCM at different levels: 0% (control C1 and C2), 13.50% experimental treatment (E1) and 22.50% experimental treatment (E2). The control treatment (C1) contained up to 3% fat, without added pigments while the control treatment (C2) contained up to 5% fat and synthetic pigments. Experimental treatments E1 and E2 (3% and 5% fat, respectively) had the same amount of natural pigments (1% carrot and 0.5% paprika). When compared with control eggs, no significant changes (p>0.05) in the egg quality characteristics were observed for E1 and E2 eggs. Desirable egg yolk colour of 12.78 RYCF (Roche Yolk Colour Fan scale) was achieved in the treatments E1 and E2. Eggs from hens fed FCM had significantly higher level (p

For many years, linseed has been attracted a great attention in animal nutrition because of its exceptionally favourable fatty acid composition and high content of essential α-linolenic acid. However, the presence of antinutritive components, cyanogenic glycosides, limits its inclusion in the animal's diet. Several ways of linseed detoxification were observed in literature, emphasizing extrusion as one of the most effective processes. In the presented study, the application of Artificial Neural Network (ANN) has been observed, as a tool for prediction of process influence on the deterioration of cyanogenic glycosides during the extrusion process of linseed-sunflower meal co-extrudate. The content of hydrogen cyanide (HCN) was determined according to the AOAC method as an indicator of cyanogenic glycosides in the produced co-extrudate. Extrusion of the material was performed on a laboratory single screw extruder. The performance of ANN model was compared with experimental data in order to develop rapid and accurate method for prediction of HCN content in co-extrudate. According to the experimental results, the highest HCN content (126 mg/kg) was determined at the lowest moisture content (7%) and the lowest screw speed (240 rpm). With the increase of moisture content and temperature during extrusion, the content of HCN drastically decreased. The ANN model showed high prediction accuracy (r2> 0.999), which indicates that the model could be easily and reliably applied in practice.

In vitro multi-enzymatic method is a two-step procedure that uses exogenous enzymes for incubation of feed that aim to imitate digestive processes in the animal. It is used for determination of organic matter digestibility (OMD) of various feedstuffs and complete mixtures used in ruminant nutrition. The aim of the present work was to determine whether this in vitro multi-enzymatic method can be applied for the assessment of the influence of thermal treatments on OMD of feed for ruminants. Samples of corn and complete mixture for cows (based on corn) were subjected to pelleting, steam flaking, micronization and extrusion. Statistical analysis of the results did not show significant increase of corn and complete mixture OMD after various thermal treatments compared to untreated samples, which can be explained by high digestibility of corn itself (exceeds 90%). Based on obtained results it can be concluded that applied in vitro method is not suitable for the assessment of the influence of thermal treatments on OMD of corn and corn based mixture, while future research should be broadened to analysis of samples with lower OMD, such as sorghum, oats and barley.

Water stability of eight samples of extruded salmon feeds was first determined by applying two gravimetric methods developed by the authors: gravimetric static and wet sieving method. Then, the conductometric method, primarily developed for investigation of nutrient leaching of feed into the water by the authors, was used for each sample. The aim of this study was to evaluate the potential of the conductometric measurement as a technique for determining water stability of extruded fish feed. In order to find any correlation between the results of two gravimetric tests and conductometric method, correlation analysis was employed. The results of static and wet sieving method were expressed as water stability index, which was expressed as the percent of remained dry matter of sample after being disintegrated in the water. The results of conductometric method were shown as conductivity curves for each sample, giving the insight in rate of nutrient leaching during the time. The obtained values of water conductivity showed no significant (p < 0.05) correlation with the results of static water method, while there was a negative significant (p < 0.05) correlation with the results of wet sieving method during first four hours of pellets soaking in water. The highest correlation coefficients were obtained within the first hour of conductivity measurement, demonstrating that proposed conductometric method had a potential to be applied as a rapid and simple method for determination and relative comparison of salmon feed water stability.[ Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III46012 and Grant no. TR31011]

Changes in the milk composition during early, middle and late stage of lactation period were monitored in 10 individual autochthonous donkeys of the Domestic Balkan breed. Animals were grazing ad libitum during early and middle lactation, while supplements (meadow hay, corn and corn stalks) were added during the late lactation period. The aim of this study was to evaluate the main compounds of donkeys’ milk during different periods of lactation. Based on the obtained results it was noticed that nutritional effects on milk composition were the greatest in the early and middle lactation. Chemical analysis indicated that donkeys’ milk was quite poor in dry matter (8.82-9.68%), fat (0.54-0.67%) and protein (1.44-1.79%), and conversely was high in lactose content (6.06-7.12%). Concentration of vitamin C varied significantly (P

Each category of pigs is susceptible to diseases caused by pathogenic bacteria, which negatively reflects on animal health, farm production results or meat quality. Animal feed is one of the potential reservoirs of pathogenic bacteria and infection source of domestic animals. Salmonella spp. is major microbiological hazard in animal feed. Thus, there is importance for implementation of strategies for preventing feed contamination with Salmonella, by minimizing dust, maximizing hygiene of space and processing equipment in feed mills and implementing control measures in each stage of feed production. Existing Salmonella feed contamination can be eliminated by conditioning and later different heat treatments (pelleting, extrusion, expansion) in production process while changing physical structure of the feed (coarsely or finely ground mash or pellets) can influence on conditions for Salmonella development in gastrointestinal tract of pigs. Contamination of feed by pathogenic bacteria and conditions for their development can be also controlled by addition of acidifiers, prebiotics, probiotics and, more recently, essential oils of plant origin, into feed. Various strategies for prevention of feed bacterial contamination, processes for feed decontamination, as well as possibilities for controlling pathogenic bacteria, especially Salmonella, in pig feed were presented and discussed in this article.

Тhe paper presents results of the investigation of the influence of extrusion temperature and moisture content of treated material on the reduction of cyanogenic glycosides (CGs) in linseed-based co-extrudate. CGs are the major limitation of the effective usage of linseed in animal nutrition. Hence, some technological process must be applied for detoxification of linseed before its application as a nutrient. Extrusion process has demonstrated several advantages in reducing the present CGs, since it combines the influences of heating, shearing, high pressure, mixing, etc. According to obtained results, the increase in both temperature and moisture content of the starting mixture decreased the content of CGs in the processed material. HCN content, as a measurement of GCs presence, ranged from 25.42 mg/kg, recorded at the moisture content of 11.5%, to 126 mg/kg, detected at the lowest moisture content of 7%. It seems that moisture content and temperature had the impact on HCN content of equal importance. However, the influence of extrusion parameters other than temperature and moisture content could not be neglected. Therefore, the impact of individual factors has to be tested together. [Projekat Ministarstva nauke Republike Srbije, br. III 46012]

The main purposes of this work are successful modeling of twin‐screw extrusion process using predictive models, investigating the effect of process parameters such as screw speed, feed rate, and feed moisture content on the process and product responses and finally optimizing the process regarding betaine content in the extruded product and energy consumption. The second order polynomial approximation models and the artificial neural network were developed to predict the betaine content, showing the high accuracy in the prediction of experimental results. This study introduces the multiobjective optimization (MOO) approach in the extrusion process of spelt flour. The maximal betaine content (between 1,506.8 and 1,605.2 mg/40 g) and minimal energy consumption (between 101.3 and 108.5 W hr/kg) were indicated by MOO procedure, which were gained using the following input parameters: feed flow rate feed about 24 kg/h, screw speed about 252 RPM and moisture content from 21.6 to 23.4%. Practical applications: This study introduces the multiobjective optimization (MOO) approach in the extrusion process of spelt flour, which provides the selection of optimal solution that enables the extruder to reach the optimum conditions of the process and provide decision maker with deeper understanding of the process. The present study analyzes the influence of extrusion cooking parameters like: screw speed, feed flow rate, and feed moisture content on the betaine content in the extrudate product and specific mechanical energy input during the processing of betaine enriched spelt flour based extrudates. One way to improve the intake of betaine in the general population can be to enrich foods with betaine. According to European Breakfast Cereal Association for extruded products portion sizes should be 40 g. Consuming a portion of a functional extrudate product with the addition of betaine (1,500 mg/day) could give expected health effects. Final extrudate product from this study satisfies these statements. [ABSTRACT FROM AUTHOR]