جستجوی مقالات مرتبط با کلیدواژه "علوفه جو" در نشریات گروه "علوم دام"

Green fodder is one of the components that is given special attention when preparing animal rations, due to its palatability and high digestibility. Green fodder in the livestock ration has an effect on maintaining health and improving the productive and reproductive efficiency of livestock, and it may also affect the quality of meat. On the other hand, the main problem in fodder production in the world is the lack of access to sufficient water for the cultivation and growth of fodder. The occurrence of continuous drought in recent years in the country has made the production of green fodder a problem and has pushed opinions towards sustainable methods including the hydroponic method. In this method, agricultural soil is not used for growing plants and feeding is done in a solution that contains all the necessary elements for the plant. There is no report regarding the effect of this food source on the quality of meat of livestock. Since at the time of introducing a feed source for livestock, all its dimensions or in fact its nutritional value must be measured, so this study was conducted with the aim of investigating the effect of consumption of different levels of barley hydroponic fodder on the qualitative and sensory characteristics of goat meat.

This experiment was performed with 28 Fars native male goats that were placed in individual cages in four treatments and seven replicates in a completely random design. The experimental treatments included the replacement of barley hydroponic fodder at three levels of 25, 50 and 75% instead of alfalfa (in terms of dry matter) in the diet and a control treatment without replacement. The ration was balanced based on the standard tables of goat nutrients recommended by Nutrient Requirements Council for Small Ruminants. After 90 days from the start of the experiment, six goats from each treatment were slaughtered and after 24 hours of cooling of the carcass at four ºC, the Longissimus dorsi muscle was separated, divided into smaller pieces and labeled to determine physical, chemical, textural and sensory factors. Chemical tests including measurement of intermuscular fat, protein and ash in meat samples were carried out by standard methods and the amount of dry matter of the samples was measured by placing about three grams of the sample at a temperature of 102 ± 2 ºC for three hours. The Keldahl method was used to measure the total content of volatile nitrogen and a digital pH meter set at 25 ºC was used to measure the pH. Fat oxidation rate in meat samples was determined by malondialdehyde method. Digital imaging and plastic bag methods were used to evaluate color and loss weight after storage of meat samples, respectively. The water holding capacity was determined by centrifuging the sample placed in filter paper for 4 minutes at 1500 rpm and recording the weight and then placing it in the oven at 70 ºC for 24 hours. Loss after cooking was calculated by placing the sample for one hour in a water bath at 90 ºC. Texture factors, including hardness, adhesiveness, cohesiveness, springiness and chewiness were measured by preparing cubic pieces with dimensions of one centimeter from the meat samples and using a texture testing machine. This device was equipped with a steel cylindrical probe with a diameter of six mm and a height of 35 mm. The probe of the device was inserted into the tested sample twice at a speed of two millimeters per second and up to 50% of the probe height, and the results were recorded by the device software. Sensory characteristics of meat samples, including color, smell, tenderness and overall acceptance wad evaluated by a panel group who completed a designed questionnaire based on the hedonic test. One-way analysis of variance was used in order to investigate the physicochemical and tissue characteristics in different treatments. In cases where there was a significant difference between the treatments, the averages were compared with Duncan's test. The results of the panel test were analyzed with the Kruskal -Wallis test.

There was not significant difference in the amount of fat (range of 10.08-13.87%), dry matter (range of 29.08-31.55%), ash (range of 0.93-1.15%) and total volatile nitrogen (range of 20.25-25.33 mg/100g) between the control group and experimental treatments. The results showed that the replacement of barley hydroponic fodder by 25% instead of alfalfa in the diet caused a significant increase in the amount of meat protein (P=0.0136) and oxidation (P=0.0497) and a significant decrease (P=0.0132) in loss of cooking compared to control treatment and other experimental treatments. There was no statistically significant difference in the recorded values for the texture evaluation and sensory scores of the meat between the experimental treatments and the control group. The overall acceptance of the meat samples in all the investigated treatments had a score of more than five and were placed in the moderately favorable level.

Finally, it can be concluded that the replacement of hydroponic barley fodder instead of alfalfa in the ration of fattening goats up to the level of 75%, did not have negative effects on the chemical, physical and oxidative stability of the meat during storage in the refrigerator or freezer. Also, the use of barley hydroponic fodder in proportions of 25, 50, and 75% (instead of alfalfa and 10, 20, and 30% of dry matter of the ration) did not have adverse effects on the redness, tenderness, and smell of meat. The scores obtained for overall acceptance showed that there was no significant difference in terms of sensory characteristics between the meat of the experimental treatments and the control.