Authors
1
Department of Animal Science, Faculty of Agriculture and Natural resources, Gonbad kavous University, Iran
2
dept. of animal sciences
3
Department of Animal Science, Faculty of Agriculture and Natural Resources, Gonbad Kavous University
4
Department of Animal Science, Faculty of Agriculture and Natural Resources,, Gonbad kavous University
Abstract
Backgrounds and objectives: Using agricultural by-products is a good strategy to compensate for the lack of common feed ingredients. Date is one of the most important products of dry regions and Middle East countries, which play an important role in the lives of people in these regions. Date kernel is a by-product that remain during date processing. Due to the high lignocellulosic part in date kernel, its proper processing will probably improve the efficiency of its use in livestock feed. The purpose of this study was to investigate the effect of chemical and biological processing methods on the nutritional value of date kernels.
Material and Methods: This research was conducted in two steps of in vitro and in vivo. First, date kernel powder using sodium hydroxide (NaOH, 50 gr/kg of DM) and hydrogen peroxide (H2O2, 57 ml/kg of DM) as chemical methods, and Aspergillus niger (5 x 105 spores/ml) and Bacillus subtilis (5×105 dilution/ml) were processed as biological methods. In the in vitro phase, the chemical composition, gas production parameters and digestibility of the samples were measured using the standard methods. Based on the results of this stage, a fattening trial was performed. This experiment was done for 84 days using 18 male Dallagh lambs (24.88±3.03 kg). The lambs were divided into 3 groups, and each group received one of the treatments. The treatments included: 1- basal diet, without date kernels, 2- diet containing date kernels treated with NaOH, and diet containing date kernels treated with H2O2. During the fattening period, the amount of feed intake was calculated daily. Lambs were weighed every two weeks. The feed conversion ratio was obtained by dividing the average dry matter intake by the average weight gain of the animals. At the end of the experiment, 4 hours after morning feeding, rumen fluid was collected to measure pH and ammonia nitrogen. The data obtained from this experiment were analyzed according to completely randomized design.
Results: Processing was effective on the chemical composition of date kernel (P < 0.05). NaOH and H2O2 treatments increased the amount of ash in the samples. All treatments increased the amount of crude protein and ether extract, which was the highest amount in the samples treated with Bacillus subtilis and NaOH. The amount of neutral detergent fiber and acid detergent fiber decreased due to treating with H2O2 and Aspergillus niger. All treatments increased total digestible nutrients, net energy for lactation and net energy for gain. Gas production rate and estimated parameters including metabolizable energy, organic matter digestibility and short-chain fatty acids were increased by H2O2 treatment (P<0.05). The in vitro digestibility of dry matter and organic matter, partitioning factor and microbial biomass produced after 24 hours of incubation in samples treated with NaOH and H2O2 was higher than other treatments (P< 0.05). In the perfirmance trial, the use of date kernel treated with chemical treatments had no effect on feed intake, weight gain and feed conversion ratio of fattening lambs. The pH value and ammonia nitrogen concentration were the same between the different treatments.
Conclusion: The results of this study showed that the use of date kernel powder in the diet had no adverse effect on the performance parameters of lambs. Therefore, due to the cost-effectiveness of this by product, it is suggested to use it up to 15% in the ration of fattening lambs
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