The Effect of Palm Kernel Powder on Performance, Microbial Fermentation, Digestibility and Some Blood Parameters of Arabi sheep

Introduction The palm date kernel is energetic by-product of animal nutrition classified as medium-quality foods and crude protein content suitable for ruminants. The results of the studies indicate that there are large amounts of nutritious fibers in the palm kernel which are very useful in nutrition. It is reported that the amount of crude protein, NDF, ADF, cellulose; hemicellulose and lignin of palm kernel meal were expressed 4.9%, 21.1%, 40.7%, 43.3%, 26.4%, 6.4%, and 7.4%, respectively. Palm kernel contains all types of amino acids, including isoleucine, leucine, methionine, threonine, valine and phenylalanine and also phenolic compounds, flavonoids and carotenoids. Gross energy, crude fiber, carbohydrates and calcium of palm kernel were 4663 Kcal/Kg, 31.1, 77.2, 10.1 and 0.61%, respectively. The accessibility of amino acids in palm kernel is 65%. The information on using of palm kernel in the ruminant diets is rare. Therefore, the aim of this study was to evaluate the effect of palm kernel powder on performance, digestibility in Arabi sheep to reduce dietary prices and optimal use of agricultural by-products.Materials and methods In the first stage of experiment, the determination of proper level of the palm kernel, the values of 0, 5, 10, 15 and 20% of date kernels in the diet were used and the best amount was determined by in vitro digestion. In the second stage, 15 Arabi sheep with average weight 39±5 kg and 10 months of age were used in the completely randomized design for 50 days period. The experimental treatments were included control diet and diets containing 5 and 10% palm kernel (5 replicates for each treatment). Forage to concentrate ratio was 60 to 40. Diets fed twice per day. The palm kernel was prepared from Dardan company and milled. At the end of the experiment, nutrient intake, performance, digestibility, protozoa population, blood and fermentation parameters of sheep were measured. Parameters of digestion and fermentation of livestock after feeding with date kernels were also evaluated.For measuring fermentation and digestibility, the animals fed with experimental diets by in vitro methods, rumen fluid was collected from animals before the morning feeding. About 200 mg wheat straw incubated with buffered rumen fluid under continuous CO2 reflux in 100 ml vials for 2, 4, 6, 8, 10, 12, 16, 24, 48, 72 and 96 h, at 39 °C. Cumulative gas production data were fitted to the exponential equation. Partitioning factor, microbial biomass, actually degradable organic matter was calculated. Digestibility of dry matter the samples were determined by using tilly and terry method. Data were subjected to analysis as a completely randomized design using the General Linear Model (GLM) procedure of SAS.Results and Discussion In the first stage, among the various levels of palm kernel, amount of 5 and 10% of palm kernel had higher digestibility, respectively (P<0.05). Results of in vivo experiment has shown dry matter intake was increased in treatments containing palm date kernel, but digestibility of organic matter, dry matter and crude protein was decreased (P<0.05).The use of palm kernel increased the weight and improved feed conversion ratio in 5 and 10% date kernel. The blood glucose concentration did not affect by experimental treatments (P>0.05). The amount of BUN, creatinine, LDL and triglyceride significantly decreased by oak kernel treatments, but amount of blood cholesterol and HDL in treatments containing 10% increased (P<0.05). Protozoa population, rumen ammonia nitrogen and pH in diets containing palm kernel decreased as compared with that of the control diet (P<0.05).The potential and rate of gas production, microbial biomass efficiency and organic matter digestibility of soybean meal with rumen fluid animals fed with experimental diets for control treatment, and PF and microbial biomass for 10% palm date kernel significantly increased (P<0.05). Also the potential and rate of gas production of wheat straw with rumen fluid animals fed with experimental diets, microbial biomass and organic matter digestibility for control treatment, and PF and microbial biomass efficiency for 10% palm kernel significantly increased (P<0.05). There were significant amounts of lignin and resistant starch in the seed, phenolic compounds, volatile compounds and unsaturated fatty acids, flavonoids, carotenoids, and other compounds in the palm kernel that can influence parameters of current study.Conclusion According to the results of current study, due to the lack of negative effect on rumen fermentation and blood parameters and improving of performance, palm kernel can be used up to 10% in the Arabi sheep diet. Therefore, the use of palm kernels with the effect on the improving of livestock performance and high source of fiber, energy and fatty acids is an acceptable alternative to sheep diets.