Effect of using different fertilizers sources on forage sorghum yield, digestibility and energy parameters by In vitro Gas Test production

Abstract

The effect of using different rates of organic and mineral fertilization on forage sorghum was studied. An experiment was conducted at the Agricultural Research and Experimental Station, Cairo University in 2013 and 2014 summer seasons. The experiment was performed in a randomized complete design with three replicates. The experiment included five treatments; the T1 (control)= 100% mineralization, T2 (C6M0) =100% compost, T3 (C4.5M25%) = 25% minerals + 75% compost, T4 (C3M50%)= 50% minerals+50% compost and T5 (C15M75%) = 75% minerals+25% compost. The results showed significant increases in plant height, stem thickness, fresh weight and dry weight for the T3 compared with the other treatments, while means value were 152.4 cm, 1.047 cm, 22.96 ton. /fed and 6 ton/fed, respectively. Moreover, T3 (C4.5M25%) led to increasing the content of CP and NFE and did not affect the EE and ash. While this treatment led to increasing the content of NDF%, ADF% and decreasing the content of hemi cellulose and higher content of cellulose compared to the other treatments. The results of gas parameters correct (GP ml /200 mg DM), gas production structure fraction (GPSF %) and gas production non-structure fraction (GPNSF %) recorded the best values with the T2 (C6M0). The highest values of each of (GP ml / 200 mg. DM), (GPSF %) and (GPNSF %) was recorded in the 1st and 2nd cut, while the T4 (C3M50%) gave the highest value in the 3rd cut. The T2 recorded the highest values ​​of ME (MJ / Kg. DM) in the 1st cut and the net energy lactation (NELMJ/kg.DM) in the 2nd cut. The short-chain fatty acids (SCFA, s m mol / ml. gas) showed the highest values ​​in the 1st and 2nd cut, while for the T4 (C3M50%) showed the highest values ​​in the 3rd cut. The T2 recorded a significant increase in dry matter and organic matter digestibility in the 1st cut followed by the T4 which recorded the highest value in the 1st cut. The economic study proved that the T3 (C4.5M25%) has the highest profit (2.29 L.E.), the T4 = (2.46 L.E.) and the lowest return of the T2 = 100% organic gave a profit of (1.90 L. E.). The T2 gave the highest digestive value for the 1st and 2nd cut, followed by the T4 which gave the highest digestive value in the 3rd cut. Finally, we can conclude that the T2 is the best treatment in terms of feeding animal and the size of the crop in the 2nd cut is like the size of the crop in the 3rd cut of the T4, which gave the best economic feasibility using the 2nd cut of the T2 to provide the time of cultivation for another crop. In addition, necessary work of the digestion and feeding trails on the animal on these 2nd cut of T2 which gave positive results in order to link the amount of yield in the 1st and 2nd cut and digestion factors and measure the amount of meat produced to determine the economic efficiency in obtaining a good crop in arms of quantity and quality and reduce the crop duration to provide land for cultivation another crop as well as reducing the mineral contamination of the fertilizer-producing soil.