†Corresponding authors, Email:email@example.com Mini abstract: Sesame stover, from Iranian plant varieties adapted to grow in semi-arid condition, was provided. Treatments were: untreated Sesame stover (SS), SS+urea, SS+NaOH and SS+ NaOH+urea. In vitro gas production parameters of the samples were determined. Gas production was increased when sesame stover was treated with urea and/or NaOH. When samples were treated with NaOH, a greater increase in gas production from fermentable fraction was observed. However, gas production fractional rate (c) in SS (0.11 ± 0.01, h-1) was greater than the other samples.
Introduction:Sesame stover is the most abundance residual of sesame cultivation in semi-arid regions of Iran, and traditionally used as a basal feed in sheep and goats nutrition. However, voluntary feed intake and total tract degradability of this stover are limited by its high complex- carbohydrate content and lignin. The feeding value of forage can often be improved with some additives such as urea and sodium hydroxide (Schingoethe et al., 1980). Amount of gas produced from a feed is used as an index of its digestibility potential (Menke and Steingass, 1988). The aim of the present study was to evaluate the vitro gas production parameters of sesame (Sesamum indicum) stover treated with NaOH and /or urea.
Materials and Methods:Samples of sesame stover were obtained from Iranian plant varieties adapted to grow in semi-arid condition. Treatments were: untreated Sesame stover (SS), SS plus urea (SSU, 3 g/100 g DM, ensiled for one week at DM= 50%), SS plus NaOH [SSN, 4 g/100 g DM of a NaOH solution (20% w/v) was sprayed on the stover and kept for 48 h] and SS plus both NaOH and urea [SSUN, NaOH (20% w/v) as 4 g/100 g DM was sprayed on the stover and kept for 48 h, then, urea (3 g/100 g DM) was added and ensiled for one week at DM= 50%]. In vitro gas production parameters of the samples were determined using the Menke and Steingass (1988) procedure. Approximately 0.3 g of dried sample (n= 3) was placed in a 100 ml glass syringes and then incubated into 40 ml of buffered rumen fluid (ratio of buffer to rumen fluid was 2:1), for 2, 4, 8, 12, 16, 24, 36, 48, 72 and 96 h. Rumen fluid was obtained from three sheep (49.5 ± 2.5 kg) fitted by rumen fistulae, before the morning feeding, and immediately strained through four layers of cheesecloth. The animals fed 1 kg d-1 of DM of lucerne hay and 0.3 kg d-1 of DM concentrates (165 g CP/ kg of DM). The gas production data were fitted in a exponential equation of P= b (1−e−Ct), where bis the gas production from quickly and slowly fermentable fraction, c is the fractional gas production rate (/ h),t is the incubation time (h) and P is the potential of gas produced at time t. Results: The effects of NaOH and/or urea on in vitro gas production parameters (b and c) of sesame stover are shown in Table 1. Gas production was increased when sesame stover was treated with urea and/or NaOH. However, NaOH caused to greater increase in gas production from fermentable fraction. Fractional rate constant (c) of gas production in SS (0.11 ± 0.01, h-1) was greater than the other samples.
Table 1 In vitro gas production parameters of sesame stover (mean± SE) treated with NaOH and/or urea
40.85 ± 0.64
46.89 ± 0.5
61.5 ± 0.6
61.0 ± 1.0
0.11 ± 0.010
0.07 ± 0.003
0.07 ± 0.002
0.09 ± 0.01
Conclusions:The in vitrogas production parameters of urea and/or NaOH treated sesame stover were greater compared with the untreated. The results of current study indicated that both urea and NaOH had a potential to enhance the stover digestibility as indicated by gas production under the present study condition. The results confirmed the findings of Schingoethe et al. (1980). However, it is a need to determine the gas composition of treated and untreated sesame stover.
Menke, K.H., and Steingass, H. 1988. Estimation of the energetic feed value obtained from chemical analysis and in vitro gas production using rumen fluid. Animal Research Development, 28: 7-55.
Schingoethe, D. J., Skyberg, E. W. and Rook, J. A.1980 Chemical composition of sunflower silage as influenced by additions of urea, dried whey and sodium hydroxide. Journal of Animal Science, 50: 625-629.
Keywords: Sesame stover, gas production, urea, NaOH