Welcome to Acta Prataculturae Sinica ! Today is Share:

Acta Prataculturae Sinica ›› 2021, Vol. 30 ›› Issue (8): 154-163.DOI: 10.11686/cyxb2020313

Previous Articles    

Associative effects between whole crop maize silage and mixed silage made from raw potato crisp processing by-product and rice straw as determined using an in vitro gas production technique

Yuan-yuan WEN1(), Mei-qi ZHANG1, Tao-tao LIU1, Yi-zhao SHEN1, Yan-xia GAO1,2, Qiu-feng LI1,2(), Yu-feng CAO1,2(), Jian-guo LI1,2()   

  1. 1.College of Animal Science and Technology,Hebei Agricultural University,Baoding 071000,China
    2.Embryo Engineering and Technological Center of Cattle and Sheep of Hebei,Baoding 071000,China
  • Received:2020-07-06 Revised:2020-08-10 Online:2021-07-09 Published:2021-07-09
  • Contact: Qiu-feng LI,Yu-feng CAO,Jian-guo LI

Abstract:

The aim of this study was to evaluate the associative effects between whole crop maize silage (WCS) and mixed silage made from raw potato crisp processing by-product and rice straw (PRS). The PRS (35% dry matter) was produced by mixing potato crisp processing by-product with rice straw at a ratio of 1∶2, adding silage additive, mixing with a blender, bundling and wrapping the silage substrate using a machine, and then fermenting for 60 days. The treatments consisted of seven combinations of PRS and WCS at different ratios: 0∶100 (T0), 20∶80 (T20), 40∶60 (T40), 50∶50 (T50), 60∶40 (T60), 80∶20 (T80), and 100∶0 (T100) on a dry matter (DM) basis. Each combination had three replicates. Gas production (GP) was measured using an in vitro method. Dry matter digestibility (DMD), pH, and the concentrations of ammonia nitrogen (NH3-N), microbial protein (MCP), and volatile fatty acids (VFA) were determined at 48 h of incubation. The GP was recorded at 2, 4, 6, 8, 10, 12, 24, 36, and 48 h of incubation. The single factor associative effects index (SFAEI) and multiple factors associative effects index (MFAEI) of different combinations were calculated. The results show that: 1) GP and DMD decreased significantly or extremely significantly (P<0.05 or P<0.01) as the proportion of PRS increased. The SFAEIs of GP and DMD were the lowest in the T50 and T80 groups, respectively, and the highest values of those indexes were in the T20 group. 2) The pH of different combinations ranged from 6.46 to 6.59. The pH of the T80 group was the highest, and was significantly or extremely significantly higher than that in other groups, except for the T100 group (P<0.05 or P<0.01). The highest SFAEI of pH was in the T80 group. 3) There was no significant difference in NH3-N concentrations and MCP production among different combinations (P>0.05), but the highest values were in the T40 group. The SFAEIs of NH3-N and MCP were highest in the T40 and T80 groups, respectively. 4) The concentrations of acetic acid, propionic acid, valeric acid, and total VFAs were highest in the T0 group and lowest in the T100 group, and the differences between the two groups were extremely significant (P<0.01). The concentration of butyric acid was highest in the T0 group and lowest in the T80 group. The highest SFAEIs of acetic acid, propionic acid, and butyric acid were in the T80, T20, and T60 groups, respectively. According to the MFAEI index evaluation, two combinations had positive associative effects; The combination in the T40 group (40∶60) had the best effect, followed by that in the T50 group (50∶50).

Key words: raw potato crisp processing by-product, rice straw, whole corn silage, in vitro fermentation, associative effects