تأثیر پرایمینگ بر عملکرد جوانه، ترکیب شیمیایی، قابلیت هضم و جمعیت پروتوزوآی شکمبه‌ای علوفه هیدروپونیک جو و مقایسه آن با قصیل جو

The escalating challenges posed by climate change and recurrent droughts have significantly intensified the need for novel and sustainable strategies to ensure adequate livestock feed supply. In this critical context, hydroponic cultivation systems have emerged as an efficient and promising alternative for producing green fodder. This innovative soil-less technology enables the commercial production of plants from germination to harvest, offering a consistent, year-round feed source. Hydroponic systems meticulously control environmental factors like temperature, light, humidity, and ventilation, facilitating the daily production of substantial quantities of nutritious green fodder, applicable for diverse livestock. A paramount advantage of this method lies in its optimized water consumption, requiring significantly less water per kilogram of fodder produced compared to conventional agriculture. Barley is a particularly suitable grain for hydroponic fodder. Its germination process activates crucial biochemical pathways, involving the breakdown of stored starch, protein, and lipid reserves, leading to enhanced soluble sugars, protein, and other nutrients in the fodder. To further optimize both the quality and speed of germination in hydroponic cultivation, seed priming has been identified as an effective strategy. Priming involves pre-soaking seeds in specific solutions (water, nutrients, or hormones) for a defined period, followed by drying, which enhances germination by activating vital metabolic pathways. While existing research has explored priming's quantitative and qualitative effects, there's a notable gap in studies specifically examining its comprehensive impact on chemical composition, digestibility, and ruminal fermentation parameters within hydroponic systems. Therefore, this study aimed to comprehensively evaluate the effects of various priming treatments on germination traits, chemical composition, digestibility, and ruminal protozoal population of hydroponic barley fodder, comparing it with traditional barley hay.
Materials and Methods: This comprehensive research was conducted in 2018 at Gonbad Kavous University laboratories, following a completely randomized design with three replications. Barley seeds, disinfected with 1% sodium hypochlorite and rinsed, underwent seven priming treatments: 1) Control (dry seeds), 2) Hydropriming (distilled water, 12 h), 3) Halopriming (1% potassium nitrate, 24 h), 4) Osmopriming (13.5% polyethylene glycol, 12 h), 5) Hormopriming with Salicylic Acid (50 ppm, 12 h), 6) Hormopriming with Cytokinin (50 ppm, 12 h), and 7) Hormopriming with Gibberellin (50 ppm, 24 h). After priming, seeds were dried and cultivated hydroponically for 7 days. For comparison, traditional barley hay was also cultivated. Chemical composition (DM, OM, Ash, EE and CP) was determined by AOAC (2005) methods. NDF and ADF were quantified following Van Soest et al. (1991). TDN, NEL, and NEg were estimated using NRC (2001) relationships. In vitro gas production was assessed using rumen fluid from fistulated sheep. Gas production was recorded over time, and parameters were calculated using the Ørskov and McDonald (1979) model. SCFA, estimated OMD and ME were also determined. In vitro digestibility was measured via the batch culture method (Theodorou et al., 1994), including microbial biomass production and ammonia nitrogen. Ruminal protozoa were enumerated microscopically. Data were statistically analyzed using SAS (2000) GLM procedure, with means compared by LSD test.
Results: Results showed that priming significantly improved germination speed (P<0.01) and seedling vigor index (P<0.01); specifically, cytokinin exhibited the highest germination speed (23.64), and potassium nitrate resulted in the highest seedling vigor index (20838.1). Regarding chemical composition, the control (non-primed) treatment showed the highest dry matter (26.37%) and crude protein (19.61%), while priming with cytokinin and salicylic acid led to increased gas production potential (approx. 387 mL/g DM) and short-chain fatty acids (approx. 1.51 mmol). In vitro dry matter and organic matter digestibility of control and distilled water-primed hydroponic fodder (e.g., 78.2% DMD and 79.01% OMD for control) were significantly higher than other treatments and conventional barley forage (55.53% DMD). Priming generally reduced the total rumen protozoa population compared to the control (approx. 323×105 cells/mL).
CThe escalating challenges posed by climate change and recurrent droughts have significantly intensified the need for novel and sustainable strategies to ensure adequate livestock feed supply. In this critical context, hydroponic cultivation systems have emerged as an efficient and promising alternative for producing green fodder. This innovative soil-less technology enables the commercial production of plants from germination to harvest, offering a consistent, year-round feed source. Hydroponic systems meticulously control environmental factors like temperature, light, humidity, and ventilation, facilitating the daily production of substantial quantities of nutritious green fodder, applicable for diverse livestock. A paramount advantage of this method lies in its optimized water consumption, requiring significantly less water per kilogram of fodder produced compared to conventional agriculture. Barley is a particularly suitable grain for hydroponic fodder. Its germination process activates crucial biochemical pathways, involving the breakdown of stored starch, protein, and lipid reserves, leading to enhanced soluble sugars, protein, and other nutrients in the fodder. To further optimize both the quality and speed of germination in hydroponic cultivation, seed priming has been identified as an effective strategy. Priming involves pre-soaking seeds in specific solutions (water, nutrients,
Materials and Methods: This comprehensive research was conducted in 2018 at Gonbad Kavous University laboratories, following a completely randomized design with three replications. Barley seeds, disinfected with 1% sodium hypochlorite and rinsed, underwent seven priming treatments: 1) Control (dry seeds), 2) Hydropriming (distilled water, 12 h), 3) Halopriming (1% potassium nitrate, 24 h), 4) Osmopriming (13.5% polyethylene glycol, 12 h), 5) Hormopriming with Salicylic Acid (50 ppm, 12 h), 6) Hormopriming with Cytokinin (50 ppm, 12 h), and 7) Hormopriming with Gibberellin (50 ppm, 24 h). After priming, seeds were dried and cultivated hydroponically for 7 days. For comparison, traditional barley hay was also cultivated. Chemical composition (DM, OM, Ash, EE and CP) was determined by AOAC (2005) methods. NDF and ADF were quantified following Van Soest et al. (1991). TDN, NEL, and NEg were estimated using NRC (2001) relationships. In vitro gas production was assessed using rumen fluid from fistulated sheep. Gas production was recorded over time, and parameters were calculated using the Ørskov and McDonald (1979) model. SCFA, estimated OMD and ME were also determined. In vitro digestibility was measured via the batch culture method (Theodorou et al., 1994), including microbial biomass production and ammonia nitrogen. Ruminal protozoa were enumerated microscopically. Data were statistically analyzed using SAS (2000) GLM procedure, with means compared by LSD test.
Results: Results showed that priming significantly improved germination speed (P<0.01) and seedling vigor index (P<0.01); specifically, cytokinin exhibited the highest germination speed (23.64), and potassium nitrate resulted in the highest seedling vigor index (20838.1). Regarding chemical composition, the control (non-primed) treatment showed the highest dry matter (26.37%) and crude protein (19.61%), while priming with cytokinin and salicylic acid led to increased gas production potential (approx. 387 mL/g DM) and short-chain fatty acids (approx. 1.51 mmol). In vitro dry matter and organic matter digestibility of control and distilled water-primed hydroponic fodder (e.g., 78.2% DMD and 79.01% OMD for control) were significantly higher than other treatments and conventional barley forage (55.53% DMD). Priming generally reduced the total rumen protozoa population compared to the control (approx. 323×105 cells/mL).
Conclusion: Overall, the findings indicate that priming can influence certain aspects of hydroponic barley fodder's germination and nutritional characteristics. However, its application requires careful evaluation to ensure optimal effects on chemical composition and rumen parameters. Notably, hydroponic barley fodder consistently demonstrated superiority in many nutritional aspects compared to conventional barley forage, regardless of the specific priming treatment.