Composition and In Vitro Gas Production Evaluation of Corn Silage Cultivated at Twenty and Thirty Thousand Plants per Feddan

Corn hybrid single cross ۱۰ (S.C. ۱۰) was cultivated at two planting density rates of low density was ۲۰ thousand plants per feddan (۲۰ TPF) or high density was ۳۰ thousand plants per feddan (۳۰ TPF) with a split-plot design with randomized complete blocks arrangement in two plant density. Whole corn plants were harvested at the dough stage of maturity (۹۲ days), chopped and ensiled in double plastic bags in three replicates for each density, pressed by hand to exclude the air from the bags and ensiled for ۳۵ days. Results showed that the contents of NFE and NFC were higher, but CF and fiber fractions of corn silage were lower significantly (P<۰.۰۵) for low plant density compared to high plant density. Gas production and its fractions of soluble (a) and insoluble (b) as well as gas production rate (c) values were significantly (P<۰.۰۵) higher for low plant density. However, methane production was significantly (P<۰.۰۵) higher for high plant density. Gas production from soluble fraction (GPSF), insoluble fraction (GPNSF), short chain fatty acids (SCFA), predicted dry matter intake (DMI), organic matter digestibility (OMD), in vitro dry matter degradability (IVDMD) and microbial protein (MP) were significantly higher (P<۰.۰۵) for low plant density compared to high plant density. While, predicted metabolizable energy (ME) and net energy (NE) were nearly similar for both low and high plant density.Corn hybrid single cross ۱۰ (S.C. ۱۰) was cultivated at two planting density rates of low density was ۲۰ thousand plants per feddan (۲۰ TPF) or high density was ۳۰ thousand plants per feddan (۳۰ TPF) with a split-plot design with randomized complete blocks arrangement in two plant density. Whole corn plants were harvested at the dough stage of maturity (۹۲ days), chopped and ensiled in double plastic bags in three replicates for each density, pressed by hand to exclude the air from the bags and ensiled for ۳۵ days. Results showed that the contents of NFE and NFC were higher, but CF and fiber fractions of corn silage were lower significantly (P<۰.۰۵) for low plant density compared to high plant density. Gas production and its fractions of soluble (a) and insoluble (b) as well as gas production rate (c) values were significantly (P<۰.۰۵) higher for low plant density. However, methane production was significantly (P<۰.۰۵) higher for high plant density. Gas production from soluble fraction (GPSF), insoluble fraction (GPNSF), short chain fatty acids (SCFA), predicted dry matter intake (DMI), organic matter digestibility (OMD), in vitro dry matter degradability (IVDMD) and microbial protein (MP) were significantly higher (P<۰.۰۵) for low plant density compared to high plant density. While, predicted metabolizable energy (ME) and net energy (NE) were nearly similar for both low and high plant density.

Keywords:

Corn silage , plant density , gas production , energy content , microbial protein