The effect of various doses of an exogenous acid protease on the fermentation and nutritive value of corn silage

Abstract

The objective of this experiment was to evaluate the effects of treating whole-plant corn at harvest with various doses of an exogenous acidic protease on fermentation and changes in nutritive value after a short period (45 d) of ensiling. Whole-plant corn (37% dry matter) was chopped and treated with 0, 20, 200, 1,000, or 2,000 mg of protease/kg of wet forage. Forages (~500 g) were packed in bag silos and ensiled at 22 to 23°C for 45 d. Data were analyzed as a 5 × 2 factorial arrangement of treatments with the main effects of the dose of protease, day of ensiling, and their interaction. Treatment with protease did not alter the concentrations of dry matter, neutral detergent fiber, acid detergent fiber, starch, lactic acid, or acetic acid compared with untreated silage, with the exception that the concentration of starch was lower in silage treated with 20 mg of protease/kg compared with untreated silage. However, the 2 highest doses of protease resulted in silages with higher concentrations of ethanol and more yeasts compared with untreated silage. Protease treatment did not affect the ruminal in vitro digestibility of neutral detergent fiber. Concentrations of soluble protein (percentage of crude protein) increased after ensiling for all treatments but was not different between silage treated with the lowest dose of protease and untreated silage. Soluble protein increased in a dose-dependent manner above the low dose of protease in silages. Concentrations of NH 3-N were higher only in silages treated with the 2 highest doses of protease compared with untreated silage. Silages treated with the 3 highest doses of protease were higher in ruminal in vitro digestibility of starch compared with untreated silage but were similar to each other. The concentrations of total AA were determined in fresh forage and silages for the untreated and 200 and 2,000 mg/kg doses of protease. Neither amount of added protease affected the total concentrations of essential, nonessential, or total AA in silage. However, of the essential AA, treatment with protease resulted in silages with lower concentrations of lysine and arginine but higher concentrations of leucine compared with untreated silage. The 200 mg/kg dose of protease substantially improved ruminal in vitro starch digestion in corn silage after a short period of ensiling without affecting concentrations or numbers of ethanol and yeasts, respectively.

Effects of Age, Diet CP, NDF, EE, and Starch on the Rumen Bacteria Community and Function in Dairy Cattle

“…The digestive enzyme could catalyze and decompose feedstuff into molecules for animals to use, for example, amylase could decompose the starch into glucose and further enhance the ruminants’ starch digestibility [ 7 ]. The exogenous protease could alert the amino acid composition and improve the starch digestibility of corn silage [ 8 ]. Bacteria, enzymes, and the VFA, MCP, pH, and NH 3 -N, are closely related and jointly assist in completing the rumen digestive function.…”

Effects of exogenous α-amylases, glucoamylases, and proteases on ruminal in vitro dry matter and starch digestibility, gas production, and volatile fatty acids of mature dent corn grain

“…In agreement, Colombatto and Beauchemin (2009) , when testing an exogenous protease have reported greater IVDMD of several substrates including a TMR after 22 h of incubation. Similarly, studies evaluating the effects of proteases as silage additives have reported greater IVSD when compared with control ( Ferraretto et al, 2015a ; Ferraretto et al, 2015b ; Der Bedrosian and Kung Jr, 2019 ).…”

“…Similarly, exogenous proteases or blends of enzymes containing proteases have been evaluated as feed additives in total mixed ration (TMR) of both dairy and beef cows; however, studies have reported greater ( Eun and Beauchemin, 2005 ; Gado et al, 2009 ) or no effect ( Vera et al, 2012 ; Meschiatti et al, 2019 ) on animal performance when compared with control. Exogenous proteases have also been used as additives in high-moisture and whole-plant corn silage and results showed greater corn starch digestibility when compared to control due to the breakdown of the protein matrix surrounding the starch granules ( Young et al, 2012 ; Kung Jr et al, 2014 ; Ferraretto et al, 2015a ; Der Bedrosian and Kung Jr, 2019 ). Despite these studies, there is limited literature available on the effects of the direct addition of endo-acting α-amylases and proteases on mature corn grain on in vitro dry matter and starch digestibility.…”

Effect of Forage Processor Roll Gap Width and Storage Length on Fermentation Profile, Nutrient Composition, Kernel Processing Score, and Starch Disappearance of Whole-Plant Maize Silage Harvested at Three Different Maturities

“…The effects of mechanical processing and storage on the AA profile of WPMS are often overlooked in silage research. Der Bedrosian and Kung [52] observed that ensiling had no effect on the concentrations of total NEAA and total AA. However, ensiling caused a slight decrease in total EAA [52].…”

“…Der Bedrosian and Kung [52] observed that ensiling had no effect on the concentrations of total NEAA and total AA. However, ensiling caused a slight decrease in total EAA [52]. Changes in concentrations of the total AA have been reported when forages are ensiled [53].…”