Yield, Chemical Composition, and Ruminai Fermentability of Corn Whole Plant, Ear, andStover as Affected by Hybrid

Abstract

Total dry matter (DM) yield and grain content are commonly considered the most important factors forevaluating corn (Zea mays L.) hybrids for silage production with no considerationgiven to the nutritive value of the nongrain portion of the plant. Because the nongrain portion mayrepresent over 50% of the total DM in corn silage, we hypothesized that hybrid differences inchemical composition and ruminai fermentability of the stover portion of the plant may account forimportant nutritional differences in corn hybrids. Six corn hybrids were planted at two locations(Nampa, ID, and Modesto, CA) and were harvested at three stages of plant maturity. Differences (P <0.01) in content of fiber components in whole plant and stover were observed amonghybrids. Ranges in hybrid means for whole plant and stover samples were: neutral detergent fiber(NDF), 41.7 to 49.0 and 50.3 to 64.1%; acid detergent fiber (ADF), 23.9 to 28.3 and 31.7 to 41.0%;cellulose, 19.2 to 22.6 and 25.5 to 33.1%; and lignin, 2.6 to 3.3 and 3.1 to 4.4%, respectively.Hybrid composition differences in total sugar and starch of stover and total sugar of whole plantalso were observed. In situ DM degradability after 24 h of ruminai incubation ranged among hybridsfrom 53.7 to 60.6% for whole‐plant samples and from 44.0 to 52.3% for stover samples. Importantly,those hybrids with lower fiber content or higher in situ fermentability did not necessarily havegreater proportion of grain in the whole plant, suggesting that selection of high quality silagehybrids may be accomplished by selecting for both high stover digestibility and high grain yields.Correlation coefficients for whole‐plant in situ DM degradability with neutral detergent fiber, aciddetergent fiber, cellulose, lignin, and starch were −0.85, −0.80, −0.79, −0.58, and 0.69,respectively. Results of this study indicate that differences among corn hybrids in whole‐plant andstover fiber content may be important in identification of hybrids with improved silage feedingvalue.

Corn Forage Yield and Quality for Silage in Short Growing Season Areas of the Canadian Prairies

“…In the present study, mean DMD ranged between 600 and 700 g kg −1 and mean NDFD between 500 and 550 g kg −1 of NDF, respectively. These mean values are consistent with the literature (from 450 to 700 g kg −1 for DMD, [9,32,33]; from 350 to 550 g kg −1 NDF for NDFD, [39,40]) and confirm that it is possible to achieve CS with high digestibility in Northern areas. The large range of digestibility reported in the literature is related to hybrid, planting date, environmental growing conditions, maturity at harvest, cutting height, and so forth.…”

“…In the present study, the mean NDF concentration (530 g kg −1 ) was greater than previously reported for CS (430 g kg −1 DM, 193,210 samples, [29]; 450 g kg −1 DM, [31]). Fiber concentration of CS typically declines with maturity due to dilution effects of increasing starch concentration [32,33]. Therefore, the greater mean NDF concentration is consistent with the lower mean starch concentration in this study (r = −0.71).…”

Utilization of Cellulolytic Enzymes to Improve the Nutritive Value of Date Kernels and the Investigation of the Impact of Adding these Enzymes to Lactating Goat’s Diets on Rumen Fermentation and Nutrients Digestibility

“…Therefore, to increase digestibility of these lignocellulosic materials, it is important to destroy the linkage between cellulose, hemicellulose and lignin or destroy the compact nature of the tissue. There have been attempts to increase the nutritive values of the by-products by mechanical, chemical or biological treatments (McHan, 1986a;Iyo and Antai, 1988;Hunt et al, 1992;Singh et al, 1993).…”

Apparent digestibility and nitrogen utilization of diets based on maize silage harvested at three stages of maturity and fed to steers

“…Advancing maize crop maturity is associated with an increase in ear‐to‐stover ratio. These two plant components differ widely in their chemical composition and rumen fermentation characteristics (Hunt et al. , 1992) which suggests that the nutritive value of maize silage may change with crop maturity.…”