Effect of Spring Maize Genotypes on Fermentation and Nutritional Value of Whole Plant Maize Silage in Northern Pakistan

Abstract

In the current study, we evaluated the growth, biomass yield, ensiling, and nutritional characteristics of spring maize genotypes grown under the climatic conditions of Northern Pakistan. Six promising spring maize genotypes were grown under uniform standard agronomic conditions in 72 plots (8 m × 10 m), blocked within three replicate fields. Maize crops were harvested at targeted dry matter (DM) content (33 g/100 g DM). Data were collected on plant phonological characteristics and biomass yield, and then the harvested crop of each plot was chopped, and subsamples were ensiled in three replicate 1.5 L laboratory silos (n = 12/genotype). After 90 days of ensiling, subsamples were analyzed for fermentation quality, nutrient composition, Cornell Net Carbohydrate and Protein System (CNCPS) carbohydrate subfractions, digestible nutrients, metabolizable energy (ME), and in vitro dry matter digestibility (DMD). Results revealed large differences (p < 0.001) among maize genotypes in the yields (tons/ha) of DM (13.0 to 17.9), crude protein (CP; 0.83 to 1.24), and starch (4.16 to 6.67). Except for total carbohydrates (CHO) and NH3-N, the contents of all measured chemical components varied (p < 0.001) among the spring maize genotypes. Similarly, all reported CNCPS subfractions varied (p < 0.01) among the genotypes, except for the non-digestible (CC) subfraction. Among the genotypes, there were large variations in the contents (g/100 g DM) of CP (6.60 to 8.05), starch (32.0 to 37.3), non-fiber carbohydrates (40.3 to 43.8), in vitro DMD (61.5 to 67.9), total digestible nutrients (68.1 to 70.6), digestible energy (2.80 to 3.07 Mcal/kg), and metabolizable energy (2.28 to 2.44 Mcal/kg), with genotype QPM300 having the highest values and genotype Azam having the lowest values. It was concluded that QPM300 is the most suitable spring maize genotype for silage production in terms of yields and silage nutritional and fermentation quality under the environmental condition of Northern Pakistan.

Effect of growing regions on morphological characteristics, protein subfractions, rumen degradation and molecular structures of various whole-plant silage corn cultivars

“…These results demonstrated that the cultivar of DK301 had great and stable CP quality, which might be explained by genetic composure [ 37 , 38 ]. Similar variation in CP content among maize genotypes have been reported earlier studies [ 8 , 28 ].…”

“…The CP content (g/100 g) was greatest in Beijing (8.66), followed by Tianjin (8.57), Cangzhou (7.82), Liaoyuan (7.80) and Urumchi (7.35). The CP content of the maize silages in the current study was higher than the range of CP values (6.3 to 7.5 g/100 g) reported for different maize genotypes [ 28 ], which could be related to the early harvest stage selected in the present study. Nevertheless, the CP values were within the range (5.7 to 12.4 g/100 g CP) reported for WPSC in the meta-analysis of Khan et al 2015 [ 2 ] Meanwhile, the soluble protein contents, such as NPN and SCP, of WPSC planted in Beijing were higher ( P < 0.05) than other regions.…”

“…Cultivars grown in Beijing represented greatest ( P < 0.05) stem diameter, ear diameter and rows of kernel, whereas those in Urumchi showed the lowest values for these parameters ( P < 0.05). The variation in growth and morphological characteristics of WPSC affects biomass yield, fermentation quality, and nutritional value of silages [ 28 ]. Maize plant with greater height and cobs weight are associated with high biomass yield and starch yields, and reflects crop growth attained during the growing period [ 28 ].…”

“…The variation in growth and morphological characteristics of WPSC affects biomass yield, fermentation quality, and nutritional value of silages [ 28 ]. Maize plant with greater height and cobs weight are associated with high biomass yield and starch yields, and reflects crop growth attained during the growing period [ 28 ]. The effect of growing regions on yield and morphological characteristics of WPSC could be related to differences in soil fertility, growing temperature, and day length, and to the intrinsic variation in the adaptability of the different cultivars to these conditions [ 2 , 28 ].…”

“…Maize plant with greater height and cobs weight are associated with high biomass yield and starch yields, and reflects crop growth attained during the growing period [ 28 ]. The effect of growing regions on yield and morphological characteristics of WPSC could be related to differences in soil fertility, growing temperature, and day length, and to the intrinsic variation in the adaptability of the different cultivars to these conditions [ 2 , 28 ]. Mean number of kernels in a row was highest ( P < 0.05) in Tianjin and lowest ( P < 0.05) in Beijing.…”