Grain filling, starch degradation and feeding value of maize for ruminants

M. Ali

Research output: Thesisinternal PhD, WU

Abstract

Keywords; Maize (Zea mays L), Genotypes, Grain filling, Growth temperature, Kernels, Gas production, Starch degradation, Oven-drying, Silage, Ensiling temperature, Ensiling duration, Feeding value, Lactating cows

Maize (Zea mays L.) is a major component in the ration of dairy cows in many parts of the world. The currently increasing economic importance of maize has highlighted the need to determine its nutritional value, and to assess the factors influencing its nutritive value. Genotypic make-up (especially differences in starch and endosperm), growing conditions, maturity stage at harvest, and post handling processes, like oven-drying, can influence nutritive value of maize kernels. Similarly, ensiling temperature and duration can affect feeding value of maize silage. This thesis is divided into three parts; the first aim was to characterize the dry matter (starch) accumulation of maize different genotypes in different environments under controlled (glasshouse) and on different locations (sand and clay) in field conditions. Maize genotypes used were different in starch structure and composition, and in type of endosperm. Starch structure refers to amylose and amylopectin; and composition refers to their proportions, whereas type of endosperm defines levels of vitreousness. The vitreousness is the ratio of vitreous (hard) to floury (soft) endosperm. Six maize genotypes, differing in amylose content and vitreousness, were grown under three contrasting day/night temperature regimes during grain filling and harvested at different maturity stages from two greenhouse experiments. Similar investigations were carried on another set of genotypes grown on sandy and clay soils and with different sowing times under field conditions. Water contents and dry matter (starch) accumulation were significantly influenced by growth temperature, genotype, soil type and sowing time (P<0.0001). The second aim of thesis was to establish a relationship between rumen in vitro starch degradation (feeding value) of maize kernels and different factors, like genotype, growth temperature during grain filling, and maturity stage. Oven-dried kernels of six maize genotypes, from the two greenhouse experiments mentioned before were investigated. Starch content was measured using an enzymatic method and the gas production technique was used to assess starch degradation in rumen fluid of dairy cows. The extent of starch degradation at different incubation times was calculated from measured gas production data (6, 12 and 20 h, respectively) and a published equation. At each maturity stage, whole kernel and starch degradation in rumen fluid depended on the genotype (P<0.0001), growing conditions (P<0.0001), starch content (P<0.0001) and starch amount (P<0.0001) in the kernels. The same but fresh (not oven-dried) maize kernel samples were investigated using gas production technique to determine the impact of oven-drying on rumen in vitro starch degradation of maize kernels. Oven-drying significantly (P<0.0001) influenced the rumen in vitro starch degradation in maize kernels various incubation times, with more starch being degraded in the fresh than in the oven-dried maize kernels, although the differences were small. There was a consistent and highly significant (P<0.009 to 0.0002) interaction between oven-drying and genotype, with the high-amylose genotype showing larger effects of oven-drying than the other genotypes. The third aim of thesis was to investigate effect of ensiling temperature and duration on feeding value of maize silage. Samples of maize whole plants (dry matter 33%) were collected from the medium vitreous endosperm cultivar, grown in different seasons on sandy soils. Maize plants were chopped and ensiled in mini silos at three different temperatures. Samples from the silos were taken after 0 (not ensiled, i.e. control), 4, 8 and 16 weeks of ensiling. The gas production technique was used to evaluate the influence of the ensiling temperature and duration of ensiling on the degradation of the fresh ground silage samples in rumen fluid. The final pH of the silages and the gas production was significantly influenced by ensiling temperature in both seasons (P<0.0001). Gas production and pH decreased with an increase in ensiling duration (P<0.0001). The relationship between pH and gas production was quadratic and depended on the ensiling temperature (P<0.002). It was found that ensiling temperature and ensiling duration determine the rate of change and final pH, and play a significant role in feeding value of maize silage. The finding of thesis can be used to determine the exact feeding value of maize kernels and silage, and also can be used as a tool to revise the current feeding evaluation systems i.e. shift from oven-dried to fresh samples.

Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • Struik, Paul, Promotor
  • Hendriks, Wouter, Promotor
  • Cone, John, Co-promotor
Award date2 Dec 2013
Place of PublicationWageningen
Publisher
Print ISBNs9789461738196
Publication statusPublished - 2013

Fingerprint

filling period
silage making
ruminants
nutritive value
starch
ovens
gas production (biological)
corn
degradation
genotype
seeds
endosperm
drying
temperature
maturity stage
silage
duration
rumen fluids
corn silage
amylose

Keywords

  • maize
  • zea mays
  • maturity stage
  • genotypes
  • starch digestion
  • rumen digestion
  • nutritive value
  • ruminant feeding
  • kernels
  • maize silage
  • silage making
  • crop physiology
  • nutrition physiology

Cite this

Ali, M.. / Grain filling, starch degradation and feeding value of maize for ruminants. Wageningen : Wageningen UR, 2013. 177 p.
@phdthesis{df86881bfaea44ff8db5c1ea2e93da03,
title = "Grain filling, starch degradation and feeding value of maize for ruminants",
abstract = "Keywords; Maize (Zea mays L), Genotypes, Grain filling, Growth temperature, Kernels, Gas production, Starch degradation, Oven-drying, Silage, Ensiling temperature, Ensiling duration, Feeding value, Lactating cows Maize (Zea mays L.) is a major component in the ration of dairy cows in many parts of the world. The currently increasing economic importance of maize has highlighted the need to determine its nutritional value, and to assess the factors influencing its nutritive value. Genotypic make-up (especially differences in starch and endosperm), growing conditions, maturity stage at harvest, and post handling processes, like oven-drying, can influence nutritive value of maize kernels. Similarly, ensiling temperature and duration can affect feeding value of maize silage. This thesis is divided into three parts; the first aim was to characterize the dry matter (starch) accumulation of maize different genotypes in different environments under controlled (glasshouse) and on different locations (sand and clay) in field conditions. Maize genotypes used were different in starch structure and composition, and in type of endosperm. Starch structure refers to amylose and amylopectin; and composition refers to their proportions, whereas type of endosperm defines levels of vitreousness. The vitreousness is the ratio of vitreous (hard) to floury (soft) endosperm. Six maize genotypes, differing in amylose content and vitreousness, were grown under three contrasting day/night temperature regimes during grain filling and harvested at different maturity stages from two greenhouse experiments. Similar investigations were carried on another set of genotypes grown on sandy and clay soils and with different sowing times under field conditions. Water contents and dry matter (starch) accumulation were significantly influenced by growth temperature, genotype, soil type and sowing time (P<0.0001). The second aim of thesis was to establish a relationship between rumen in vitro starch degradation (feeding value) of maize kernels and different factors, like genotype, growth temperature during grain filling, and maturity stage. Oven-dried kernels of six maize genotypes, from the two greenhouse experiments mentioned before were investigated. Starch content was measured using an enzymatic method and the gas production technique was used to assess starch degradation in rumen fluid of dairy cows. The extent of starch degradation at different incubation times was calculated from measured gas production data (6, 12 and 20 h, respectively) and a published equation. At each maturity stage, whole kernel and starch degradation in rumen fluid depended on the genotype (P<0.0001), growing conditions (P<0.0001), starch content (P<0.0001) and starch amount (P<0.0001) in the kernels. The same but fresh (not oven-dried) maize kernel samples were investigated using gas production technique to determine the impact of oven-drying on rumen in vitro starch degradation of maize kernels. Oven-drying significantly (P<0.0001) influenced the rumen in vitro starch degradation in maize kernels various incubation times, with more starch being degraded in the fresh than in the oven-dried maize kernels, although the differences were small. There was a consistent and highly significant (P<0.009 to 0.0002) interaction between oven-drying and genotype, with the high-amylose genotype showing larger effects of oven-drying than the other genotypes. The third aim of thesis was to investigate effect of ensiling temperature and duration on feeding value of maize silage. Samples of maize whole plants (dry matter 33{\%}) were collected from the medium vitreous endosperm cultivar, grown in different seasons on sandy soils. Maize plants were chopped and ensiled in mini silos at three different temperatures. Samples from the silos were taken after 0 (not ensiled, i.e. control), 4, 8 and 16 weeks of ensiling. The gas production technique was used to evaluate the influence of the ensiling temperature and duration of ensiling on the degradation of the fresh ground silage samples in rumen fluid. The final pH of the silages and the gas production was significantly influenced by ensiling temperature in both seasons (P<0.0001). Gas production and pH decreased with an increase in ensiling duration (P<0.0001). The relationship between pH and gas production was quadratic and depended on the ensiling temperature (P<0.002). It was found that ensiling temperature and ensiling duration determine the rate of change and final pH, and play a significant role in feeding value of maize silage. The finding of thesis can be used to determine the exact feeding value of maize kernels and silage, and also can be used as a tool to revise the current feeding evaluation systems i.e. shift from oven-dried to fresh samples.",
keywords = "ma{\"i}s, zea mays, groeifasen, rijp, genotypen, zetmeelvertering, pensvertering, voedingswaarde, herkauwersvoeding, korrels (granen), ma{\"i}skuilvoer, kuilvoerbereiding, gewasfysiologie, voedingsfysiologie, maize, zea mays, maturity stage, genotypes, starch digestion, rumen digestion, nutritive value, ruminant feeding, kernels, maize silage, silage making, crop physiology, nutrition physiology",
author = "M. Ali",
note = "WU thesis 5623",
year = "2013",
language = "English",
isbn = "9789461738196",
publisher = "Wageningen UR",
school = "Wageningen University",

}

Ali, M 2013, 'Grain filling, starch degradation and feeding value of maize for ruminants', Doctor of Philosophy, Wageningen University, Wageningen.

Grain filling, starch degradation and feeding value of maize for ruminants. / Ali, M.

Wageningen : Wageningen UR, 2013. 177 p.

Research output: Thesisinternal PhD, WU

TY - THES

T1 - Grain filling, starch degradation and feeding value of maize for ruminants

AU - Ali, M.

N1 - WU thesis 5623

PY - 2013

Y1 - 2013

N2 - Keywords; Maize (Zea mays L), Genotypes, Grain filling, Growth temperature, Kernels, Gas production, Starch degradation, Oven-drying, Silage, Ensiling temperature, Ensiling duration, Feeding value, Lactating cows Maize (Zea mays L.) is a major component in the ration of dairy cows in many parts of the world. The currently increasing economic importance of maize has highlighted the need to determine its nutritional value, and to assess the factors influencing its nutritive value. Genotypic make-up (especially differences in starch and endosperm), growing conditions, maturity stage at harvest, and post handling processes, like oven-drying, can influence nutritive value of maize kernels. Similarly, ensiling temperature and duration can affect feeding value of maize silage. This thesis is divided into three parts; the first aim was to characterize the dry matter (starch) accumulation of maize different genotypes in different environments under controlled (glasshouse) and on different locations (sand and clay) in field conditions. Maize genotypes used were different in starch structure and composition, and in type of endosperm. Starch structure refers to amylose and amylopectin; and composition refers to their proportions, whereas type of endosperm defines levels of vitreousness. The vitreousness is the ratio of vitreous (hard) to floury (soft) endosperm. Six maize genotypes, differing in amylose content and vitreousness, were grown under three contrasting day/night temperature regimes during grain filling and harvested at different maturity stages from two greenhouse experiments. Similar investigations were carried on another set of genotypes grown on sandy and clay soils and with different sowing times under field conditions. Water contents and dry matter (starch) accumulation were significantly influenced by growth temperature, genotype, soil type and sowing time (P<0.0001). The second aim of thesis was to establish a relationship between rumen in vitro starch degradation (feeding value) of maize kernels and different factors, like genotype, growth temperature during grain filling, and maturity stage. Oven-dried kernels of six maize genotypes, from the two greenhouse experiments mentioned before were investigated. Starch content was measured using an enzymatic method and the gas production technique was used to assess starch degradation in rumen fluid of dairy cows. The extent of starch degradation at different incubation times was calculated from measured gas production data (6, 12 and 20 h, respectively) and a published equation. At each maturity stage, whole kernel and starch degradation in rumen fluid depended on the genotype (P<0.0001), growing conditions (P<0.0001), starch content (P<0.0001) and starch amount (P<0.0001) in the kernels. The same but fresh (not oven-dried) maize kernel samples were investigated using gas production technique to determine the impact of oven-drying on rumen in vitro starch degradation of maize kernels. Oven-drying significantly (P<0.0001) influenced the rumen in vitro starch degradation in maize kernels various incubation times, with more starch being degraded in the fresh than in the oven-dried maize kernels, although the differences were small. There was a consistent and highly significant (P<0.009 to 0.0002) interaction between oven-drying and genotype, with the high-amylose genotype showing larger effects of oven-drying than the other genotypes. The third aim of thesis was to investigate effect of ensiling temperature and duration on feeding value of maize silage. Samples of maize whole plants (dry matter 33%) were collected from the medium vitreous endosperm cultivar, grown in different seasons on sandy soils. Maize plants were chopped and ensiled in mini silos at three different temperatures. Samples from the silos were taken after 0 (not ensiled, i.e. control), 4, 8 and 16 weeks of ensiling. The gas production technique was used to evaluate the influence of the ensiling temperature and duration of ensiling on the degradation of the fresh ground silage samples in rumen fluid. The final pH of the silages and the gas production was significantly influenced by ensiling temperature in both seasons (P<0.0001). Gas production and pH decreased with an increase in ensiling duration (P<0.0001). The relationship between pH and gas production was quadratic and depended on the ensiling temperature (P<0.002). It was found that ensiling temperature and ensiling duration determine the rate of change and final pH, and play a significant role in feeding value of maize silage. The finding of thesis can be used to determine the exact feeding value of maize kernels and silage, and also can be used as a tool to revise the current feeding evaluation systems i.e. shift from oven-dried to fresh samples.

AB - Keywords; Maize (Zea mays L), Genotypes, Grain filling, Growth temperature, Kernels, Gas production, Starch degradation, Oven-drying, Silage, Ensiling temperature, Ensiling duration, Feeding value, Lactating cows Maize (Zea mays L.) is a major component in the ration of dairy cows in many parts of the world. The currently increasing economic importance of maize has highlighted the need to determine its nutritional value, and to assess the factors influencing its nutritive value. Genotypic make-up (especially differences in starch and endosperm), growing conditions, maturity stage at harvest, and post handling processes, like oven-drying, can influence nutritive value of maize kernels. Similarly, ensiling temperature and duration can affect feeding value of maize silage. This thesis is divided into three parts; the first aim was to characterize the dry matter (starch) accumulation of maize different genotypes in different environments under controlled (glasshouse) and on different locations (sand and clay) in field conditions. Maize genotypes used were different in starch structure and composition, and in type of endosperm. Starch structure refers to amylose and amylopectin; and composition refers to their proportions, whereas type of endosperm defines levels of vitreousness. The vitreousness is the ratio of vitreous (hard) to floury (soft) endosperm. Six maize genotypes, differing in amylose content and vitreousness, were grown under three contrasting day/night temperature regimes during grain filling and harvested at different maturity stages from two greenhouse experiments. Similar investigations were carried on another set of genotypes grown on sandy and clay soils and with different sowing times under field conditions. Water contents and dry matter (starch) accumulation were significantly influenced by growth temperature, genotype, soil type and sowing time (P<0.0001). The second aim of thesis was to establish a relationship between rumen in vitro starch degradation (feeding value) of maize kernels and different factors, like genotype, growth temperature during grain filling, and maturity stage. Oven-dried kernels of six maize genotypes, from the two greenhouse experiments mentioned before were investigated. Starch content was measured using an enzymatic method and the gas production technique was used to assess starch degradation in rumen fluid of dairy cows. The extent of starch degradation at different incubation times was calculated from measured gas production data (6, 12 and 20 h, respectively) and a published equation. At each maturity stage, whole kernel and starch degradation in rumen fluid depended on the genotype (P<0.0001), growing conditions (P<0.0001), starch content (P<0.0001) and starch amount (P<0.0001) in the kernels. The same but fresh (not oven-dried) maize kernel samples were investigated using gas production technique to determine the impact of oven-drying on rumen in vitro starch degradation of maize kernels. Oven-drying significantly (P<0.0001) influenced the rumen in vitro starch degradation in maize kernels various incubation times, with more starch being degraded in the fresh than in the oven-dried maize kernels, although the differences were small. There was a consistent and highly significant (P<0.009 to 0.0002) interaction between oven-drying and genotype, with the high-amylose genotype showing larger effects of oven-drying than the other genotypes. The third aim of thesis was to investigate effect of ensiling temperature and duration on feeding value of maize silage. Samples of maize whole plants (dry matter 33%) were collected from the medium vitreous endosperm cultivar, grown in different seasons on sandy soils. Maize plants were chopped and ensiled in mini silos at three different temperatures. Samples from the silos were taken after 0 (not ensiled, i.e. control), 4, 8 and 16 weeks of ensiling. The gas production technique was used to evaluate the influence of the ensiling temperature and duration of ensiling on the degradation of the fresh ground silage samples in rumen fluid. The final pH of the silages and the gas production was significantly influenced by ensiling temperature in both seasons (P<0.0001). Gas production and pH decreased with an increase in ensiling duration (P<0.0001). The relationship between pH and gas production was quadratic and depended on the ensiling temperature (P<0.002). It was found that ensiling temperature and ensiling duration determine the rate of change and final pH, and play a significant role in feeding value of maize silage. The finding of thesis can be used to determine the exact feeding value of maize kernels and silage, and also can be used as a tool to revise the current feeding evaluation systems i.e. shift from oven-dried to fresh samples.

KW - maïs

KW - zea mays

KW - groeifasen, rijp

KW - genotypen

KW - zetmeelvertering

KW - pensvertering

KW - voedingswaarde

KW - herkauwersvoeding

KW - korrels (granen)

KW - maïskuilvoer

KW - kuilvoerbereiding

KW - gewasfysiologie

KW - voedingsfysiologie

KW - maize

KW - zea mays

KW - maturity stage

KW - genotypes

KW - starch digestion

KW - rumen digestion

KW - nutritive value

KW - ruminant feeding

KW - kernels

KW - maize silage

KW - silage making

KW - crop physiology

KW - nutrition physiology

M3 - internal PhD, WU

SN - 9789461738196

PB - Wageningen UR

CY - Wageningen

ER -