Nutrition of grazing cattle in the Mid Rift Valley of Ethiopia: use of an improved n-alkane method to estimate nutrient intake

M.B. Derseh

Research output: Thesisinternal PhD, WU

Abstract

Nutrient intake is an important factor that determines the performance of production animals. In free ranging animals, direct measurement of nutrient intake is difficult to conduct, and it is frequently estimated indirectly by the aid of markers. The aim of this thesis was to investigate the potential of using cuticular n-alkanes and their carbon isotope enrichments (δ13C) as markers to study the nutritional ecology of grazing animals under tropical conditions. In addition, this improved method was used to determine the seasonal patterns of nutrient intake and diet composition of grazing cattle in the Mid Rift Valley grasslands of Ethiopia. The first focus of the thesis was to quantify the interspecies variability in the n-alkane profile and δ13C values of alkanes among commonly available pasture species in the Mid Rift Valley of Ethiopia. The analysis showed that the variability is sufficiently large to allow n-alkane and their δ13C values to be used as diet composition markers, with a combined use of the two increasing the discriminatory power. Faecal recovery of dosed and natural alkanes in cattle consuming low-quality tropical roughages was investigated in an indoor balance study. The recovery of synthetic alkanes dosed in the form of molasses boluses was considerably higher than adjacent natural odd-chain alkanes, and correction appears necessary when intake is estimated with the double n-alkane method. The next focus of the thesis was to generate information on the nutritive value of pasture species and nutritional status of grazing cattle in the region. Large variability was observed in the nutritive value and methane production potential of pasture species as evaluated in vitro, with scope for selection of genotypes with high nutritive value and low methane production potential for a sustainable pastureland management. The nutritional status of grazing cattle measured using a combination of n-alkanes, their δ13C values and visual observations showed that diet composition and nutrient intake of the animals is highly dependent on rainfall patterns, with a cyclic positive (wet period) and negative (dry period) energy and nutrient balance observed over the grazing seasons. Energy intake was more limiting than crude protein for body weight gain in most of the grazing seasons. While mature and non-producing animals appeared to tolerate nutritional restriction in the dry period and regain lost body condition in the following wet periods, young animals before the age of puberty may need supplementary feeding. Furthermore, concentrate supplementation of finishing animals needs to coincide with the onset of the wet season to take advantage of compensatory growth. In conclusion, the n-alkanes method coupled with isotope enrichment in n-alkanes and visual observations as used in the present study can provide realistic nutritional data for free-ranging cattle which correlates well with changes in body conditions.

 

Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • Hendriks, Wouter, Promotor
  • Pellikaan, Wilbert, Co-promotor
  • Tolera, A., Co-promotor, External person
Award date8 Feb 2013
Place of PublicationS.l.
Publisher
Print ISBNs9789461734686
Publication statusPublished - 2013

Fingerprint

Ethiopia
nutrient intake
alkanes
valleys
grazing
nutrition
cattle
methodology
nutritive value
pastures
animals
methane production
body condition
nutritional status
isotopes
diet
protein bodies
balance studies
overgrazing
nutrient balance

Keywords

  • cattle
  • grazing
  • pastures
  • markers
  • nutrient intake
  • food composition
  • nutritive value
  • digestibility
  • roughage
  • animal nutrition
  • ethiopia

Cite this

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title = "Nutrition of grazing cattle in the Mid Rift Valley of Ethiopia: use of an improved n-alkane method to estimate nutrient intake",
abstract = "Nutrient intake is an important factor that determines the performance of production animals. In free ranging animals, direct measurement of nutrient intake is difficult to conduct, and it is frequently estimated indirectly by the aid of markers. The aim of this thesis was to investigate the potential of using cuticular n-alkanes and their carbon isotope enrichments (δ13C) as markers to study the nutritional ecology of grazing animals under tropical conditions. In addition, this improved method was used to determine the seasonal patterns of nutrient intake and diet composition of grazing cattle in the Mid Rift Valley grasslands of Ethiopia. The first focus of the thesis was to quantify the interspecies variability in the n-alkane profile and δ13C values of alkanes among commonly available pasture species in the Mid Rift Valley of Ethiopia. The analysis showed that the variability is sufficiently large to allow n-alkane and their δ13C values to be used as diet composition markers, with a combined use of the two increasing the discriminatory power. Faecal recovery of dosed and natural alkanes in cattle consuming low-quality tropical roughages was investigated in an indoor balance study. The recovery of synthetic alkanes dosed in the form of molasses boluses was considerably higher than adjacent natural odd-chain alkanes, and correction appears necessary when intake is estimated with the double n-alkane method. The next focus of the thesis was to generate information on the nutritive value of pasture species and nutritional status of grazing cattle in the region. Large variability was observed in the nutritive value and methane production potential of pasture species as evaluated in vitro, with scope for selection of genotypes with high nutritive value and low methane production potential for a sustainable pastureland management. The nutritional status of grazing cattle measured using a combination of n-alkanes, their δ13C values and visual observations showed that diet composition and nutrient intake of the animals is highly dependent on rainfall patterns, with a cyclic positive (wet period) and negative (dry period) energy and nutrient balance observed over the grazing seasons. Energy intake was more limiting than crude protein for body weight gain in most of the grazing seasons. While mature and non-producing animals appeared to tolerate nutritional restriction in the dry period and regain lost body condition in the following wet periods, young animals before the age of puberty may need supplementary feeding. Furthermore, concentrate supplementation of finishing animals needs to coincide with the onset of the wet season to take advantage of compensatory growth. In conclusion, the n-alkanes method coupled with isotope enrichment in n-alkanes and visual observations as used in the present study can provide realistic nutritional data for free-ranging cattle which correlates well with changes in body conditions.  ",
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author = "M.B. Derseh",
note = "WU thesis 5408",
year = "2013",
language = "English",
isbn = "9789461734686",
publisher = "s.n.",
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Nutrition of grazing cattle in the Mid Rift Valley of Ethiopia: use of an improved n-alkane method to estimate nutrient intake. / Derseh, M.B.

S.l. : s.n., 2013. 160 p.

Research output: Thesisinternal PhD, WU

TY - THES

T1 - Nutrition of grazing cattle in the Mid Rift Valley of Ethiopia: use of an improved n-alkane method to estimate nutrient intake

AU - Derseh, M.B.

N1 - WU thesis 5408

PY - 2013

Y1 - 2013

N2 - Nutrient intake is an important factor that determines the performance of production animals. In free ranging animals, direct measurement of nutrient intake is difficult to conduct, and it is frequently estimated indirectly by the aid of markers. The aim of this thesis was to investigate the potential of using cuticular n-alkanes and their carbon isotope enrichments (δ13C) as markers to study the nutritional ecology of grazing animals under tropical conditions. In addition, this improved method was used to determine the seasonal patterns of nutrient intake and diet composition of grazing cattle in the Mid Rift Valley grasslands of Ethiopia. The first focus of the thesis was to quantify the interspecies variability in the n-alkane profile and δ13C values of alkanes among commonly available pasture species in the Mid Rift Valley of Ethiopia. The analysis showed that the variability is sufficiently large to allow n-alkane and their δ13C values to be used as diet composition markers, with a combined use of the two increasing the discriminatory power. Faecal recovery of dosed and natural alkanes in cattle consuming low-quality tropical roughages was investigated in an indoor balance study. The recovery of synthetic alkanes dosed in the form of molasses boluses was considerably higher than adjacent natural odd-chain alkanes, and correction appears necessary when intake is estimated with the double n-alkane method. The next focus of the thesis was to generate information on the nutritive value of pasture species and nutritional status of grazing cattle in the region. Large variability was observed in the nutritive value and methane production potential of pasture species as evaluated in vitro, with scope for selection of genotypes with high nutritive value and low methane production potential for a sustainable pastureland management. The nutritional status of grazing cattle measured using a combination of n-alkanes, their δ13C values and visual observations showed that diet composition and nutrient intake of the animals is highly dependent on rainfall patterns, with a cyclic positive (wet period) and negative (dry period) energy and nutrient balance observed over the grazing seasons. Energy intake was more limiting than crude protein for body weight gain in most of the grazing seasons. While mature and non-producing animals appeared to tolerate nutritional restriction in the dry period and regain lost body condition in the following wet periods, young animals before the age of puberty may need supplementary feeding. Furthermore, concentrate supplementation of finishing animals needs to coincide with the onset of the wet season to take advantage of compensatory growth. In conclusion, the n-alkanes method coupled with isotope enrichment in n-alkanes and visual observations as used in the present study can provide realistic nutritional data for free-ranging cattle which correlates well with changes in body conditions.  

AB - Nutrient intake is an important factor that determines the performance of production animals. In free ranging animals, direct measurement of nutrient intake is difficult to conduct, and it is frequently estimated indirectly by the aid of markers. The aim of this thesis was to investigate the potential of using cuticular n-alkanes and their carbon isotope enrichments (δ13C) as markers to study the nutritional ecology of grazing animals under tropical conditions. In addition, this improved method was used to determine the seasonal patterns of nutrient intake and diet composition of grazing cattle in the Mid Rift Valley grasslands of Ethiopia. The first focus of the thesis was to quantify the interspecies variability in the n-alkane profile and δ13C values of alkanes among commonly available pasture species in the Mid Rift Valley of Ethiopia. The analysis showed that the variability is sufficiently large to allow n-alkane and their δ13C values to be used as diet composition markers, with a combined use of the two increasing the discriminatory power. Faecal recovery of dosed and natural alkanes in cattle consuming low-quality tropical roughages was investigated in an indoor balance study. The recovery of synthetic alkanes dosed in the form of molasses boluses was considerably higher than adjacent natural odd-chain alkanes, and correction appears necessary when intake is estimated with the double n-alkane method. The next focus of the thesis was to generate information on the nutritive value of pasture species and nutritional status of grazing cattle in the region. Large variability was observed in the nutritive value and methane production potential of pasture species as evaluated in vitro, with scope for selection of genotypes with high nutritive value and low methane production potential for a sustainable pastureland management. The nutritional status of grazing cattle measured using a combination of n-alkanes, their δ13C values and visual observations showed that diet composition and nutrient intake of the animals is highly dependent on rainfall patterns, with a cyclic positive (wet period) and negative (dry period) energy and nutrient balance observed over the grazing seasons. Energy intake was more limiting than crude protein for body weight gain in most of the grazing seasons. While mature and non-producing animals appeared to tolerate nutritional restriction in the dry period and regain lost body condition in the following wet periods, young animals before the age of puberty may need supplementary feeding. Furthermore, concentrate supplementation of finishing animals needs to coincide with the onset of the wet season to take advantage of compensatory growth. In conclusion, the n-alkanes method coupled with isotope enrichment in n-alkanes and visual observations as used in the present study can provide realistic nutritional data for free-ranging cattle which correlates well with changes in body conditions.  

KW - rundvee

KW - begrazing

KW - weiden

KW - merkers

KW - voedingsstoffenopname (mens en dier)

KW - voedselsamenstelling

KW - voedingswaarde

KW - verteerbaarheid

KW - ruwvoer (roughage)

KW - diervoeding

KW - ethiopië

KW - cattle

KW - grazing

KW - pastures

KW - markers

KW - nutrient intake

KW - food composition

KW - nutritive value

KW - digestibility

KW - roughage

KW - animal nutrition

KW - ethiopia

M3 - internal PhD, WU

SN - 9789461734686

PB - s.n.

CY - S.l.

ER -