Evaluation of n-alkanes and their carbon isotope enrichments (d13C) as diet composition markers

Plant cuticular n-alkanes have been successfully used as markers to estimate diet composition and intake of grazing herbivores. However, additional markers may be required under grazing conditions in botanically diverse vegetation. This study was conducted to describe the n-alkane profiles and the carbon isotope enrichment of n-alkanes of common plant species from the Mid Rift Valley rangelands of Ethiopia, and evaluate their potential use as nutritional markers. A total of 23 plant species were collected and analysed for long-chain n-alkanes ranging from heptacosane to hexatriacontane (C27 to C36), as well as their carbon isotopic ratio (13C/12C). The analysis was conducted by gas chromatography/combustion isotope ratio mass spectrometry following saponification, extraction and purification. The isotopic composition of the n-alkanes is reported in the delta notation (d13C) relative to the Vienna Pee Dee Belemnite standard. The dominant n-alkanes in the species were C31 (mean ± s.d., 283 ± 246 mg/kg dry matter) and C33 (149 ± 98 mg/kg dry matter). The carbon isotopic enrichment of the n-alkanes ranged from -19.37‰ to -37.40‰. Principal component analysis was used to examine interspecies differences based on n-alkane profiles and the carbon isotopic enrichments of individual n-alkanes. Large variability among the pasture species was observed. The first three principal components explained most of the interspecies variances. Comparison of the principal component scores using orthogonal procrustes rotation indicated that about 0.84 of the interspecies variances explained by the two types of data sets were independent of each other, suggesting that the use of a combination of the two markers can improve diet composition estimations. It was concluded that, while the n-alkane profile of the pasture species remains a useful marker for use in the study region, the d13C values of n-alkanes can provide additional information in discriminating diet components of grazing animal

Prospects for integrating food and feed production in Welayta Sodo, Ethiopia

A diagnostic survey was carried out in 1988 to assess feed resource and animal production situation in Welayta Sodo. Information was collected by interviewing 102 heads of households. Supplementary information was also collected from the Ministry of Agriculture. Discusses type and nutritional quality of available feed resources; estimated quality of feed resources available in Welayta District including crop residues; availability of feed DM relative to livestock population of the District; livestock productivity, major constraints to livestock production, and prospects for integrating food and feed production with ref. to traditional complementarity of food & feeds; stratification of livestock production; and temporal interaction between forage supply and demand

Feed Intake, Digestibility and Growth Performance of Horro Lambs Fed Natural Pasture Hay Supplemented Graded Level of Vernonia amygdalina Leaves and Sorghum Grain Mixture

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Carcass Yield and Quality of Pork from Pigs Fed Graded Levels of Fig (Ficus sur) Fruits Mixed with Maize Grain

Twenty growing Yorkshire piglets of 27.8±1.4kg (mean ± SD) average initial weight were used to investigate the effect of feeding different proportions of ground Ficus sur fruits (FSF) mixed with ground maize grain (MG) on carcass yield and quality attributes. The experiment was conducted in randomized complete block design (RCBD) with four treatments and five replications per treatment. The treatment diets were: 100% FSF and 0%MG represented as (100FSF), 67% FSF and 33% MG (67FSF), 33% FSF and 67% MG (33FSF) and 0% FSF and 100% MG (0FSF). For all treatments protein supplement (NSC+SBM) was given to provide about 18% CP to make the ration isonitrogenous. Except for the slaughter weight, which significantly (P<0.05) increased with increase in MG level in the diets, all other carcass measurements and primal cuts did not differ (P>0.05) among the treatments. However, lungs (P=0.012) and gastro intestinal tract (GIT) (P=0.001) among the viscera organs were varied. None of the quality attributes of the pork significantly differed (P>0.05) in color, taste, flavor, juiciness, tenderness and texture among the treatments. This indicates that similar quality pork can be produced by feeding FSF as those fed with MG. It is, therefore, concluded that substitution of MG with FSFs in the diets of pigs can result in comparable carcass yield and quality attributes

Selecting for food-feed traits in early and late maturing lentil genotypes(Lens culinaris)

To explore genetic and environmental variability of food-feed traits in lentil genotypes, straws of 78elite genotypes and 4 checks of early and late maturing lentil types were evaluated for their nutritive value and potential trade-offs of the nutritive parameters with straw yield and grain yield. Further, effects of genotypic and environmental sources on variation in the nutritive value were also determined. Straw nutritive traits were analyzed by a combination of conventional laboratory techniques and Near Infrared Reflectance Spectroscopy. Results from eight trials carried out across 3 different sites in Ethiopia showed highly significant genotypic variation (P<0.05) in grain yield, straw yields and straw nutritive traits. This confirmed the existence of exploitable genetic variation in these traits. Similarly, the relationship between grain yield and straw yield was positive. The correlation between grain yield and nutritive parameters of straw was insignificant or negative. The correlation between maturity types and straw traits was either neutral or negative. Genotype by environment interactions were significant (P<0.05) for straw yield and nutritive traits indicating that variation in the traits is dependent of environment. It is possible to develop genotypes with a combination of food-feed traits from early and late maturing lentil types to address the high demand for grain and livestock fodder in various agro ecological zones in mixed crop-livestock farming systems using appropriate breeding approaches