Non-genetic factors affecting morphometric and fleece traits in guanaco (Lama guanicoe guanicoe) populations from Argentinean Patagonia

Bacchi, C.S.; Lanari, M. R.; Thüngen, J. Von

doi:10.1016/j.smallrumres.2009.11.011

Cited by 8 publications

(6 citation statements)

References 11 publications

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“…In his own findings, Isaac (2005) reported that sexual dimorphism in body size is clearly widespread among mammalian taxa, with male-biased dimorphism being the more common, but certainly not exclusive pattern. However, Bacchi et al (2010) found no sexual dimorphism in the morphometric characters considered in Lama guanicoe guanicoe in Argentina.…”

Section: Resultsmentioning

confidence: 76%

An evaluation of sexual size dimorphism in Uda sheep using multifactorial discriminant analysis

Yakubu¹,

Akinyemi²

2010

Acta Agriculturae Scandinavica, Section A - Animal Science

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This investigation aimed at evaluating sexual size dimorphism in Uda sheep using multivariate discriminant analysis. Eleven morphological traits were measured on a total of 296 adult sheep of both sexes randomly selected in Nasarawa State, northcentral Nigeria. The univariate analysis showed that Uda rams had significantly (P B0.05) higher values in nine of the morphological traits examined. Measurements that were best able to separate the rams and the ewes as revealed by the canonical discriminant analysis were head width and face length. These two variables were included in the single discriminant function used to classify the two sexes. The discriminant model was able to allocate correctly 70.8% of Uda ewes and 58% of rams to their a priori sexes. Ward's option of the cluster analysis further revealed the morphological distinctness of the population. The discriminant function obtained in the present study could be useful in management, ecological and conservation studies.

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Section: Resultsmentioning

confidence: 76%

An evaluation of sexual size dimorphism in Uda sheep using multifactorial discriminant analysis

Yakubu¹,

Akinyemi²

2010

Acta Agriculturae Scandinavica, Section A - Animal Science

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“…Isaac et al (2005) reported that sexual dimorphism in body size is clearly widespread among many mammalian taxa, with male-biased dimorphism being the more common, but certainly not the exclusive pattern. However, Bacchi et al, (2010) found no sexual dimorphism in the morphometric characters considered in Lama guanicoe guanicoe in Argentina. Yakubu (2009) reported that the morphological traits of male and female goats were similar, although this submission were for kids compared to data reported for relatively mature animals in the present study.…”

Section: Body Weight and Morphology Traitsmentioning

confidence: 76%

Application of multivariate principal component analysis to morphological characterization of indigenous goats in Southern Nigeria

Okpeku¹,

Yakubu²,

Peters³

et al. 2011

Acta Agriculturae Slovenica

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Application of multivariate principal component analysis to morphological characterization of indigenous goats in Southern NigeriaPhenotypic variation present in a population arises due to genotypic and environmental effects, and the magnitude of phenotypic variability differs under different environmental conditions, therefore, the purpose of this study was to objectively describe the linear type traits of extensively managed mature indigenous goats of Southern Nigeria and to predict body weight from their orthogonal shape characters using principal component analysis. Body weight and four body measurements namely, height at withers, neck length, body length and heart girth were measured in 265 randomly selected West African Dwarf (WAD) and Red Sokoto (RS) goats of both sexes. RS goats had significantly (P < 0.05) higher morphological traits compared to their WAD counterparts. Sexual dimorphism was observed in all the traits with higher values recorded for males. Phenotypic correlations among body weight and biometric traits were positive and highly significant (r = 0.76-0.91 versus 0.82-0.97 and 0.66-0.94 versus 0.83-0.91 for WAD and RS female and male goats, respectively). In the varimax rotated principal component factor analysis, two factors were extracted for each sex of the two breeds, although with varying degrees of factor loadings. The principal component based regression models, which are preferable for selecting animals for optimal balance, accounted for 89.00 and 96.00% as well as 81.00 and 91.00% of the variation in body weight of female and male WAD and RS goats, respectively. The information obtained could be useful in designing appropriate management, selection and breeding programmes for utilization of goat genetic resources.Key words: goats / autochthonous breeds / body traits / multivariate analysis / Nigeria Uporaba multivariatne analize glavnih komponent pri morfološki karakterizaciji avtohtonih koz v južni NigerijiFenotipska variabilnost v populaciji je pogojena z delovanjem genetskih in okoljskih dejavnikov. Ker je obseg fenotipske variabilnosti različen v različnih okoljih, smo skušali v tej študiji objektivno predstaviti linearne eksterierne lastnosti ekstenzivno vzrejanih avtohtonih koz v južni Nigeriji in z analizo glavnih komponent napovedati telesno maso na osnovi lastnosti, ki opredeljujejo njihovo telesno obliko. Izmerili smo telesno maso in štiri telesne mere (višina v vihru, dolžina vratu, dolžina trupa in obseg prsi) pri 265 naključno izbranih zahodno afriških pritlikavih kozah (West African Dwarf, WAD) in rdečih sokoto kozah (Red Sokoto, RS) obeh spolov. Vrednosti za merjene lastnosti so bile pri RS kozah statistično značilno (p < 0,05) večje kot pri WAD kozah. Spolni dimorfizem smo zabeležili pri vseh lastnostih, z večjimi vrednostmi za samce. Fenotipske korelacije med telesno maso in biometričnimi lastnostmi so bile pozitivne in statistično visoko značilne (r = 0,76-0,91 in 0,82-0.97 ter 0,66-0,94 in 0,83-0,91 za WAD in RS živali ženskega ter moškega spola). S faktorsko ana...

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“…However, Bacchi et al [30] found no sexual dimorphism in the morphometric characters considered in Lama guanicoe guanicoe in Argentina. The higher values recorded for intensively managed animals might be as a result of better nutrition and management practices as they tend to gain more attention than those reared semi-intensively.…”

Section: Discussionmentioning

confidence: 99%

Morphological and microsatellite DNA diversity of Nigerian indigenous sheep

Agaviezor

Peters

Adefenwa

et al. 2012

J Animal Sci Biotechnol

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BackgroundSheep is important in the socio-economic lives of people around the world. It is estimated that more than half of our once common livestock breeds are now endangered. Since genetic characterization of Nigerian sheep is still lacking, we analyzed ten morphological traits on 402 animals and 15 microsatellite DNA markers in 384 animals of the 4 Nigerian sheep breeds to better understand genetic diversity for breeding management and germplasm conservation.ResultsMorphological traits of Uda and Balami were significantly (P < 0.05) higher than Yankasa, which were both higher than West African Dwarf (WAD) sheep. Stepwise discriminant analysis showed tail length, rump height, chest girth, ear length and chest depth as the most discriminating variables for classification. Mahalanobis distances show the least differentiation between Uda and Balami and the largest between WAD and Balami sheep. While 93.3% of WAD sheep were correctly assigned to their source genetic group, 63.9% of Yankasa, 61.2% of Balami and 45.2% of Uda were classified correctly by nearest neighbour discriminant analysis. The overall high Polymorphism Information Content (PIC) of all microsatellite markers ranged from 0.751 to 0.927 supporting their use in genetic characterization. Expected heterozygosity was high for all loci (0.783 to 0.93). Mean heterozygote deficiency across all populations (0.171 to 0.534) possibly indicate significant inbreeding (P < 0.05). Mean values for FST, FIT and FIS statistics across all loci were 0.088, 0.394 and 0.336 respectively. Yankasa and Balami are the most closely related breeds (DA = 0.184) while WAD and Balami are the farthest apart breeds (DA = 0.665), which is coincident with distance based on morphological analysis and population structure assessed by STRUCTURE.ConclusionsThese results suggest that within-breed genetic variation in Nigerian sheep is higher than between-breeds and may be a valuable tool for genetic improvement and conservation. The higher genetic variability in Yankasa suggests the presence of unique ancestral alleles reflecting the presence of certain functional genes which may result in better adaptability in more agro-ecological zones of Nigeria. These genetic characteristics are potentially useful in planning improvement and conservation strategies in Nigerian indigenous sheep.

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Non-genetic factors affecting morphometric and fleece traits in guanaco (Lama guanicoe guanicoe) populations from Argentinean Patagonia

Cited by 8 publications

References 11 publications

An evaluation of sexual size dimorphism in Uda sheep using multifactorial discriminant analysis

An evaluation of sexual size dimorphism in Uda sheep using multifactorial discriminant analysis

Application of multivariate principal component analysis to morphological characterization of indigenous goats in Southern Nigeria

Morphological and microsatellite DNA diversity of Nigerian indigenous sheep

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