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1.
PLoS One ; 18(10): e0287219, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37883516

RESUMO

In Tunisia, agriculture is the main source of livelihood for more than 75% of small and subsistence farmers with minimal use of technology. The use of information and communication technology (ICT),such as mobile applications, represents a pertinent opportunity for these smallholders to access agricultural innovation and market information and improve their farming technologies and farm management. Thus, ICT can act as a replacement to foster access to innovation for this category of farmers. Unfortunately, the underuse of mobile applications has contributed to low and slow adoption of agricultural innovation and consequently the benefits of this technology have not been attained. The purpose of this study is to identify the factors affecting the adoption of Short Message Service (SMS) through a contextual ICT model for livestock, olive crop, and beekeeping. Data were collected from 200 small-scale beekeepers, 225 olive growers, and 140 livestock breeders selected in Jendouba, Kairouan, and Zaghouan in Tunisia. The objective of this paper is to examine the factors that influence mobile applications using the partial least squares structural equation modelling technique, for livestock, olive crop, and beekeeping agricultural activities. The results showed that the final ICT-induced structural models were highly predictive of the use of SMS and its increased adoption. Factors affecting the use of SMS differed according to the farming system. The major perceived factor affecting the use of SMS was 'observability' for livestock farmers, 'compatibility' for olive growers, and 'information quality' for beekeepers. Understanding these factors by taking into account the specificity of the agricultural activity leads to a better understanding of the adoption of ICT tools by smallholder farmers in Tunisia.


Assuntos
Aplicativos Móveis , Animais , Tunísia , Países em Desenvolvimento , Agricultura/métodos , Fazendeiros , Comunicação , Gado
2.
Front Genet ; 14: 1200770, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37745840

RESUMO

Introduction: The African Goat Improvement Network Image Collection Protocol (AGIN-ICP) is an accessible, easy to use, low-cost procedure to collect phenotypic data via digital images. The AGIN-ICP collects images to extract several phenotype measures including health status indicators (anemia status, age, and weight), body measurements, shapes, and coat color and pattern, from digital images taken with standard digital cameras or mobile devices. This strategy is to quickly survey, record, assess, analyze, and store these data for use in a wide variety of production and sampling conditions. Methods: The work was accomplished as part of the multinational African Goat Improvement Network (AGIN) collaborative and is presented here as a case study in the AGIN collaboration model and working directly with community-based breeding programs (CBBP). It was iteratively developed and tested over 3 years, in 12 countries with over 12,000 images taken. Results and discussion: The AGIN-ICP development is described, and field implementation and the quality of the resulting images for use in image analysis and phenotypic data extraction are iteratively assessed. Digital body measures were validated using the PreciseEdge Image Segmentation Algorithm (PE-ISA) and software showing strong manual to digital body measure Pearson correlation coefficients of height, length, and girth measures (0.931, 0.943, 0.893) respectively. It is critical to note that while none of the very detailed tasks in the AGIN-ICP described here is difficult, every single one of them is even easier to accidentally omit, and the impact of such a mistake could render a sample image, a sampling day's images, or even an entire sampling trip's images difficult or unusable for extracting digital phenotypes. Coupled with tissue sampling and genomic testing, it may be useful in the effort to identify and conserve important animal genetic resources and in CBBP genetic improvement programs by providing reliably measured phenotypes with modest cost. Potential users include farmers, animal husbandry officials, veterinarians, regional government or other public health officials, researchers, and others. Based on these results, a final AGIN-ICP is presented, optimizing the costs, ease, and speed of field implementation of the collection method without compromising the quality of the image data collection.

3.
Front Genet ; 14: 1183240, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37712066

RESUMO

The African Goat Improvement Network (AGIN) is a collaborative group of scientists focused on genetic improvement of goats in small holder communities across the African continent. The group emerged from a series of workshops focused on enhancing goat productivity and sustainability. Discussions began in 2011 at the inaugural workshop held in Nairobi, Kenya. The goals of this diverse group were to: improve indigenous goat production in Africa; characterize existing goat populations and to facilitate germplasm preservation where appropriate; and to genomic approaches to better understand adaptation. The long-term goal was to develop cost-effective strategies to apply genomics to improve productivity of small holder farmers without sacrificing adaptation. Genome-wide information on genetic variation enabled genetic diversity studies, facilitated improved germplasm preservation decisions, and provided information necessary to initiate large scale genetic improvement programs. These improvements were partially implemented through a series of community-based breeding programs that engaged and empowered local small farmers, especially women, to promote sustainability of the production system. As with many international collaborative efforts, the AGIN work serves as a platform for human capacity development. This paper chronicles the evolution of the collaborative approach leading to the current AGIN organization and describes how it builds capacity for sustained research and development long after the initial program funds are gone. It is unique in its effectiveness for simultaneous, multi-level capacity building for researchers, students, farmers and communities, and local and regional government officials. The positive impact of AGIN capacity building has been felt by participants from developing, as well as developed country partners.

4.
Front Genet ; 14: 1114381, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37007959

RESUMO

Community-based breeding programs (CBBPs) have shown, at pilot scale, to be effective and beneficial in achieving genetic progress and in improving livelihoods of smallholder communities. In Ethiopia 134 sheep and goat CBBPs were operational producing their own improved rams and bucks. Based on experience the implementation of further programs is possible with appropriate private and public support. A different challenge is the efficient dissemination of the improved genetics produced in current CBBPs to create population-wide economic impact. We present a framework applied to the Ethiopian Washera sheep breed to meet this challenge. We propose the establishment of a genetic improvement structure that supports a meat commercialization model based on the integration of community-based breeding program cooperatives, client communities and complementary services such as fattening enterprises. We calculated that the recently established 28 community-based breeding programs in the Washera breeding tract can provide genetically improved rams to 22% of the four million head. To reach the whole population 152 additional CBBPs are needed. We simulated the genetic improvements obtainable in the current 28 CBBPs assuming realized genetic progress in CBBPs of a similar breed and calculated the expected additional lamb carcass meat production after 10 years of selection to be 7 tons and the accumulated discounted benefit 327 thousand USD. These benefits could be increased if the CBBPs are linked to client communities by providing them with improved rams: additional meat production would be 138 tons with a value of 3,088 thousand USD. The total meat production of the existing Washera CBBPs was calculated at 152 tons and the joint meat production of CBBPs if integrated with client communities would be 3,495 tons. A full integration model, which includes enterprises purchasing lambs for fattening, can produce up to 4,255 tons of meat. We conclude that Washera CBBPs cooperatives can benefit from a higher level of organization to produce population-wide genetic improvement and economic benefits. Unlike in the dairy and chicken industries, for low input sheep and goat smallholder systems the proposed commercialization model puts breeder cooperatives at the center of the operation. Cooperatives need to be capacitated and supported to become fully functional business ventures.

5.
Front Genet ; 14: 1119024, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37020995

RESUMO

Breeding programs involving either centralized nucleus schemes and/or importation of exotic germplasm for crossbreeding were not successful and sustainable in most Africa countries. Community-based breeding programs (CBBPs) are now suggested as alternatives that aim to improve local breeds and concurrently conserve them. Community-based breeding program is unique in that it involves the different actors from the initial phase of design up until implementation of the programs, gives farmers the knowledge, skills and support they need to continue making improvements long into the future and is suitable for low input systems. In Ethiopia, we piloted CBBPs in sheep and goats, and the results show that they are technically feasible to implement, generate genetic gains in breeding goal traits and result in socio-economic impact. In Malawi, CBBPs were piloted in local goats, and results showed substantial gain in production traits of growth and carcass yields. CBBPs are currently being integrated into goat pass-on programs in few NGOs and is out-scaled to local pig production. Impressive results have also been generated from pilot CBBPs in Tanzania. From experiential monitoring and learning, their success depends on the following: 1) identification of the right beneficiaries; 2) clear framework for dissemination of improved genetics and an up/out scaling strategy; 3) institutional arrangements including establishment of breeders' cooperatives to support functionality and sustainability; 4) capacity development of the different actors on animal husbandry, breeding practices, breeding value estimation and sound financial management; 5) easy to use mobile applications for data collection and management; 6) long-term technical support mainly in data management, analysis and feedback of estimated breeding values from committed and accessible technical staff; 7) complementary services including disease prevention and control, proper feeding, and market linkages for improved genotypes and non-selected counterparts; 8) a system for certification of breeding rams/bucks to ensure quality control; 9) periodic program evaluation and impact assessment; and 10) flexibility in the implementation of the programs. Lessons relating to technical, institutional, community dynamics and the innovative approaches followed are discussed.

6.
Anim Genet ; 53(3): 447-451, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35428998

RESUMO

In recent times, community-based breeding programs (CBBPs) have been advocated as the best strategy for genetic improvement of local breeds in smallholder farms in developing countries. Since 2009, CBBPs have been implemented for Ethiopian Bonga and Menz sheep to improve growth rates resulting in significant genetic gains in 6-month weights. With the hypothesis that selection could be impacting their genomes, we systematically screened for possible genome changes in the two breeds by analyzing 600K BeadChip genotype data of 151 individuals (with the highest breeding values for 6-month weights) from CBBP flocks against 98 individuals from non-CBBP flocks. We observed no differences in genetic diversity and demographic dynamics between CBBP and non-CBBP flocks. Selection signature analysis employing ROH, logistic regression genome-wide association study , FST , XP-EHH and iHS revealed 5 (Bonga) and 11 (Menz) overlapping regions under selection, that co-localized with QTLs for production (body size/weight, growth, milk yield), meat/milk quality, and health/parasite resistance, suggesting that the decade-long selection has likely started to impact their genomes. However, genome-wide genetic differentiation between the CBBP and non-CBBP flocks is not yet clearly evident.


Assuntos
Estudo de Associação Genômica Ampla , Genoma , Animais , Etiópia , Genômica , Genótipo , Polimorfismo de Nucleotídeo Único , Seleção Genética , Ovinos/genética
7.
BMC Genomics ; 23(1): 167, 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35227193

RESUMO

BACKGROUND: Ticks are obligate haematophagous ectoparasites considered second to mosquitos as vectors and reservoirs of multiple pathogens of global concern. Individual variation in tick infestation has been reported in indigenous sheep, but its genetic control remains unknown. RESULTS: Here, we report 397 genome-wide signatures of selection overlapping 991 genes from the analysis, using ROH, LR-GWAS, XP-EHH, and FST, of 600 K SNP genotype data from 165 Tunisian sheep showing high and low levels of tick infestations and piroplasm infections. We consider 45 signatures that are detected by consensus results of at least two methods as high-confidence selection regions. These spanned 104 genes which included immune system function genes, solute carriers and chemokine receptor. One region spanned STX5, that has been associated with tick resistance in cattle, implicating it as a prime candidate in sheep. We also observed RAB6B and TF in a high confidence candidate region that has been associated with growth traits suggesting natural selection is enhancing growth and developmental stability under tick challenge. The analysis also revealed fine-scale genome structure indicative of cryptic divergence in Tunisian sheep. CONCLUSIONS: Our findings provide a genomic reference that can enhance the understanding of the genetic architecture of tick resistance and cryptic divergence in indigenous African sheep.


Assuntos
Infestações por Carrapato , Animais , Bovinos , Genoma , Genótipo , Mosquitos Vetores , Polimorfismo de Nucleotídeo Único , Ovinos/genética , Infestações por Carrapato/genética , Infestações por Carrapato/veterinária
8.
Animals (Basel) ; 11(12)2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34944187

RESUMO

Multidimensional improvement programs of chickpea require screening of a large number of genotypes for straw nutritive value. The ability of near infrared reflectance spectroscopy (NIRS) to determine the nutritive value of chickpea straw was identified in the current study. A total of 480 samples of chickpea straw representing a nation-wide range of environments and genotypic diversity (40 genotypes) were scanned at a spectral range of 1108 to 2492 nm. The samples were reduced to 190 representative samples based on the spectral data then divided into a calibration set (160 samples) and a cross-validation set (30 samples). All 190 samples were analysed for dry matter, ash, crude protein, neutral detergent fibre, acid detergent fibre, acid detergent lignin, Zn, Mn, Ca, Mg, Fe, P, and in vitro gas production metabolizable energy using conventional methods. Multiple regression analysis was used to build the prediction equations. The prediction equation generated by the study accurately predicted the nutritive value of chickpea straw (R2 of cross validation > 0.68; standard error of prediction < 1%). Breeding programs targeting improving food-feed traits of chickpea could use NIRS as a fast, cheap, and reliable tool to screen genotypes for straw nutritional quality.

9.
Front Vet Sci ; 8: 610610, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34395567

RESUMO

Improved breeding practices and participatory health services have been designed and implemented by a partnership between national and international institutions in various parts of Ethiopia since 2014. Based on a panel data of two waves, we have estimated the impact of these interventions on small ruminant fertility, offtake, return per head of animal, and gross income per adult equivalent. Different specifications of the difference-in-differences model revealed that access to small ruminant health services has increased offtake, return per head of sheep/goat, and gross income per adult equivalent. Participants in community-based small ruminant breeding have also higher offtake and gross income per capita than those who are not taking part. The findings of this study are expected to help understand the economic benefits that accrue to rural areas when livestock development interventions are made based on the right diagnosis. The results of this study will also be useful in informing the ongoing discussion in Ethiopia on the transformation of the livestock sector.

10.
J Anim Breed Genet ; 138(6): 719-730, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34337791

RESUMO

We analysed options to optimize the use of sires in sheep and goat community-based breeding programmes (CBBP) for three scenarios occurring under field conditions: premature sale of selection candidates, fixed service periods of selected sires and incomplete sire pedigrees. The first scenario was studied by looking at the outcome of combinations of selection pressures in successive selection stages. A compromise of early sale of sire candidates and genetic progress can be obtained by selecting in two stages, such that selection pressure in the first stage is chosen in terms of achieving an acceptable selection potential after the second stage. Simulations showed the dependency of this compromise on selection accuracies and correlation between selection criteria. For a typical sheep CBBP, only 20% of the top three months weighting male lambs need to be retained to achieve 80% of the potential selection differential on six months weight. For the second scenario, two alternatives to fixed service periods were analysed. When across-age BLUP EBVs are not available, individual sires can be programmed to stay in service according to their initial ranking. In typical sheep, CBBPs genetic progress can be increased by about 9% over response to selection with optimum fixed sire service periods. When BLUP EBVs are available, a simulated retrospective analyses of across-age selection of sires in two current sheep CBBPs increased more than twofold the average breeding values actually observed. Thirdly, we studied the benefit of considering possible sires and their mating probabilities when estimating BLUP breeding values instead of setting such sires as unknown. In a current goat CBBP with up to three possible sires included in the pedigree, the accuracy of breeding values nears the accuracy when sires are known and are higher than accuracies when sires are unknown or when possible sires are ignored.


Assuntos
Cabras , Reprodução , Animais , Cabras/genética , Masculino , Linhagem , Estudos Retrospectivos , Ovinos/genética
11.
Evol Appl ; 14(7): 1716-1731, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34295359

RESUMO

Knowledge on how adaptive evolution and human socio-cultural and economic interests shaped livestock genomes particularly in sub-Saharan Africa remains limited. Ethiopia is in a geographic region that has been critical in the history of African agriculture with ancient and diverse human ethnicity and bio-climatic conditions. Using 52K genome-wide data analysed in 646 individuals from 13 Ethiopian indigenous goat populations, we observed high levels of genetic variation. Although runs of homozygosity (ROH) were ubiquitous genome-wide, there were clear differences in patterns of ROH length and abundance and in effective population sizes illustrating differences in genome homozygosity, evolutionary history, and management. Phylogenetic analysis incorporating patterns of genetic differentiation and gene flow with ancestry modelling highlighted past and recent intermixing and possible two deep ancient genetic ancestries that could have been brought by humans with the first introduction of goats in Africa. We observed four strong selection signatures that were specific to Arsi-Bale and Nubian goats. These signatures overlapped genomic regions with genes associated with morphological, adaptation, reproduction and production traits due possibly to selection under environmental constraints and/or human preferences. The regions also overlapped uncharacterized genes, calling for a comprehensive annotation of the goat genome. Our results provide insights into mechanisms leading to genome variation and differentiation in sub-Saharan Africa indigenous goats.

12.
Parasite ; 28: 44, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34009121

RESUMO

In this study, we report the results of a survey of Hyalomma ticks infesting one-humped camels in southern Tunisia. Examinations were conducted every second or third month on 406 camels in Tataouine district from April 2018 to October 2019. A total of 1902 ticks belonging to the genus Hyalomma were collected. The ticks were identified as adult H. impeltatum (41.1%; n = 782), H. dromedarii (32.9%; n = 626), H. excavatum (25.9%; n = 493), and H. marginatum for a single specimen. Although the camels were infested by ticks throughout the year, the highest overall infestation prevalence was observed in April 2018 (p < 0.01). The overall infestation intensity varied between 2.7 and 7.4 ticks/animal. There were no statistically significant differences in tick infestation prevalence based on age categories of the camels, and the overall infestation prevalence was between 82.7% and 97.4%. Female camels were significantly more infested with ticks (88.3%) than males (65.5%) (p < 0.01). The infestation prevalence of camels varied significantly according to the region where sampling took place (p < 0.01), but no correlations were found with abiotic factors. The preferred attachment sites for adult Hyalomma ticks were the sternum (38.3%; n = 729/1902), around the anus (36.2%; n = 689/1902), udder (18.4%; n = 350/1902), and inner thigh (6.9%; n = 132/1902). Morphological classification of ticks was corroborated by sequencing the cytochrome c oxidase I (Cox1) and 16S rDNA genes, and these sequences were also used to infer phylogenetic relationships. A single H. dromedarii seemed to be a natural hybrid with H. rufipes. More attention should be devoted by the veterinary services to the infestation of camels by ticks.


TITLE: Phénologie et phylogénie des tiques Hyalomma spp. infestant les dromadaires (Camelus dromedarius) dans la zone bioclimatique saharienne tunisienne. ABSTRACT: Dans cette étude, les résultats d'une enquête concernant les tiques Hyalomma infestant les dromadaires dans le sud de la Tunisie sont présentés. Des examens ont été menés tous les deux ou trois mois sur 406 dromadaires dans le district de Tataouine entre avril 2018 et octobre 2019. Au total, 1902 tiques appartenant au genre Hyalomma ont été collectées. Les tiques adultes ont été identifiées comme H. impeltatum (41,1 % ; n = 782), H. dromedarii (32,9 % ; n = 626), H. excavatum (25,9 % ; n = 493) et un seul spécimen de H. marginatum. Bien que les dromadaires aient été infestés par les tiques tout au long de l'année, la prévalence globale d'infestation la plus élevée a été observée en avril 2018 (p < 0,01). L'intensité globale d'infestation variait entre 2,7 et 7,4 tiques/animal. Il n'y avait pas de différence statistiquement significative de l'infestation par les tiques en fonction des catégories d'âge des dromadaires, et la prévalence globale d'infestation se situait entre 82,7 et 97,4 %. Les dromadaires femelles étaient significativement plus infestés par les tiques (88,3 %) que les mâles (65,5 %) (p < 0,01). La prévalence d'infestation variait significativement en fonction des régions (p < 0.01) mais il n'y avait pas de corrélation avec les facteurs abiotiques. Les sites de fixation préférés des tiques Hyalomma adultes étaient le sternum (38,3 % ; n = 729/1902), autour de l'anus (36,2 % ; n = 689/1902), la mamelle (18,4 % ; n = 350/1902) et la face interne de la cuisse (6,9 % ; n = 132/1902). La classification morphologique a été corroborée par le séquençage des gènes de l'ADNr du cytochrome c oxydase I (Cox1) et du 16S, et ces séquences ont également été utilisées pour déduire les relations phylogénétiques. Un seul spécimen de H. dromedarii semblait être un hybride naturel avec H. rufipes. Une plus grande attention doit être accordée par les services vétérinaires quant à l'infestation des dromadaires par les tiques.


Assuntos
Ixodidae , Infestações por Carrapato , Carrapatos , Animais , Camelus , Feminino , Masculino , Filogenia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/veterinária , Tunísia/epidemiologia
13.
Trop Anim Health Prod ; 53(1): 42, 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33231745

RESUMO

Investigation was carried out to assess the effects of environmental factors and to estimate genetic parameters and trends for reproductive traits in Bonga sheep, Ethiopia. Animals used in this study were managed by two communities involved in a community-based breeding programs (CBBPs) from 2009 to 2018. The database consisted of 15,595 individual phenotypic information from about 1500 ewes with variable number of records for each trait. The traits analyzed were age at first lambing (AFL), lambing interval (LI), and litter size (LS). Fixed effect analysis was done using the general linear model procedures of SAS. The Average Information Restricted Maximum Likelihood method of WOMBAT, fitting univariate animalmodel, was used to estimate heritabilities, repeatabilities and breeding values. Results showed that Bonga sheep had overall mean AFL, LI, and LS of 453 ± 109 days, 254 ± 51 days, and 1.43 ± 0.008, respectively. All traits were influenced (p < 0.01) by lambing year, lambing season, breeder communities, and parity of ewes. Estimates of heritability for AFL, LI, and LS were 0.015 ± 0.143, 0.009 ± 0.070, and 0.085 ± 0.110, respectively. The low heritabilities for the traits are expected and indicate low possibility of achieving rapid genetic progress through phenotypic selection. The repeatability estimates for LI and LS were low (0.109 and 0.196, respectively) indicating that non-genetic factors had significant influence to the variation in these traits among parities; therefore, selection decision on ewes should consider repeated records. The genetic trend for AFL, LI, and LS over the years was significant (p < 0.01). Positive values for LS and negative for AFL and LI were recorded, implying that the well-structured CBBPs have resulted in measurable genetic gains for the reproductive traits.


Assuntos
Cruzamento , Reprodução/genética , Carneiro Doméstico/fisiologia , Animais , Etiópia , Feminino , Variação Genética , Carneiro Doméstico/genética
14.
Vet Med Sci ; 6(4): 834-845, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32588559

RESUMO

In Tunisia, livestock plays an important role in the economy; unfortunately, Tunisian sheep population faces several health challenges. The aim of this trial was to study phenotypic variability of four local sheep breeds and strains to abomasum nematodes infection and to Babesia/Theileria parasites. Faeces, blood and abomasum contents were collected from 310 sheep slaughtered in eight commercial slaughterhouses across North Tunisia. Haematological and biochemical parameters were assessed. DNA was extracted and catch-all primers were used to detect both Theileria spp. and Babesia spp. DNA. Faecal egg counts (FEC) was quantitatively assessed using simple flotation technique followed by McMaster technique. Male and female worms were collected from all abomasum contents and counted under a stereomicroscope. The percentage of faeces samples positive for GIN's eggs was 30.82%. After worms' recovery, the infection prevalence was estimated to 75.90%. The overall infection prevalence by Babesia spp. and Theileria spp. was 4.21%. The dispersion of observations plots obtained by principal component analysis (PCA) showed two clusters of individuals. The first cluster contains animals having positive Babesia/Theileria PCR, presence of nematodes in the abomasum contents and relatively low total worm count (TWC < 500) expect one animal which was found bearing high TWC (>500). In this same group, with a suspected form of resistance, animals showed normal values of albumin and normal haematological parameters (red blood cell count [RBC], haemoglobin [Hb] and packed cell volume [PCV]). The second cluster represents all the other observations in which subgroups of animals were distinguished on the basis of their potential resistance to abomasum nematodes. Multiple correlations showed significant positive correlations between RBC/Hb, RBC/PCV, PCV/Hb and FEC/TWC. Significant negative correlations were observed between TWC/RBC and TWC/Hb. It is concluded that the phenotypic variability among local sheep breeds is essential for more advanced genetic and genomic studies.


Assuntos
Babesiose/epidemiologia , Infecções por Nematoides/veterinária , Doenças dos Ovinos/epidemiologia , Theileriose/epidemiologia , Abomaso , Animais , Babesia/isolamento & purificação , Babesiose/parasitologia , Variação Biológica Individual , Feminino , Individualidade , Masculino , Nematoides/isolamento & purificação , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia , Ovinos , Doenças dos Ovinos/parasitologia , Carneiro Doméstico , Theileria/isolamento & purificação , Theileriose/parasitologia , Tunísia/epidemiologia
15.
Trop Anim Health Prod ; 52(6): 2977-2985, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32529602

RESUMO

In the traditional Menz sheep breeding, communities select against black coat color and therefore its frequency is declining over time. We hypothesize that this exercise is causing the loss of an important gene pool. Data collected from on-station Menz sheep nucleus (n = 1992) and community-based breeding program (CBBP) (n = 5578) were analyzed to (1) assess color proportion dynamics over years and (2) associate phenotypic performances and estimated breeding values (EBVs) for growth traits with coat color of the animals. The on-station nucleus considered growth trait as selection criteria, while CBBP focused on a combination of growth and morphological characters. The results showed that the proportion of black coat color increased across years in the on-station nucleus flock (2.1% per year). However, in the CBBP, flocks' proportion of black coat color declined over time (1.03-1.05% per year). Birth and growth traits of black-colored sheep were consistently superior (P < 0.05) to white-colored sheep. Mean yearling weight and EBV of black rams used in the on-station flock was 24.3 kg and 3.7 kg, respectively, while the values for white-colored sheep were 19.7 kg and 1.6 kg, respectively. This variation in growth performances of Menz sheep among different colors may be due to the linkage between color and growth performance genes. Thus, selection against black coat color in the CBBPs seems to have an adverse effect on the genetic progress of growth traits in the Menz sheep. Understanding the core reasons behind the prevailing selection against black coat color and devising measures to address them should be considered. Developing a black line targeting specific markets might also be worthy to maximize production as well as maintain qualities associated with black color.


Assuntos
Pelo Animal , Pigmentação , Carneiro Doméstico , Animais , Peso Corporal , Masculino , Fenótipo , Carneiro Doméstico/genética , Carneiro Doméstico/crescimento & desenvolvimento
16.
Anim Sci J ; 91(1): e13384, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32462805

RESUMO

To understand the ovarian basis for prolificacy of Bonga sheep, a total of 31 ewes were selected based on litter size (LS) records and divided into two groups: High Prolificacy (HP) (n = 20) with LS ≥ 2 and Low Prolificacy (LP) (n = 11) with LS = 1. At a synchronized estrus, follicular dynamics were determined using transrectal ultrasonography. Plasma estradiol concentrations were also monitored. In total 27 ewes were observed in estrus being 9/11 LP (82%) and 18/20 HP (90%). On the day of estrus (day 0), the mean number of large follicles was higher (p < .05) in HP (1.78 ± 0.19) than in LP (1.0 ± 0.28) ewes. Prior to estrus, more (p < .05) medium follicles were visible for HP compared to LP ewes. Plasma estradiol concentrations were higher in HP compared to LP ewes (18.91 ± 0.41 vs. 14.51 ± 0.65 pg/ml; p < .05) and similarly was ovulation number (2.3 ± 0.15 vs. 1.28 ± 0. 14; p < .05). Higher ovulation rates and litter size in Bonga sheep are evidenced by the previous presence of more large follicles and the existence of co-dominance effects as most likely medium follicles are selected to ovulate.


Assuntos
Tamanho da Ninhada de Vivíparos , Folículo Ovariano/anatomia & histologia , Folículo Ovariano/fisiologia , Ovulação/fisiologia , Ovinos/fisiologia , Animais , Estradiol/sangue , Estro/fisiologia , Feminino
17.
Mamm Genome ; 30(11-12): 339-352, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31758253

RESUMO

Maximizing the number of offspring born per female is a key functionality trait in commercial- and/or subsistence-oriented livestock enterprises. Although the number of offspring born is closely associated with female fertility and reproductive success, the genetic control of these traits remains poorly understood in sub-Saharan Africa livestock. Using selection signature analysis performed on Ovine HD BeadChip data from the prolific Bonga sheep in Ethiopia, 41 candidate regions under selection were identified. The analysis revealed one strong selection signature on a candidate region on chromosome X spanning BMP15, suggesting this to be the primary candidate prolificacy gene in the breed. The analysis also identified several candidate regions spanning genes not reported before in prolific sheep but underlying fertility and reproduction in other species. The genes associated with female reproduction traits included SPOCK1 (age at first oestrus), GPR173 (mediator of ovarian cyclicity), HB-EGF (signalling early pregnancy success) and SMARCAL1 and HMGN3a (regulate gene expression during embryogenesis). The genes involved in male reproduction were FOXJ1 (sperm function and successful fertilization) and NME5 (spermatogenesis). We also observed genes such as PKD2L2, MAGED1 and KDM3B, which have been associated with diverse fertility traits in both sexes of other species. The results confirm the complexity of the genetic mechanisms underlying reproduction while suggesting that prolificacy in the Bonga sheep, and possibly African indigenous sheep is partly under the control of BMP15 while other genes that enhance male and female fertility are essential for reproductive fitness.


Assuntos
Estudo de Associação Genômica Ampla , Característica Quantitativa Herdável , Reprodução/genética , Ovinos/genética , África Subsaariana , Animais , Análise por Conglomerados , Haplótipos/genética , Análise de Componente Principal , Mapas de Interação de Proteínas/genética
18.
J Anim Breed Genet ; 136(5): 319-328, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31037758

RESUMO

Ethiopia has a large and diverse population of small ruminants, which contribute substantially to the livelihood and income of the rural poor and the country at large. However, the sector faces a number of challenges. Productivity per animal and flock offtake are both very low. Reasons attributed for the apparent low productivity are as follows: absence of appropriate breeding programmes, lack of technical capacity, inadequate and poor-quality feeds, diseases leading to high lamb mortality, and underdeveloped markets in terms of infrastructure and information. Historically, sheep and goats have received little policy or investment attention. Genetic improvement of small ruminants could contribute to bridging the productivity gap. In the past, the government of Ethiopia has placed much emphasis on importing exotic genetics and cross-breeding with local stock as a strategy for genetic improvement. However, this has not led to a significant productivity improvement and the programmes have generally been unsustainable. Currently, there is a change in approach and a recognition of the need to focus genetic improvement efforts on the local genetic resources that are well adapted to the diverse agro-ecologies and production environments in the country. Community-based breeding programmes (CBBPs), which focus on indigenous stock and consider farmers' needs, views, decisions and active participation, from inception through to implementation, have been identified as programmes of choice. The Ethiopian government and the private sector need to invest in strategic areas around CBBPs to make the programme work for the poor and be sustainable in low-input systems.


Assuntos
Criação de Animais Domésticos/métodos , Cruzamento/métodos , Cabras , Carneiro Doméstico , Criação de Animais Domésticos/economia , Animais , Biotecnologia/métodos , Cruzamento/economia , Etiópia
19.
Asian-Australas J Anim Sci ; 31(8): 1221-1229, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29268588

RESUMO

OBJECTIVE: A study was conducted to evaluate the varietal differences among faba bean straws and also to assess the potentials of faba bean straws supplemented with concentrate fed at the rate 70% straws and 30% concentrate mixture on feed intake, digestibility, body weight gain and carcass characteristics of the animals. METHODS: Forty yearling Arsi-Bale sheep with initial body weight of 19.85±0.29 kg (mean± standard deviation) were grouped in a randomized complete block design into eight blocks of five animals each based on their initial body weight. Straws included in the study were from Mosisa (T1M), Walki (T2W), Degaga (T3D), Shallo (T4S), and local (T5L) varieties of faba bean and concentrate (2:1 ratio of wheat bran to "noug" seed cake). The experiment consisted of seven days of digestibility and 90 days of feeding trials followed by evaluation of carcass parameters at the end. RESULTS: Local variety had lower (p<0.05) in grain and straw yield compared to improved varieties but higher in crude protein, metabolizable energy contents and in vitro organic matter digestibility. The apparent digestibility of dry matter and crude protein of sheep fed Walki and Mosisa straws were higher than (p<0.05) straws from Shallo varieties. Sheep fed Walki straw had greater (p<0.05) dry matter intake, average daily gain and feed conversion efficiency than sheep fed local and Shallo straws. Slaughter body weight and empty body weight were higher (p<0.05) for sheep fed Mosisa and Walki straws as compared to sheep fed Shallo straws. Apart from this, the other carcass components were not affected (p>0.05) by variety of the faba bean straws. CONCLUSION: There is significant varietal differences between faba bean straws both in quality and quantity. Similarly, significant variation was observed in feed intake, digestibility, body weight gain and feed conversion efficiency among sheep fed different straws of faba bean varieties with concentrate supplement. Based on these results, Walki and Mosisa varieties could be recommended as pulse crop rotation with cereals in the study area.

20.
Sci Rep ; 7(1): 17647, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29247174

RESUMO

African indigenous sheep are classified as fat-tail, thin-tail and fat-rump hair sheep. The fat-tail are well adapted to dryland environments, but little is known on their genome profiles. We analyzed patterns of genomic variation by genotyping, with the Ovine SNP50K microarray, 394 individuals from five populations of fat-tail sheep from a desert environment in Egypt. Comparative inferences with other East African and western Asia fat-tail and European sheep, reveal at least two phylogeographically distinct genepools of fat-tail sheep in Africa that differ from the European genepool, suggesting separate evolutionary and breeding history. We identified 24 candidate selection sweep regions, spanning 172 potentially novel and known genes, which are enriched with genes underpinning dryland adaptation physiology. In particular, we found selection sweeps spanning genes and/or pathways associated with metabolism; response to stress, ultraviolet radiation, oxidative stress and DNA damage repair; activation of immune response; regulation of reproduction, organ function and development, body size and morphology, skin and hair pigmentation, and keratinization. Our findings provide insights on the complexity of genome architecture regarding dryland stress adaptation in the fat-tail sheep and showcase the indigenous stocks as appropriate genotypes for adaptation planning to sustain livestock production and human livelihoods, under future climates.


Assuntos
Adaptação Fisiológica/genética , Genótipo , Ovinos/fisiologia , Estresse Fisiológico/fisiologia , África , Animais , Ásia Ocidental , Evolução Biológica , Reparo do DNA/genética , Secas , Ecossistema , Egito , Especiação Genética , Genética Populacional , Genômica , Gado , Análise em Microsséries , Pigmentação/genética , Seleção Artificial , Especificidade da Espécie , Transcriptoma , Raios Ultravioleta
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