Letteratura scientifica selezionata sul tema "Sheep South Australia Breeding"

In the conditions of the hot climate of the South of Russia, purebred Texel sheep of Australian breeding by the beginning of the main breeding season in sheep breeding in the North Caucasus zone (end of August, fi rst decade of September) have reduced sexual activity, ejaculate volume and unsatisfactory seed quality, compared with Texel sheep of Finnish breeding and Kuban Lincolns. The reproductive ability of texel sheep of Australian breeding is restored at a later date.

Summary. White clover was introduced to Australia with the early European settlers in the late 18th century and is now the most valuable pasture legume in high rainfall temperate regions of Australia. Through a process of ingress and naturalising in conjunction with pastoral expansion during the 19th century and widespread pasture improvement in the 20th century, white clover now occupies 6 million hectares in Australia and is of major significance for the sheep, beef cattle and dairy industries. This paper describes these historical influences on formation of the white clover zone in Australia and the continuing requirement for better adapted cultivars in key agro-geographic regions, with particular close reference to the northern tablelands of New South Wales—the most extensive dryland region. These considerations provide a basis for defining breeding objectives for white clover improvement in Australia.

Sheep worm infections increasingly threaten the profitability of the Australian sheep industry as the prevalence and severity of anthelmintic resistance continues to rise. Field experiments have demonstrated that the use of drenches that are of reduced efficacy due to resistance can reduce wool production by 10% and significantly reduce sheep sale value. The major factor in benzimidazole (BZ) and levamisole (LV) resistance, and in part macrocyclic lactone (ML) resistance in Haemonchus contortus, is considered to be the excessive frequency of treatment. In Ostertagia circumcincta, ML resistance appears to be related chiefly to interactions between the environment and the time of treatment, where resistant worms surviving drenches are not significantly diluted by worms acquired after treatment. Resistance to the BZs and LV affects almost all Australian sheep farms, and on most drench efficacy is now below a useful level. ML resistance is common in O. circumcincta in Western Australia, and increasingly prevalent in H. contortus in summer rainfall regions. Closantel resistance is a major threat to H.�contortus control in northern New South Wales and southern Queensland. The organophosphate naphthalophos, especially when used in combination with other compounds, has proved useful although variable in efficacy. It is essential that the sheep industry adopts approaches that minimise reliance on chemical control, such as the breeding of worm resistant sheep, use of specific grazing strategies for worm control and apply flock treatment tactics to minimise further resistance development. New non-chemical technologies under development are also expected to contribute to more sustainable worm control. Nutritional regimens that minimise the impact of worm infections and enhance the immune response require investigation and integration into sustainable control practices.

In conditions of Povolzhye steppe zone development of productive qualities of Stavropol breed sheep was conducted by meat merino sheep. Experimental research was carried out in ZAO «Novaya Zhizn» in Novouzensky district of Saratov region, located in semi desert zone, bordering upon South-West Khazakhstan. The research aim was the increase and maintenance of genetic potential of Stavropol breed sheep of Povolzhye population. Working procedure is based on guidelines of the All-Union Academy of Agricultural sciences, All Union research institute of sheep and goat breeding. The study materials were Stavropol pure breed sheep and 1/8 –thoroughbred cross breed with Australian meat merino herdmates. As the result of stepped breeding of local Stavropol ewe with half bred by Australian meat merino ram- breeder of Stavropol breed animals of 1/2 ,1/4, 1/8 –blood were obtained, which then one- shear tupped by breeding «inter se». It is proved that in applying such selective method 1/8-blood by Australian meat merino sheep were characterized with higher body weight, better wool quality in contrast to Stavropol pure –breed herdmates. So, in 1/8-blood by Australian meat merino of hybrid ewe during breeding «inter se» live body at birth was higher than at pure breed herdmates for 5,56 %, during ablactation –at the age of 4 months - for 6,38 % (difference isn’t accurate). According to sharing of wool in grease, superiority of ewe of hybrid origin over pure breed was 5,6 % (Р≥0,99), but in terms of washed fiber it increases to 8,3 % (Р≥0,999). So, in dry steppe zone of Povolzhye new improved, according to its productive qualities, genotype of Stavropol breed sheep is created with retention of genetic resource that is essential economic factor for the modern maintenance of fine-wool sheep breeding field.

The sheep grazing tolerance of a diverse range of lucerne germplasm (Medicago sativa subspp. sativa, falcata and caerulea) was investigated at Roseworthy in South Australia. Lucerne entries were established on a sandy loam soil in 1998 and managed with rotational grazing management for the first 12 months. Continuous grazing by sheep in the following year reduced the plant density of each entry as measured by plant frequency estimates by 2–98%. Lucerne was allowed to recover, then grazed continuously for another 12 months. There was great diversity in tolerance to sheep grazing among the entries tested, with final plant frequency ranging from 0–13% for highly winter-active entries, 7–23% (at least 7–23 plants/m2) for winter-active entries and 11–40% for winter dormant entries. A grazing tolerance index of commercial cultivars was determined by comparing their plant frequency decline under continuous grazing to that under rotational grazing in an adjacent experiment. Australian-bred highly winter-active cultivars displayed a greater level of tolerance than those developed overseas. The superior performance of several breeders’ lines in the continuously grazed trial indicates there is further scope for improvement with selection and breeding.

We used the PCR–SSCP method followed by sequencing in order to assess the genetic variability of coding and non- coding parts of the genome of Echinococcus granulosus (Cestoda; Taeniidae) and to test whether or not the parasite populations are mainly self-fertilizing. For this, we analysed a sample of 110 E. granulosus metacestode isolates collected from different geographical regions (Southern Brazil, Europe and Australia) and from different intermediate hosts (ovine, bovine, human, macropod, swine and equine). Using appropriate controls, we were able to identify 4 strains in that sample (sheep, cattle, pig and horse strains). The high degree of genetic differentiation between strains, but not within, and the monomorphism found in most loci (EgAg4, EgActII, EgHbx2 and EgAg6 – non-coding – EgAgB/1 and EgND1 – coding) indicated that they are largely selfed. On the other hand, outcrossing was also shown to occur, since 5 potential hybrid genotypes between cattle and sheep strains were found in populations of Southern Brazil, but absent in other geographical areas. We suggest that both processes are adaptive. The article also reports, for the first time, the occurrence of the E. granulosus cattle strain in South America.

Number of not woolly and molty sheep exceeds 60 million throughout the world. Their numbers and their importance is growing, still they have appeared in the past two decades all over in North-America, Australia, New-Zealand and also in Europe. The South African Dorper has been a pioneer among them in Hungary. It was introduced in 2006 in the country. The Dorper sheep is the second largest breed in South Africa, which was developed from the crossing of Dorset Horn and the Blackhead Persian. The aim of the EU Member States in terms of this specific breed is increasing the small populations, improving the productive qualities, in addition to this avoiding inbreeding. However, finding appropriate breeding stock is difficult due to the small size of available populations and also to the suspected common of origin. With the help of various molecular genetic methods we could get a total view of the genetic background of these flocks. Nowadays the most commonly known and used genetic markers are microsatellites, because their applications give fast, accurate and easily reproducible results. There is no specific descriptive information on the genetic background of Dorper populations in the various EU countries , also regarding diversity between populations. Therefore in our work we want to optimize the conditions of applicability of 31 selected microsatellite reactions as a first step of mapping the entire genetic background of the different EU Dorper populations.

The development and use of perennial ryegrass (Lolium perenne L.), cocksfoot (Dactylis glomerata L.), phalaris (Phalaris aquatica L.) and tall fescue (Lolium arundinaceum Darbysh.) in the high-rainfall zone and the wheat–sheep zone is reviewed through the pastoral era of extensive grazing (from European settlement to ~1930), the expansive era of pasture improvement (1930–80) and in the modern era. Their adoption, in conjunction with inoculated clover seed, rose steadily in specifically Australian systems of animal production, designed with an appreciation of the environment, and aided by technical developments such as single-disc and aerial spreaders for mineral fertiliser, chemical fallowing and direct-drilling. These species remain vital contributors to the competitive productivity of Australia’s cattle and sheep industries. Perennial ryegrass (~6 Mha by 1994) and cocksfoot emerged as the most important after a wide range of species was introduced through the 19th Century; many of these became naturalised. Regional strains of perennial ryegrass were subsequently selected for commercialisation in Victoria, New South Wales and Tasmania. In the modern era, persistent ecotypes were harnessed to breed persistent cultivars. Vision to both improve grass persistence and extend the area of adaptation encouraged the adoption of phalaris (~2.7 Mha by 2009) and, to a lesser extent, early-flowering types of cocksfoot and tall fescue, particularly for the marginal-rainfall, wheat–sheep zone. The sowing of grass and clover seed expanded after the wide adoption of superphosphate, which became recognised as essential for correcting the severe deficiency of soil phosphorus and nitrogen associated with ancient, intensely weathered soils. The initial and dramatic response of clover to superphosphate increased farm revenue, so fostering a phase in which perennial grasses could be successfully sown, due to having the benefit of (biologically fixed) nitrogen. The influence of European practice, agricultural societies, the Welsh Plant Breeding Station, CSIRO, universities, state Departments of Agriculture, collaborative arrangements and individuals that nurtured and managed pasture technology, plant breeding, cultivar registration and evaluation are outlined. Future considerations emerging from the review include monitoring the national pasture inventory, promotion of the great potential for increasing livestock carrying capacity, cultivar discrimination and information, relevance of models, and national coordination of collaborative research.

In recent years, sheep farms in the Lenin-grad region began to increase import from abroad of sheep breed "Dorper" This breed were bred in the 1930s in the deserts of South Africa. Later this breed began to be exported to Australia, the UK and in small quantities to Russia. Breed "Dorper" very precocious, young quickly gaining live weight up to 500 grams per day. Adult sheep reach a weight up to 90 kg or more. Rams can be used as producers from 5 months. Taking into account that, like all meat breeds of sheep, dorpers are very sensitive to drafts, high humidity, dampness in sheep-fields. The object of research- breeding sheep breed "Dorper". The research was carried out in the farm "SP A. Krylov" Leningrad re-gion. Two groups of 3 heads each were formed to treat the rams. In the scheme of treatment of animals of the first (experimental) group, a finely dispersed soft powder (manganese-acid potassium+copper sulfate+ boric acid + streptocide 1:1:3:5) was used, which was applied on the ulcer with the help of a powder blower. For animals of the second group were applied "Konkov ointment". For the rams of both groups were used a short novocaine blockade with an antibiotic (streptomycin) directly under the pathological focus. Repeated treatments were carried out after 3,6,12 16 days. It should be noted that balanoposthitis in rams appears mainly in autumn and spring. The use of complex powders in rams with ulcerative balanoposthitis showed positive dynamics of the course of this disease, re-duces the healing time of the ulcer surface by 3-4 days, compared to the conventional treatment in the farm with the use of "Konkov ointment

Profitability of sheep production systems in southern Australia is optimised at a stocking rate that provides adequate nutrition for breeding ewes and enables efficient utilisation of grown pasture and supplements. In this paper we used bio-economic modelling to develop optimum liveweight1 profiles for spring-lambing Merino ewes in different environments. The modelling included the impacts of the ewe liveweight profile on the production of the ewe and the survival and lifetime wool production of her progeny. Fifteen ewe liveweight profiles were analysed for each region to determine the profitability of varying ewe liveweight at joining, varying rate of loss of liveweight after joining and the rate of gain in liveweight from the minimum to lambing. The analyses support the hypotheses that whole-farm profitability is sensitive to the liveweight profile of Merino ewe flocks and that there is a liveweight profile that maximises whole-farm profit. The variation between the most and least profitable ewe liveweight profile was $69 0002 per farm ($14.30/ewe) for south-west Victoria, $51 000 per farm ($8.70/ewe) for Great Southern Western Australia and $33 300 per farm ($9.70/ewe) for southern New South Wales. The changes in profit were due to differences in costs of feeding to achieve the ewe liveweight profile and its influence on the production of both the ewes and their progeny. Failure to include the impacts of liveweight profile on progeny survival and lifetime wool production incorrectly identifies the optimum ewe liveweight profile and provided inaccurate estimates of profitability. The optimum liveweight profiles for ewes lambing in spring were similar for all three regions and insensitive to changing commodity prices, pasture productivity and management. The optimum profile was to join ewes at ~90% of the standard reference weight of the genotype, lose a small amount of weight after joining and regain weight in late pregnancy to return to the joining weight by lambing. Regaining the liveweight lost in early pregnancy by lambing is the most important target to achieve. The cost per farm of missing this liveweight target by 1 kg was $13 000 ($2.60/ewe) for south-west Victoria, $8900 ($1.45/ewe) for Great Southern Western Australia and $5500 ($1.65/ewe) for southern New South Wales. By contrast, the cost per farm of missing the joining target by 1 kg was $5500 for south-west Victoria and less than $2000 across the other two regions. Whole-farm profit increased with increasing stocking rate up to an optimum and regardless of stocking rate there is an additional opportunity to increase whole-farm profit by up to 15% by managing ewes to achieve the optimum liveweight profile. This indicates that the optimum liveweight profile should be achieved by increasing the level of grain feeding and altering the timing of utilising the farm feed resources rather than manipulating stocking rate.

The South African sheep industry has experienced an increase in the price of meat and wool over the past several years. This has led to an interest in intensification of sheep production off planted pastures. Due to this phenomenon an economic viability study was done on the intensification of sheep production on cultivated pastures under irrigation. When intensifying sheep production, certain management practices need to be incorporated in order to enhance the output obtained per hectare and to overcome the higher input cost of production. Management practices that could be included are creep feeding, accelerated breeding and feedlotting of lambs after weaning. In order to determine the economic viability of such a system, certain production parameters need to be obtained for producing sheep intensively from cultivated pastures. Three studies were conducted to obtain the required production parameters; these were then followed by an economic evaluation incorporating the parameters obtained from the studies. All the studies were conducted at Kromme Rhee and Langgewens, two research farms of the Department of Agriculture in the Western Cape.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2009.
ENGLISH ABSTRACT: Fluctuations and a general decline in the ratio between wool and meat prices resulted in marked changes in the South African sheep industry. Commercial producers now exploit other mechanisms such as terminal crossbreeding of Merino-type with meat type breeds or dual-purpose breeds to attain short-term benefits resulting from price fluctuations between wool and mutton without compromising the wool-producing capacities of ewe flocks. Most components of lamb production have low heritability. However, heterosis can be achieved by mating wool-type breeds with specialist meat breed rams. Genetic improvement of livestock depends on defining breeding objectives, estimation of genetic parameters and accurately identifying the right animals to be used for future breeding. Genetic parameters for traits of economic importance in terminal sire sheep breeds that could be used on Merino-type ewes in commercial operations in South Africa had not been published for the national flock apart from a preliminary study having been conducted by Olivier et al. (2004). Selection objectives were poorly defined due to lack of parameter estimates for variance and covariance components. Against this background, this study obtained pedigree information and live weight data from the National Small Stock Improvement Scheme for the Dormer, Ile de France and Merino Landsheep and estimated non-genetic factors and genetic parameters influencing early growth traits. Genetic and phenotypic trends for early growth traits were constructed for the three breeds to monitor genetic progress. Non-genetic factors influencing early growth traits in the Dormer, Ile de France and Merino Landsheep were estimated using data obtained from the National Small Stock Improvement Scheme of South Africa. The original data sets for the Dormer, Ile de France and Merino Landsheep consisted of the following number of records respectively: 52 202, 35 553 and 7 772. However, pre-weaning weights were available for the Ile de France and Merino Landsheep breeds only and post-weaning weights were available only for the Dormer breed. The data sets were complicated to such an extent that smaller data sets had to be generated to analyse for fixed effects. The traits that were analysed were birth weight, pre-weaning weight, weaning weight and post-weaning weight. The fixed effects, identified as having a significant effect (P < 0.01) on early growth traits were sex of lamb, birth type, age of dam, contemporary groups, age at which the trait was recorded and month of birth and year of birth in the Merino Landsheep breed. Although some significant interactions were found, they were subsequently ignored owing to their very small effects. In all three breeds, male lambs were significantly (P < 0.001) heavier than female lambs and single-borne lambs were significantly heavier at birth than multiple borne lambs. The age of dam had a significant curvilinear regression on all early growth traits in all three terminal sire sheep breeds. It was concluded from the study that the influence of non-genetic factors on early growth traits should be adjusted for or eliminated statistically in genetic evaluations to get accurate genetic parameter estimations. (Co)variance estimates for birth weight, weaning weight and post-weaning weight were obtained for the Dormer breed using restricted maximum likelihood procedures (REML). Direct heritabilities (h2) in single-trait analyses were 0.21 ± 0.03, 0.23 ± 0.02 and 0.29 ± 0.05 for birth weight, weaning weight and post-weaning weight, respectively. Direct heritabilities of 0.28 ± 0.04, 0.55 ± 0.06 and 0.32 ± 0.02 for birth weight, weaning weight and post-weaning weight respectively were obtained using three-trait analysis. Direct maternal genetic effects (m2) were excluded from the analyses because of the failure to partition maternal effects into maternal genetic and maternal permanent environmental effects (m2 and c2). This culminated as a consequence of poor data and population structures emanating from the loss of genetic links across flocks due to the random entrance and exit of flocks from the recording scheme. Maternal permanent environment was estimated at 0.15 ± 0.02, 0.13 ± 0.02 and 0.20 ± 0.03 for birth weight, weaning weight and post-weaning weight respectively using single-trait analysis. The correlation between direct effects and maternal effects (ram) was excluded from the analyses due the structure of the data. Genetic, phenotypic and environmental correlations between early growth traits were low to moderate. The medium to high heritability estimates for early growth traits obtained in the study led to the conclusion that Dormer sheep can successfully be used in terminal crossbreeding programs to improve meat production characteristics. Direct heritability estimates were 0.31 ± 0.14, 0.09 ± 0.02 and 0.14 ± 0.003 for birth weight, pre-weaning weight and weaning weight respectively using single-trait analysis for the Ile de France breed. Maternal effects were significant for all the traits studied despite the failure to properly partition them into their components due to the loss of genetic linkages across generations emanating from poor data structure. Genetic, phenotypic and environmental correlations were estimated using three-trait analysis and were found to be low to moderate for early growth traits. Direct genetic and maternal permanent environmental ratios were also computed and they did not differ much from the results obtained using single-trait analyses. The reasonable genetic parameter estimates obtained in the study led to the conclusion that the Ile de France can be selected to use as sires in crossbreeding programs. Genetic parameters were estimated for early growth traits in the Merino Landsheep breed. REML estimates of birth weight, pre-weaning weight and weaning weight were obtained using animal models in single-trait analyses. The direct heritability estimate for birth weight was 0.23 ± 0.13 using an animal model with additive direct genetic effects and dam permanent environmental effects as the only random factors. The dam permanent environmental effect for birth weight amounted to 0.10 ± 0.07. Direct heritability for pre-weaning weight was 0.36 ± 0.05 and the dam permanent environmental effect 0.56 ± 0.03. Weaning weight was estimated using an animal model that contained direct additive effects and dam permanent environmental effects. The direct heritability estimate for weaning weight was 0.17 ± 0.03. Maternal genetic effects were estimated to be 0.02 ± 0.01. Genetic and phenotypic trends were constructed for early growth traits in the Dormer, Ile de France and Merino Landsheep breeds. The traits that were considered were birth weight, pre-weaning weight, weaning weight and post-weaning weight. However, pre-weaning weights were available for the Ile de France and Merino Landsheep breeds only and post-weaning weights were available only for the Dormer breed. The Dormer exhibited significant improvement in the phenotypic and genetic aspects of early growth traits during the 17 years of evaluation (1990-2007). The average predicted direct breeding values of birth weight decreased by 0.055 % during the evaluation period. The predicted direct breeding value for weaning weight increased by 0.12 % during the 17 year period. Post-weaning weight improved by 0.32 % per annum. The Ile de France registered an increase in the predicted breeding value of birth weight which amounted to 0.025 % per annum. Averaged direct breeding values for pre-weaning weight increased at an annual rate of 0.23 %. and that of weaning weight increased by 1.21 %. In the Merino Landsheep the predicted direct breeding value for birth weights decreased by 0.04 % per annum and pre-weaning and weaning weights increased by 0.36 % and 0.10 % respectively. The trends were obviously biased due to inconsistencies in data structure and very few records available for analysis in this breed. In conclusion, it was evident that the additive genetic variation was available for all the early growth traits in all the three breeds. Although adequate genetic variation for substantial genetic progress was available, only modest rates of progress were attained for all the traits in all three breeds. The only possible exception was weaning weight in the Ile de France breed, which improved at > 1 % per annum. At least all changes were in the desired direction. Breeders should be encouraged to record data consistently, as one of the major shortcomings in the data for all breeds were a lack of continuity in the submission of data to the NSIS. More informative analyses ought to be feasible if this requisite could be met.
AFRIKAANSE OPSOMMING: Die wisselende en algemene afname in die prysverhouding van wol tot vleis het merkbare veranderinge in die Suid-Afrikaanse skaapbedryf teweeggebring. Kommersïele produsente maak nou gebruik van ander metodes soos terminale kruisteling van Merino-tipe ooie met vleis tipe vaars of dubbel-doel rasse om korttermynvoordele uit die wisselende wol en vleis pryse te behaal, sonder om die wol-produksie potensiaal van die ooi-kudde te benadeel. Die meeste van die lamproduksie eienskappe het ‘n lae oorerflikheid. Nietemin, kan heterose wel behaal word deur die kruisteling van wol-tipe rasse met spesialis vleisramme. Genetiese verbetering van vee is afhanklik van die beskrywing van die teeltdoelwitte, die akkurate beraming van genetiese parameters en die noukeurige identifikasie van die geskikste diere vir toekomstige teling. Genetiese parameters vir ekonomies belangrike eienskappe van terminale ramrasse wat gebruik kan word op Merino-tipe ooie in die kommersiële skaapbedryf in Suid-Afrika is nog nie gepubliseer vir die nasionale kudde nie, behalwe vir ‘n voorlopige studie wat gedoen is deur Olivier et al. (2004). Seleksiedoelwitte is nie duidelik beskryf nie a.g.v ‘n tekort aan akkurate parameterberamings vir (ko)variansie komponente. Hierdie studie het dus stamboominligting en lewende gewig data verkry vanaf die Nasionele Kleinveeverbeteringsskema vir die Dormer-, Ile de France- en die Merino landskaaprasse en nie-genetiese faktore sowel genetiese parameters vir vroeë lamgewigte beraam. Genetiese en fenotipiese tendense vir vroeë lamgewigte is vervolgens opgestel vir drie rasse om genetiese vordering te evalueer. Die oorspronklike datastelle vir die Dormer, Ile de France en die Merino Landskaap het uit die volgende aantal rekords bestaan, onderskeidelik: 52 202, 35 553 en 7 772. Voor-speen gewigte was net beskikbaar vir die Ile de France- en die Merino Landskaaprasse, en na-speen gewigte was net beskikbaar vir die Dormerras. Die beperkings in die datastelle het genoodsaak dat dat kleiner datastelle ontwikkel moes word om die vaste effekte te analiseer. Die eienskappe wat ge-analiseer was, was geboortegewig, voor-speengewig, speengewig en naspeengewig. Die vaste effekte wat vroeë lamgewigte betekenisvol (P < 0.01) beïnvloed het, was geslag van die lam, geboortestatus, ouderdom van die ooi, kontemporêre groep, die ouderdom waarop die eienskap aangeteken is en (in sommige gevalle) die maand en jaar van geboorte. Alhoewel daar sommige betekenisvolle interaksies was, is dit nie in die finale modelle ingesluit nie, omdat dit min tot die verklaarde variasie bygedra het. In al die rasse het ramlammers swaarder (P < 0.001) geweeg as ooilammers. Enkelinge was ook swaarder (P<0.001) as meerlinge. Die ouderdom van die moer van die lam het ‘n beduidende kromlynige invloed op alle vroeë lamgewigte by al drie terminale ramrasse gehad. Die gevolgtrekking van hierdie studie is dat die invloed van nie-genetiese faktore op vroeë lamgewigte in ag geneem moet word, of dat dit moet statisies elimineer word in die genetiese evaluasie om akkurate genetiese beramings te verkry. (Ko)variansie beramings vir geboortegewig, speengewig en na-speengewig is deur gebruik te maak van die “restricted maximum likelihood procedures” (REML) vir die Dormerras verkry. Die direkte oorerflikheid (h2) wat verkry was deur die mees geskikste diere model in ‘n enkel-eienskap analise te gebruik was onderskeidelik 0.21 ±0.02, 0.23 ±0.02 en 0.29± 0.05 vir geboortegewig, speengewig en na-speengewig. Direkte ooreenstemende oorerflikheid wat uit die drie-eienskap analise was 0.28±0.04, 0.55±0.06 en 0.32±0.02 onderskeidelik vir geboortegewig, speengewig en na-speengewig. Direkte maternale genetiese effekte (m2) is uitgesluit vanaf die analise weens die onvermoë om die maternale effekte te verdeel in maternale genetiese effekte en maternale permanente omgewings effekte (m2 en c2). Dit was a.g.v onvolledige data en populasiestrukture wat gelei het tot die gebrek in genetiese bande oor kuddes, wat ontstaan het weens kuddes wat slegs tydelik data tot die skema bygedra het. Maternale permanente omgewingeffekte is geskat op onderskeidelik 0.15±0.02, 0.13±0.02 en 0.20±0.03 vir geboortegewig, speengewig en na-speengewig met die gebruik van die enkel-eienskap analise. Die korrelasie tussen direkte effekte en maternale effekte (ram) is uitgesluit a.g.v die gebrekkige struktuur van die data. Genetiese-, fenotipiese- en omgewingskorrelasies tussen die vroeë lamgewigte was laag tot matig. Die matige tot hoë oorerflikheidberamings vir vroeë lamgewigte uit hierdie studie het gelei tot die gevolgtrekking dat Dormer skape suksesvol gebruik kan word in terminale kruisteel programme om vleisproduksie te verbeter. Direkte oorerflikheid skattings was 0.31±0.14, 0.09±0.02 en 0.14±0.003 vir die geboorte gewig, voor-speen gewig en speen gewig onderskeidelik met die gebruik van ‘n enkel-faktor analise vir dir Ile de France skaap ras. Maternale effekte was beduidend vir al die eienskappe wat bestudeer was , ten spyte van die onvermoë om dit behoorlik te verdeel in hul komponente weens die verlies van genetiese bande dwarsoor die generasies wat uitvloei vanaf ‘n swak data struktuur. Genetiese, fenotipiese en omgewings korrelasies was geskat deur gebruik te maak van ‘n drie-faktor analise en was gevind om laag tot matig te wees vir die vroeë groei eienskappe. Direkte genetiese en maternale permanente omgewings ratios was bereken en dit het nie veel verskil van die resultate verkry deur die enkel-faktor analise. Die aanvaarbare genetiese parameter skattings verkry in hierdie studie het gelei tot die gevolgtrekking dat die Ile de France geselekteer kan word as teelramme in kruisteel programme. Genetiese parameters was geskat vir vroeë groei eienskappe in die Merino Landskaa ras. REML skattings van geboorte gewig, voor-speen gewig en speen gewig was verkry deur diere modelle in enkel-faktor analises. Die direkte oorerflikheid skatting vir geboorte gewig was 0.23±0.13 met die gebruik van die diere model met additiewe direkte genetiese effekte en ooi permanente omgewings faktore as die enigste ewekansige faktore. Die ooi permanente omewings effek vir geboorte gewig was 0.10±0.07. Direkte oorerflikheid vir voor-speen gewig was 0.36±0.05 en die ooi permanente omgewings effek 0.56±0.03. Speen gewig was geskat deur die gebruik van ‘n diere model wat die direkte additiewe effekte en die ooi permanente omgewings effekte bevat het. Die direkte oorerflikheids skatting vir speen gewig was 0.17±0.03. Maternale genetiese effekte was geskat as 0.02±0.01. Genetiese en fenotipiese tendense is verkry vir vroeë lamgewigte in die Dormer-, Ile de France- en Merino Landskaaprasse. Die eienskappe wat oorweeg is, was geboortegewig, voor-speengewig, speengewig en naspeengewig. Voor-speengewigte was net beskikbaar was vir die Ile de France- en die Merino Landskaap rasse en die na-speense gewigte net vir die Dormerras. Die Dormer het beduidende verbetering vertoon in die fenotipiese en genetiese aspekte vir vroeë lamgewigte gedurende die 17 jaar van evaluasie (1990-2007). Die gemiddelde voorspelde direkte teeltwaarde van speen gewig het met 0.12% per jaar gestyg gedurende die 17- jaar periode. Na-speen gewig het met 0.32% per jaar verbeter. By die Ile de France het ‘n toename in die voorspelde teelwaarde van geboortegewig (0.025% per jaar) voorgekom. Gemiddelde direkte teelwaardes vir voor-speengewig het toegeneem teen ‘n jaarlikse tempo van 0.23% en speengewig het met 1.21% per jaar toegeneem. In die Merino Landskaapras het die voorspelde direkte teelwaarde vir geboortegewig met 0.04% per jaar gedaal, terwyl voor-speen- en speengewigte met 0.36% en 0.10% onderskeidelik toegeneem het. Die tendense was ooglopend gekompromiteer weens probleme met die data struktuur, en a.g.v van die relatief min rekords wat beskikbaar was vir die analise in die ras. Dit was duidelik dat die additiewe genetiese variasie beskikbaar was vir al die vroeë groei eienskappe in al die drie rasse. Alhoewel voldoende genetiese variasie vir wesentlike genetiese vordering beskikbaar was, is daar slegs matige vordering verkry vir al die eienskappe in al drie rasse. Die enigste moontlike uitsondering was speengewig in die Ile de France ras, wat met 1.21 % per jaar gestyg het. Alle veranderinge was minstens in die gewensde rigting. Telers word versoek om data deurlopend en akkuraat aan te teken , aangesien een van die groot tekortkominge met die data van al die rasse ‘n tekort aan deurlopendheid in die indiening van die data aan die NISS was. ‘n Meer verteenwoordigende analise sal uitvoerbaar wees, as daar aan al die bogenoemde aanbeveling voldoen kan word.

Over the last 60 years, grass tetany has been recognised as a significant lethal condition in sheep and cattle.Outcomes from this study include documentation of the likely precursors to grass tetany, ways to recognise these precursors, and long term practices that will enable producers to minimise livestock deaths. The benefit of this research to beef producers is that the environmental circumstances thought to be associated with outbreaks of grass tetany have been identified, along with remedial action that can be taken to prevent deaths occurring.Recommendations to industry on best practice to be adopted by leading producers to minimise outbreaks of grass tetany are made.This study provides an alternate strategy for the management of grass tetany in beef cattle, to the more clinical approaches previously recommended. It is suggested that losses from this economically important metabolic disease can be minimised if management practices of beef cattle producers in eastern Australia can incorporate a more holistic approach to farm management, which takes account of the soil/plant/animal/climate inter-relationships.
Master of Science (Hons)

Thesis (PhD)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: Reproduction and robustness traits are integral in ensuring sustainable, efficient and profitable sheep farming. Increases in genetic gain of reproduction and robustness traits are however, hampered by low heritability coupled with the difficulty in quantification of these traits for traditional selective breeding strategies. The aim of the current study was therefore to identify genomic regions underlying variation in reproduction traits and elucidate quantitative trait loci (QTL) and/or genes associated with reproductive traits. The Elsenburg Merino flock has been divergently selected for the ability to raise multiple offspring and has resulted in a High and a Low line that differ markedly with regard to reproductive output and other robustness traits. The flock thus served as an ideal platform to identify genomic regions subject to selection for reproductive traits. To pinpoint genomic regions subject to selection, a whole-genome genotyping platform, the OvineSNP50 chip, was selected to determine the genotype of more than 50 000 SNPs spread evenly across the ovine genome. The utility of the OvineSNP50 chip was determined for the Elsenburg Merino flock as well as additional South African Merino samples and three other important South African sheep breeds, the Blackheaded Dorper, South African Mutton Merino (SAMM) and the Namaqua Afrikaner. Although genotyping analysis of the Elsenburg Merino flock indicated some signs of poor genotype quality, the overall utility of the genotype data were successfully demonstrated for the South African Merino and the other two commercial breeds, the Dorper and SAMM. Genotyping results of the Namaqua Afrikaner and possibly other indigenous African breeds may be influenced by SNP ascertainment bias due to the limited number of indigenous African breeds used during SNP discovery. Analysis of pedigree, phenotypic records and SNP genotype data of the Elsenburg Merino cohort used in the current study, confirmed that the lines are phenotypically as well as genetically distinct. Numerous putative genomic regions subject to selection were identified by either an FST outlier approach or a genomic scan for regions of homozygosity (ROH) in the High and Low lines. Although annotated genes with putative roles in reproduction were identified, the exact mechanism of involvement with variation in reproduction traits could not be determined for all regions and genes. Putative ROH overlapped with QTL for several reproduction, milk, production and parasite resistance traits, and sheds some light on the possible function of these regions. The overlap between QTL for production and parasite resistance with putative ROH may indicate that several, seemingly unrelated traits add to the net-reproduction and may have been indirectly selected in the Elsenburg Merino flock. A SNP genotyping panel based solely on reproduction traits may therefore be ineffective to capture the variation in all traits influencing reproduction and robustness traits. A holistic selection strategy taking several important traits, such as robustness, reproduction and production into account may as such be a more effective strategy to breed animals with the ability to produce and reproduce more efficiently and thereby ensure profitable and sustainable sheep farming in South Africa.
AFRIKAANSE OPSOMMING: Reproduksie- en gehardheids-eienskappe is noodsaaklik om volhoubare, doeltreffende en winsgewende skaapboerdery te verseker. ‘n Toename in genetiese vordering in reproduksie- en gehardheids-eienskappe word egter bemoeilik deur lae oorerflikhede tesame met die probleme in kwantifisering van hierdie eienskappe vir tradisionele selektiewe diereteelt strategieë. Die doel van die huidige studie was dus om gebiede in die genoom onderliggend tot variasie in reproduksie-eienskappe te identifiseer en die rol van verwante kwantitatiewe eienskap loki (KEL) en/of gene met reproduktiewe eienskappe te bepaal. Die Elsenburg Merinokudde is uiteenlopend geselekteer vir die vermoë om meerlinge groot te maak en het gelei tot 'n Hoë en 'n Lae lyn wat merkbaar verskil ten opsigte van reproduksie-uitsette en ander gehardheids-eienskappe. Die kudde het dus gedien as 'n ideale platform om genomiese areas onderhewig aan seleksie vir reproduksie-eienskappe te identifiseer. Om vas te stel waar genomiese areas onderhewig aan seleksie gevind kan word, is ‘n heel-genoom genotiperingsplatform, die OvineSNP50 skyfie, gekies om die genotipes van meer as 50 000 enkel nukleotied polimorfismes (ENPs) eweredig versprei oor die skaap genoom, te bepaal. Die nut van die OvineSNP50 skyfie is bepaal vir die Elsenburg Merinokudde sowel as addisionele Suid-Afrikaanse Merinos en drie ander belangrike Suid-Afrikaanse skaaprasse, die Swartkop Dorper, Suid-Afrikaanse Vleismerino (SAVM) en die Namakwa Afrikaner. Hoewel genotipe resultate van die Elsenburg Merino kudde sommige tekens van swak genotipe gehalte getoon het, kon die algehele nut van die genotipering resultate vir die Suid-Afrikaanse Merino en die ander twee kommersiële rasse, die Dorper en SAVM, bevestig word. Genotipering resultate van die Namakwa Afrikaner en moontlik ook ander inheemse Afrika rasse kan deur ENP vasstellingspartydigheid beïnvloed word as gevolg van die beperkte aantal inheemse Afrika rasse gebruik tydens ENP ontdekking. Ontleding van stamboom inligting, fenotipe rekords en ENP genotipe data van die Elsenburg Merino-kohort gebruik in die huidige studie, het bevestig dat die lyne fenotipies asook geneties verskil. Talle vermeende genomiese areas onderhewig aan seleksie is geïdentifiseer deur 'n FST uitskieter benadering of deur ‘n genomiese skandering vir gebiede van homogositeit (GVH) in die Hoë en Lae lyne. Hoewel geannoteerde gene met potensiële rolle in reproduksie geïdentifiseer is, kan die presiese meganisme van betrokkenheid by variasie in reproduksie-eienskappe nie bevestig word vir al die gebiede en gene nie. Vermeende GVH oorvleuel met KEL vir 'n paar reproduksie-, melk-, produksie- en parasietweerstand-eienskappe, en werp daarom lig op die moontlike funksie van hierdie gebiede. Die oorvleueling tussen KEL vir produksie en parasietweerstand met vermeende GVH kan daarop dui dat 'n hele paar, skynbaar onverwante, eienskappe bydrae tot net-reproduksie, wat indirek geselekteer mag wees in die Elsenburg Merino-kudde. ‘n ENP genotiperingspaneel uitsluitlik gebaseer op reproduksie-eienskappe mag daarom onvoldoende wees om die variasie in alle eienskappe wat betrekking het op reproduksie- en gehardheids-eienskappe, in te sluit. ‘n Holistiese seleksie strategie wat verskeie belangrike eienskappe, soos gehardheid, reproduksie en produksie in ag neem, mag ‘n meer effektiewe strategie wees om diere te teel met die vermoë om in 'n meer doeltreffende manier te produseer en reproduseer en om daardeur winsgewende en volhoubare skaapboerdery in Suid-Afrika te verseker.

In Graaff-Reinet, domestic livestock farming and springbuck ranching are similar in that they both rely on the rangeland for their sustainability. However, as a consequence of repeated monotonous domestic livestock farming, resulting in compromised biological productivity and diversity, the rangelands have disintegrated. This, unfortunately, has placed the future sustainability of these rangelands and the livelihoods of the local people in an indeterminate state. In recent years, there has been an increasing interest in springbuck ranching for meat production as an alternative to domestic livestock farming in the area following (a) fears of worsening environmental challenges; (b) declining profitability in commercial domestic livestock farming and; (c) growing calls for the sustainable use of these rangelands for the benefit of future generations. The springbuck has emerged as a credible alternative to utilising the rangelands - as opposed to sheep - because of its promise to addressing the above challenges. This is in an attempt to tap into the multitude of benefits that the springbuck possesses (by virtue of being part of the natural capital of the area) that have a potential towards restoring ecological integrity by extenuating some of the detrimental effects of sheep farming on the rangelands and presenting opportunities for diversifying incomes. Yet, despite the general increase in interest, a resistance towards the uptake of springbuck ranching for meat production exists. The main contention is that springbuck meat production cannot out-perform the economic returns of wool sheep farming. This study attempts to address these concerns by investigating the profitability and economic sustainability of converting a sheep farm into a springbuck ranch in Graaff-Reinet. The study uses stochastic simulation to estimate the probability distribution of some key output variables, namely: net cash income, ending cash balance, real net worth and the net present value (NPV) in evaluating the profitability of converting a 5 000ha sheep-dominated farm into a springbuck-dominated ranch under three alternative scenarios. The use of stochastic simulation allows for the incorporation of downside risk associated with the production and marketing of wool, mutton and springbuck meat. The study uses stochastic prices and yields to calculate net returns variability. Incorporating scenario analysis helped to evaluate how alternative wool sheep-dominated and springbuck-dominated combinations would perform based on the probable outcomes of different assumptions in the various scenarios. By applying stochastic efficiency with respect to a function (SERF) criterion to the simulated NPVs, this study compares the profitability of alternative scenarios based on various risk aversion coefficients. The study finds that converting a 5 000ha wool sheep dominated farm into a springbuck dominated ranch could potentially be a more profitable investment than wool sheep farming over a 15 year planning horizon, in Graaff-Reinet. The SERF results indicate that for all scenarios tested, the best strategy of converting a wool sheep dominated farm into a springbuck ranch would be one which comprise a combination of 70% springbuck, 20% mutton and 10% wool production as the likely profitable enterprise mix. Using economic sustainability analysis, the study reveals that because of low costs in springbuck ranching, springbuck meat production enterprises are most likely to be more financially sustainable than wool sheep-dominated enterprises. This suggests that rangeland owners may be better off converting their wool sheep-dominated farms into springbuck-dominated ranches. Thus, as the call for more environmentally benign rangeland utilising economic-ecological systems intensifies, rangeland owners in the Eastern Cape Karoo have a practicable option. At the very least, there exists an option to broaden their incomes whilst promoting ecological restoration with springbuck meat production.

The 16th Biennial Conference of the Association for the Advancement of Animal Breeding and Genetics (AAABG) gathers together scientists, extension workers, producers and industry personnel to review developments in the application of new technologies to animal breeding. Conference presentations include 30 invited reviews and papers, and 95 contributed papers. All papers are peer-reviewed, and cover session topics that focus on genetic evaluation systems, gene expression profiling, identification and manipulation of quantitative trait loci, progress in applied programs and advanced statistical and computing techniques. Industry applications are discussed for improvement in production, health and reproduction of domestic livestock, aquaculture species and even crocodiles and ostriches. Institutions and industries in Australia, New Zealand, USA, South Africa, South-East Asia and Japan are represented with significant participation of major Cooperative Research Centres. These proceedings contain the full text of all contributed papers and summaries of the invited reviews which are published separately in the Australian Journal of Experimental Agriculture.

This book looks at current knowledge on management of pastures and rangelands for sheep production, of problems, of practical solutions where possible, and of priority areas for research. The areas considered extend from the high rainfall perennial pastures of south-east Australia and New Zealand, through the annual pasture, cropping zones to the semi-arid rangelands. Pasture Management is the major reference on managing Australia's greatest natural resource: the resource which provides directly and indirectly a major part of Australia's export income.

Abstract Bananas are a staple for more than 400 million people. Additionally, more than 16.5 million tonnes are exported, making it both an important food security and a cash crop. Productivity of Cavendish-type bananas is threatened by both abiotic and biotic stresses. The fact that triploid bananas are sterile, parthenocarpic and obligate vegetatively propagated makes them particularly susceptible to diseases, including Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc) tropical race 4 (Foc TR4). This is because continual clonal propagation has led to loss of genetic diversity. Additionally, lack of meiosis limits methods for breeding. Foc TR4 has been devastating Cavendish bananas in South-east Asia but has recently also been reported from Queensland in Australia, the Middle East and Mozambique, thus threatening global banana production. To address this, we are performing mutagenesis of in vitro propagated bananas to broaden the genetic diversity in order to find new alleles conferring disease resistance. We have developed methods for efficient induction of mutations in isolated apical meristems from shoot tips using chemical mutagens and ionizing radiation. Mutation discovery methods have been adapted to recover mutations including single point mutations and large deletions spanning millions of base pairs. We have created approximately 5000 mutated lines for forward-genetic screens to identify TR4 resistance in greenhouse- evaluated material. A subset of ca. 500 in vitro plantlets was subjected to glasshouse-based screening using a virulent F. oxysporum isolate. To date, 23 lines showing altered resistance responses to Foc TR4 have been identified.

Abstract Black gram (Vigna mungo (L.) Hepper), popularly known as urdbean or mash or black gram, is a grain legume rich in protein (25-28%), widely cultivated in the Indian subcontinent and to a lesser extent in Thailand, Australia and other Asian and South Pacific countries. Genetic improvement in this crop is hindered due to the narrow genetic base. As genetic variability is a prerequisite for any crop improvement programme, induced mutations provide an important source for generating variability. Radiation (gamma, X-rays and neutron) induced mutants were identified for various morphological and biochemical traits, creating a pool of genetic variability. These mutants were used in a cross-breeding programme to develop high-yielding, disease-resistant varieties in black gram. The effective blend of mutation and recombination breeding at the Bhabha Atomic Research Centre has resulted in the release of five black gram varieties (TAU-1, TAU-2, TPU-4, TU94-2 and TU-40) by incorporating desirable traits like large seed, wider adaptability, resistance to disease and improved quality. These varieties have been developed from mutants directly or by using them in cross-breeding programmes. For example, a black gram variety, N0.55, was irradiated with gamma-rays and electron beams to obtain a large number of mutants. The large-seed mutants, UM-196 and UM-201, were used in cross-breeding with the elite cultivar T-9 for developing the high-yielding varieties TAU-1, TAU-2, TPU-4, TU94-2 and TU-40. TAU-1 has become the most popular variety in Maharashtra state, occupying the maximum area under black gram cultivation. Induced mutations will continue to play an increasing role in generating genetic variability for various traits as a major component of environmentally sustainable agriculture.

Succeeding phases of British economic growth prompted strikingly different imperatives for expansion, for natural resource exploitation, and for the social organization of extra-European production. In the eighteenth century, sugar, African slaves, and shipping in the Atlantic world provided one major dynamic of empire. But in the nineteenth century, antipodean settlement and trade, especially that resulting from expanding settler pastoral frontiers, was responsible for some of the most dramatic social and environmental transformations. Plantations occupied relatively little space in the new social geography of world production. By contrast, commercial pastoralism, which took root most energetically in the temperate and semi-arid regions of the newly conquered world, was land-hungry but relatively light in its demands for labour. The Spanish Empire based in Mexico can be considered a forerunner. By the 1580s, within fifty years of their introduction, there were an estimated 4.5 million merino sheep in the Mexican highlands. The livestock economy, incorporating cattle as well as sheep, spread northwards through Mexico to what became California by the eighteenth century. Settler intrusions followed in the vast landmasses of southern Latin America, southern Africa, Australia, and New Zealand. Australia was one of the last-invaded of these territories, and, in respect of the issues that we are exploring, was in some senses distinctive. Unlike Canada and South Africa, there was no long, slow period of trade and interaction with the indigenous population; like the Caribbean, the Aboriginal people were quickly displaced by disease and conquest. The relative scale of the pastoral economy was greater than in any other British colony. Supply of meat and dairy products to rapidly growing ports and urban centres was one priority for livestock farmers. Cattle ranching remained a major feature of livestock production in Australia. Bullock-carts, not dissimilar to South African ox-wagons, were essential for Australian transport up to the 1870s. But for well over a century, from the 1820s to the 1950s and beyond, sheep flooded the southern lands. Although mutton became a significant export from New Zealand and South America, wool was probably the major product of these pastoral hinterlands—and a key focus of production in Australia and South Africa. The growth in antipodean sheep numbers was staggering.

Reproductive wastage is a major economic burden in sheep production globally, especially within Australia as livestock production systems face increased pressure from climatic variability (e.g. prolonged droughts or flooding). Sheep are sensitive to acute changes in their environment such as heat stress, which if not adequately monitored will result in significant production losses such as reproductive failure, increased parasite and worm burden, morbidity and mortality risks. Through basic and applied research in the areas of stress and reproductive physiology our team has made significant advancements in the understanding of sheep behaviour and physiological responses to acute and chronic stressors. Using minimally invasive hormone monitoring technology in combination with field based assessment of sheep health and productivity traits, our team has delivered new knowledge on how sheep react to acute environmental stress and how it impacts on sheep reproduction. In this chapter, we evaluated the fertility rates and embryo quality of Merino ewes under AI breeding program. We discuss factors such as heat stress that can impact on ewe and offspring quality.

The sixth and final chapter is the most original in terms of methodology, for it takes a single technoscientific organism – Karakul sheep – and follows its role in the settlement of the frontier for the three fascist empires. The ability of Karakul to thrive under harsh environmental conditions and its high value in the fur market made it a perfect companion species for white settler’s imperial expansion. The Animal Breeding Institute at the University of Halle is taken as center of circulation, establishing standards and producing the rams to be used not only in white settlers farms in German possessions in Eastern Europe, but also in Italian settlement schemes in Libya and Ethiopia, and in Portuguese colonization of South-western Angola. The different local karakul sheep experiment stations located in frontier spaces are treated as experiments in colonial sociability, revealing the connections between sheep breeding and the genocides perpetrated by the three regimes.

The exploitation of small ruminants (goat and sheep) has always been linked to the development of human civilizations, where they have mainly fed on their derived products such as milk and meat. Currently, the sheep population is around 1 billion head concentrated above 50% in three countries, China, Australia, and New Zealand, contrary to goats with around 720 million heads, distributed mainly in Asia, Africa, and South America. Both species have similar characteristics in some anatomical aspects (a pair of nipples), gestation period (150 days), and presence of seasonal anestrus, differing in terms of magnitude and depth and presence of the male effect. However, they are completely different in feeding habits, nutrient needs, and grazing systems, with differences in terms of the female’s reproductive tract, among other characteristics. Currently, the study of reproduction has intensified over the years in the goats and its counterpart that is the buck. Therefore, in the following topics, the importance of global reproduction of the goat will be discussed, considering that progress has been made today in the application of third generation reproductive techniques and that today they are already consolidated and developed in the bovine species.

This chapter addresses the wholesale exportation of Hereford cattle to North and South America, Australia, and New Zealand in the 1870s as part of a concerted effort to feed Britons with “British” meat bred and raised abroad, and returned to the metropole as frozen meat. In their enthusiasm to profit from foreign demand for British stock, Hereford breeders allowed their (quasi-)colonial competitors to establish their own reservoirs of the breed’s genetic potential. After American breeders severed ties with their British counterparts over the lack of stringency in English pedigrees, these two branches of the bovine family tree developed in isolation. While English Herefords increasingly gained status as a national breed, shedding their regional association with the county of Hereford for a perceived Britishness, Herefords in America became a new, quasi-colonial “native” breed, much like New Zealand’s Corriedale breed of sheep.

Insects are the biggest animal group on earth. They constitute as much as 80% of the animal kingdom. Over 2000 species of insects are consumed in Central and South America, Africa, Asia, Australia, and New Zealand. Currently almost 1 billion people on this planet suffer from hunger, and we must strive to increase the efficiency of food production. One of the possible solutions is to use insects as a source of food. An important advantage of insect production is the high environmental safety compared to conventional livestock. Conventional animal husbandry is responsible for at least 18% of total greenhouse gas emissions and large consumption of drinking water. A much smaller amount of water is used to produce insect meat and insects require far less feed. Production of insect protein requires much less land and energy than the more widely consumed forms of animal protein. The nutritional usefulness of edible insects varies depending on the species, on the stage of development of the insect and the method of breeding and feeding. Insects have a high nutritional value. They are a rich source of protein which includes all eight essential amino acids (phenylalanine, isoleucine, leucine, lysine, methionine, threonine, tryptophan, and valine). Edible insects contain on average 10-30% of fat in dry matter and they are good source of edible oil which contains more than 50% of polyunsaturated fatty acids (PUFA) desirable for nutritional and health reasons. The average energy value of edible insects is about 400-500 kcal/100g of dry matter. Insects also contain a variety of water soluble or lipophilic vitamins and minerals. Their consumption can build a well-balanced diet. Insects can be regarded as safe, if properly managed and consumed, but international food regulations are needed.

Insects are the biggest animal group on earth. They constitute as much as 80% of the animal kingdom. Over 2000 species of insects are consumed in Central and South America, Africa, Asia, Australia, and New Zealand. Currently almost 1 billion people on this planet suffer from hunger, and we must strive to increase the efficiency of food production. One of the possible solutions is to use insects as a source of food. An important advantage of insect production is the high environmental safety compared to conventional livestock. Conventional animal husbandry is responsible for at least 18% of total greenhouse gas emissions and large consumption of drinking water. A much smaller amount of water is used to produce insect meat and insects require far less feed. Production of insect protein requires much less land and energy than the more widely consumed forms of animal protein. The nutritional usefulness of edible insects varies depending on the species, on the stage of development of the insect and the method of breeding and feeding. Insects have a high nutritional value. They are a rich source of protein which includes all eight essential amino acids (phenylalanine, isoleucine, leucine, lysine, methionine, threonine, tryptophan, and valine). Edible insects contain on average 10-30% of fat in dry matter and they are good source of edible oil which contains more than 50% of polyunsaturated fatty acids (PUFA) desirable for nutritional and health reasons. The average energy value of edible insects is about 400-500 kcal/100g of dry matter. Insects also contain a variety of water soluble or lipophilic vitamins and minerals. Their consumption can build a well-balanced diet. Insects can be regarded as safe, if properly managed and consumed, but international food regulations are needed.

In September 2006 an outbreak of 'Bluetongue like' disease struck the cattle herds in Israel. Over 100 dairy and beef cattle herds were affected. Epizootic hemorrhagic disease virus (EHDV) (an Orbivirusclosely related to bluetongue virus (BTV)), was isolated from samples collected from several herds during the outbreaks. Following are the aims of the study and summary of the results: which up until now were published in 6 articles in peer-reviewed journals. Three more articles are still under preparation: 1. To identify the origin of the virus: The virus identified was fully sequenced and compared with the sequences available in the GenBank. It appeared that while gene segment L2 was clustered with EHDV-7 isolated in Australia, most of the other segments were clustered with EHDV-6 isolates from South-Africa and Bahrain. This may suggest that the strain which affected Israel on 2006 may have been related to similar outbreaks which occurred in north-Africa at the same year and could also be a result of reassortment with an Australian strain (Wilson et al. article in preparation). Analysis of the serological results from Israel demonstrated that cows and calves were similarly positive as opposed to BTV for which seropositivity in cows was significantly higher than in calves. This finding also supports the hypothesis that the 2006 EHD outbreak in Israel was an incursive event and the virus was not present in Israel before this outbreak (Kedmi et al. Veterinary Journal, 2011) 2. To identify the vectors of this virus: In the US, Culicoides sonorensis was found as an efficient vector of EHDV as the virus was transmitted by midges fed on infected white tailed deer (WTD; Odocoileusvirginianus) to susceptible WTD (Ruder et al. Parasites and Vectors, 2012). We also examined the effect of temperature on replication of EHDV-7 in C. sonorensis and demonstrated that the time to detection of potentially competent midges decreased with increasing temperature (Ruder et al. in preparation). Although multiple attempts were made, we failed to evaluate wild-caught Culicoidesinsignisas a potential vector for EHDV-7; however, our finding that C. sonorensis is a competent vector is far more significant because this species is widespread in the U.S. As for Israeli Culicoides spp. the main species caught near farms affected during the outbreaks were C. imicolaand C. oxystoma. The vector competence studies performed in Israel were in a smaller scale than in the US due to lack of a laboratory colony of these species and due to lack of facilities to infect animals with vector borne diseases. However, we found both species to be susceptible for infection by EHDV. For C. oxystoma, 1/3 of the Culicoidesinfected were positive 11 days post feeding. 3. To identify the host and environmental factors influencing the level of exposure to EHDV, its spread and its associated morbidity: Analysis of the cattle morbidity in Israel showed that the disease resulted in an average loss of over 200 kg milk per cow in herds affected during September 2006 and 1.42% excess mortality in heavily infected herds (Kedmi et al. Journal of Dairy Science, 2010). Outbreak investigation showed that winds played a significant role in virus spread during the 2006 outbreak (Kedmi et al. Preventive Veterinary Medicine, 2010). Further studies showed that both sheep (Kedmi et al. Veterinary Microbiology, 2011) and wild ruminants did not play a significant role in virus spread in Israel (Kedmi et al. article in preparation). Clinical studies in WTD showed that this species is highly susceptibile to EHDV-7 infection and disease (Ruder et al. Journal of Wildlife Diseases, 2012). Experimental infection of Holstein cattle (cows and calves) yielded subclinical viremia (Ruder et al. in preparation). The findings of this study, which resulted in 6 articles, published in peer reviewed journals and 4 more articles which are in preparation, contributed to the dairy industry in Israel by defining the main factors associated with disease spread and assessment of disease impact. In the US, we demonstrated that sufficient conditions exist for potential virus establishment if EHDV-7 were introduced. The significant knowledge gained through this study will enable better decision making regarding prevention and control measures for EHDV and similar viruses, such as BTV.