Study for Trend of genetic Resource on Wild Yak in China

In this paper, comprehensively studied inhabit environments, population size, population density and distribution regions on wild yak, the results showed that genetic resource of wild yak has been decreased from 1950' to 1980 ', after that, and its genetic resource began to show increasing trend in nature reserves due to protection measures strengthened.     

Population genetic structure of Santa Inês sheep in Brazil

This study aimed to describe the population genetic structure and evaluate the state of conservation of the genetic variability of Santa Inês sheep in Brazil. We used pedigree data of the Santa Inês breed available in electronic processing of the Brazilian Association of Sheep Breeders. A file with 20,206 records, which enabled the calculation of the genetic conservation index (GCI), individual inbreeding coefficient (F), change in inbreeding (ΔF), effective population size (Ne), effective number of founders (?_e), effective number of ancestors (?_ɑ), generation interval (L), average relatedness coefficient of each individual (AR), and Wright’s F-statistics (F _IT, F _IS, and F _ST). For pedigree analysis and calculation of population parameters, the program ENDOG was used. The average inbreeding coefficient (\( \overline{F} \)) was 0.97% and the mean average relatedness (\( \overline{\mathrm{AR}} \)) 0.49%. The effective numbers of founders and ancestors were, respectively, 199 and 161. The average values of F and AR increased significantly over the years. The effective population size fluctuated over the years concurrently to oscillations in inbreeding rates, wherein N _e reached just 68 in the year 2012. The mean average generation interval was 5.3 years. The Santa Inês breed in Brazil is under genetic drift process, with loss of genetic variation. It requires the implementation of a genetic management plan in the herd, for conservation and improvement of the breed.     

Control of canine leptospirosis in Europe: time for a change?

Changes in the formulation of the Leptospira components of dog vaccines are being considered in Europe, following changes in North America. This article discusses the options for change and recommends the continued inclusion of serovars Icterohaemorrhagiae and Canicola plus the inclusion of serovars Bratislava and Grippotyphosa (for mainland Europe only). If other serovars, such as Pomona, are to be considered in the future, then there is a need for additional clinical, cultural and serological studies across Europe to support their inclusion.     

Behavioural development in groups of pen‐housed pullets in relation to genetic strain,age and food form

1. Behavioural development in groups of 8 pullets kept in pens with litter floors, and fed on either mash or pellets, was studied from 0 to 10 weeks in a White Leghorn X broiler (F2) hybrid line (experiment 1) and from 0 to 24 weeks in Hisex, White Leghorn and Brown Leghorn strains (experiment 2). The aim was to identify precursors of feather pecking and cannibalism.

2. Rates of body weight gain were consistently greater with pellets than with mash in both experiments. In experiment 2, the onset of lay was at 17 weeks of age in Hisex, 21 weeks in White Leghorns and 23 weeks in Brown Leghorns.

3. Persistent feather pecking, which was not seen in experiment 1, developed in 2 of 12 groups (one Hisex and one White Leghorn, both fed on pellets) in experiment 2, and was studied in detail at 23 and 24 weeks. The more damaging pecking in the Hisex group was followed by cannibalism in the same group.

4. Based on the (often inconsistent) effects of genetic strain, age and food form on behaviour diat were observed, a working hypothesis was constructed to account for the aetiology of feather pecking and cannibalism in situations where there is floor litter.

5. An age‐related decline in one or more foraging activities may coincide with increases in preening and non‐damaging pecking at other birds. Consumption of litter particles and moulted feathers may be reinforcing. Dustbathing may enhance the stimulus value of litter particles when they are contrasted against background plumage colour. This may direct pecking towards the backs of birds, where feathers as well as litter particles may be removed and eaten. Regular pecking and feather removal may lead eventually, after the onset of lay, to vent pecking and cannibalism. This sequence of events may be more likely in groups where activity levels are high.     

Drivers and trajectories of social and ecological change in the Karoo,South Africa§

This review article explores past, present and possible future drivers of change in Karoo social-ecological systems. Biogeographically, the Karoo comprises the arid Succulent Karoo and Nama-Karoo biomes covering significant portions of the Northern Cape, Eastern Cape and Western Cape provinces and a smaller part of the Free State. Despite the Karoo’s specific environment and spatial importance nationally (covering some 30% of South Africa), no government structures address its needs holistically. Today it is a politically and economically marginalised region; perceptions of it as a desert easily morph into perceptions of it as deserted and ripe for exploitation for the benefit of external constituencies, whether in the name of astronomy, shale-gas and uranium mining or renewable energy. To manage the Karoo better for present and future generations, it is clearly desirable for social and natural scientists to work collaboratively, yet there is relatively little interdisciplinary work to date. Against this background this review article provides an overview of social and ecological changes historically and in the present, and offers some cautious reflections concerning climate change, changing land use and governance as key drivers affecting trajectories of change into the future.     

Spatial distribution of Dermacentor reticulatus and Ixodes ricinus in Hungary: evidence for change?

A survey was conducted to investigate the spatial distribution of Ixodes ricinus and Dermacentor reticulatus in Hungary and to compare these data with the results of a previous large-scale survey. In the survey conducted in the 1950s, D. reticulatus adults were detected in two isolated areas of two counties, and the presence of these ticks in the collection was explained by accidental introduction. In the present survey, D. reticulatus became the second most common species occurring in all 16 counties involved in the monitoring and showed high prevalence. The change in the spatial distribution of this tick species, the increase of incidence of Babesia canis infection in Hungary, and the increasing number of canine babesiosis case reports from other Central and Central Eastern European countries since the 1970s suggest an expansion of the geographic range of D. reticulatus and intensification of the transmission rate of B. canis and probably other D. reticulatus-borne diseases (e.g. tularemia and tick-borne lymphadenopathy) in the region. The spatial distribution of I. ricinus was roughly in line with the results of the earlier survey. I. ricinus was the most common tick species being present in all 16 counties with the highest prevalence. Nevertheless, the comparison of the data of the previous and current survey cannot be used for fine-scale analysis; thus, it cannot be dismissed that the spatial distribution of I. ricinus also changed during the past decades. The spatial distribution patterns of tick-borne encephalitis in Hungary and other Central Eastern European countries may indicate such a change.     

Open‐field and tonic immobility responses in domestic chicks of two genetic lines differing in their propensity to feather peck

1. The open‐field and tonic immobility reactions of female domestic chicks of 2 genetic lines which showed high (HP) or low (LP) levels of feather pecking were compared.

2. Chicks of the LP line showed less freezing, and vocalised and walked sooner and more in the open field than did their HP counterparts.

3. There were no differences between lines in the durations of their tonic immobility responses, at least in the present study.

4. The pattern of results may reflect line divergence in underlying social motivation rather than fearfulness.     

Biology of fibre growth and possible genetic and non-genetic means of influencing fibre growth in sheep and goats—a review

This paper reviews the biology of wool, mohair and cashmere growth and the options available to sheep and goat farmers to manipulate the quantity and characteristics of fibre produced to meet processors' requirements. The annual pattern of fibre growth in sheep and fibre producing goats is photodependent and regulated by hormone action. In sheep and Angora goats, fibre growth rate is greater in summer than winter with the amplitude varying between breeds. Cashmere-producing goats grow fibre between the longest and shortest day after which it is shed. The large diversity in fleece and fibre characteristics between genotypes of sheep and goats can be used to change characteristics by selection. Fibre characteristics of greatest importance to processors are all of medium to high heritability. Negative genetic correlations between some important characteristics limit overall genetic progress achievable through selection. The principal non-genetic factors affecting fleece and fibre characteristics in both sheep and goats are age, nutrition, physiological status, disease and shearing regime. Further work is required to gain a greater understanding of biological changes occurring within the follicle and fibre during growth to facilitate the production of fibre of specific characteristics through breeding or altering animal management.     

On estimating non‐additive genetic parameters in chickens 1

1. Several economically important traits in two Leghorn populations (over 9000 birds) were examined for additive and non‐additive components of genetic variance and sex‐linked effects. Data were analysed by two different statistical models based on least‐squares procedures.

2. Six different covariances were first calculated between relatives; i.e., full‐sibs, 3/4‐sisters, half‐sisters, dam‐daughters, grandam‐granddaughters and aunt‐nieces.

3. From the covariances, weighted least‐squares equations were used to obtain estimates of variance components for additive genetic, dominance, maternal and sex‐linkage effects.

4. The estimates of non‐additive components were highly variable but generally small compared with the additive genetic estimates.

5. In general this study suggests that for most traits, with the possible exception of rate of egg production, there is relatively little non‐additive genetic variation.

6. The consequences of possible negative correlations between additive effects and maternal effects are considered as they might apply to egg production in poultry.     

Is neutral genetic diversity related to quantitative variation in semen traits in bulls?

Conservation decisions based on neutral genetic diversity have been observed to promote retention of useful quantitative variation in biological populations. An experiment was undertaken to determine the association between microsatellite marker polymorphisms and phenotypic variation in semen production and cryosurvival traits in bulls. Thirty-five ejaculates were collected from ten bulls of two breeds and evaluated before and after cryopreservation for several semen traits. The bulls were also genotyped using a set of sixteen bovine-specific microsatellite marker loci. Fixation indices (F_ST), heterozygosity and Nei's genetic distance measures were computed from allele frequency data for each of the bulls. Molecular and phenotypic data were used to compute tri-distance matrices for the ten bulls and correlated using Mantel's test in GenAIEx 6.5. The study revealed extensive heterogeneity in semen traits, heterozygosity and F_ST values among the bulls. Large pairwise phenotypic and genetic distances were also observed. Correlation between pairwise genetic distances and phenotypic distances was significant and highly positive for sperm viability (r = .61, p < .001) and moderately positive for sperm motility (r = .40–42, p < .05) variables. For sperm morphology, ejaculate volume and sperm concentration, correlation with genetic distances was positive, low and not significantly different from zero (p > .05). A tendency for a triangular-shaped relationship between genetic and phenotypic distances for post-thaw motility and viability traits was also observed. Accordingly, association with neutral genetic diversity was absent for semen production traits and moderate to highly positive for sperm cryosurvival traits. Given these findings, conservation decisions based on neutral genetic diversity may capture variation in some adaptive traits, but not others.     

Long-term impacts of livestock grazing and browsing in the Succulent Karoo: a 20-year study of vegetation change under different grazing regimes in Namaqualand§

This study used a fence-line contrast approach to investigate the long-term impact of high grazing pressure on the vegetation at a site in Namaqualand, South Africa. Forty pairs of permanently marked plots were surveyed in 1996, 2006 and 2016. The main objective was to investigate changes in the vegetation structure and species composition between the near-continuously grazed communal rangelands and the relatively lightly grazed commercial rangelands over the 20-year period. The results showed a decline in total vegetation cover in both commercial and communal rangelands in 2016 relative to the two earlier sampling periods. This can be attributed to the low rainfall in 2016 and was due largely to a reduction in annual plant cover, especially on the communal rangeland. Perennial shrub species provide a fodder bank that can be utilised by livestock in times of drought and can buffer short-term deficits in forage supply. However, the annuals that dominate the vegetation of the communal rangeland do not form such fodder banks and consequently do not have the same multi-year buffering capacity as perennial shrubs. This provides the mechanism whereby long-term continuous grazing decreases resilience to rainfall fluctuations and increases livestock variability, thereby promoting non-equilibrium-type dynamics in the system.     

Practical aspects of genetic management of small populations – The Olkuska sheep example

Abstract

The study aimed to identify important factors threatening genetic diversity within small sheep populations, and to propose sustainable management strategies. Demographic evolution, genetic diversity and current genetic management practices were analyzed in a population of Polish Olkuska sheep. Unbalanced contributions of individual rams to the next generation were observed due to differences in the period of their utilization, the number of progeny and the number of daughters used in reproduction. Matings between closely related animals were common. Pedigree completeness was satisfactory and inbreeding coefficient was high, 11.71% for lambs born in 2012. Relatively high values of potential and realized coancestries within flocks showed the importance of keeping more than one ram. The genetic conservation index and average relatedness coefficient, and their comparison between regions was helpful in considering management options. The information on genetic relationships and genetic conservation parameters of rams should be provided to breeders with simple interpretations.     

Vaccination against Taenia solium cysticercosis in underfed rustic pigs of México: roles of age, genetic background and antibody response

Vaccination of pigs of mixed genetic make-up, raised as rustically as done in rural Mexico, resulted in effective protection to experimental challenge against Taenia solium cysticercosis. Maximum protection was achieved if pigs were immunized at 70 days of age. There was large variation of viable parasite load within vaccinated pigs and controls, which is suggestive of significant genetic factors influencing susceptibility, besides immunization. Our results strengthen the advisability of pig vaccination for control of T. solium cysticercosis, since it lowers the number of viable cysticerci capable of transforming into tapeworms.     

Tail docking in dogs: can attitude change be achieved?

The debate about tail docking in domestic dogs continues to rage in many developed countries and attitudes expressed by different community groups remain diametrically opposed. Veterinary associations and welfare organisations typically want the practice banned, while many breeders and pure-bred dog associations just as vigorously oppose the introduction of anti-docking legislation. In recent years, much data have been accumulated concerning the welfare implications of tail docking. A recent evaluation of this literature suggests that the practice has little to recommend it and that, in the absence of reasonable case-by-case justification, it may constitute an unacceptable abuse of a sentient species. Given this situation, it is difficult to understand why many canine interest groups, presumably representing those people who care most about the welfare of companion dogs, should continue to hold such strong attitudes in favour of tail docking. In this review we attempt to explain why different community groups might espouse strong but opposing attitudes, despite having access to the same information. We argue that the theory of cognitive dissonance, popular among social psychologists, may provide a useful framework within which to understand, and attempt to alter, attitudes that persist even though they appear contrary to available empirical evidence.     

The future of veterinary parasitology: a time for change?

The future of veterinary parasitology is discussed at a time when R&D funding from the pharmaceutical industry is declining, yet the opportunities for veterinary parasitologists to diversify their activities has never been greater. Emerging and re-emerging areas requiring input from veterinary parasitologists include: veterinary public health; conservation and wildlife diseases; emerging and exotic infectious diseases; surveillance strategies; economic effects of parasitic diseases; aquaculture; molecular epidemiology; dietary and biological control of parasitic diseases; animal welfare; organic agricultural systems; novel vaccination strategies; drug target characterisation and rational drug design. Without change, the survival of veterinary parasitology as a viable, distinct discipline is under threat. In this environment, veterinary parasitologists must be adaptable, imaginative and pro-active in terms of setting the agendas for establishing strategic alliances, promoting research needs and developing research programs.     

Animal production and genetic resources in Guinea Bissau: II–Tombali province

A survey of the animal production systems and genetic resources was conducted in Tombali Province, Guinea Bissau. Animal owners and their families, village chiefs, shepherds and local officials were interviewed. The vast majority of the population is dedicated to very small-scale subsistence farming where animal ownership has an important role in both food supply, ceremonial events and as form of cash reserve. Animal production in the area is characterized by the existence of several ethnic groups: Balanta, Nalú, Sosso, Biafada and Fula. Only Balanta raise cattle (N'Dama and West African Shorthorn) and pig (crioulo breed) whereas all ethnic groups own goats (West African Dwarf), chickens and ducks. Sheep are limited to specific areas and ethnic groups. The survey is intended to serve as a basis to possible agricultural and animal production development projects in this area.