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PubMed2002

History, environment and social behaviour: experimentally induced cooperative breeding in the carrion crow.

Kin-based cooperative breeding, where grown offspring delay natal dispersal and help their parents to rear new young, has a long history in some avian lineages. Family formation and helping behaviour in extant populations may therefore simply represent the retention of ancestral features, tolerated under current conditions, rather than a current adaptive process driven by environmental factors. Separating these two possibilities challenges evolutionary biologists because of the tight coupling that normally exists between phylogeny and the environmental distribution of species and populations. The carrion crow Corvus corone corone, which exhibits extreme interpopulational variation in the extent of cooperative breeding, with populations showing no delayed dispersal and helping at all, provides a unique opportunity for an experimental approach. Here we show that offspring of non-cooperative carrion crows from Switzerland will remain on the natal territory and express helping behaviour when raised in a cooperative population in Spain. When we transferred carrion crow eggs from Switzerland to Spain, five out of six transplanted juveniles delayed dispersal, and two of those became helpers in the following breeding season. Our results provide compelling experimental evidence of the causal relationship between current environmental conditions and expression of cooperative behaviour.

Animals↗
PubMed2004

An association study using AFLP markers and application to a beef cattle breeding population.

Using amplified fragment length polymorphism (AFLP) fingerprinting, selective genotyping was performed to determine if this method was effective for selecting superior breeding stock. Forty-eight cows with extreme genetic merit for beef marbling score (BMS) were selected from a population of Japanese Black cattle (n = 4462), including 25 with the highest for predicted breeding value (PBV) and 23 with the lowest. Sixteen AFLP fragments were selected for further analysis based on fragment frequency differences between the high and low groups. A linear discriminant analysis using these AFLP fragments was applied in order to derive a discriminant function that classified the cows into high and low groups. Seven of the 16 fragments were included in the resulting function and the discriminant scores (general genetic values, GGV) of the 48 cows were calculated using the function. These cows were clearly separated into high and low groups by GGV with a correlation ratio of 0.91 (discriminative error of 2.1%). The same function was then applied to 121 additional cows that were randomly selected from the original population. A significant regression coefficient of GGV on BMS-PBV (R2 = 0.45) was obtained, which indicates that the GGV can be used as a selection criterion for BMS in this population. These results suggest that AFLP fingerprinting can be used for animal breeding without identifying the underlying genes affecting the trait of interest.

Agriculture↗
PubMed2005

Myostatin and its implications on animal breeding: a review.

Myostatin, or growth and differentiation factor 8 (GDF8), has been identified as the factor causing a phenotype known as double muscling, in which a series of mutations render the gene inactive, and therefore, unable to regulate muscle fibre deposition. This phenotype occurs at a high frequency in some breeds of cattle such as Belgian Blue and Peidmontese. Phylogenetic analysis has shown that there has been positive selection pressure for non-synonymous mutations within the myostatin gene family, around the time of the divergence of cattle, sheep and goats, and these positive selective pressures on non-ancestral myostatin are relatively recent. To date, there have been reports of nine mutations in coding regions of myostatin that cause non-synonymous changes, of which three cause missense mutations, including two in exon 1 and one in exon 2. The remaining six mutations, located in exons 2 and 3, result in premature stop codons, which are the mutations responsible for the double-muscling phenotype. Unfortunately, breed management problems exist for double-muscled cattle, such as birthing difficulties, which can be overcome through genetically controlled breeding programmes, as shown in this review.

Animals↗
PubMed2005

Frequencies of PrP gene haplotypes in British sheep flocks and the implications for breeding programmes.

AIMS: To analyse the frequencies of prion (PrP) gene haplotypes in UK sheep flocks and evaluate their relevance to transmissible spongiform encephalopathies (TSEs) and TSE resistance breeding programmes in sheep. METHODS AND RESULTS: Genomic DNA isolated from sheep blood was PCR amplified for the coding region of the PrP gene and then sequenced. This study has analysed the sequence of PrP between codons 110 and 245 in 6287 ARQ haplotypes revealing a total of eight variant sequences, which represent a higher than expected 41% of all ARQ haplotypes. The additional PrP gene dimorphisms were M112T, L141F, M137T, H143R, H151C, P168L, Q175E and P241S. CONCLUSION: The results do not suggest a correlation between the occurrence of a specific ARQ haplotype and the scrapie disease status of a flock. The ARQ haplotype variability appears to be different in the UK sheep flocks compared with sheep flocks from outside the UK. SIGNIFICANCE AND IMPACT OF THE STUDY: Additional PrP dimorphisms may impact on the methodologies used for standard PrP genotyping in sheep breeding programmes. Some of these polymorphisms were found with significant frequencies in the UK sheep flocks and should therefore be considered in breeding programmes.

Amino Acid Sequence↗
PubMed1993

Ecology of the biting midge Leptoconops albiventris in French Polynesia. III. Influence of abiotic factors on breeding sites. Towards ecological control?

Correspondance Analysis was used to determine the significant abiotic factors influencing the ecology of the immature stages of Leptoconops albiventris (Diptera: Ceratopogonidae). The breeding places required strict environmental conditions: fine and well-sorted sand, with low conductivity and humidity. However, the microdistribution of the immature stages within a breeding site does not depend on such factors. Modifying physical parameters in the larval breeding areas might be an important component in future ecological control programmes against L. albiventris populations.

Animals↗
PubMed2006

Genetic variability in French dog breeds assessed by pedigree data.

Pedigree data of nine French dog breeds, namely Barbet (BAR), Basset fauve de Bretagne (BAF), Beauceron (BEN), Berger des Pyrénées (BRP), Bouledogue Français (BUF), Braque Saint-Germain (BQG), Dogue de Bordeaux (DOB), Epagneul Breton (EPB) and Montagne des Pyrénées (MOP), were analysed. The effective numbers of ancestors of dogs born from 1997 to 2001 were equal to 6.7 (BAR), 40.2 (BAF), 36.5 (BEN), 16.0 (BRP), 37.0 (BUF), 13.1 (BQG), 28.9 (DOB), 33.3 (EPB) and 34.0 (MOP). The expected contributions of the major ancestors were found to be highly unbalanced in the EPB and BRP. The average coefficient of inbreeding of dogs born from 1997 to 2001 with both parents known was equal to 12.4% (BAR), 3.9% (BAF), 5.4% (BEN), 7.2% (BRP), 3.3% (BUF), 6.0% (BQG), 4.1% (DOB), 4.5% (EPB) and 4.0% (MOP). These values were found to be significantly higher than the average coefficient of kinship between the male and the female parents of these animals, except in the BAR and BQG, revealing an usual practice of mating between related animals. The results are discussed in relation with the demographic situation and the use of each breed. The method used to class an endangered breed and the ways to preserve the genetic variability, when necessary, are evoked.

Animals↗
PubMed2006

Milk progesterone profile at and after artificial insemination in repeat-breeding cows: effects on conception rate and embryonic death.

The aim of this study was to investigate whether the skim milk progesterone concentrations at artificial insemination (AI) and day of rise of post-ovulatory progesterone concentration thereafter affect the conception and embryonic death rates in repeat-breeding cows. Milk samples were obtained from 96 repeat-breeding cows that failed to conceive to three or more AIs. The samples were taken from the cows at the day of AI and three times/week until day 45 post-AI. Skim milk was obtained after centrifugation and used for progesterone assay. The cows with a progesterone concentration more than 0.5 ng/ml at AI showed a significantly higher incidence of late embryonic death than those having a progesterone concentration<0.5 ng/ml at AI (p<0.01). As the progesterone level at insemination rose, conception rate declined. A negative correlation was shown between conception rate and skim milk progesterone level at AI. Of 56 cows showing a rise of progesterone to 1 ng/ml or more within 6 days after AI, 28 cows (50%) conceived. On the contrary, only eight of 39 cows (20.5%) conceived when the progesterone rose up to 1 ng/ml after day 6 post-AI. We concluded that increased progesterone concentration at the time of AI and delayed rise of progesterone post-AI might lead to decrease in fertility in repeat-breeding cows.

Animals↗
PubMed1987

Quantification of individual sensitivities to ethanol in selective breeding experiments: difference scores versus regression residuals.

Nagoshi et al. (Alcohol Clin Exp Res 10:343-349, 1986) have argued recently that the use of postdrug minus predrug difference scores to assess individual variability in sensitivity or tolerance to ethanol is not to be recommended. Unreliability of variables can result in biased estimates of response to treatment. Instead of difference scores, they recommend using residual scores from the regression of posttreatment on pretreatment measures. We were interested in the consequences of employing difference scores versus regression residuals for a related, but different purpose: the choice of individual animals to be mated for a selective breeding study. The availability of data from such a selective breeding experiment ongoing in the laboratory of one of us (JCC) allowed us to compare directly the effects of use of change and residual scores as criteria for selection. The selection is for maximal hypothermic sensitivity of mice to an acute dose of ethanol. In our sample, difference scores were highly correlated with regression residuals. In practical terms, almost 75% of the individuals chosen for mating by the change score method would also have been chosen by the residual score method. We conclude that for selective breeding experiments, the use of difference scores does not necessarily introduce sampling bias, is unlikely to affect the ultimate outcome of selection, and may be a more meaningful variable for the physiological process studied.

Animals↗
PubMed1978

Pregnancy rates and non-return rates following artificial and natural breeding in dairy herds.

Information routinely supplied during the conduct of a dairy herd health program was analysed to evaluate the performance of artificial breeding in Victoria. A comparison was made between 60 to 90-day non-return rates (supplied by artificial breeding centres) and pregnancy rates (determined by manual pregnancy diagnosis) for first artificial inseminations in 108 herd years in which both items were available in the 1973 and 1974 breeding seasons. The values were 69.3% and 58.2% respectively (P less than 0.001). Non-return rates and conception rates were found to decline as herd size increased. Pregnancy rates to first artificial and natural services did not differ significantly from each other but pregnancy rates were significantly more variable to natural than artificial service (P less than 0.001). The mean pregnancy rate to artificial insemination for all herd years studied was 57.5% and the pregnancy rate to natural service was 58.0%.

Animals↗
PubMed2003

Kin discrimination and the benefit of helping in cooperatively breeding vertebrates.

In many cooperatively breeding vertebrates, a dominant breeding pair is assisted in offspring care by nonbreeding helpers. A leading explanation for this altruistic behavior is Hamilton's idea that helpers gain indirect fitness benefits by rearing relatives (kin selection). Many studies have shown that helpers typically provide care for relatives, but relatively few have shown that helpers provide closer kin with preferential care (kin discrimination), fueling the suggestion that kin selection only poorly accounts for the evolution of cooperative breeding in vertebrates. We used meta-analysis to show that (i) individuals consistently discriminate between kin, and (ii) stronger discrimination occurs in species where the benefits of helping are greater. These results suggest a general role for kin selection and that the relative importance of kin selection varies across species, as predicted by Hamilton's rule.

Altruism↗
PubMed2002

Breeding together: kin selection and mutualism in cooperative vertebrates.

In cooperatively breeding vertebrates, nonbreeding helpers raise young produced by dominant breeders. Although the evolution of cooperative breeding has often been attributed primarily to kin selection (whereby individuals gain "indirect" benefits to their fitness by assisting collateral relatives), there is increasing evidence that helpers can be unrelated to the young they are raising. Recent studies also suggest that the indirect benefits of cooperative behavior may often have been overestimated while the direct benefits of helping to the helper's own fitness have probably been underestimated. It now seems likely that the evolutionary mechanisms maintaining cooperative breeding are diverse and that, in some species, the direct benefits of helping may be sufficient to maintain cooperative societies. The benefits of cooperation in vertebrate societies may consequently show parallels with those in human societies, where cooperation between unrelated individuals is frequent and social institutions are often maintained by generalized reciprocity.

Altruism↗
PubMed1977

Breeding record analysis in pig herds and its veterinary applications--1: Development of a program to monitor reproductive efficiency and weaner production.

Analyses of breeding records and herd efficiency factors are important for veterinary surgeons supervising reproductive efficiency and piglet performance in breeding herds. These data include: the number of litters produced per sow per year; the distribution of weaning to service intervals; the number of sows returning to service by 30, 60, 90 and 120 days; the percentage of sows farrowing to first service; the percentage of sows found to be not pregnant; and the percentage of sows aborting. Boar performance data, piglet mortality percentages, piglet growth rates, feed efficiency factors and the percentage of sows culled from the herd are also analysed. A computer program was developed to produce these and other data from simple breeding records.

Animals↗
PubMed1994

An evaluation of some breeding management options in beef herds in the United Kingdom.

The feasibility of replacing natural service in the suckler herd with artificial breeding (artificial insemination or embryo transfer), following synchronisation of oestrus in breeding animals, was investigated. In 1991 a herd of 143 spring-calving beef cows, matched for date and ease of calving, sex of calf, parity, body condition score and liveweight, were assigned to one of five controlled breeding programmes: natural service (group 1); single oestrus synchronisation using a norgestomet implant and fixed time insemination followed by natural service (group 2); double synchronisation with two consecutive norgestomet implants each with fixed-time insemination followed by natural service (group 3); synchronised as for group 2, but subjected to a movement stress two days after insemination (group 4); and cows synchronised by intravaginal progesterone/prostaglandin regimen with non-surgically transferred in vitro fertilised embryos followed by natural service (group 5). The percentage pregnancy rates to the first and second heats and overall were, respectively: group I, 55.5, 66.7 and 92.6; group 2, 44.4, 71.4 and 89.9; group 3, 52.0, 78.0 and 96.0; group 4, 55.0, 58.3 and 81.5, and group 5, 40.0, 68.2 and 85.7 per cent. In groups 2, 3, 4 and 5 the costs per pregnancy for artificial insemination or embryo transfer were 40.50 pounds, 56.62 pounds, 32.40 pounds and 149.98 pounds, respectively, and the calf weaning weights for groups 1, 2, 3, 4 and 5, adjusted for date of calving, were 250 kg, 255 kg, 252 kg, 261 kg and 259 kg, respectively.

Animal Husbandry↗
PubMed1999

Longevity of British breeds of dog and its relationships with sex, size, cardiovascular variables and disease.

The results of a questionnaire provided data about owners' perceptions of the cause of death of over 3000 British dogs. The mean age at death (all breeds, all causes) was 11 years one month, but in dogs dying of natural causes it was 12 years eight months. Only 8 per cent of dogs lived beyond 15, and 64 per cent of dogs died of disease or were euthanased as a result of disease. Nearly 16 per cent of deaths were attributed to cancer, twice as many as to heart disease. Neutered females lived longer than males or intact females, but among dogs dying of natural causes entire females lived slightly longer. In neutered males the importance of cancer as a cause of death was similar to heart disease. Mongrels lived longer than average but several breeds lived longer than mongrels, for example, Jack Russells, miniature poodles and whippets. There was no correlation between longevity and cardiovascular parameters (heart rate, systolic, diastolic, pulse and mean arterial pressure, or the combination of heart rate and pulse pressure) but smaller dogs had longer lifespans. The results also include breed differences in lifespan, susceptibility to cancer, road accidents and behavioural problems as a cause of euthanasia.

Accidents, Traffic↗
PubMed2005

Morbidity of Swedish horses insured for veterinary care between 1997 and 2000: variations with age, sex, breed and location.

The aim of this study was to evaluate the potential usefulness of the database maintained by the Swedish insurance company Agria for providing disease statistics on Swedish horses. The demography of the horses insured for veterinary care during the period 1997 to 2000 was recorded and the incidence of morbidity, defined as horses that required veterinary care that cost more than the policy excess, was calculated. Yearly incidences were calculated for horses that required veterinary care at least once, first overall, and then for horses with complete insurance, by sex, age, breed group, breed, location and human population density. Poisson regression was applied to a multivariable model to produce estimates of relative risk adjusted for other factors in the model, such as age. The total number of horse-years at risk for those with complete insurance was over 72,000 each year. The annual incidence rate for horses that required veterinary care at least once varied from 1080 to 1190 events per 10,000 horse-years at risk; for geldings the averaged incidence rate was 1398 events, for mares it was 1042 events, and for stallions it was 780 events per 10,000 horse-years at risk. There were considerable variations in incidence rate between breeds.

Age Distribution↗
PubMed2006

Mortality of Swedish horses with complete life insurance between 1997 and 2000: variations with sex, age, breed and diagnosis.

The aim of this study was to evaluate the potential usefulness of the database maintained by the Swedish insurance company Agria for providing mortality statistics on Swedish horses. Mortality statistics (incidence rates and survival) were calculated, both crudely and stratified by sex, age, breed, breed group and diagnosis, for the horses with complete life insurance, which covers most health problems. The total mortality was 415 (95 per cent confidence interval [CI] 399 to 432) deaths per 10,000 horse-years at risk, and the diagnostic mortality, including only deaths with an assigned diagnosis, was 370 (95 per cent CI 355 to 386) deaths per 10,000 horse-years at risk. The diagnostic mortality of geldings was 459 (95 per cent CI 431 to 487), of mares 345 (95 per cent CI 322 to 365) and of stallions 214 (95 per cent CI 182 to 247) deaths per 10,000 horse-years at risk. The mortality rates increased with age and differed widely between breeds. Survival analysis showed that the median age at death of the horses enrolled before they were one year of age was 18.8 years. The most common cause of death or euthanasia was joint problems, which were responsible for 140 (95 per cent CI 130 to 149) deaths per 10,000 horse-years at risk. The results of multivariable models developed by using Poisson regression generally agreed well with the crude results.

Age Distribution↗
PubMed2003

Identification of a novel ovine PrP polymorphism and scrapie-resistant genotypes for St. Croix White and a related composite breed.

Susceptibility to scrapie is primarily controlled by polymorphisms in the ovine prion protein gene (PRNP). Here, we report a novel ovine exon three PRNP polymorphism (SNP G346C; P116), its association with the ovine ARQ allele (P116A136R154Q171), and two new genotypes (PARQ/ARR; PARQ/ARQ) for the St. Croix White (SCW) breed and a related composite (CMP) breed developed for meat production. The (P116) polymorphism occurs between the N-terminal cleavage site and the hydrophobic region of the ovine prion protein, a region which exhibits extreme conservation across mammalian taxa. The relatively high frequency (0.75) of resistant ARR alleles and the absence of ARQ alleles for the SCW ewes used as breeding stock for CMP resulted in significant genic differentiation (P = 0.0123; S.E. = 0.00113). Additionally, the majority of the SCW (66.7%) and CMP (65.4%) sampled possessed genotypes considered resistant or nearly resistant to scrapie and experimental BSE (bovine spongiform encephalopathy.

Alleles↗
PubMed2005

Cytogenetics of Hordeum chilense: current status and considerations with reference to breeding.

Hordeum chilense Roem. et Schult. has a number of characteristics interesting for breeding: high crossability with other Triticeae, resistance to biotic and abiotic stresses and high variability for quality traits such as endosperm storage proteins or carotenoid content. xTritordeum, the amphiploids between H. chilense and different Triticum spp, are bridge species which facilitate the transfer of traits from H. chilense to wheat or triticale. The chromosome pairing between H. chilense and wheat chromosomes is very low (if existing) even in the absence of the action of the Ph1 gene. Nevertheless, translocation between H. chilense and wheat chromosomes has been observed frequently in genomic combinations where univalents of both species are present and therefore a method is available for using H. chilense in wheat or triticale breeding. Hybrids and amphiploids with other crop species of the Triticeae, such as rye or barley, have also been obtained, although to date the production of stable introgression stocks has not been completed. The technique of chromosome painting, using both high- and low-repeated DNA sequences in combination with genomic in situ hybridization have been used as effective methods for basic cytogenetic research in H. chilense, allowing analysis of genome evolution, and monitoring H. chilense chromosomes in interspecific hybridization breeding programs.

Breeding↗