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PubMed1986

[PorkCHOP: an economic microcomputer replacement model for sows].

A computer model called PorkCHOP, was developed in an electronic spreadsheet on the microcomputer to help farmers, veterinarians and other livestock specialists reach economically sound culling decisions in swine breeding herds. It quantifies the benefits of a longer herd life and a shorter farrowing interval, calculates an economic index (Retention Pay-Off) to be used as a culling guide for individual sows within a herd and determines the maximum number of permissible services when sows fail to conceive following the first service. PorkCHOP runs with 'default' settings for the major factors affecting replacement economics, but the user can modify all variables to represent a specific herd more precisely.

Animal Husbandry↗

PubMed1975

Changes in social organization during the breeding season of wild talapoin monkeys.

Two adjacent troops of talapoin monkeys were studied near Mbalmayo, Cameroon, during a predicted 3-month breeding season. Mating continued for just over 2 months. One troop began to mate at least 2 weeks before the other, suggesting that, though climatic changes were probably important, precise timing was mediated through some intra-troop social facilitation effect. Before the breeding season, adult males and females lived in separate sub-groups. Males began to move into female sub-groups before there was any sign of the perineal swellings characteristic of receptive talapoin females. Copulation occurred only with females with medium or large swellings, except towards the end of the season. It is probable that the majority of females were monoestrous. At the height of the mating period, females joined mainly male sub-groups, leaving their infants with the mainly female groups which also included a few males. Copulations were observed in both these types of sub-groups. Consort behaviour was not observed, males frequently returning to all-male sub-groups immediately after ejaculation. Intersexual grooming was not characteristic of sexual interactions. At the end of the season, adults were seen more frequently in groups of their own sex or with juveniles only, and there was some indication that increased aggressiveness by newly pregnant females might be partly responsible for this separation.

Age Factors↗

PubMed2026

Development of a highly efficient prime editing platform for cucurbits enables breeding of multi-disease-resistant cucumber.

The prime editing (PE) system is a precise genome editing technology that works efficiently in monocots; however, its application is limited by low editing efficiency in dicots, particularly Cucurbitaceae and Solanaceae plants. Here, we first significantly improved the transformation efficiency by introducing spectinomycin in cucurbits, then used the tomato elongation factor 1-alpha (SlEF1α) promoter to enhance PE protein expression, and incorporated the Csy4 ribonuclease to process pegRNAs, collectively addressing multiple constraints limiting PE efficiency in cucurbits. The optimized PE systems, particularly Csy4-PE6d, achieved an average desired editing frequency of 80.83% at targeted loci in cucumber via stable genetic transformation, with frequencies reaching up to 100% at certain sites. Moreover, Csy4-PE6d generated homozygous edits in 36.43% of transgenic lines and demonstrated robust editing activity in melon, pumpkin, and potato. Using the Csy4-PE6d tool, we generated heritable edited cucumber lines with dual resistance to bacterial angular leaf spot and downy mildew by targeting the CsSGR gene. Collectively, this optimized system substantially enhances PE efficiency in Cucurbit crops, providing an effective solution to common challenges such as low editing efficiency and limited heritability in these species.

Disease Resistance↗

PubMed2001

Evaluation of an artificial insemination programme in a seasonal breeding dairy system through milk progesterone.

In order to evaluate an artificial insemination programme and reproductive efficiency of dairy herds in Uruguay, a survey was conducted with five dairy farms, utilizing a total of 768 lactating Holstein cows. Precision of oestrous detection was assessed by one milk progesterone sample taken on day of breeding and was 11.1%. Two additional samples taken at day 10 and 23 were used to confirm ovulation and early pregnancy. Accuracy of pregnancy estimation by milk progesterone was 70.4%. Reproductive efficiency was determined by the analysis of records. Average intervals from calving to first service were 101 days and to conception 132 days and these were affected by parity, body weight and body condition at calving, but not at breeding, or by milk production. Oestrous detection rates and pregnancy rates were 37.5 and 15.6%, respectively. It was concluded that losses in reproductive efficiency in dairy farms of Uruguay in a seasonal artificial insemination programme were mainly due to unobserved heats, rather than incorrect oestrous detection.

Animals↗

PubMed2003

Homing in pelagic birds: a pilot experiment with white-chinned petrels released in the open sea.

During the breeding period white-chinned petrels (Procellaria aequinoctialis) repeatedly perform long foraging trips in the open ocean from their breeding island, and are able to home with an astonishing precision. The orientation mechanisms involved are not yet known. By analogy with those used by desert ants moving in a similarly "featureless" environment, one can hypothesise that petrels may home using path-integration. We displaced 11 white-chinned petrels 725-785km from their burrows to the open sea, preventing them from using visual and magnetic route-based information. Three birds carried satellite transmitters. Our results showed that they can home rather efficiently in such conditions.

Journal Article↗

PubMed2026

CamK-DB: A k-mer MinHash fingerprint database for reference-free genotyping of Camellia accessions.

Tea (Camellia sinensis L.), a major global economic crop in Asia, poses challenges for genetic identification because its highly heterozygous, repetitive genome reduces the efficacy of conventional single-nucleotide polymorphism (SNP) and microsatellite markers, and interspecific hybridization further complicates the situation. To address these issues, CamK-DB was developed as a reference-free Camellia fingerprinting database built on MIKE MinHash sketches. We curated 418 candidate resequencing datasets, and built a database using standardized 5× genome-coverage fingerprints. Each accession is stored as a MIKE. jac fingerprint generated with k = 21 and recommended sketch/pre_cnt = 2000. CamK-DB provides a command-line interface for data management and a custom C++ query engine that computes top-10 matches using Jaccard similarity, complemented by a QT-based graphical interface for interactive analysis. This resource offers a robust and scalable framework for precise and routine germplasm identification, genomic phylogenetic inference, and strategic breeding program design. CamK-DB (database and code) is publicly available at https://github.com/sc-zhang/CamK-DB. CamK-DB binaries are provided for Windows 10/11 and Linux (x86_64, glibc ≥ 2.27).

Databases, Genetic↗

PubMed1998

Elbow dysplasia in the dog: pathophysiology, diagnosis and control.

Elbow dysplasia is a non-specific term denoting abnormal development of the elbow. Elbow dysplasia encompasses the clinical and radiographic manifestation of ununited anconeal process, fragmented medical coronoid process, osteochondritis dissecans, erosive cartilage lesions and elbow incongruity. The net result is elbow arthrosis, which may be clinically inapparent or result in marked lameness. These conditions may be diagnosed by means of routine or special radiographic views and other imaging modalities, or the precise cause of the arthrosis or lameness may remain undetermined. Breeds most commonly affected are the rottweiler, Bernese mountain dog, Labrador and golden retriever and the German shepherd dog. Certain breeds are more susceptible to a particular form of elbow dysplasia and more than 1 component may occur simultaneously. The various conditions are thought to result from osteochondrosis of the articular or physeal cartilage that results in disparate growth of the radius and ulna. Heritability has been proven for this polygenic condition and screening programmes to select suitable breeding stock have been initiated in several countries and have decreased the incidence of elbow dysplasia.

Age Factors↗

PubMed1994

Progress and emerging problems in livestock transgenesis: a summary perspective.

The creation of transgenic livestock is a complex multistep procedure the successful execution of which demands a high level of skill and application. Useful animals have been generated by transfer of genes to zygotes by microinjection, but further extension to livestock breeding is severely limited by the present low efficiency and lack of precision in gene transfer procedures. There are major developments in alternative approaches to gene transfer and those based on embryonic stem (ES) cell lines show particular promise as a broadly adaptable means of allowing precise manipulation of specific genes within the animal genome. Rapid progress is being made in adapting ES cell technology to livestock species but as yet no one has demonstrated the totipotency of the putative cell lines so far generated. The demonstration of the feasibility of the chimaeric route for reinstating an ES cell genome into the germ line of the pig is a major advance. For other livestock breeds, particularly those with long generation times and bearing single young where the chimaeric route is much less useful, there are encouraging developments in nucleus transfer (cloning) technology which could provide practical solutions. Overall, there are now good reasons to be optimistic that transgenesis will eventually be available to all livestock breeders with the proviso that there are no further unanticipated phenomena such as the effect of tissue culture on imprinting, to be discovered to threaten the predictability of outcome of ES cell-derived pregnancies and further limit the potential usefulness of this futuristic technology to the livestock industry.

Animals↗

PubMed2001

Use of dual energy x-ray absorptiometry for noninvasive body composition measurements in clinically normal dogs.

OBJECTIVE: To determine quantitative values for components of body composition in clinically normal dogs of various breeds by use of dual energy x-ray absorptiometry (DEXA) and validate the precision and accuracy of DEXA technology in dogs. ANIMALS: 103 clinically normal sexually intact adult dogs. PROCEDURE: In a cross-sectional study, Beagles, Pembroke Welsh Corgis, Golden Retrievers, Great Danes, Pointers, Rottweilers, and nonpurebred dogs received total body DEXA scans. For the validation portion of the study, the results of DEXA scans of 6 dogs were compared with values obtained by chemical analyses of tissues from euthanatized dogs to determine the accuracy of this modality in dogs. RESULTS: Results (coefficient of variation) of the precision tests ranged from 0.10% for lean tissue to 5.19% for fat tissue, whereas accuracy tests revealed a difference between percentage bone mineral content and ash values. Body composition differed by sex, such as higher lean tissue and bone mineral content in males within some breeds, and among breeds. Regardless of body size or weight, the percentage of body weight that was bone mineral ranged from 3 to 4.0% [corrected]. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this cross-sectional study provide valuable body composition data for clinically normal adult dogs, which may have research and clinical applications.

Absorptiometry, Photon↗

PubMed2000

Mutations in an oocyte-derived growth factor gene (BMP15) cause increased ovulation rate and infertility in a dosage-sensitive manner.

Multiple ovulations are uncommon in humans, cattle and many breeds of sheep. Pituitary gonadotrophins and as yet unidentified ovarian factors precisely regulate follicular development so that, normally, only one follicle is selected to ovulate. The Inverdale (FecXI) sheep, however, carries a naturally occurring X-linked mutation that causes increased ovulation rate and twin and triplet births in heterozygotes (FecXI/FecX+; ref. 1), but primary ovarian failure in homozygotes (FecXI/FecXI; ref. 2). Germ-cell development, formation of the follicle and the earliest stages of follicular growth are normal in FecXI/FecXI sheep, but follicular development beyond the primary stage is impaired. A second family unrelated to the Inverdale sheep also has the same X-linked phenotype (Hanna, FecXH). Crossing FecXI with FecXH animals produces FecXI/FecXH infertile females phenotypically indistinguishable from FecXI/FecXI females. We report here that the FecXI locus maps to an orthologous chromosomal region syntenic to human Xp11.2-11.4, which contains BMP15, encoding bone morphogenetic protein 15 (also known as growth differentiation factor 9B (GDF9B)). Whereas BMP15 is a member of the transforming growth factor beta (TGFbeta) superfamily and is specifically expressed in oocytes, its function is unknown. We show that independent germline point mutations exist in FecXI and FecXH carriers. These findings establish that BMP15 is essential for female fertility and that natural mutations in an ovary-derived factor can cause both increased ovulation rate and infertility phenotypes in a dosage-sensitive manner.

Amino Acid Sequence↗

PubMed2002

Inheritance of hypoadrenocorticism in bearded collies.

OBJECTIVE: To assess heritability and mode of inheritance for hypoadrenocorticism in Bearded Collies. ANIMALS: 635 Bearded Collies. PROCEDURES: Dogs were classified as affected by hypoadrenocorticism or unaffected. Phenotypic and pedigree data were analyzed. Heritability was estimated by use of Bayesian statistical methods. Regressive logistic models for complex segregation analyses were used to characterize mode of inheritance. RESULTS: Hypoadrenocorticism was diagnosed in 60 (9.4%) dogs. Heritability of hypoadrenocorticism was estimated to be 0.76 with both sexes affected with equal probability. Evaluation of the pedigrees did not support a Mendelian autosomal dominant mode of inheritance. Evidence from the complex segregation analysis for a single locus of large effect on hypoadrenocorticism was not convincing. CONCLUSIONS AND CLINICAL RELEVANCE: Hypoadrenocorticism in Bearded Collies is highly heritable. Although a precise genetic mechanism responsible for inheritance of the disorder remains undetermined, breeding decisions must include consideration of the genetic likelihood of passing on this deleterious disorder to offspring of affected dams and sires.

Adrenal Insufficiency↗

PubMed1999

Spatial and temporal patterns of imported malaria cases and local transmission in Trinidad.

Over a 30-year period (1968-1997) 213 malaria cases in Trinidad were investigated by the Trinidad and Tobago Ministry of Health. Using a global positional system and a geographic information system, we mapped the precise location of all reported malaria cases, and associated them with breeding habitats of anopheline vectors. The majority of the cases (138, 63%) were individual imported cases around the big port cities. Plasmodium falciparum was the most common parasite, and Africa the most common source of imported cases. Two clusters of cases occurred: an introduced P. vivax outbreak associated with Anopheles aquasalis in 1990-1991, and an autochtonous focus of P. malariae associated with An. bellator and An. homunculus in 1994-1995. Application of a space-time statistic showed a significant clustering of P. malariae cases, and, to a lesser extent of P. vivax cases, but not of P. falciparum cases. Based on potential for occurrence of local transmission, we are developing risk maps to determine surveillance priorities, outbreak potential, and necessary degree and spatial range of control activities following case detections.

Animals↗

PubMed1989

Mosquito breeding in rice fields and its role in malaria transmission in Mandla district, M.P.

A study of the breeding of mosquitoes in the rice field agro-ecosystem was carried out in Mandla district during 1987 and 1988. Results revealed that mosquito breeding commences in July and ends in October. Mosquito breeding in rice fields is inversely proportional to the distance from village. A. culicifacies breeds in rice fields up to a plant height of 20 cm and then gradually declines and becomes scarce, and is taken over by A. theobaldi and A. splendidus. A. fluviatilis breeds in irrigation channels almost throughout the rice growing season. There were a large number of other mosquito breeding sites which increased enormously with the onset of rains. The precise role of rice fields in maintaining high malaria transmission could not be established but the rice field agro-ecosystem contributed significant vector populations.

Adult↗

PubMed1997

[Examination of the appropriateness of anamnestic and clinical parameters for the prediction of the course of pregnancy under field conditions].

In this paper, fertility relevant parameters which are routinely examined in practice were evaluated on the basis of their correlation to one another and their influence on the foaling rates and incidence of early embryonic death in 175 brood mares of the Hanover breeding stock. The aim was to evaluate the suitability of these parameters for inclusion in a scheme for increasing the precision of predicting the subsequent course of pregnancy, as compared to such prognoses based exclusively on the histological evaluation of the endometrium. After establishing the breeding history and completing a clinical examination, two swab specimens were obtained for bacteriological culture and cytologic smears and one biopsy specimen was taken from the endometrium for histological examination. The most statistically significant effect on the foaling rate (analysed by logistic regression with two variables) have biopsy grade (p = 0.0087) and mare age (p = 0.0259). A mare between two and nine years of age with a biopsy grade of 1 has a 71% probability of carrying a pregnancy to term. This probability decreases to 43% for a mare 15 years and older with the same biopsy grade. Mare age had a statistically significant effect on biopsy grade (p = 0.005) and on the frequency and degree of endometrosis (p = 0.001). The mare group was significantly correlated (p = 0.012) with the foaling rate (maiden mares 70.6%, foaling mares 60%, problem mares 36.1%). There is a difference of 24% between the foaling rates of foaling and problem mares, although the age and biopsy grade distributions are almost identical in the two groups. The number of barren years had a statistically significant effect (p = 0.0235) on the foaling rate. Mares that bore a foal in the previous breeding period had a foaling rate of 50.7% in the year of examination; mares that had been barren for one year hat a subsequent foaling rate of 40.6%. Mares that had been barren for two years or more had a foaling rate of only 22.7%. The overall impression resulting from the clinical examination was significantly correlated with the foaling rate (p = 0.018%). Mares without abnormal findings had a foaling rate of 54.2%, mares with poor vulval conformation a rate of 46.7%. Mares with a history of pregnancy loss in the current breeding period had a foaling rate of 25% and mares with clinical evidence of endometritis had one of 22.2%.

Animals↗

PubMed2000

New opportunities in animal breeding and production - an introductory remark.

New opportunities in animal breeding and production will be offered by methods for embryo production and the introduction of precise genetic changes in livestock species. A review of current procedures shows that they have been improved during the last 4 years, but still have significant limitations. In the light of experience over the past 50 years it seems likely that these methods will contribute to animal health and productivity, but at some unknown time in the future and in ways that cannot be predicted precisely. When looking to the future, delegates to this meeting should take pride in what science continues to contribute.

Animal Husbandry↗

PubMed1999

Natural and man-made mutagens and carcinogens in the human diet.

Around 40% of human cancers may relate to dietary factors, including both exogenous and endogenous mutagens. Of exogenous factors, alcohol, certain metals and certain pesticides (both naturally produced or manufactured by the chemical industry), N-nitroso compounds, heterocyclic amines and polycyclic aromatic hydrocarbons are all probable human carcinogens. Despite current negative publicity, genetic engineering appears to be a more precise process and no more likely to lead to cancer risks than conventional breeding processes. Many traditional assessments of cancer hazard from endogenous or exogenous chemicals ignore the presence of modifying factors in the human diet. For example, dietary fat and dietary fibre probably either enhance or protect against cancer, depending upon the exact amounts and chemical nature of the fat fibre. Considerable numbers of other types of antimutagen/anticarcinogens have been identified, with varying modes of action. Additionally, there is an interaction of dietary factors with genetics. Epidemiology will always be important in assessing relative risks, but it is essential to continue developing more sensitive biomonitoring methodologies. It would be desirable to compare precise measures of individual exposure to dietary carcinogens with levels of oxidative damage and evidence of genotoxic effects in a given tissue. Such experimental approaches might be expected to lead a better understanding of the interplay between different dietary factors and also between diet, hereditary and the environment.

Amines↗

PubMed2003

Positive assortative mating with selection restrictions on group coancestry enhances gain while conserving genetic diversity in long-term forest tree breeding.

Selection and mating principles in a closed breeding population (BP) were studied by computer simulation. The BP was advanced, either by random assortment of mates (RAM), or by positive assortative mating (PAM). Selection was done with high precision using clonal testing. Selection considered both genetic gain and gene diversity by "group-merit selection", i.e. selection for breeding value weighted by group coancestry of the selected individuals. A range of weights on group coancestry was applied during selection to vary parent contributions and thereby adjust the balance between gain and diversity. This resulted in a series of scenarios with low to high effective population sizes measured by status effective number. Production populations (PP) were selected only for gain, as a subset of the BP. PAM improved gain in the PP substantially, by increasing the additive variance (i.e. the gain potential) of the BP. This effect was more pronounced under restricted selection when parent contributions to the next generation were more balanced with within-family selection as the extreme, i.e. when a higher status effective number was maintained in the BP. In that case, the additional gain over the BP mean for the clone PP and seed PPs was 32 and 84% higher, respectively, for PAM than for RAM in generation 5. PAM did not reduce gene diversity of the BP but increased inbreeding, and in that way caused a departure from Hardy-Weinberg equilibrium. The effect of inbreeding was eliminated by recombination during the production of seed orchard progeny. Also, for a given level of inbreeding in the seed orchard progeny or in a mixture of genotypes selected for clonal deployment, gain was higher for PAM than for RAM. After including inbreeding depression in the simulation, inbreeding was counteracted by selection, and the enhancement of PAM on production population gain was slightly reduced. In the presence of inbreeding depression the greatest PP gain was achieved at still higher levels of status effective number, i.e. when more gene diversity was conserved in the BP. Thus, the combination of precise selection and PAM resulted in close to maximal short-term PP gain, while conserving maximal gene diversity in the BP.

Computer Simulation↗

PubMed1995

Pattern of ecological shifts in the diversification of Hawaiian Drosophila inferred from a molecular phylogeny.

BACKGROUND: The endemic Hawaiian drosophilids, a unique group that are remarkable for their diversity and rapid proliferation, provide a model for analysis of the process of insular speciation. Founder events and accompanying random drift, together with shifts in sexual selection, appear to explain the dramatic divergence in male morphology and mating behaviour among these flies, but these forces do not account for their spectacular ecological diversification into a wide array of breeding niches. Although recognized as contributing to the success of this group, the precise role of adaptive shifts has not been well defined. RESULTS: To delineate the pattern of ecological diversification in the evolution of Hawaiian Drosophila, we generated a molecular phylogeny, using nucleotide sequences from the yolk protein gene Yp1, of 42 endemic Hawaiian and 5 continental species. By mapping ecological characters onto this phylogeny, we demonstrate that monophagy is the primitive condition, and that decaying leaves were the initial substrate for oviposition and larval development. Shifts to decaying stems, bark and tree fluxes followed in more derived species. By plotting female reproductive strategies, as reflected in ovarian developmental type, on the molecular tree, we also demonstrate a phylogenetic trend toward increasing fecundity. We find some statistical support for correlations between ecological shifts and shifts in female reproductive strategies. CONCLUSIONS: Because of the short branches at the base of the phylogram, which lead to ecologically diverse lineages, we conclude that much of the adaptive radiation into alternate breeding substrates occurred rapidly, early in the group's evolution in Hawaii. Furthermore, we conclude that this ecological divergence and the correlated changes in ovarian patterns that adapt species to their ecological habitats were contributing factors in the major phyletic branching within the Hawaiian drosophilid fauna.

Adaptation, Physiological↗