Analyze Diet

Topic:Population Dynamics

The population dynamics of horses refers to the study of changes in horse populations over time, influenced by factors such as birth rates, death rates, immigration, and emigration. These dynamics are shaped by environmental conditions, resource availability, predation, and human intervention. Understanding population dynamics is essential for managing wild horse populations and ensuring sustainable practices in breeding and conservation efforts. This page compiles peer-reviewed research studies and scholarly articles that explore the factors affecting horse population dynamics, including genetic diversity, habitat utilization, and the impact of management strategies on population stability and growth.
The genetic structure of Spanish Celtic horse breeds inferred from microsatellite data.
Animal genetics    February 26, 2000   Volume 31, Issue 1 39-48 doi: 10.1046/j.1365-2052.2000.00591.x
Cañon J, Checa ML, Carleos C, Vega-Pla JL, Vallejo M, Dunner S.Partition of the genetic variability, genetic structure and relationships among seven Spanish Celtic horse breeds were studied using PCR amplification of 13 microsatellites on 481 random individuals. In addition, 60 thoroughbred horses were included. The average observed heterozygosity and the mean number of alleles were higher for the Atlantic horse breeds than for the Balearic Islands breeds. Only eight percentage of the total genetic variability could be attributed to differences among breeds (mean FST approximately 0.08; P < 0.01). Atlantic breeds clearly form a separate cluster from th...
Toward the incrimination of epidemic vectors of eastern equine encephalomyelitis virus in Massachusetts: abundance of mosquito populations at epidemic foci.
Journal of the American Mosquito Control Association    December 28, 1999   Volume 15, Issue 4 479-492 
Moncayo AC, Edman JD.Putative epidemic/epizootic eastern equine encephalomyelitis virus (EEE) vector populations were compared at 15 recent (1982-90) human and horse case sites in Bristol and Plymouth counties in southeastern Massachusetts. Carbon dioxide-baited American Biophysics Corporation light traps were used for trapping adult mosquitoes to estimate biting risk in these foci of known transmission. Population data suggest that Coquillettidia perturbans, Aedes canadensis, and Culex salinarius are more likely vectors of EEE in Massachusetts than Aedes vexans, Anopheles punctipennis, and Anopheles quadrimaculat...
Stallion harassment and the mating system of horses.
Animal behaviour    November 30, 1999   Volume 58, Issue 2 295-306 doi: 10.1006/anbe.1999.1155
Linklater WL, Cameron EZ, Minot EO, Stafford KJ.Feral horse, Equus caballus, breeding groups, called bands, usually include one but sometimes up to five stallions. We found that mares were loyal to single-stallion (SS) or multistallion (MS) bands or were social dispersers (maverick mares, Mv). The spacing and social behaviour of mares and stallions in single- and multistallion bands was measured. Indices of mare well-being were also measured including activity budgets (feeding: MS>SS=Mv; resting: MSSS), maternal effort in maintaining contact with foals (MS=Mv>SS), parasite levels in faeces (MS>Mv>SS), body condition (MS=Mv<SS...
Demographic characteristics of the equine population of northern Britain.
The Veterinary record    October 9, 1999   Volume 145, Issue 11 299-304 doi: 10.1136/vr.145.11.299
Mellor DJ, Love S, Gettinby G, Reid SW.The size, composition and distribution of the equine population of Scotland and the five northernmost counties in England were estimated through a series of mailed questionnaire surveys of sentinel veterinary practices and horse owners. An estimated 96,622 equine animals were kept by an estimated 26,114 owners. The mean (sd) age of the population was 11.0 (7.5) years (range one month to 37 years). Thoroughbred or thoroughbred-cross animals were the most numerous, constituting 30 per cent (95 per cent confidence interval 27 to 33 per cent) of the total population. The ratio of males:females was...
Parasite diversity and anthelmintic resistance in two herds of horses.
Veterinary parasitology    September 15, 1999   Volume 85, Issue 2-3 205-225 doi: 10.1016/s0304-4017(99)00100-4
Young KE, Garza V, Snowden K, Dobson RJ, Powell D, Craig TM.Diversity of parasite populations was compared between two herds of horses, one a regularly treated herd the other a feral herd which has bad no anthelmintic treatment for at least 25 years. Eggs obtained from fecal samples of both herds were tested for anthelmintic resistance by use of an in-vitro larval hatch/development assay (LDA), DrenchRite. A fecal egg reduction test was also performed with the domesticated herd using fenbendazole, pyrantel pamoate and ivermectin. Cyathostomes were the predominant group of worms present in both herds. Trichostrongylus axei was seen in both herds, but St...
Factors affecting the harem formation process by young Misaki feral stallions.
The Journal of veterinary medical science    July 29, 1999   Volume 61, Issue 6 667-671 doi: 10.1292/jvms.61.667
Khalil AM, Murakami N.For the past 12 years, a study was conducted in the Misaki area (southern Kyushu Island, Japan) to investigate young males form new harems, how they acquire the mares and the factors affecting the process of new harem formation. Young males formed new harems between the ages of 3.8 and 7.6 yr, and 93% of these new harem groups were formed at the beginning of the breeding season. The most common way (87%) for young males to form a new harem was by acquiring wandering mares which had separated from their groups, whereas 13% stole unstable mares from established bands. The fact that all young mal...
[Associations between the coat color and the blood-group system D antigens in horses].
Genetika    July 27, 1999   Volume 35, Issue 4 499-503 
Kniazev SP, Nikitin SV.The study of the association between the coat-color variants and the blood-group system D antigens in the populations of two related trotter breeds (Orlov Trotter and Russian Trotter) showed the presence of three associations between these characters in the Orlov Trotter breed. In the populations of Russian trotters, these associations were not detected. Possible reasons for the formation and maintenance of these associations and the role of the selection for coat color in the differentiation of breeds by the frequencies of some system D antigens are discussed.
Phylogenetic relationships of Cheju horses to other horse breeds as determined by mtDNA D-loop sequence polymorphism.
Animal genetics    June 22, 1999   Volume 30, Issue 2 102-108 doi: 10.1046/j.1365-2052.1999.00419.x
Kim KI, Yang YH, Lee SS, Park C, Ma R, Bouzat JL, Lewin HA.Historical records suggest that horses inhabiting the island of Cheju in Korea are descendants of Mongolian horses introduced in 1276. Other studies, however, suggest that horses may have been present on the island prior to the Mongolian introduction. To determine the origin of the Cheju horses we used a phylogenetic analysis of sequences of the mitochondrial DNA (mtDNA) D-loop region, including tRNA Pro and parts of tRNA thr and tRNA Phe sequences (1102-bp excluding the tandem repeat region). Maximum parsimony and neighbor-joining trees were constructed using sequences determined for seven Ch...
Mitochondrial control region and 12S rRNA variation in Przewalski’s horse (Equus przewalskii).
Animal genetics    January 12, 1999   Volume 29, Issue 6 456-459 doi: 10.1046/j.1365-2052.1998.296380.x
Oakenfull EA, Ryder OA.Variation in the control region and the 12S rRNA gene of all surviving mitochondrial lineages of Przewalski's horse was investigated. Variation is low despite the present day population being descended from 13 individuals probably representing animals from three different regions of its range. Phylogenetic comparison of these sequences, with sequences for the domestic horse, does not resolve the ancestral status of either horse.
[The intraspecific differentiation of Przhewalski’s horse and the domestic horse by 5 molecular genetic markers].
TSitologiia i genetika    January 8, 1999   Volume 32, Issue 3 97-103 
Glazko VI, Oblap RV, Iasinetskaia NA, Kushnir AN.Analysis of albumin, transferrin, receptor to vitamin D, esterase, alpha 1-beta glycoprotein polymorphisms in Przhewalski's horse, Orlov's and Russian trotters, Guzul and Yakutian domestic horse breeds was carried out. The data about similarity of intraspecies differentiation of Przewalski's horse's populations and interbreed distinctions were obtained. Locus-specific particularities of genetic structures of investigated animal groups were revealed.
Population pharmacokinetics of gentamicin in horses.
American journal of veterinary research    December 19, 1998   Volume 59, Issue 12 1589-1598 
Martín-Jiménez T, Papich MG, Riviere JE.To develop and validate a population pharmacokinetic model for gentamicin in horses, using retrospective clinical data. Methods: 62 horses that had been treated IV with multiple doses of gentamicin at our veterinary teaching hospital between 1987 and 1996. Procedure-46 horses were assigned to the study group, and 16 to the validation group. Detailed history of dosage, sample collection times, and selected pathophysiologic variables were recorded for each patient. Samples were analyzed by use of a fluorescence polarization immunoassay method. Pharmacostatistical analysis was conducted, using co...
Seroprevalence of equine herpesvirus 1 in thoroughbred foals before and after weaning.
Australian veterinary journal    November 27, 1998   Volume 76, Issue 10 677-682 doi: 10.1111/j.1751-0813.1998.tb12282.x
Gilkerson JR, Love DN, Drummer HE, Studdert MJ, Whalley JM.To investigate the seroprevalence of equine herpesvirus 1 in foals around weaning and after weaning on two large Thoroughbred farms using a type-specific enzyme-linked immunosorbent assay to determine exposure to infection. Methods: A longitudinal population study in groups of Thoroughbred weanling foals. Methods: Two hundred weanling Thoroughbred foals from a population of about 380 foals were enrolled on two adjacent stud farms in the Hunter Valley of New South Wales. Foals on both farms were weaned from February to May 1995 into randomly selected groups of 10 to 15 foals. Farms were selecte...
Polymorphism of Old Kladruber horses, a surviving but endangered baroque breed.
European journal of immunogenetics : official journal of the British Society for Histocompatibility and Immunogenetics    November 7, 1998   Volume 25, Issue 5 357-363 doi: 10.1046/j.1365-2370.1998.00117.x
Horín P, Cothran EG, Trtková K, Marti E, Glasnák V, Henney P, Vyskocil M, Lazary S.Analysis of MHC class I and class II polymorphism, as well as data from other polymorphic systems (non-MHC lymphocyte alloantigen, blood groups systems, biochemical polymorphisms and microsatellite loci), was used to characterize the extent and distribution of the genic polymorphism of Kladruber horses. A breed-characteristic distribution of the MHC polymorphism was found. The repertoire of defined MHC class I specificities was restricted, especially in the grey subpopulation and in stallions, but a high frequency of blanks suggests the possible existence of undetected specificities. Despite t...
Accuracy of different methods of estimating the weight of horses.
The Veterinary record    October 31, 1998   Volume 143, Issue 12 335-336 doi: 10.1136/vr.143.12.335
Ellis JM, Hollands T.Six hundred horses of different ages, heights and breeds were weighed on a weighbridge and had their weights estimated by two weigh tapes, 1 and 2, by a formula, and by a visual estimate. For the population as a whole, the most accurate method was the formula (mean [sd] 98.6 [10.6] per cent) closely followed by weigh tape 2 (98.1 [8.1] per cent). Tape 1 and the visual estimate were the least accurate (112.0 [9.3] and 88.3 [20.1] per cent respectively). When the population was divided into two height groups, the formula and weigh tape 2 were the most accurate for horses or = 15 hh weigh tape 1...
Relationship between hind limb lameness and radiographic signs of bone spavin in Icelandic horses in Sweden.
Acta veterinaria Scandinavica    October 27, 1998   Volume 39, Issue 3 349-357 doi: 10.1186/BF03547783
Axelsson M, Eksell P, Ronéus B, Broström H, Häggström J, Carlsten J.A field study was designed to estimate the prevalence of hind limb lameness in a population of Icelandic horses in Sweden. All available Icelandic horses at 11 different farms within 150 km from Uppsala were examined once during a study period of 13 months. The relationship between hind limb lameness and radiographic signs of bone spavin (RSBS) was investigated. The rate of agreement between the outcome after palpation, motion evaluation and flexion test and radiographic examination was established. A total of 379 horses including 238 geldings, 125 mares and 16 stallions, with mean age 8.1 yea...
Farm and animal exposures and pediatric brain tumors: results from the United States West Coast Childhood Brain Tumor Study. Holly EA, Bracci PM, Mueller BA, Preston-Martin S.Nineteen counties from San Francisco and Los Angeles, California and Seattle, Washington were the United States sites for a large population-based case-control study of childhood brain tumors (CBTs), sponsored by the National Cancer Institute. CBT patients who were 1 year and were first on a farm when they were < 6 months of age also had increased risk for CBTs (OR = 3.9, 95% CI = 1.2-13). A somewhat increased risk for CBTs was found for children of mothers who ever had worked on livestock farms compared with mothers who never had worked on a farm (OR = 7.4, 95% CI = 0.86-64, based on five...
[Population genetic parameters of aboriginal Yakut horses as related to modern breeds of the domestic horse Equus caballus L].
Genetika    August 28, 1998   Volume 34, Issue 6 796-809 
Tikhonov VN, Cothran EG, Kniazev SP.This study was the first to analyze the polymorphic characteristics of a wide range of biochemical markers in aboriginal Yakut horses. A total of 124 alleles, including 48 alleles of seven blood-group loci and 76 alleles of ten loci for enzymes and other proteins, were studied. For these polymorphic systems, a computer analysis of the genetic distances between 85 horse breeds of different origin from all parts of the world was performed. The low level of hereditary variation in the Yakut horses confirmed that this breed is old and has long been an isolated population. Phylogenetic analysis dem...
Risk factors associated with the likelihood of leptospiral seropositivity in horses in the state of New York.
American journal of veterinary research    November 5, 1997   Volume 58, Issue 10 1097-1103 
Barwick RS, Mohammed HO, McDonough PL, White ME.To determine and quantify risk factors associated with exposure of horses to the following serovars of Leptospira interrogans: pomona, autumnalis, and bratislava. Methods: 2,551 horses were randomly selected from a target population during the period of May 1991 to August 1993. Methods: Blood was collected from the horses and tested for antibodies to serovars, using the microscopic agglutination test. A titer > or = 1:100 indicated seropositivity. Information was collected on each horse, its environment, and each farm's management practices. Logistic regression analysis was used to develop a m...
Causes of natal dispersal and emigration and their effects on harem formation in Misaki feral horses.
Equine veterinary journal    July 1, 1997   Volume 29, Issue 4 262-266 doi: 10.1111/j.2042-3306.1997.tb03121.x
Kaseda Y, Ogawa H, Khalil AM.Misaki feral horses were separated into 2 herds and the difference between dispersal from natal group (natal dispersal) and dispersal from natal area (natal emigration) was studied. The causes of dispersal and emigration and their effects on harem formation were studied 1979-1994. The number of horses ranged from 73 (mature males: 8, mature females: 26, young males: 8, young females: 3, colt foals: 6, filly foals: 10 and geldings: 12) in 1979 and 86 (mature males: 14, mature females: 37, young males: 12, young females: 7, colt foals: 5, filly foals: 7 and geldings: 4) in 1994 when the present ...
Cortisol concentrations in post competition horse urine: a French and British survey.
Equine veterinary journal    May 1, 1997   Volume 29, Issue 3 226-229 doi: 10.1111/j.2042-3306.1997.tb01673.x
Popot MA, Houghton E, Ginn A, Jones M, Teale P, Samuels T, Lassourd V, Dunnett N, Cowan DA, Bonnaire Y, Toutain PL.The purpose of the present report was to estimate the population parameters of cortisol concentrations in urine, an endogenous hormone used as a 'doping' agent and for which an international threshold (1.0 micrograms/ml) has been proposed. Two data bases (French and UK) corresponding to 112 and 142 samples, respectively were considered. Urine was collected under specific post competition conditions. Cortisol concentrations were obtained by validated methods (HPLC for the French samples, and GC-MS for UK samples). No difference was observed between the 2 data sets and statistical analyses were ...
The Michigan equine monitoring system. I. Design, implementation and population estimates.
Preventive veterinary medicine    February 1, 1997   Volume 29, Issue 4 263-275 doi: 10.1016/s0167-5877(96)01079-3
Kaneene JB, Saffell M, Fedewa DJ, Gallagher K, Chaddock HM.The Michigan equine monitoring system (MEMS) was designed and implemented in the State of Michigan, starting in 1991. The program was designed systematically to track the State's equine population, its health, and its economic implications to the equine industry. The MEMS was designed as a two-phase program. Phase I (the population and economic survey; the subject of this paper) was designed to provide new and statistically valid information describing the size, composition, location and economic characteristics of the Michigan equine industry. A standardized questionnaire was used to collect ...
Case studies in wildlife immunocontraception: wild and feral equids and white-tailed deer.
Reproduction, fertility, and development    January 1, 1997   Volume 9, Issue 1 105-110 doi: 10.1071/r96052
Kirkpatrick JF, Turner JW, Liu IK, Fayrer-Hosken R, Rutberg AT.Non-lethal management methods are required for wild equids that are protected by law and for deer inhabiting areas where lethal controls are not legal or safe. Single or multiple inoculations of porcine zona pellucida (PZP) vaccine have been delivered to wild horses and deer by means of darts. Contraceptive efficacy in horses after two inoculations ranged from 90% to 100%, and after a single inoculation ranged from 19% to 28%. Mares given a controlled-release form of the vaccine had foaling rates ranging from 7% to 20%. No detectable changes in social organization or behaviours among treated h...
Linear assessment of the thoroughbred horse: an approach to conformation evaluation.
Equine veterinary journal    November 1, 1996   Volume 28, Issue 6 461-467 doi: 10.1111/j.2042-3306.1996.tb01618.x
Mawdsley A, Kelly EP, Smith FH, Brophy PO.A linear assessment trait evaluation system is proposed to allow quantitative description of the static conformation of the horse. Measurements were made on 27 selected traits. The system was tested initially for repeatability of measurements on 4 horses. Twenty-one of the selected traits were satisfactory and 6 proved unsatisfactory in terms of reproducibility. A population of 101, superior 2- and 3-year-old Thoroughbreds and 19 premium Thoroughbred stallions were similarly assessed. More than 65% of the traits exhibited large (CV > 10%) phenotypic variation within the sampled population. ...
A study (1977-1992) of population dynamics of endoparasites featuring benzimidazole-resistant small strongyles (population S) in Shetland ponies.
Veterinary parasitology    November 1, 1996   Volume 66, Issue 1-2 75-86 doi: 10.1016/s0304-4017(96)00998-3
Lyons ET, Tolliver SC, Drudge JH, Stamper S, Swerczek TW, Granstrom DE.Critical tests (91) were done between 1977 and 1992 in Shetland ponies to evaluate drug susceptibility and population dynamics (present paper) of endoparasites. The test ponies, most less than 1 year old, were from a herd where older animals were treated every 8 weeks initially with cambendazole (CBZ) (1974-1978) and then with oxibendazole (OBZ) (1978-1992). Previous field test data (1974-1992) on older ponies in the breeding herd indicated the presence of benzimidazole (BZ) resistant small strongyles. Data on population dynamics from the present critical tests indicated that 28 species of sma...
Fertility control using intrauterine devices: an alternative for population control in wild horses.
Theriogenology    October 1, 1995   Volume 44, Issue 5 629-639 doi: 10.1016/0093-691x(95)00243-2
Daels PF, Hughes JP.The purpose of this study was to develop a contraceptive method for feral horses. The feral horse population has increased significantly in recent years despite attempts to control numbers. As in most wild animal population control programs, contraceptive methods must be easy to apply, cause minimal disruption to the social structure and be fully reversible. In the present study, we tested the effectiveness of an intrauterine device (IUD) for fertility control in mares. Six mares were fitted with a silastic O-ring-shaped IUD on July 1 of Year 1. The IUD-treated mares were turned out with 12 no...
Multiple genotypes of mitochondrial DNA within a horse population from a small region in Yunnan Province of China.
Biochemical genetics    October 1, 1994   Volume 32, Issue 9-10 371-378 doi: 10.1007/BF02426899
Wang W, Liu AH, Lin SY, Lan H, Su B, Xie DW, Shi LM.mtDNA genotypes of six domestic horses (three adult short horses whose heights are under 1 m and three common domestic horses) from a small region of 15 km2 in Malipo county of Yunnan province of China were investigated by the technique of restriction fragment length polymorphism (RFLP) with 16 restriction endonucleases which recognize 6-bp sequences. An average of 56 fragments for an individual was obtained. Unlike other domestic animals, this population of horses exhibits high mtDNA genetic diversity. Each of the six horses has a specific mtDNA genotype showing a pattern of multiple maternal...
Demographics of companion animals in South Africa.
Journal of the South African Veterinary Association    June 1, 1994   Volume 65, Issue 2 67-72 
Odendaal JS.A survey conducted in 1992, using a standardised, stratified sample was used to determine companion animal numbers in South Africa as a single geographical entity. The results indicated that there were 3.93 million dogs, 0.97 million cats, 0.98 million birds, 0.22 million other companion animals and 0.1 million horses in South African households. Thirty-seven per cent of households keeping companion animals, kept dogs; cats (13.4%); birds (4.8%); other companion animals (1.1%) and horses (2%). These results may provide information about possible markets in terms of numbers of species kept.
Population genetics of Great Basin feral horses.
Animal genetics    June 1, 1994   Volume 25 Suppl 1 67-74 doi: 10.1111/j.1365-2052.1994.tb00405.x
Bowling AT.The genetic make-up of Great Basin wild (feral) horses was investigated by blood typing studies. Blood samples of 975 feral horses from seven trap sites in Nevada and Oregon were tested by serological and electrophoretic techniques for genetic markers at 19 polymorphic loci. The average number of variants for the seven feral populations [72.1 +/- 3.2 (SEM), range 62-85] was not significantly different from that of 16 domestic breeds (75.0 +/- 11.5, range 58-105). The expected average frequency of heterozygotes per locus (average heterozygosity) for the feral populations (0.402 +/- 0.009, range...
Control of cambendazole-resistant small strongyles (Population S) with oxibendazole in a pony band: an 8 year field test (1984-1992).
Veterinary parasitology    April 1, 1994   Volume 52, Issue 3-4 271-277 doi: 10.1016/0304-4017(94)90118-x
Lyons ET, Drudge JH, Tolliver SC, Swerczek TW, Stamper S, Granstrom DE.Studies in a band of ponies harboring Population S benzimidazole-resistant small strongyles were initiated in 1974 and have continued for 18 years. Treatment (bimonthly) was with cambendazole for the first 4 years and with oxibendazole (OBZ) for the next 14 years. Data on the first 10 years have been published. The present investigation includes the last 8 years (4 October 1984-11 September 1992), which are the seventh through fourteenth years, of treatment with OBZ. Pre- and posttreatment mean counts of strongyle eggs (epg) and larvae (lpg) per gram of feces were determined biweekly during th...
Epidemiological observations on sarcoids in a population of donkeys (Equus asinus).
The Veterinary record    February 26, 1994   Volume 134, Issue 9 207-211 doi: 10.1136/vr.134.9.207
Reid SW, Gettinby G, Fowler JN, Ikin P.An epidemiological study of equine sarcoid in a population of 4126 donkeys showed that the peak incidence of the disease was 15.2 cases per 100 animal-years and occurred in animals in their fourth year of life. The crude incidence of the disease was 0.6 cases per 100 animal-years. The disease occurred most frequently in younger, male animals during their first five years in the population. The lesions were observed most commonly in the paragenital region. Pre-entry quarantine procedures did not appear to play a significant role in the spread of the disease but there was an indication that clos...