Analyze Diet

Topic:Age Factors

Age factors in horses encompass a range of physiological and developmental changes that occur as horses mature from foals to adults and eventually into their senior years. These factors include variations in metabolic rate, immune function, and musculoskeletal development, which can influence a horse's health, performance, and nutritional needs. Age-related changes can also affect how horses respond to medications, recover from injuries, and maintain overall vitality. Researchers study these aspects to understand better how age impacts equine health and management. This page compiles peer-reviewed research studies and scholarly articles that explore the effects of age on equine physiology, health management, and disease susceptibility.
Effect of exercise, training, circadian rhythm, age, and sex on insulin-like growth factor-1 in the horse.
Journal of animal science    December 21, 2006   Volume 85, Issue 1 163-171 doi: 10.2527/jas.2006-210
Noble GK, Houghton E, Roberts CJ, Faustino-Kemp J, de Kock SS, Swanepoel BC, Sillence MN.Insulin-like growth factor-1 could be a useful marker in the horse for diagnostic, selection, or forensic purposes, provided its physiological regulation is well understood. The objective of this study was to investigate factors, such as acute exercise, fitness training, time of day, sex, and age, that may influence serum IGF-1 in normal, healthy horses. Throughout a 9-wk training program, 6 geldings maintained a mean (+/- SEM) IGF-1 concentration of 302 +/- 29 ng/mL. Moderate or high intensity exercise had no effect on IGF-1 concentrations, when pre- and postexercise values were compared. Ove...
Reliability of 1,9-dimethylmethylene blue tests in comparison to agarose gel electrophoresis for quantification of urinary glycosaminoglycans.
Clinica chimica acta; international journal of clinical chemistry    December 14, 2006   Volume 378, Issue 1-2 206-215 doi: 10.1016/j.cca.2006.11.025
de Lima CR, Baccarin RY, Michelacci YM.The relevance of glycosaminoglycan determination in biological fluids is gradually gaining importance in the literature. Nevertheless, the results obtained by different methods vary widely. We evaluated 1,9-dimethylmethylene blue (DMB) dye-binding assays for quantification of urinary glycosaminoglycans, in comparison to densitometry after agarose gel electrophoresis. Methods: Urinary glycosaminoglycans from different mammalian species were quantified by 3 different DMB dye-binding assays. The results were compared to those obtained by densitometry after agarose gel electrophoresis of glycosami...
The blood vessel system in the periodontal ligament of the equine cheek teeth–part I: The spatial arrangement in layers.
Annals of anatomy = Anatomischer Anzeiger : official organ of the Anatomische Gesellschaft    December 5, 2006   Volume 188, Issue 6 529-533 doi: 10.1016/j.aanat.2006.06.010
Masset A, Staszyk C, Gasse H.Corrosion casts of blood vessels in the periodontium of cheek teeth from eight horses were observed three-dimensionally with a dissection microscope. Selected specimens were examined in a scanning electron microscope. Periodontal blood vessels communicated with those from the gingiva, the alveolar bone, and the apical region. In the upper jaw, there were anastomoses with the blood vessels of the mucosa of the maxillary sinus. The periodontal vascular system was organized in two or three layers. The peripheral layer was mainly composed of large venules, the inner one consisted of capillaries. I...
Prevalence of osteochondrosis in the limb joints of South German Coldblood horses.
Journal of veterinary medicine. A, Physiology, pathology, clinical medicine    November 16, 2006   Volume 53, Issue 10 531-539 doi: 10.1111/j.1439-0442.2006.00881.x
Wittwer C, Hamann H, Rosenberger E, Distl O.This study aimed to quantify the factors associated with the prevalence of the radiological signs of osteochondrosis (OC) and osteochondrosis dissecans (OCD) in South German Coldblood (SGC) horses. The prevalence of OC and OCD in fetlock and hock joints was analysed in 167 young coldblood horses with a mean age of 14 months. The presence of at least one osteochondrotic lesion (OC) in fetlock or hock joints was documented for 61.7% of the horses and 26.9% of the horses had osseus fragments. Osteochondrotic findings at the dorsal aspect of the sagittal ridge of the third metacarpal/metatarsal bo...
Clinical, laboratory, and histopathologic features of equine lymphoma.
Veterinary pathology    November 14, 2006   Volume 43, Issue 6 914-924 doi: 10.1354/vp.43-6-914
Meyer J, Delay J, Bienzle D.Clinical, laboratory and tissue findings from 37 horses with lymphoma were investigated. Horses ranged in age from 0.3 to 20.5 years (median 5.0 years) and included 18 females and 19 males. Weight loss (n = 25) and ventral edema (n = 21) were the most common historical and physical abnormalities. The most common laboratory abnormalities were hyperfibrinogenemia (n = 26), hypoalbuminemia (n = 19), anemia (n = 19), leukemia (n = 14), hyperglobulinemia (n = 13), and thrombocytopenia (n = 13). Thirty-four tumors involved multiple lymphoid tissues and abdominal or thoracic organs, and 3 tumors were...
Altered homeostasis of extracellular matrix proteins in joints of standardbred trotters during a long-term training programme.
Journal of veterinary medicine. A, Physiology, pathology, clinical medicine    October 24, 2006   Volume 53, Issue 9 445-449 doi: 10.1111/j.1439-0442.2006.00877.x
Skiöldebrand E, Heinegård D, Olofsson B, Rucklidge G, Ronéus N, Ekman S.This study evaluates how strenuous training, age and lameness influence the release of cartilage oligomeric matrix protein (sf-COMP), aggrecan and collagen type II into synovial fluid in 28 (19.5-40 months) Standardbred trotters (STB), during a long-term training programme (24 months). All the horses were trained by the same trainer and were healthy on entering the training programme. Synovial fluid (sf) from the left middle carpal joint in each subject was sampled every third month. Enzyme-linked immunosorbent assay was used to determine the concentrations of sf-COMP, sf-aggrecan and sf-colla...
Seroepidemiological survey of Rhodoccocus equi infection in asymptomatic horses from Bursa, Izmir and Istanbul provinces, Turkey.
Comparative immunology, microbiology and infectious diseases    October 10, 2006   Volume 29, Issue 5-6 323-333 doi: 10.1016/j.cimid.2006.08.002
Attili AR, Kennerman E, Takai S, Or ME, Marenzoni ML, Torun S, Pieramati C, Kayar A, Golcu E, Parkan C, Yilmaz Z, Gonul R, Valente C, Cuteri V.In order to assess the Rhodococcus equi infection in three provinces of Turkey (Bursa, Izmir and Istanbul), 696 sera from healthy foals and adult horses were tested by indirect ELISA using a R. equi reference strain (ATCC 6939) as antigen. 103 sera (14.80%) with titres >0.646 resulted positive. Seroprevalence was significantly higher (P=0.0053) in male than in female horses of Istanbul province, although higher antibody titres (mean value) were observed in the female group of Bursa and Izmir provinces with differences estimated between provinces (P=0.0002). Seroprevalence was correlated wit...
Collagen fiber architecture of the periodontal ligament in equine cheek teeth.
Journal of veterinary dentistry    October 7, 2006   Volume 23, Issue 3 143-147 doi: 10.1177/089875640602300303
Staszyk C, Wulff W, Jacob HG, Gasse H.The objective of this study was to examine the spatial arrangement of the fiber apparatus of the equine periodontium which is supposed to meet two contrary requirements: (1) to attach the tooth firmly and elastically to the alveolar bone; and, to be appropriately remodeled and reconstructed in order to facilitate the prolonged eruption of the tooth. Specimens of periodontal ligament were obtained from the buccal and lingual/palatal aspects of the first molars from the maxilla and mandible of 12 horses. The animals were assigned to three age groups. Histological sections were prepared from thre...
[First-time endoscopic detection of larvae of Gasterophilus spp. in the oral cavity in 14 warmblood horses].
Berliner und Munchener tierarztliche Wochenschrift    September 30, 2006   Volume 119, Issue 9-10 416-420 
Griss R, Simhofer H.Intraoral endoscopy is used as a standard diagnostic technique at the reporting clinics in horses presented with stomatological problems. Endoscopy of the oral cavity was performed using a chip camera, camera control unit, xenon cold light source and a rigid endoscope. In a three year period (2002 to 2004), second instars of Gasterophilus spp. were diagnosed in 14 warmblood horses 2 to 17 years of age. All horses were presented with masticatory problems or problems accepting the bit. In one horse oesophageal obstruction occurred in the course of larval migration. Oral endoscopy can not only be...
Fracture rate in Thoroughbred racehorses is affected by dam age and parity.
Veterinary journal (London, England : 1997)    September 25, 2006   Volume 174, Issue 2 295-301 doi: 10.1016/j.tvjl.2006.07.023
Verheyen KL, Price JS, Wood JL.This study's aim was to determine the effects of dam age and parity on the rate of fracture in offspring in Thoroughbred racehorses in training for flat racing. It was hypothesised that first foals and those from older mares would have a higher fracture rate than subsequent foals and those from younger mares. A two-year observational cohort study collected data from eight trainers on 335 horses that were monitored since the start of their training as yearlings. Multivariable Poisson regression analyses showed that first foals had a significantly lower fracture rate than subsequent ones (RR=0.3...
Racing performance after arthroscopic removal of apical sesamoid fracture fragments in Thoroughbred horses age > or = 2 years: 84 cases (1989-2002).
Equine veterinary journal    September 22, 2006   Volume 38, Issue 5 446-451 doi: 10.2746/042516406778400655
Schnabel LV, Bramlage LR, Mohammed HO, Embertson RM, Ruggles AJ, Hopper SA.Studies have shown that surgical removal of apical fracture fragments in Standardbred racehorses carries the best prognosis for return to racing performance, but there are no reports involving mature Thoroughbred (TB) racehorses. Objective: To describe the incidence of apical proximal sesamoid fractures in TB racehorses and determine probability and quality of racing performance after arthroscopic removal of such fractures in TB racehorses age > or = 2 years. Methods: Medical records and pre- and post operative race records of TB racehorses age > or = 2 years that underwent arthroscopic surger...
Dynamic obstructions of the equine upper respiratory tract. Part 1: observations during high-speed treadmill endoscopy of 600 Thoroughbred racehorses.
Equine veterinary journal    September 22, 2006   Volume 38, Issue 5 393-399 doi: 10.2746/042516406778400583
Lane JG, Bladon B, Little DR, Naylor JR, Franklin SH.To review the prevalence of single and complex forms of dynamic airway obstructions within a large group of Thoroughbred horses in training referred for investigation of poor performance. Methods: Video-endoscopic recordings of the upper respiratory tract made during a standardised treadmill exercise test of 600 Thoroughbred racehorses were reviewed and analysed in real time and slow motion to identify dynamic collapse by the tissues bordering onto the pharyngeal and laryngeal airways. Results: Dynamic collapse within the nasopharynx or larynx was confirmed in 471 of the 600 horses. Dorsal dis...
Age-related and non-age-related changes in 100 surveyed horse brains.
Veterinary pathology    September 13, 2006   Volume 43, Issue 5 740-750 doi: 10.1354/vp.43-5-740
Jahns H, Callanan JJ, McElroy MC, Sammin DJ, Bassett HF.Brains from 100 horses, aged 2-25 years, were systematically examined by histopathology at 46 different neuroanatomical sites. The horses were sourced from a slaughterhouse (group A, n = 57), from a kennel that collected dead animals, and from 2 diagnostic laboratories (group B, n = 43). All horses from group A and 26 horses from group B were examined by a veterinarian in the period before death. None of the horses were known to exhibit clinical signs suggestive of neurologic disease. Among the main changes identified were vacuolation in the neuropil (n = 73), neurons (n = 32), white matter (n...
Serum lipid and lipoprotein parameters of Turkman horses.
Veterinary clinical pathology    September 13, 2006   Volume 35, Issue 3 332-334 doi: 10.1111/j.1939-165x.2006.tb00142.x
Asadi F, Mohri M, Adibmoradi M, Pourkabir M.Lipid transport systems in animals have been evaluated both as experimental models for lipid and lipoprotein metabolism in humans and to gain insight into the lipid metabolism of specific breeds. The Turkman horse is a pure-blooded horse that lives on the margins of the Caspian Basin; information about serum lipids and lipoproteins in this breed is lacking. Objective: The purpose of this study was to evaluate serum lipid and lipoprotein concentrations in clinically healthy Turkman horses. Methods: Concentrations of triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol...
Prevalence of serum neutralising antibody to equine rhinitis A virus (ERAV), equine rhinitis B virus 1 (ERBV1) and ERBV2.
Veterinary microbiology    September 10, 2006   Volume 119, Issue 1 65-71 doi: 10.1016/j.vetmic.2006.08.031
Black WD, Wilcox RS, Stevenson RA, Hartley CA, Ficorilli NP, Gilkerson JR, Studdert MJ.The objective of this study was to determine the incidence of serum neutralising (SN) antibody to ERAV, ERBV1 and ERBV2 in a population of horses from birth to 22 years of age. The prevalences of ERAV, ERBV1 and ERBV2 SN antibodies in 381 sera obtained from 291 horses were 37%, 83% and 66%, respectively. ERAV, ERBV1 and ERBV2 maternal antibody was present in foals 12 h postsuckling but by 10-12 months, ERAV SN antibody was not detected in any of the horses, while ERBV1 and ERBV2 SN antibodies were common (83% and 100%, respectively). Sera were obtained from 44 Thoroughbred horses when they wer...
Evaluation of the combined dexamethasone suppression/ thyrotropin-releasing hormone stimulation test for detection of pars intermedia pituitary adenomas in horses.
Journal of veterinary internal medicine    September 8, 2006   Volume 20, Issue 4 987-993 doi: 10.1892/0891-6640(2006)20[987:eotcdt]2.0.co;2
Frank N, Andrews FM, Sommardahl CS, Eiler H, Rohrbach BW, Donnell RL.A combined dexamethasone (DEX) suppression/thyrotropin-releasing hormone (TRH) test (DEX/TRH test) has been developed to evaluate horses for presence of a pars intermedia pituitary adenoma (PIPA), but to the authors' knowledge, the accuracy of this test has not been previously determined. Objective: The sensitivity and specificity of the DEX/TRH test can be determined by comparing test results with histopathologic examination findings. Methods: Age of 42 horses of various breeds ranged from 2 to 33 years. Methods: Plasma cortisol concentration was measured before and 24 hours after IV administ...
Clinical features and outcomes of phacoemulsification in 39 horses: a retrospective study (1993-2003).
Veterinary ophthalmology    August 31, 2006   Volume 9, Issue 5 361-368 doi: 10.1111/j.1463-5224.2006.00494.x
Fife TM, Gemensky-Metzler AJ, Wilkie DA, Colitz CM, Bras ID, Klages DC.To identify visual outcome and postoperative complications following phacoemulsification of equine cataracts. Methods: Records of 39 horses (55 eyes) with cataracts were reviewed. Methods: Eyes with cataracts removed by phacoemulsification were included in the study. Data collected included age, breed, sex, stage and etiology of cataract, unilateral vs. bilateral involvement, and ultrasound findings. Horses were grouped by etiology of the cataract. Visual outcome and complications were evaluated for each group and the overall population. Results: Immediately postoperatively 46 out of 47 eyes (...
Association between costly veterinary-care events and 5-year survival of Swedish insured warmblooded riding horses.
Preventive veterinary medicine    August 28, 2006   Volume 77, Issue 1-2 122-136 doi: 10.1016/j.prevetmed.2006.07.002
Egenvall A, Bonnett BN, Olson P, Penell J, Emanuelson U.Our objective was to estimate the 5-year survival to death in insured warmblooded riding horses (as reflected by a life-insurance claim) in horses with or without at least one costly veterinary-care event (VCE) in 1997. We also determined the impacts of gender, age, previous diagnosis of veterinary claim, geographic variables, cost for veterinary claims and life-insurance value upon the survival. The design was a retrospective cohort study using a population of warmblooded riding horses insured in a Swedish animal-insurance company (Agria Insurance, P.O. 70306, SE-107 23 Stockholm, Sweden) in ...
The prevalence of laryngeal disease in a large population of competition draft horses.
Veterinary surgery : VS    August 17, 2006   Volume 35, Issue 6 579-583 doi: 10.1111/j.1532-950X.2006.00192.x
Brakenhoff JE, Holcombe SJ, Hauptman JG, Smith HK, Nickels FA, Caron JP.(1) To determine the effect of age, height, weight, breed, sex, and specific use on the prevalence of idiopathic left laryngeal hemiplegia (ILH) in a population of draft performance horses; (2) to determine the association between tracheal mucus and laryngeal dysfunction, and the prevalence of exercise-induced pulmonary hemorrhage (EIPH) in a population of draft performance horses. Methods: Cross-sectional. Methods: Draft horses competing at the 2005 Michigan Great Lakes Draft Horse Show. Methods: Endoscopic examinations were performed on horses competing at the 2005 Michigan Great Lakes Draft...
The use of a random regression model to account for change in racing speed of German trotters with increasing age.
Journal of animal breeding and genetics = Zeitschrift fur Tierzuchtung und Zuchtungsbiologie    August 3, 2006   Volume 123, Issue 4 239-246 doi: 10.1111/j.1439-0388.2006.00596.x
Bugislaus AE, Roehe R, Willms F, Kalm E.In a genetic analysis of German trotters, the performance trait racing time per km was analysed by using a random regression model on six different age classes (2-, 3-, 4-, 5- and 6-year-old and older trotters; the age class of 3-year-old trotters was additionally divided by birth months of horses into two seasons). The best-fitting random regression model for the trait racing time per km on six age classes included as fixed effects sex, race track, condition of race track (fitted as second-order polynomial on age), distance of race and each driver (fitted as first-order polynomial on age) as ...
Nitrite and nitrotyrosine concentrations in articular cartilage, subchondral bone, and trabecular bone of normal juvenile, normal adult, and osteoarthritic adult equine metacarpophalangeal joints.
The Journal of rheumatology    August 2, 2006   Volume 33, Issue 8 1662-1667 
van der Harst M, Bull S, Brama PA, Barneveld AB, van Weeren PR, van de Lest C.Osteoarthritis (OA) is a chronic debilitating joint disorder in which the importance of inflammation is increasingly recognized. In advanced cases, both the articular cartilage and the underlying bony layers are affected, but the exact sequence of events and their localization in the initial phase of pathogenesis remain uncertain. We measured nitric oxide (NO) end products in tissue layers that constitute the bearing surface of the joint, as possible indicators of physiological and pathological processes. Methods: Nitrite as a measure for NO and nitrotyrosine was measured in articular cartilag...
Temporomandibular joint cytokine profiles in the horse.
Journal of veterinary dentistry    August 2, 2006   Volume 23, Issue 2 83-88 doi: 10.1177/089875640602300204
Carmalt JL, Gordon JR, Allen AL.It has been suggested that dental abnormalities lead to temporomandibular joint inflammation and pain that may be mitigated by regular dental care. There is considerable literature on the pathophysiology of equine joint disease including studies on cytokine profiles in diseased appendicular joints. This study examined the effects of age and dental malocclusions summarized as a dental pathology score on equine temporomandibular joint cytokine (IL-1, IL-6, IL-8, TNF alpha and TGF-beta1, -beta2, -beta3) concentrations. TGF-beta3 was not detected in any joint sample. IL-1, IL-6 and TNF alpha were ...
Airway inflammation in Michigan pleasure horses: prevalence and risk factors.
Equine veterinary journal    July 27, 2006   Volume 38, Issue 4 293-299 doi: 10.2746/042516406777749281
Robinson NE, Karmaus W, Holcombe SJ, Carr EA, Derksen FJ.Although subclinical airway inflammation is thought to be common in horses, there is little information on its prevalence and none on risk factors. Objective: To determine the prevalence and risk factors for an increased number of inflammatory cells and for mucus accumulation in the trachea of pleasure horses. Methods: Horses (n = 266) in stables (n = 21) in Michigan were examined endoscopically, once in winter and once in summer 2004. Visible tracheal mucoid secretions were graded 0-5 and inflammatory cell numbers counted in a tracheal lavage sample. Information collected about each horse inc...
Onset of puberty and duration of seasonal cyclicity in Lipizzan fillies.
Equine veterinary journal    July 27, 2006   Volume 38, Issue 4 350-353 doi: 10.2746/042516406777749137
Cebulj-Kadunc N, Cestnik V, Kosec M.The onset of puberty and duration of seasonal cyclicity in Lipizzan fillies and young mares have been determined mostly by empirical data, but very little is known about the hormonal changes at puberty and during the seasonal cyclicity in this breed. Objective: To determine the onset of puberty and the course of the cyclicity in young Lipizzan mares from age 1-4 years. Methods: Blood samples were collected twice a month for 2 years from 46 Lipizzan fillies age 1-4 years. Progesterone concentrations, indicating ovarian activity, were measured using an EIA kit. Values above 6.4 nmol/l were taken...
[Influence of animal breeding manner on the occurence of internal parasites].
Wiadomosci parazytologiczne    July 27, 2006   Volume 50, Issue 3 647-651 
Romaniuk K, Reszka K, Lasota E.On the turn of July and August the prevalence and intensity of internal parasites of cattle, deer, and primitive Polish horses were estimated. It was determined, that all groups of animals were infected with parasites. The prevalence and intensity of infection were diversified and depended on the animal species, breed, age, and even sex. For instance, dairy cows of lowland black-and-white breed were six times stronger infected than Polish red breed, despite using the same pasture and the same cowshed. Nematodes and coccidia were present in calves using small, frequently wet, calf-runs and at h...
Cartilage-derived biomarkers and lipid mediators of inflammation in horses with osteochondritis dissecans of the distal intermediate ridge of the tibia.
American journal of veterinary research    July 5, 2006   Volume 67, Issue 7 1156-1162 doi: 10.2460/ajvr.67.7.1156
de Grauw JC, Brama PA, Wiemer P, Brommer H, van de Lest CH, van Weeren PR.To assess whether reported alterations in metabolism of cartilage matrix in young (0 to 24 months old) horses with osteochondritis dissecans (OCD) may also be found in older (24 to 48 months old) horses with clinical signs of OCD and to investigate the role of eicosanoids in initiating these clinical signs. Methods: Synovial fluid was collected from 38 tarsocrural joints of 24 warmblood horses with (22 joints of 16 horses) or without (16 joints of 8 horses) clinical signs and a radiographic diagnosis of OCD of the distal intermediate ridge of the tibia. Methods: Turnover of type II collagen wa...
Age-related expression of molecular regulators of hypertrophy and maturation in articular cartilage.
Journal of orthopaedic research : official publication of the Orthopaedic Research Society    June 22, 2006   Volume 24, Issue 8 1773-1781 doi: 10.1002/jor.20227
Semevolos SA, Nixon AJ, Fortier LA, Strassheim ML, Haupt J.The purpose of this study was to determine changes in the expression of regulatory molecules in normal equine articular cartilage throughout development up to 18 months of age. The hypothesis was that expression of these regulatory molecules would decrease from birth to postpubescence. Cartilage was harvested from normal femoropatellar or scapulohumeral joints from 34 fresh horse cadavers. Horses were placed in four age groups [prenatal (n = 5); prepubertal, 0-6 months (n = 11); pubertal, 7-14 months (n = 13); and postpubertal, 15-18 months (n = 5)]. Indian hedgehog (Ihh), Gli1, Gli3, Patched1...
Equine herpesvirus type 1-associated myeloencephalopathy in The Netherlands: a four-year retrospective study (1999-2003).
Journal of veterinary internal medicine    June 1, 2006   Volume 20, Issue 3 601-607 doi: 10.1892/0891-6640(2006)20[601:ehtami]2.0.co;2
Goehring LS, van Winden SC, van Maanen C, Sloet van Oldruitenborgh-Oosterbaan MM.Equine herpesvirus type 1(EHV-1)-associated myeloencephalopathy (EHM) is a rare disease affecting the central nervous system and, in particular, the spinal cord of horses. Epidemiologic data are limited, and usually are restricted to the description of a single outbreak. During an observational period of 4 years, we evaluated 9 outbreaks of EHM in The Netherlands. A risk factor analysis was done on the data from 6 outbreaks. Findings were: regular appearance of EHM outbreaks in The Netherlands (2-3/y); strong association of EHM with season; and risk factors, such as breed, sex, age, and fever....
Equine frozen semen: freezability and fertility field results.
Theriogenology    May 27, 2006   Volume 48, Issue 6 907-917 doi: 10.1016/s0093-691x(97)00319-1
Vidament M, Dupere AM, Julienne P, Evain A, Noue P, Palmer E.The freezability of stallion semen defined as the number of selected ejaculates/total number of ejaculates frozen from 161 different stallions was analyzed. Of the stallions, 19, 30, 27 and 24% had a freezability of 0%, 0 to 33%, 33 to 66%, over 66%, respectively In 85 different stallions, the correlation of freezability between first and second year was 0.60 (P < 0.001). The relationship between fertility with fresh and frozen semen and freezability was analyzed in 40 stallions whose freezability and fertility information was recorded during 5 years. There was a strong relationship between fe...
Social relationships in a herd of Sorraia horses Part I. Correlates of social dominance and contexts of aggression.
Behavioural processes    May 19, 2006   Volume 73, Issue 2 170-177 doi: 10.1016/j.beproc.2006.05.004
Heitor F, do Mar Oom M, Vicente L.Factors related to dominance rank and the functions of aggression were studied in a herd of Sorraia horses, Equus caballus, under extensive management. Subjects were 10 adult mares 5-18 years old and a stallion introduced into the group for breeding. Dominance relationships among mares were clear, irrespective of rank difference, and remained stable after introduction of the stallion. The dominance hierarchy was significantly linear and rank was positively correlated with age and total aggressiveness. Higher-ranking mares received lower frequency and intensity of agonistic interactions. Nevert...
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