Sex differences in horses refer to the biological and physiological distinctions between male and female horses. These differences can manifest in various aspects such as anatomy, behavior, and reproductive physiology. In equine research, sex differences are examined to understand their impact on health, performance, and disease susceptibility. For instance, hormonal variations between stallions and mares can influence metabolism, growth rates, and responses to training. Additionally, sex-specific behaviors may affect herd dynamics and management practices. This page aggregates peer-reviewed research studies and scholarly articles that explore the implications of sex differences in equine biology and how they affect veterinary care and management strategies.
Wubuli A, Su Y, Yao X, Meng J, Wang J, Zeng Y, Li L, Ren W.The Kazakh horse, a versatile breed, is renowned for stable genetic performance and strong tolerance to coarse feed. Sex is a key factor influencing skeletal muscle development. However, the mechanisms underlying sex-specific regulation of equine muscle growth remain obscure. This study employed transcriptomic analysis to investigate sex-associated molecular differences in skeletal muscle of Kazakh horses. The experimental cohort comprised four three-year-old Kazakh stallions and four three-year-old Kazakh mares. After slaughter, six groups of muscle samples were collected immediately, includi...
Kondo T, Sato F, Tsuzuki N, Yamada K.Cervical vertebral stenotic myelopathy (CVSM), a common cause of cervical spinal cord compression, is a neurological disease characterized by general proprioceptive ataxia and weakness of hindlimbs that tends to develop in young adult Thoroughbred horses. Although male horses seem to be at increased risk for CVSM, the mechanism for the occurrence of sex differences in the prevalence of CVSM is still poorly understood. Hence, we hypothesized that sex differences in the development of cervical spinal cord and spinal canal would affect the development of CVSM. This study aimed to evaluate sex dif...
Lauteri E, Mariella J, Beccati F, Roelfsema E, Castagnetti C, Pepe M, Peric T, Barbato O, Montillo M, Rouge S, Freccero F.Adrenal hormones, ACTH plasma concentrations and the ultrasonographic evaluation of the adrenal glands are considered complementary in clinical evaluations of the hypothalamic-pituitary-adrenal (HPA) axis function in several species. In dogs, age, size and weight have a significant effect on the ultrasonographic size of the adrenal glands. In neonatal foals, ultrasonographic evaluation and measurements of the adrenal glands have been demonstrated to be reliable; however, the effect of individual variables on ultrasonographic features has not been investigated, and the clinical usefulness of ad...
Jezierski T, Jaworski Z, Sobczyńska M, Ensminger J, Górecka-Bruzda A.The aim of the study was to assess whether adult stallions differentiate their olfactory and marking behaviour towards the excreta of their potential male rivals and mares. Four Konik polski stallions were individually exposed simultaneously to their own and each others' faeces as well as faeces of mares in oestrus vs. dioestrus. Five series of 30min observation sessions were conducted in a round pen each on two consecutive days from March to July, totaling in 5h observation per stallion. Stallions sniffed and displayed flehmen reaction towards mares' faeces significantly longer (P<0.01) th...
Velie BD, Stewart BD, Lam K, Wade CM, Hamilton NA.Research in Thoroughbred racehorses is often specific to horses from a given racing population or region. In order to investigate trends in racehorse careers across populations accurately, population-specific benchmarks for performance outcomes must be established. Objective: To provide summary statistics for performance outcomes for Thoroughbreds racing in Hong Kong between 2000 and 2010 and to document and provide evidence on the current differences in racing careers across sexes and regions of origin for horses racing in Hong Kong. Methods: Performance data on the population of Thoroughbred...
Thompson DL, DePew CL, Ortiz A, Sticker LS, Rahmanian MS.Three experiments were conducted to determine 1) the relationship between prolactin and growth hormone (GH) secretion in mares and the response to GH-releasing hormone (GHRH), 2) whether plasma GH and prolactin concentrations differed among mares, stallions, and geldings, and 3) whether sexual differences existed after administration of GHRH and acute exercise. In Exp. 1, 10-min blood samples were collected from 12 mares for 8 h, and GHRH (0, 45, 90, or 180 micrograms) was administered at 6 h. In Exp. 2, 15-min blood samples were collected for 4 h from 10 mares, stallions, and geldings. In Exp...
Benton RE, Lyons ET.A total of 118 horses was examined at necropsy in central Kentucky for the tapeworm Anoplocephala perfoliata. The examination period was between 28 August and 21 December 1992. Prevalence was 64% for Thoroughbreds (n = 81 examined) and 54% for non-Thoroughbreds (n = 37 examined). The number of tapeworms per infected horse varied from one to 853. Data on infections are categorized by breed, sex (n = 38 males, 8 geldings, and 72 females), age (1-31 years), and month of necropsy of the horses.
Proudman CJ, Edwards GB.Faeces samples from 116 horses with colic and 115 non-colic cases were assayed by a centrifugation/floatation method for the presence of tapeworm eggs. Analysis of these data failed to demonstrate an association between tapeworm infection and colic of all types. The data were further analysed according to anatomical site of the lesion causing colic. The risk of ileocaecal colic was increased in the presence of tapeworms. Age, breed and sex were evaluated as possible confounding factors but had no association with the incidence of colic. This study suggests an association between tapeworms and ...
The Journal of heredityJuly 1, 1976
Volume 67, Issue 4 247-248 doi: 10.1093/oxfordjournals.jhered.a108721
Field JK, Cunningham EP.In an analysis of handicap ratings of 1158 3-year-old thoroughbred racehorses, estimates were obtained for the effects of sex differences, the correlation between mates, the effectiveness of selection in males and females, and the heritability of racing performance. The results agreed closely with those of a previous study, and indicated a heritability of about 0.35 to 0.40, some assortative mating, and highly effective selection for performance.
Proudman CJ, Edwards GB.Faeces samples from 116 horses with colic and 115 non-colic cases were assayed by a centrifugation/floatation method for the presence of tapeworm eggs. Analysis of these data failed to demonstrate an association between tapeworm infection and colic of all types. The data were further analysed according to anatomical site of the lesion causing colic. The risk of ileocaecal colic was increased in the presence of tapeworms. Age, breed and sex were evaluated as possible confounding factors but had no association with the incidence of colic. This study suggests an association between tapeworms and ...
Thompson DL, DePew CL, Ortiz A, Sticker LS, Rahmanian MS.Three experiments were conducted to determine 1) the relationship between prolactin and growth hormone (GH) secretion in mares and the response to GH-releasing hormone (GHRH), 2) whether plasma GH and prolactin concentrations differed among mares, stallions, and geldings, and 3) whether sexual differences existed after administration of GHRH and acute exercise. In Exp. 1, 10-min blood samples were collected from 12 mares for 8 h, and GHRH (0, 45, 90, or 180 micrograms) was administered at 6 h. In Exp. 2, 15-min blood samples were collected for 4 h from 10 mares, stallions, and geldings. In Exp...
Benton RE, Lyons ET.A total of 118 horses was examined at necropsy in central Kentucky for the tapeworm Anoplocephala perfoliata. The examination period was between 28 August and 21 December 1992. Prevalence was 64% for Thoroughbreds (n = 81 examined) and 54% for non-Thoroughbreds (n = 37 examined). The number of tapeworms per infected horse varied from one to 853. Data on infections are categorized by breed, sex (n = 38 males, 8 geldings, and 72 females), age (1-31 years), and month of necropsy of the horses.
Jezierski T, Jaworski Z, Sobczyńska M, Ensminger J, Górecka-Bruzda A.The aim of the study was to assess whether adult stallions differentiate their olfactory and marking behaviour towards the excreta of their potential male rivals and mares. Four Konik polski stallions were individually exposed simultaneously to their own and each others' faeces as well as faeces of mares in oestrus vs. dioestrus. Five series of 30min observation sessions were conducted in a round pen each on two consecutive days from March to July, totaling in 5h observation per stallion. Stallions sniffed and displayed flehmen reaction towards mares' faeces significantly longer (P<0.01) th...
Velie BD, Stewart BD, Lam K, Wade CM, Hamilton NA.Research in Thoroughbred racehorses is often specific to horses from a given racing population or region. In order to investigate trends in racehorse careers across populations accurately, population-specific benchmarks for performance outcomes must be established. Objective: To provide summary statistics for performance outcomes for Thoroughbreds racing in Hong Kong between 2000 and 2010 and to document and provide evidence on the current differences in racing careers across sexes and regions of origin for horses racing in Hong Kong. Methods: Performance data on the population of Thoroughbred...
The Journal of heredityJuly 1, 1976
Volume 67, Issue 4 247-248 doi: 10.1093/oxfordjournals.jhered.a108721
Field JK, Cunningham EP.In an analysis of handicap ratings of 1158 3-year-old thoroughbred racehorses, estimates were obtained for the effects of sex differences, the correlation between mates, the effectiveness of selection in males and females, and the heritability of racing performance. The results agreed closely with those of a previous study, and indicated a heritability of about 0.35 to 0.40, some assortative mating, and highly effective selection for performance.
Kondo T, Sato F, Tsuzuki N, Yamada K.Cervical vertebral stenotic myelopathy (CVSM), a common cause of cervical spinal cord compression, is a neurological disease characterized by general proprioceptive ataxia and weakness of hindlimbs that tends to develop in young adult Thoroughbred horses. Although male horses seem to be at increased risk for CVSM, the mechanism for the occurrence of sex differences in the prevalence of CVSM is still poorly understood. Hence, we hypothesized that sex differences in the development of cervical spinal cord and spinal canal would affect the development of CVSM. This study aimed to evaluate sex dif...
Lauteri E, Mariella J, Beccati F, Roelfsema E, Castagnetti C, Pepe M, Peric T, Barbato O, Montillo M, Rouge S, Freccero F.Adrenal hormones, ACTH plasma concentrations and the ultrasonographic evaluation of the adrenal glands are considered complementary in clinical evaluations of the hypothalamic-pituitary-adrenal (HPA) axis function in several species. In dogs, age, size and weight have a significant effect on the ultrasonographic size of the adrenal glands. In neonatal foals, ultrasonographic evaluation and measurements of the adrenal glands have been demonstrated to be reliable; however, the effect of individual variables on ultrasonographic features has not been investigated, and the clinical usefulness of ad...
Wubuli A, Su Y, Yao X, Meng J, Wang J, Zeng Y, Li L, Ren W.The Kazakh horse, a versatile breed, is renowned for stable genetic performance and strong tolerance to coarse feed. Sex is a key factor influencing skeletal muscle development. However, the mechanisms underlying sex-specific regulation of equine muscle growth remain obscure. This study employed transcriptomic analysis to investigate sex-associated molecular differences in skeletal muscle of Kazakh horses. The experimental cohort comprised four three-year-old Kazakh stallions and four three-year-old Kazakh mares. After slaughter, six groups of muscle samples were collected immediately, includi...
