Pablo Ignacio Trigo

Serum activity of creatine kinase and aminotransferase aspartate enzymes of horses submitted to muscle biopsy and incremental jump test

Objetivou-se avaliar a atividade serica das enzimas creatina quinase (CK) e aspartato aminotransferase (AST), enzimas de extravazamento responsivas a lesao muscular, de equinos de salto submetidos a biopsia muscular e a um teste de exercicio padronizado, envolvendo saltos incrementais. Foram utilizados tres grupos de animais, um com historico de desempenho superior (SP), um com historico inferior (IP) e um grupo controle (CG). Todos os grupos foram submetidos a biopsia muscular no gluteus medius e somente os grupos SP e IP ao teste de saltos incrementais (IJT), 24h apos a biopsia. O IJT foi constituido de tres estagios de alturas progressivas, com 40 saltos cada, nas alturas de 40, 60 e 80cm. Amostras de sangue foram coletadas antes da biopsia, 6h e 24h apos o exercicio. Os niveis de atividade serica da CK elevaram-se 6h e diminuiram 24h apos o exercicio em todos os grupos, inclusive no CG. A atividade da AST nao demonstrou aumento apos a realizacao da biopsia e do exercicio. Nao foi visto aumento da atividade de ambas enzimas mensuradas que pudesse ser atribuido ao exercicio, possivelmente pela baixa duracao e/ou intensidade do mesmo. Conclui-se que a biopsia muscular caracterizou estimulo suficiente para haver extravasamento somente da enzima muscular CK para o plasma, e consequente deteccao de aumento de sua atividade serica, enquanto o teste de exercicio padronizado realizado nao.

Acupuncture Affects Autonomic and Endocrine but Not Behavioural Responses Induced by Startle in Horses.

Startle is a fast response elicited by sudden acoustic, tactile, or visual stimuli in a variety of animals and in humans. As the magnitude of startle response can be modulated by external and internal variables, it can be a useful tool to study reaction to stress. Our study evaluated whether acupuncture can change cardiac autonomic modulation (heart rate variability); and behavioural (reactivity) and endocrine (cortisol levels) parameters in response to startle. Brazilian Sport horses (n = 6) were subjected to a model of startle in which an umbrella was abruptly opened near the horse. Before startle, the horses were subjected to a 20-minute session of acupuncture in acupoints GV1, HT7, GV20, and BL52 (ACUP) and in nonpoints (NP) or left undisturbed (CTL). For analysis of the heart rate variability, ultrashort-term (64 s) heart rate series were interpolated (4 Hz) and divided into 256-point segments and the spectra integrated into low (LF; 0.01–0.07 Hz; index of sympathetic modulation) and high (HF; 0.07–0.50 Hz; index of parasympathetic modulation) frequency bands. Acupuncture (ACUP) changed the sympathovagal balance with a shift towards parasympathetic modulation, reducing the prompt startle-induced increase in LF/HF and reducing cortisol levels 30 min after startle. However, acupuncture elicited no changes in behavioural parameters.

Comparison between specific and nonspecific tests for evaluating the physical fitness of show jumping horses

Show jumping is a century-old Olympic sport performed worldwide. However, despite the prominence of this sport, there is currently no satisfactory evaluation of the physical fitness of its horses. Our study compared two standardised exercise tests (specific and nonspecific for show jumpers) to determine the importance of a show jumping specific evaluation test. Sixteen horses were divided into two performance groups (high and low performance), and all horses performed standardised exercise tests without jumps (SET1) and with jumps (SET2). Heart rate, blood lactate, glucose, blood gas, haematological parameters, and plasma ions were measured before and after the tests, and performance indices were calculated. Both exercise tests (SET1 and SET2) resulted in changes in nearly all measured variables that were expected, based on other studies, for the duration and nature of the exercise performed. Differences between the two performance groups were observed for lactate and glucose, as well as some blood gas va...

Blood and urinary variables in horses supplemented with electrolytes

This study was designed to evaluate changes on variables in blood, urine and water balance in horses in response to a single dose of electrolyte supplementation. The essay was conducted on a randomised 3×3 Latin Square design repeated over time, with three animals and three treatments: Treatment 1: control group (without supplementation); Treatment 2: supplementation with a medium dose of electrolytes composed of: 0.25 g of NaCl + 0.125 g of KCl + 0.05 g of CaCl + 0.025 g of MgCl per kg of BW; Treatment 3: supplementation with a high dose of electrolytes composed of: 0.625 g of NaCl + 0.3125 g of KCl + 0.125 g of CaCl + 0.0625 g of MgCl per kg of BW, equivalent to 2.5 times the medium dose of supplementation. The electrolytes were supplied through a nasogastric tube 4 h after the morning meal. The diet provided had a forage:concentrate ratio of 70:30, composed of coastcross hay and commercial concentrate, with an estimated consumption of 2% of body weigth (BW). Horses received 116 mg/kg of BW of commercia...

Effects of electrolyte supplementation on colonic contents and faeces in horses

This work aimed to evaluate electrolyte supplementation effects on physicochemical characteristics of right dorsal colon digesta of horses. Three crossbreed horses fitted with a cannula at right dorsal colon (RDC) were used in a Latin square 3×3 replicated design. Treatments were different electrolyte supplementations: control, medium dose and high dose electrolytes. Digesta from RDC and faeces were collected at 2, 4, 6, 9 and 12 hours after supplementation, and dry matter (DM), pH, buffering capacity were evaluated. Horses supplemented with medium and high doses of electrolytes showed higher RDC digesta DM (10.3 and 9.9%) and faeces DM (27.9 and 27.1%) when compared with control horses. Right dorsal colon buffering capacity did not show any difference (P>0.05). Faeces pH and BC did not show any difference (P>0.05). These results showed that electrolyte supplementation promoted hydration of the hindgut, increasing water intake and water contents in RDC and faeces of horses

In vitro gas production from colon contents in electrolyte supplemented horses

Electrolyte overload is a common preventive practice. However, its impact on the fermentation process has never been studied. This work aimed to evaluate the impact of different levels of electrolyte supplementation on fermentation process from right dorsal colon contents of horses. Experimental design was a split-plot randomized blocks and treatments were electrolyte supplementation: control; medium and high dose. Inoculum was obtained from three horses cannulated at right dorsal colon. Coast-cross hay was used as substrate. In vitro gas production technique and a bicompartimental fermentation model were used. No significant effects of electrolyte supplementation were observed on coast-cross hay fermentation profile. The model parameters observed were Vf1 20.3 ml; C1 23.4% h-1; L 6.4 h; Vf2 121.9 ml; C2 2.8% h-1. Oral electrolyte did not alter in vitro fermentation characteristics of inoculum from right dorsal colon collected after 12 hours of supplementation.