Chiara Albano de Araújo Oliveira

Estimativa da digestibilidade aparente de nutrientes em dietas para eqüinos, com o uso de óxido crômico e indicadores internos

Two assays were performed to evaluate the apparent digestibility of nutrients in horses diets, using the total collection of feces method and the markers chromic oxide, indigestible acid detergent fiber (iADF), indigestible neutral detergent fiber (iNDF), indigestible cellulose (iCEL), lignin (LIG), and insoluble acid detergent ashes (ADTA), as markers. In the first assay, five crossbred colts were used, fed five diets with different levels of crude protein, maintaining the relationship 50:50 concentrate to forage. The chromic oxide was used as external marker. In the second assay, four crossbred colts were fed diets composed by coastcross hay as forage and concentrate in the proportions of 40:60, 60:40, 80:20 and 100:00. In both assays, the cotents of indigestible acid detergent fiber, indigestible neutral detergent fiber, indigestible cellulose, lignin and acid detergent insoluble ash were obtained after in vitro incubation. In the first assay, the FDAi showed to be appropriate as internal marker to estimate the digestibility, and in both assays the CELi showed to be appropriate as internal marker for the estimate of apparent digestibility of nutrients of horses diets. The chromic oxide showed low fecal recovery in the first assay and the LIG showed low fecal recovery in both assays, underestimating the apparent digestibility coefficients of nutrients, and was inadequate to estimate the digestibility. ADIA, compared to the total collection of feces method, also showed to be inadequate to estimate the nutrient digestibility in equine.

Cinética de passagem da digesta, balanço hídrico e de nitrogênio em eqüinos consumindo dietas com diferentes proporções de volumoso e concentrado

Este trabalho foi conduzido com os objetivos de avaliar a cinetica de passagem da digesta no trato digestivo e estimar o balanco hidrico e de nitrogenio em equinos consumindo dietas com diferentes niveis de volumoso. Foram utilizados quatro potros nao castrados, mesticos, com idade de 18 meses, alojados em baias individuais e exercitados uma vez ao dia. O delineamento experimental utilizado foi o quadrado latino 4 x 4, em que cada periodo experimental teve duracao de 14 dias de adaptacao a dieta e cinco dias de coleta fecal. As dietas foram compostas por feno de capim-coastcross e concentrado, fornecidos simultaneamente, duas vezes ao dia, nas proporcoes de 40:60, 60:40, 80:20 e 100:0. A cinetica de passagem da digesta foi estimada pelo tempo medio de retencao da digesta (TMR), da taxa de passagem (TxP) e do tempo de trânsito (TT), utilizando dois indicadores externos, o cromo fixado como mordente na fibra em detergente neutro (Cr-FDN) e o complexo cobalto-EDTA (Co-EDTA). O balanco hidrico foi avaliado de acordo com as quantidades de agua ingerida in natura e na dieta e excretada na urina e nas fezes. O balanco de nitrogenio foi avaliado de acordo com as quantidades diarias de compostos nitrogenados consumidos e excretados. As medias dos valores da cinetica de passagem nas fases solida e liquida da digesta foram 42,7 e 33,8 horas para TMR e de 2,4 e 3,1 %/hora para TxP. O TT da fase liquida da digesta apresentou efeito linear negativo, em funcao da inclusao de volumoso na dieta. O consumo medio de agua foi de 13,8 litros. O balanco hidrico variou de 7,9 a 1,8 litros para as dietas com 40 e 100% de volumoso, respectivamente, reduzindo de forma linear, com a inclusao do volumoso na dieta.

Hematologia e bioquímica sérica de equinos de concurso completo de equitação em treinamento

Was evaluated the hematology and serum biochemistry in event horses (CCE) in training during incremental treadmill tests. Sixteen horses were used in a completely randomized design with four treatments and four repetitions in subdivided parcels, using age and previous history of training in events as sources of treatment variation. The parcels constituted of incremental treadmill tests performed at the beginning and end of training. The subparcels were represented by the time of evaluation and collection of samples. The equines of new beginners group had mean hematocrit value of 43.24%, being lower than the hematocrit of adult beginners group, 45.63%, new experienced group, 46.39%, and competitors group, 47.74%. There were differences (P<0.05) between the tests performed at the beginning and end of training, with reduction in glucose plasma concentration, from 112 to 98,88mg/dL, in seric concentration of creatinine, 1.41 to 1.29mg/dL, and total protein, 6.52 to 6.38 g/dL, in monocyte count, 0.54 to 0.48 103/mm3, and an increase of lactate plasma concentration, from 3.31 to 3.79mmol/L, in seric concentration of uric acid, 44 to 1.77mg/dL, in hematocrit, 44.19 to 46.90%, in hemoglobin concentration, 14.33 to 15.10 g/dL, and blood cell count, 9.26 to 9.61 103/mm3. The training of event horses improves physical performance of horses, with increased capacity of lactate metabolism after exercise and increased basal hematocrit and hemoglobin concentration.

The impact of dietary protein levels on nutrient digestibility and water and nitrogen balances in eventing horses

This study was performed to evaluate the impact of dietary protein levels on nutrient digestibility and water and nitrogen balances in conditioning eventing horses. Twenty-four Brazilian Sport Horses, male and female (8.0 to 15.0 yr; 488 ± 32 kg BW), were used in a randomized design with 4 levels of CP diets: 7.5%, 9.0%, 11.0%, and 13.0%. A digestion assay was performed with partial feces collection over 4 d, followed by 1 d of total urine collection. Data were submitted to regression analysis and adjusted to linear and quadratic models (P < 0.05). No differences were observed in the intake of DM, OM, EE, ADF, and NDF as a function of dietary protein levels. Dry matter intake average was 1.7% of BW. CP and N intake showed a linear increase as a function of increasing protein level in diets. A quadratic response (P < 0.05) was observed on the CP and NDF digestibility coefficients, with the maximum estimated level of digestibility at 11.6% and 11.4% CP in the diet, respectively. There was a linear effect on ADF digestibility coefficients, digestible DM and protein intake, and CP/DE ratio according to dietary protein levels. There was no impact of dietary protein levels on daily water intake, total water intake, or fecal water excretion. Urinary excretion values showed a linear increase in response to increased dietary protein levels, but no impact was observed on water balance, with an average of 8.4 L/d. Nitrogen intake (NI), N absorption (NA), and urinary N increased linearly as a function of increasing dietary protein levels. There was no impact of dietary protein levels on N retention (NR), with an average of 7.5 g N/d. Nitrogen retention as a percentage of NI or NA showed no significant changes in the function of dietary protein levels. There was an impact of dietary protein levels on the digestibility coefficient of CP, NDF, ADF, and digestible protein intake on conditioning eventing horses. The 11.6% CP level in the diet provided an intake of 2.25 g CP/kg BW and 0.37 g N/kg BW, and this intake was the most appropriate for the conditioning of intensely exercised horses, considering the responses related to NI, NA, and the estimated NR to NA ratio. The NDF and ADF responses indicated that dietary fiber was more digested with an increased amount of N in the digestive tract.

Avaliação de dietas para eqüinos de uso militar em atividade física moderada

This study aims to evaluate diets for military horses in moderate activity. This experiment was conducted at Cavalry School of Brazilian Army where diets for horses of Ceremonial Squadron was evaluated. Diets were composed by commercial concentrate, Coast-cross grass hay and hydroponic oat. An performance trial in an randomized block design with three blocks (age of animals) and three treatments (experimental diets) were used. Diet I, fifteen horses fed diets composed by commercial concentrate with alfalfa hay into the pellets; Diet II, fifteen animals fed diets composed by commercial concentrate pellets; Diet III, fourteen animals fed diets composed by commercial concentrate pellets plus 3.0 kg hydroponic oat. Three kilograms of Coast-cross grass hay were added in all diets. At the end of this trial, a digestion trial was carried, in a complete randomized design, with three treatments (diets) and four replications (animals) to evaluate digestibility nutrients of diets, according total feces collection method. Values were submitted by variance analysis and means compared by Tukey test at 5% probability. Animals fed experimental diets maintained body weight and corporal score without any change according to nutrients contents in the diets. The coefficients digestibility of nutrients were changed in function of the diets and experimental diet composed by commercial concentrate with alfalfa hay into the pellets were more digestible. Intake of digestible energy and protein were adequate to military horses in moderate activity. Intake of dietetic fiber as NDF and ADF were adequate to minimum recommendations for horses.

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