Elizabeth Regina Rodrigues da Silva

Heart rate and velocity in Vaquejada horses during field tests

The use of heart rate (HR) monitors for horse training assessment under field conditions has been expanded because its use facilitates the understanding of horse fitness levels. Work has been carried out to determine the HR, velocity (V) and exercise time for pull and helper horses submitted to the Vaquejada simulation test (VST). The test was used on 70 Quarter Horses that had trained and competed for more than 6 months. The VST consists of two horses, a puller and a helper, and a bull, all running on a soft sand track. A race cycle consists of three runs with the bull. Pull horses run one cycle and helper horses run two cycles. A Polar V800-GPS HR monitor for equines was used to measure several parameters: time, V and HR. The results were analysed by ANOVA and a Tukey test with P set at 5%. It was shown that pull horses developed an HRmax of ~200 bpm and an HRmin ~110 bpm, both higher than the helper horses (P<0.05). However, the HRmed of pull horses (~150 bpm) and helper horses (~139 bpm) in C-2 trials...

Effects of L-Arginine Supplementation on Lactating Mares and the Development of Foals

Background: Most animal species are able to produce Arginine (Arg) under normal conditions. However, in some situations, its degradation can be higher than its production. For example, during a period of lactation or disease, there is an increase in the consumption of Arg. In this case, endogenous production is not enough for the animal’s demands. Indeed, Arg supplementation in animals has several benefits for the animal’s body, such as the increase of angiogenesis, improvements in immunity and the reproductive system, as well as the stimulation of lactogenesis. During the early phase of growth, a deficiency of Arg could cause a reduction in the growth rate and metabolic activity of animals. Therefore, this amino acid is considered essential in some phases of the life of animals. However, very few studies of the supplementation of this amino acid in horses have been carried out. The aim of the present study was to characterize the effects of supplementing lactating mares and their foals with Arg. Materials, Methods & Results: Lactating mares (n = 10) were divided into two groups (control group: n = 3 / supplemented group: n = 7) and maintained exclusively under grazing. The supplemented group received 50 g of Arg during the lactation period. Samples of milk and blood from mares and blood from foals were collected at different phases of the lactation period. The following parameters were measured in milk: Glutamine (Gln); Glutamate (Glu); protein; fat; casein; lactose; urea and total solids. The following parameters were measured in blood: Gln; Glu; total plasmatic protein (TPP); albumin; urea; creatinine; uric acid; triglycerides; total cholesterol; calcium (C); phosphorous (P); magnesium (Mg) and ferrous (Fe). In addition, the biometric parameters of Wither Height (WH), Chest Perimeter (CP), Cannon Bone Circumference (CBC) and Fat Percentage (FP) of foals were obtained. A significant increase of Gln was observed in the milk in both groups (P 0.05), although Glu was higher in the control group in the first month of the lactation period (~ 0.21 mmol/mL) (P 0.05). Even when they were added (Gln + Glu), no differences were observed (P > 0.05). However, when the biometric parameters were analyzed, significant variations were detected in almost all characteristics (weight, WH, CP and CBC). In particular, the control group exhibited higher body mass and CP in the fifth month, when compared with the group of foals born from supplemented mares (P 0.05). Discussion: The results indicate that the supplementation of lactating mares with Arg produced few alterations in the parameters analyzed for both mares and foals. In addition, the supplementation did not produce side effects among the supplemented animals.

Characterization of the Development of Foals in Natural Mating and Embryo Transfer

Background: Several reproductive biotechnologies are used in horses and embryo transfer (ET) is one of the most frequent in countries like Brazil and the USA. It has been shown that animals originated by new reproductive technology can have compromised growth in extreme conditions, however there are still only a few researches on the influence of embryo transfer over lactating foals under different raising methods. Due to the lack of studies on ET products development and the need to understand the process and it’s relate with lactating foal’s growth, the aim of this study was to evaluate the influence of the embryo transfer and natural mate over the newborn foals. Materials, Methods & Results: From a group of 20 mares, 20 Quarter Horse lactating foals were used (10 natural matting + 10 embryo transfer). The mares weren’t given any concentrate feed during whole gestation and lactation. Foals were kept with the mare, however was used creep feeding to give commercial feed ad libitum. The foals biometric evaluation were made at the day of birth (day 0) and at 30th, 60th, 90th, 120th and 150th day (weaning) for the following parameters: body mass (BM), height at the withers (H), heart girth (HG), cannon bone girth (CBG) and fat mass percentage (FMP). The fat thickness percentage at rump it was determined by ultrasound device. All statistics were considered significant when a P 0.05) and so did foals at birth (P > 0.05). However, by the time of weaning, body mass (BM) was 25% higher on ET foals group. These results indicate some influence of ET on foals’ growth since milk’s composition on both groups (G-NM and G-ET) was similar (P > 0.05), as well as dietary and sanitary handling that foals and mares were submitted to. It is a fact that one’s phenotype is determined not only by its genotype, there is evidence that environmental modification during intra uterine period, as well as extra uterine environment may affect epigenetic features. Changes of physical and skeleton progress patterns on suckling foals remained after weaning. However it could be observed that the present study foals had their development under proposed parameters according to prior studies, which affirm that animals have to duplicate their birth weight at the first month of age and should be five times higher at weaning. It stands out that ET treatment foals reported slightly high values indicating this research and future studies relevance to assure if growth beyond observed commonly is beneficial or damaging. In conclusion, there is little influence of the reproductive method over the lactating foal’s development when we compered two groups of foals obtained from natural mate and embryo transfer. However, foals from embryo transfer had large body mass at weaning when compared with natural mate group. Finally, the mares’ milk composition was similar between both groups of mares used in this study.

Metabolic profile of lactating goats fed integral mango meal

The work was conducted to evaluate the metabolic profile of lactating goats fed diets containing integral mango meal as a replacement for corn. Four levels of replacement (0, 33, 66 and 100%) were evaluated in diets with forage:concentrate ratio of 60:40. Eight crossbred multiparous lactating Saanen goats (48.72 ± 1.99 kg of BW) were introduced in the experiment 48 days postpartum and maintained up to 124 days of lactation. It was used a double Latin Square (4x4) experimental design, with four treatments, four periods and four animals per square. There was no effects (P>0.05) for the integral mango meal level on the intake of DM (1890 g/day), CP (278 g/day) and NDF (959 g/day). However, the intake of NFC and TDN decreased (P 0.05) by replacement levels, with average values of 54.52 mg/dl, 0.71 mg/dl, 52.59 UI, 77.37 UI, 4.69 g/dl, 9.32 g/dl, 74.44 mg/dl, 40.10 mg/dl, 39.39 mg/dl, and 11.09 mg/dl, respectively. Considering the metabolic profile, mango meal whole can totally replace corn in diets of dairy goats.