Débora Andréa Evangelista Façanha

Variação anual de características morfológicas e da temperatura de superfície do pelame de vacas da raça Holandesa em ambiente semiárido

This work aimed to study the annual variation of temperature of the coat surface and other traits of coat in Holstein cows managed in a tropical environment by separately considering black coat and white coat. It was measured the coat thickness (mm) characteristic, hair length (mm), hair number (hair/cm2) and coat surface temperature on 191 crossbred cows with 7/8 and 31/32 Holstein composition distributed in 3 herds in a semi-arid environment. Less dense coats with shorter, flattened hair occurred predominantly in March, a time coinciding to high levels of solar radiation. This type of coat shows low resistance to the flux of latent and sensitive heat through the skin, thus favoring heat loss. The black coat surface temperature was on average 4oC higher than that of the white one during all the year and its variation followed that of the mean radiant temperature. The models developed to predict the effective thermal conductivity of the coat must take these differences into account because the thermal gradient parallel to the skin surface is not negligible for Holstein cows under the sun in a tropical environment, as well as the other traits.

Tendências metodológicas para avaliação da adaptabilidade ao ambiente tropical

The adaptation of animals to breeding environment is essential to the success of any livestock enterprise. In Brazil, some decades ago, several breeds were imported, originated from temperate climates, from various species of farm animals whose progeny were evaluated and selected taking into account only the productive aspects. In the last ten years it was found that both creators and the academic community awoke to the promotion of adaptive aspects when selecting animals to be created in many different biomes. There is thus, the recovery of native breeds of zebu cattle and small ruminants for meat and milk productions. However, evaluate and select animals for adaptive traits require the standardization of parameters and methodologies for the collection of reliable data. Whereas homeostasis represents the equilibrium condition in a biological system and that animals adapted to the environment exhibit clear signs of homeostasis, this study sought to address a methodology composed of a multifactorial matrix to evaluate the adaptation, which are considered the thermoregulatory reactions As a way to maintain homeothermy indicated by rectal and surface temperatures and activation of evaporative heat loss, represented by the respiratory rate and sweating rate. For evaluation of homeostasis is recommended the association of endocrine reactions, such as circulating levels of thyroid hormones and cortisol, to the biochemical parameters within the normal range. All of these factors in balance allow the animals to express satisfactorily the reproductive and productive roles.

Thermoregulatory responses related to coat traits of Brazilian native ewes: an adaptive approach

ABSTRACT Semi-arid conditions can adversely affect livestock productivity and change certain physiological parameters. The relationship between hair coat and thyroxine levels in Morada Nova ewes was evaluated through environmental factors, such as air temperature, relative air humidity, radiant and Black Globe Humidity Index to gain a better understanding of thermoregulation mechanisms in these animals. Measurements were taken from July to January in 383 Morada Nova ewes. The variables studied included rectal temperature (RT), respiratory rate (RR), coat thickness (CT), hair length (HL), hair diameter (HD), hair density (D) and thyroid hormones. The data underwent multivariate statistical analyses and a significant inverse relationship was found between coat traits and Thyroxine (T4). The animals that exhibited greater HL, coat density and CT showed lower T4 concentrations. Coat traits showed a strong interaction with physiological mechanisms and can be considered relevant in maintaining homeostasis. Hair traits play an important role in this process, since T4 reduction was stronger in animals that showed difficulties in eliminating heat, which were the ones that had greater HL, hair density and HD. By contrast, animals with a hair coat more favourable to heat losses had higher levels of thyroid hormones.

Performance, endoparasitary control and blood values of ewes locally adapted in semiarid region

This study evaluated the variation in the prevalence of endoparasitoses and their impact on body condition and blood values of sheep of the Morada Nova breed. A total of 138 ewes were examined for their morphology (body weight, BW; body condition score, BCS), parasitology (faecal egg count, FEC; Famacha© score; coproculture), hematology (red blood cell count,RBC); hemoglobin concentration, HE; packet cell volume, PCV; mean corpuscular volume, MCV,; mean corpuscular hemoglobin, MCH; mean corpuscular hemoglobin concentration, MCHC; leukocytes, WBC) and serum biochemistry (glucose, cholesterol, triglycerides, urea, creatinine, total protein, albumin, globulin, AST and ALT). Overall the animals presented higher BW and BCS in the months of September and December, however, with high FEC, in addition to a large number of animals with Famacha score 4 and 5. The results showed that the main hematophagous worm affecting the sheep, the genus Haemonchus ssp, appeared in a greater proportion (30-71.66%) than the other worms in all months of the study, except in March. About 30% of the hematological values found in the study are outside the reference ranges for suable sheep e 45.50% for serum biochemistry. These findings demonstrate the most healthy period of the year was from March to June for endoparasites control, however, in the months of September and December the animals showed better performance measures.

A multivariate approach to the diagnosis of gastrointestinal infection in ewes

Diagnosing the effects of helminth infections is an efficient way to manage the problem in ruminant production systems. Selection of animals in a flock that are infected with Haemonchus has traditionally involved differential packed cell volume measurements (PCV), and in recent years, the FAMACHA© system has been used. However, few small analytical changes have been made. The objective of this study was to examine the influence of different diagnoses linked to packed cell volume (PCV) and FAMACHA© system scores in native ewes, using a multivariate approach. Ewes were classified into three categories according to their score in the FAMACHA© system (FS) and their packed cell volumes (PCV) as follows: Group AG (FS between 1 and 2 and PCV ≥ 30%); Group BG (FS score of 3 and PCV between 21 and 29%); Group CG (FS between 4 and 5 and PCV ≤ 20%). The animals were evaluated using performance characteristics, parasitological examinations, blood values and serum biochemistry. The data show that the use of a multivariate approach for different diagnoses using the FAMACHA© system and PCV measurements gives similar results, although they have particular pathophysiological indicator patterns.

Detecting estrus in Canindé goats by two infrared thermography methods

The aim of study was to evaluate the diagnosis of estrous in Caninde goats used infrared thermographic images. The Caninde goats used in experiment, belong to Production Center of Small Ruminants. The goats were subjected to estrus induction and monitored with regard to their behavior and blood levels of hormones. Temperature measurements were continuous during estrous signs and even disappearance of behavioral characteristics. Were evaluated different areas in females: vulva, perivulvar, dorse and venter regions, delimited by a quadrant that allowed the specification of assessed region. In addition to specific behavior of estrus in ruminants were observed in vulvar region perivulvar signals swelling and redness and parallel identified the temperature rise of region by thermographic images. Were observed in vulvar region perivulvar signals swelling and redness and parallel identified the temperature rise of that region by thermographic images in goats in estrus. There was a significant effect for all temperatures of the regions evaluated for the thermographic images and infrared thermometer, except for the temperature of the vulvar region. The temperatures measured using the thermographic camera submitted a difference in the data set, allowing measurements observed higher temperatures compared with the temperatures measured with an infrared thermometer. So, due the precision and speed of the method the thermographic images used for detecting estrus is applicable and important. In animal production, thermography has seen used in detection of metabolic disorders, diseases and infections. In addiction, is used in understanding thermoregulation due to chenges in temperature and the impact of environmental conditions.

Atualidades na cadeia produtiva e a biossegurança dos alimentos

A busca por maiores producoes e intensa e vem inovando a cadeia produtiva ao longo dos anos, seja com racas de animais melhoradas ou com plantas forrageiras mais produtivas. Com a populacao crescendo a cada ano, a demanda de alimentos tambem cresce e a producao se torna mais intensa e mais centralizada, diminuindo o numero de pequenos produtores e aumentando a capacidade produtiva das grandes empresas. A biosseguranca e outro fator cada vez mais enfatizado, fazendo parte da evolucao da cadeira produtiva, que surgiu principalmente devido a doencas epidemicas que acometeram os animais, e que se tenta controlar ate hoje para evitar novos surtos. Ha sempre preocupacao com a sanidade do ambiente e do animal, visando uma carne de melhor qualidade, atendendo as exigencias do consumidor. Normal 0 21 false false false PT-BR X-NONE X-NONE