Magda Maria Guilhermino

Evaluation of thermal stress indexes for dairy cows in tropical regions

Data from 359 Holstein and 54 Jersey cows (total of 1359 observations) collected in commercial herds in the northeast of Brazil were used to evaluate six environmental stress indexes. The selection criterion was the correlation between the index value with the rectal temperature (RT) and the respiratory rate (RR) of cows. Both Temperature-Humidity Index (THI) and Black Globe-Humidity Index (BGHI) had the lowest correlations with animal RT and RR. The selected indexes were the Equivalent Temperature Index (r = 0.293 and 0.520 with RT and RR, respectively) and the Heat Load Index (0.286 and 0.542, respectively).

Variação anual de hormônios tireoideanos e características termorreguladoras de vacas leiteiras em ambiente quente

This work was carried out with the objective to study the annual behavior of thermo regulators traits in dairy cows. Two hundred cows were used during two consecutive years and the respiratory rate (RR), rectal temperature (RT), as well as a blood sample was collected for triiodothyronin (T3) and thyroxin (T4) dosages, were recorded. Air temperature and humidity were also recorded and the black globe humidity index (BGHI) and radiant heat load (RHL) were calculated in the same days of data collection. There was no significative effect of the year for the majority of studied variables, however, the effects of month of collection and herd were significative for all variables. All values of RT were inside of the amplitude of normality, indicating homoeothermic condition. The RR was altered in every seasons of the year and herds, showing a constant necessity of thermolisys. In herds with higher RT and RR, there was a reduction T3 and T4 liberation. In seasons of higher BGHI and RHL, there was increase in the RT, followed for higher RR and lower T3 and T4 plasmatic concentrations.

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.

Características Termorreguladoras de Caprinos, Ovinos e Bovinos em Diferentes Épocas do Ano em Região Semi-Árida

Esta pesquisa foi realizada com o objetivo de se avaliar o comportamento de caracteristicas termorreguladoras de caprinos, ovinos e bovinos durante os periodos seco e chuvoso e correlacionar com variaveis meteorologicas registradas ao longo do ano em ambiente semi-arido. Foram utilizadas dez cabras e dez ovelhas “sem padrao racial definido” (SPRD), alem de dez vacas mesticas de Holandes. A temperatura retal (TR), frequencia respiratoria (FR) e a taxa de sudacao (TS) dos animais foram medidas a cada 15 dias, a 9 h e a 15 h, durante os meses de abril a junho e outubro a dezembro. Nos mesmos horarios o ambiente foi monitorado quanto a temperatura e umidade do ar, carga termica radiante (CTR) e Indice de Temperatura de Globo e Umidade (ITGU). Os resultados mostraram medias de variaveis ambientais superiores ao considerado adequado para as tres especies. Os valores criticos foram concentrados na epoca chuvosa, que ocorreu do mes de janeiro a junho e no horario das 15:00, quando foram verificadas maiores TR e FR e menores TS. A especie caprina foi a que apresentou menor elevacao da temperatura retal e necessitou acionar em menor escala os mecanismos de termolise respiratoria e cutânea. A TR, FR e TS foram correlacionadas de maneira positiva e significativa com taxa de sudacao e com todas as variaveis meteorologicas. No periodo chuvoso a tarde houve maior aquecimento corporal e reducao da termolise evaporativa cutânea, nas tres especies, alem das variaveis climaticas atingiram valores mais elevados.

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.

Heat stress indexes and the use of bovine somatotropin (bST) in crossbred dairy cows (Bos indicus x Bos taurus) raised in a semi-arid region of the Brazilian Northeast

A study was conducted to evaluate the effects of bST in crossbred dairy cows (Bos indicus x Bos taurus) raised in a semi-arid zone, in the Northeast of Brazil. Fifteen cows (second and third lactation; 42-155 days in milk) received five applications of bST, at 14-day intervals. Other 15 cows were used as controls. The animals were fed with diet consisted in elephant grass and concentrate. During the first application of bST, the milk production of the treated cows (12.6 kg/day) did not differ from the control animals (11.3 kg/day), but in the second and third applications, the difference between the groups was significant (2.0 and 2.3 kg). In the fourth application of bST, there was an increase in the difference between groups (3.0 kg) and in the fifth application, such difference was 3.4 kg (14.0 kg versus 10.6 kg/day). The bST treatment and stage of lactation interaction was not significant. Rectal and milk temperatures were higher (0.1 and 0.6 °C, respectively) in bST treated than in control animals, but differences were not significant. For the group of 30 cows, the daily milk yield was related to milk temperature (r = 0.38 to 0.69). Based on the temperature-humidity index, the cows were under light heat stress in the morning and moderate stress in the afternoon. Therefore, crossbred cows raised in the semiarid area of Brazil showed responses to bST without apparent signs of severe heat stress.O objetivo do presente experimento foi avaliar a resposta ao bST de vacas mesticas (Bos taurus x Bos indicus) criadas no semi-arido do Ceara. Quinze vacas (segunda e terceira paricoes; 42 a 155 dias pos-parto) receberam cinco aplicacoes de bST a intervalos de 14 dias e outras 15 foram utilizadas como controle. A dieta dos animais consistiu de capim-elefante e concentrado. Durante a primeira aplicacao de bST, a producao de leite dos animais tratados (12,6 kg/dia) nao diferiu dos animais controle (11,3 Kg/dia) mas, na segunda e terceira aplicacoes, a diferenca entre os grupos foi significativa (2,0 e 2,2 kg). Na quarta aplicacao de bST, houve aumento na diferenca entre os grupos (3,0 kg) e, na quinta aplicacao, esta diferenca foi de 3,4 kg (14,0 kg versus 10,6 kg/dia). A interacao tratamento com bST e estagio de lactacao nao foi significativa. As temperaturas do leite e retal foram maiores (0,6 e 0,1°C, respectivamente) nos animais tratados com bST que nos animais controles, mas estas diferencas nao foram significativas. Para o grupo de 30 animais, houve correlacoes entre producao e temperatura do leite (r = 0, 38 a 0,69). Com base no calculo do indice de temperatura e umidade, os animais estiveram submetidos a estresse termico ameno (manha) ou moderado (a tarde). Portanto, animais mesticos criados no semi-arido do Nordeste aumentaram a producao de leite devido ao bST, sem, no entanto, apresentar indicativos de estresse termico severo.

Evaluation of dairy goat welfare in different production systems in Tuscany

There is very little published information on goat farming in Tuscany and even less on animal welfare on these farms. Specific evaluation systems on animal welfare for sheep and goats are needed. For this purpose, many research groups have utilised and modified the Animal Needs Index (ANI) 35 L method. In this paper, our research group proposes a new and easy evaluation questionnaire, specifically designed for goat farms, and considers 17 different aspects: seven are related to the goat housing, seven consider the condition of the structure and equipment, and the remaining three are related to animal health. The data was analysed by a one-way general linear model considering, as factors, the production system (organic, biodynamic, conventional), the province where the farms were located and the goat breed. In conclusion, we found important differences pertaining to the goat housing, condition of the structure and equipment and animal health between provinces and reared breeds. Very few differences were found between production systems. Regarding the provinces, the geographical position appears to greatly influence the conditions in which the animals are reared, primarily attributable to cultural and economic reasons. The Alpine breed was shown to be in better condition and the Garfagnina the worst. The questionnaire utilised was able to provide a general and concise idea on the animal welfare level of goat farms in Tuscany.

Características do Perfil da Comunidade da Universidade Federal do Rio Grande do Norte como Consumidora de Produtos Lácteos

O o bj e t iv o d e st e es tudo foi c a racter iz ar a c o munidade da Universidade Federal d o Ri o Gr a nd e do N o rt e c omo c o n s um i d o r a d e leit e e d e ri v ados . Foram entrevistados 50 r e pre se n ta nt es d as cat egor i a s : alun os , p r o f esso r es e fun c ion a r io s . O m e todo utilizado para coleta d as i nformacoes f oi o d a e ntr ev i s ta si s t e mati z ada . A s var iave i s fo ram analisadas atraves de es t at i st ic as d esc riti v a s e tab e l as d e co nting e nci a t es t a d as p e lo m etodo do qui-quadrado. A maioria do s e ntr ev i s t a d os c o n so m e l e it e lon g a v ida e e m po o qu e s u ge r e se r a praticidade do produto que d et ermin a a sua compra. D o s consumidore s d e l e ite de s natad o , 70 % foram do sexo feminino s u ger ind o qu e a s mulh eres est ao mai s p r eoc upadas co m o teor d e go rdura do leite. A maioria dos en tr ev i s t ad o s na o co n so m e l e ite o u d e ri va do s qu e n ao os da e spec ie bovina , e apesar dos m es mos p a rti c ipar e m da co munid a d e un i ver s itaria , a mai or i a na o sa bia as diferenca s entre os varios ti pos d e l eite co m e r c i a l iza d os a ch a ndo qu e a uni ca dif e r e n c a era quanto a porcentag<