Effect of feeding heat-treated and unheated colostrum on immunoglobulin G absorption, health and performance of neonatal Holstein dairy calves

First colostrum is an important source of nutrients and immune factors which are necessary for calves in the first weeks of life. Despite these benefits, colostrum can also represent one of the earliest potential exposures of dairy calves to infectious agents which these patogens can act directly on growth and cause diseases such as scours or septicemia. With recent increased interest in pasteurized milk feeding systems, producers have been curious to learn if there may also be benefits from feeding pasteurized colostrum. This study was realized to determine the effects of feeding heat-treated colostrum or unheated colostrum on passive transfer of immunity, immunoglobulin G (IgG) concentration, total plate count, health and performance of neonatal dairy calves. First-milking colostrum was collected from Holstein cows and frozen at -20°C to accumulate a large batch. Pooled batches of colostrum were mixed and divided equally: One half was fed unheated colostrum; whereas the other half was fed after heat treatment at 60°C for 30 min. Forty newborn male Holstein dairy calves were fed either unheated (n = 20) and heat-treated colostrum (n = 20), 10% of their birth weight. Calves received 4 L within 1 to 2h after birth and residuals was fed 6h after birth. Serum samples collected from calves and were assayed for serum total protein (STP) and IgG. Feed intake recorded weekly and body weight and skeletal growth measures recorded at d 3 and d 63 (weaning). Every day, calves clinically diagnosed either as being healthy or suffering from respiratory disease and neonatal calf diarrhea. Heat-treated colostrum resulted in lower colostrum bacterial concentration (2.01 vs. 3.96 cfu mL-1 ). Calves fed heat treated colostrum had greater STP in 24, 72h and 23d, IgG concentrations at 24 and 72h plus unheated colostrum. Also weaning weight and average daily gain were greater in calves feed heated colostrum. There were no differences in starter intake and feed efficiency between two groups. Calves fed heat-treated colostrum had lower fecal scores, diarrhea and pneumonia incidence. There were not differences in skeletal growth measurements except body barrel. These results shows that feeding heated colostrum can provide better growth and health in neonatal calves.(AU)

Effect of feeding heat-treated and unheated colostrum on immunoglobulin G absorption, health and performance of neonatal Holstein dairy calves

First colostrum is an important source of nutrients and immune factors which are necessary for calves in the first weeks of life. Despite these benefits, colostrum can also represent one of the earliest potential exposures of dairy calves to infectious agents which these patogens can act directly on growth and cause diseases such as scours or septicemia. With recent increased interest in pasteurized milk feeding systems, producers have been curious to learn if there may also be benefits from feeding pasteurized colostrum. This study was realized to determine the effects of feeding heat-treated colostrum or unheated colostrum on passive transfer of immunity, immunoglobulin G (IgG) concentration, total plate count, health and performance of neonatal dairy calves. First-milking colostrum was collected from Holstein cows and frozen at -20°C to accumulate a large batch. Pooled batches of colostrum were mixed and divided equally: One half was fed unheated colostrum; whereas the other half was fed after heat treatment at 60°C for 30 min. Forty newborn male Holstein dairy calves were fed either unheated (n = 20) and heat-treated colostrum (n = 20), 10% of their birth weight. Calves received 4 L within 1 to 2h after birth and residuals was fed 6h after birth. Serum samples collected from calves and were assayed for serum total protein (STP) and IgG. Feed intake recorded weekly and body weight and skeletal growth measures recorded at d 3 and d 63 (weaning). Every day, calves clinically diagnosed either as being healthy or suffering from respiratory disease and neonatal calf diarrhea. Heat-treated colostrum resulted in lower colostrum bacterial concentration (2.01 vs. 3.96 cfu mL-1 ). Calves fed heat treated colostrum had greater STP in 24, 72h and 23d, IgG concentrations at 24 and 72h plus unheated colostrum. Also weaning weight and average daily gain were greater in calves feed heated colostrum. There were no differences in starter intake and feed efficiency between two groups. Calves fed heat-treated colostrum had lower fecal scores, diarrhea and pneumonia incidence. There were not differences in skeletal growth measurements except body barrel. These results shows that feeding heated colostrum can provide better growth and health in neonatal calves.

Produção de calor metabólico e transferência de calor sensível em codornas

O objetivo deste trabalho foi estudar o equilíbrio térmico de codornas comerciais adultas em fase de produção de ovos, considerando a produção de calor metabólico e os mecanismos de transferência de calor sensível entre as aves e o ambiente. A tese foi desenvolvida em dois experimentos: no experimento I, objetivou-se avaliar a produção de calor metabólico em codornas ao longo das 24 horas do dia (ciclo nictemeral) em conforto térmico. Para isso, foram utilizadas 40 codornas fêmeas, de duas subespécies japonesas (Coturnix coturnix japonica) e europeias (Coturnix coturnix coturnix). As aves foram avaliadas em duas fases, Fase I: entre 55 e 65 dias e Fase II: entre 110 e 120 dias de idade. Utilizou-se a metodologia da calorimetria indireta e uma ave de cada subespécie foi inserida em um trocador de calor e analisadas simultaneamente durante 24 horas. De forma síncrona, também foram analisadas as variáveis ambientais: temperatura do ar (ºC), concentração do ar atmosférico (dióxido de carbono e oxigênio %) e pressão parcial do vapor do ar (kPa). O calor metabólico (W m-2) das aves foi calculado considerando que 76% é proveniente do consumo de oxigênio e 23% é devido à produção de dióxido de carbono, além da ventilação (L s-1) e da superfície corporal das aves. Os dados foram analisados pelo método dos quadrados mínimos considerando os efeitos de subespécie (japonesa ou europeia), dia (1 a 20), horas do dia (meia noite às 23h00), e efeito da interação entre subespécie com o dia, e da subespécie com a hora do dia. Os resultados mostram que a todas as variáveis analisadas a produção de calor, o consumo de O2, a produção de CO2 e frequência respiratória, tiveram efeito significativo (P< 0,001). Os principais resultados encontrados da produção de calor metabólico de codornas em termoneutralidade mostrou diferença significativa entre as subespécies (P< 0,001). Quando estão com idade entre 55-65 dias, a fisiologia entre as subespécies é distinta, nesta idade as codornas europeias continuam o crescimento e ganho de massa corporal, além de coincidir com a produção de ovos, o que demanda que a produção de calor metabólico seja maior do que das japonesas. Porém, em período de pico de produção de ovos com idade entre 110-120 dias essa produção de calor continua diferente entre as subespécies (P< 0,001) sendo maior nas europeias 67,3 W m-2 do que nas japonesas 58,8 W m-2. Além disso, quanto a proporção do tamanho do ovo em relação ao tamanho da codorna, as japonesas produzem ovos que são 5,8% do seu peso vivo, enquanto as codornas europeias que produzem ovos com a proporção de 4,3% da sua massa corporal. Conclui-se que as codornas japonesas produzem menos calor metabólico para se manterem em produção, tornando-as mais eficientes para a produção de ovos, sendo que são ovos maiores em proporção ao tamanho do corpo da ave em comparação com as codornas europeias, que produzem maior quantidade de calor para a postura de um ovo por dia. Mostrou o quanto as codornas europeias são mais exigentes quando comparadas as codornas japonesas. Reforçando a necessidade de programas nutricionais e ambientais específicos para atender às demandas de cada subespécie e em diferentes exigências fisiológicas de acordo com a idade. No experimento II, objetivou-se avaliar a transferência de calor sensível em codornas japonesas, considerando os mecanismos de radiação de ondas longas e convecção, criadas em galpão convencional sem controle ambiental. Para isso, foram analisadas as variáveis meteorológicas: a temperatura do ar (TAR, ºC), a umidade relativa do ar (UR, %) e a temperatura do globo negro (TGN, ºC); e as variáveis fisiológicas: a temperatura cloacal (TC, ºC) e superficial (TS, ºC) das codornas. A temperatura superficial foi aferida por uma câmera termográfica em 50 codornas japonesas adultas, machos e fêmeas, com 270 dias de idade, durante 10 dias, nos horários das 08h00 e às 15h00. Os dados foram analisados pelo método dos quadrados mínimos e foram analisados os efeitos de gênero (macho e fêmea), período (manhã e tarde) e regiões do corpo (cabeça, corpo e pés). A temperatura da superfície das codornas apresentou alta correlação com a temperatura do ar, com a temperatura radiante e com a radiação de ondas longas. Todos esses fatores influenciaram a transferência de calor e o fluxo de calor sensível total foi de 64,02 W m-2. A transferência de calor sensível nos animais é totalmente dependente da temperatura ambiente. A temperatura operativa pela manhã foi de 22,48°C, que permitiu maior gradiente de temperatura entre o ar e a superfície da codorna, portanto, ocorreu maior transferência de calor 82,19 W m-2 das aves para o ambiente. À tarde a transferência foi menor 45,70 W m-2, porque neste momento a temperatura operativa foi maior 30,84 ° C. A comparação entre os gêneros mostrou que a transferência de calor foi maior nas fêmeas 67,37 W m-2 do que nos machos 60,53 W m-2. A cabeça mostra-se como importante janela térmica com capacidade de dissipar 78,24 W m-2, enquanto o corpo + pés de 56,80 W m-2 nas codornas. A dissipação de calor nas aves, por mecanismos de radiação de ondas longas e convecção foram eficientes em transferir calor para o meio ambiente, quando a temperatura operativa foi inferior a 28 ° C. Ao ultrapassar esta temperatura as codornas não conseguem dissipar calor para o ambiente e quando a temperatura operativa atinge 30°C torna-se nulo e o mecanismo de transferência de calor deixa de ser dissipação e passa a ser um mecanismo de ganho de calor, tornando mais um fator causador de estresse térmico. De maneira geral, conclui-se que tanto a estimativa da produção de calor metabólico quanto a determinação da transferência de calor sensível foram essenciais para a determinação do equilíbrio térmico de codornas e podem ser utilizados como ferramenta para os programas de ambiência específicos para codornas criadas em regiões tropicais ou em condições climáticas semelhantes.

The aim of this work was to study the thermal equilibrium of commercial quails in laying phase, considering the metabolic heat production and sensible heat flow between the birds and the environment. The thesis was developed in two experiments: in experiment I, the metabolic heat production in quails throughout the 24 h of the day (nictemeral cycle) in thermal comfort was evaluated. Forty female quails were used, being 20 Japanese quails (Coturnix coturnix japonica) and 20 European quails (Coturnix coturnix coturnix). The quails were evaluated in two phases: between 55 and 65 days of age and between 110 and 120 days of age. The indirect calorimetry method was used and two birds were of the each treatment analyzed simultaneously in a heat exchanger for 24 h. The environmental variables were analyzed synchronously: air temperature (ºC), atmospheric gas concentrations (carbon dioxide and oxygen %) and air partial vapor pressure (kPa). The metabolic heat production was calculated (W m2 ) considering that 76% of it is due to the oxygen consumption and 23% is due to the carbon dioxide production, in addition to ventilation (L s-1) and body surface area of the birds. The data were analyzed by the least squares method and the effects of subspecies (Japanese or European), days (1 to 20), schedules (midnight to 11:00 pm), and the interaction effect between subspecies and days, and of subspecies and schedules were analyzed. The results showed that all variables analyzed, heat production, O2 consumption, CO2 production and respiratory rate, had a significant effect (P < 0.0001). These data show that Japanese quails need less metabolic heat (58.8 W m2 ) to keep them in production, making them more efficient for egg production compared to European quails, which produce more heat (67.3 W m-2) to lay an egg per day (P < 0.0001). In relation to egg size as a proportion to body size, Japanese quails produce eggs that correspond to 5.8% of their body weight, and larger than the eggs of European quais, which produce eggs with only 4.3% of their body mass. In conclusion, the metabolic heat production in Japanese quails is lower than in European quails at thermoneutrality. When they are between 55 and 65 days old the physiology of the subspecies is different, at this age the European quails continue the growth and body mass gain, besides coinciding with the egg production, which demands that the metabolic heat production is higher than the Japanese quails. However, in the peak period of egg production with age between 110 and 120 days this rate becomes equivalent, demonstrating the high capacity of Japanese quails to produce eggs, which reinforces the need for specific nutritional and environmental programs to meet the demands of each subspecy's and for different physiological requirements according to age. The results showed that the Japanese quails are more demanding compared to European quails. In experiment II, the aim was to evaluate the sensible heat transfer in Japanese quails, considering longwave radiation and convection flows, raised in a conventional shed without environmental control. the meteorological variables - air temperature (TAR, ºC), relative humidity (RH, %) and black globe temperature (TGN, ºC); and the physiological variables - cloacal temperature (TC, ºC) and surface temperature (TS, ºC) of the quais were analyzed. The surface temperature was measured by a thermographic camera in 50 adult male and female Japanese quails, 270 days old, during 10 days, at 08:00 am and 03:00 pm. The data were analyzed by the least squares method and the effects of gender (male and female), period (morning and afternoon) and body regions (head, body and feet) were evaluated. The surface temperature of the quails was highly correlated with air temperature, mean radiant temperature and long wave radiation. All these factors influenced heat transfer. The total sensible heat flow was 64.02 W m2, the operative temperature in the morning was 22.48°C, allowing a higher gradient between the air and the quail surface, therefore a higher transfer of 82.19 W m2. In the afternoon the transfer was lower 45.70 W m2 because the operative temperature was higher 30.84°C. The comparison between genders showed that the transfer was higher in females 67.37 W m2 compared to males 60.53 W m-2. The head showed to be an important thermal window with 78.24 W m2, while the body + feet was only 56.80 W m2 in quails. Sensible heat transfer in Japanese quails is totally dependent on ambient temperature. When the operating temperature was below 28°C long wave radiation and convection flows were efficient to dissipate heat to the environment, when exceeding this temperature the quails could not dissipate heat to the environment, when it reached 30°C it became null and the mechanism becomes a way of heat gain, being one more factor to cause thermal stress. In general we conclude that both the estimation of metabolic heat production and the determination of sensible heat transfer were essential to can be used as a tool for quail ambience programs in Brazil.

INFLUÊNCIA DA IDADE E DA ESTAÇÃO DE MONTA SOBRE A RECUPERAÇÃO EMBRIONÁRIA E TAXAS DE PRENHEZ DE ÉGUAS DA RAÇA QUARTO DE MILHA NO AGRESTE MERIDIONAL DE PERNAMBUCO

Objetivou-se relatar o efeito da idade e de diferentes períodos da estação de monta sobre a taxa recuperação embrionária e taxas de prenhez de éguas da raça Quarto de Milha criadas no agreste meridional de Pernambuco. Para este propósito, recuperou-se os dados das estações de monta 2016/2017 e 2017/2018, utilizando informações de 38 éguas doadoras, criadas em sistema semi-intensivo em mesma propriedade. Estas informações foram agrupadas nas faixas etárias, 2 a 5 anos (GA), 6 a 10 anos (GB), 11 a 15 anos (GC) e 16 a 20 anos (GD), e divididas nas fases de início, alta, final e fora da estação de monta. Durante todo período o protocolo de transferência de embrião foi o mesmo e foram utilizadas todas as éguas cíclicas disponíveis. Médias de temperaturas máxima e média ambiental e insolação referentes ao período estudado e a média histórica foram obtidas no Instituto Nacional de Meteorologia (INMET) e correlacionados junto com os índices de recuperação embrionária e taxa de prenhes das diferentes faixas etárias em diferentes fases da estação de monta. A taxa de recuperação embrionária total foi de 68,24%, existindo diferenças significativas em relação a faixa etária, onde observou-se que o GA e GB apresentaram 72% embriões recuperados, o GC 60%, e o GD 71%. Em relação as fases da estação de monta houve taxas mais elevadas no início para o GB (73,17%) e GC (75,68%), com menor influência das características climáticas neste período. Para a taxa de prenhes total obteve-se 52,47%, com melhoras no início da estação de monta com 58,5% de prenhez. Para faixa etária o GC diferiu estatisticamente (p>0,05) dos GA, GB e GD. Na alta estação houve declínio dos GA e GC, e correlação positiva com o GB, menor correlação com o GA, mínima com o GC e negativa com o GD em virtude da elevação da insolação durante a estação. Conclui-se que a idade e os diferentes períodos da estação influenciam os índices de recuperação embrionária e a taxa de prenhes, sendo esses melhores em animais adultos jovens em momento de maior luminosidade. Porém bons resultados são alcançados nos demais momentos e idades proporcionalmente as condições artificiais favoráveis oferecidas.

The objective of this study was to report the effect of age and different periods of the breeding season on the embryo recovery rate and pregnancy rates of Quarter Horse mares raised in the southeastern south of Pernambuco. For this purpose, data from the 2016/2017 and 2017/2018 breeding stations were recovered, using information from 38 donor mares, raised in a semiintensive system on the same property. This information was grouped into the age groups, 2 to 5 years (GA), 6 to 10 years (GB), 11 to 15 years (GC) and 16 to 20 years (GD), and divided into the phases of beginning, discharge, end and outside the breeding season. During the whole period, the embryo transfer protocol was the same and all available cyclic mares were used. Means of maximum temperatures and environmental average and insolation for the period studied and the historical average were obtained from the National Institute of Meteorology (INMET) and correlated together with the rates of embryonic recovery and pregnancy rate of different age groups at different stages of the season. mount. The total embryonic recovery rate was 68.24%, with significant differences in relation to the age group, where it was observed that GA and GB had 72% recovered embryos, CG 60%, and GD 71%. In relation to the breeding season, there were higher rates at the beginning for GB (73.17%) and GC (75.68%), with less influence of climatic characteristics in this period. For the total pregnancy rate, 52.47% was obtained, with improvements at the beginning of the breeding season with 58.5% pregnancy. For age group, CG differed statistically (p> 0.05) from GA, GB and GD. In the high season there was a decline in GA and GC, and a positive correlation with GB, less correlation with GA, minimal with GC and negative with GD due to the increase in heat stroke during the season. It is concluded that the age and the different periods of the season influence the rates of embryonic recovery and the rate of pregnancies, which are better in young adult animals at a time of greater luminosity. However, good results are achieved at other times and ages in proportion to the favorable artificial conditions offered.

PLASTICIDADE FENOTÍPICA E INDICADORES DE PRODUTIVIDADE DE CAPRINOS LEITEIROS EM AMBIENTE TEMPERADO

O Arquipélago Canário é constituído por sete ilhas situadas a oeste do continente africano, mais precisamente na costa subsaariana. Devido a sua proximidade ao continente africano e influência dos ventos Açores, as ilhas possuem climas distintos criando diferentes tipos de fauna e flora. A partir dessa perspectiva climática surgiram raças de caprinos leiteiros em que se destacam devido aos seus bons índices produtivos, notável qualidade de seus derivados e excelente adaptação aos diferentes ambientes existentes no arquipélago. As duas raças consideradas mais expressivas na produção de leite, são a raça Majorera, que se originou na ilha de Fuerteventura, caracterizada por apresentar um clima árido e seco e a raça Palmera, evoluída em um clima mais temperado da ilha de La Palma. Partindo da hipótese que, esses animais possuem características relacionadas a adaptação em diferentes ambientes nos quais evoluíram, o estudo tem como objetivo principal, avaliar os efeitos das condições meteorológicas em cabras adultas em diferentes estações do ano, sobre as características adaptativas, associando-as com dados de produção de leite e qualidade físico química, em um mesmo ambiente térmico. As atividades serão realizadas no Instituto Canário de Investigación Agraria ICIA, localizado no norte da ilha do Tenerife, em 30 cabras da raça Majorera e 20 cabras da raça Palmera, durante o período de lactação e seco, em sistema de produção intensivo, nos quais durante 18 meses, a cada 15 dias ao mês, foram avaliadas as características morfofisiológicas de adaptação, os mecanismos de transferência de calor, assim como dados de produção de leite. Espera-se estabelecer épocas críticas do ano, tanto no que se refere à capacidade de termorregulação, homeostase e produção, bem como quais características são mais usadas por esses animais e interferindo sobre os aspectos produtivos. Portanto, é necessário investigar a relação entre as características vinculadas à adaptação dos animais com os dados produtivos, na tentativa de ampliar os critérios de seleção dos animais.

The Canary Archipelago consists of seven islands located west of the African continent, more precisely on the sub-Saharan coast. Due to their proximity to the African continent and the influence of the Azores winds, the islands have different climates creating different types of fauna and flora. From this climatic perspective, breeds of dairy goats have emerged in which they stand out due to their good production rates, remarkable quality of their derivatives and excellent adaptation to the different environments existing in the archipelago. The two breeds considered most expressive in milk production are the Majorera breed, which originated on the island of Fuerteventura, characterized by an arid and dry climate and the Palmera breed, which evolved in a more temperate climate on the island of La Palma. Based on the hypothesis that these animals have characteristics related to adaptation in different environments in which they evolved, the main objective of the study is to evaluate the effects of meteorological conditions in adult goats in different seasons of the year, on the adaptive characteristics, associating them with milk production data and physical chemical quality, in the same thermal environment. The activities will be carried out at the Instituto Canário de Investigación Agraria - ICIA, located in the north of the island of Tenerife, in 30 goats of the Majorera breed and 20 goats of the Palmera breed, during the lactation and dry period, in an intensive production system, in which for 18 months, every 15 days a month, the morphophysiological characteristics of adaptation, the mechanisms of heat transfer, as well as milk production data were evaluated. It is expected to establish critical times of the year, both with regard to the capacity for thermoregulation, homeostasis and production, as well as which characteristics are most used by these animals and interfering with the productive aspects. Therefore, it is necessary to investigate the relationship between the characteristics linked to the adaptation of the animals to the productive data, in an attempt to expand the criteria for selecting the animals.

Use of applied reproductive technologies (FTAI, FTET) to improve the reproductive efficiency in dairy cattle

Background: Reproductive inefficiency of dairy cattle, characterized by reduced estrous expression and detection rates, reduced pregnancy per artificial insemination (number of cows pregnant divided by number of cows inseminated), reduced pregnancy rates (number of cows pregnant divided by the number of cows eligible to become pregnant during a time interval), and increased pregnancy losses, has a large financial impact on dairy operations across the world. Although the most important component of reduced reproductive efficiency in dairy cattle is unquestionably poor management and diseases that result from it, the genetic selection and the resulting increased milk yield have caused physiological changes in lactating dairy cows that also affect fertility. The most important of these changes is the increased feed intake and the consequent increased mesenteric and liver blood flow to supply the nutrients necessary for milk yield. This causes significant decreases in concentrations of progesterone and estradiol that affect estrous expression, follicular growth, oocyte quality, and embryo development and survival. This review will discuss reproductive technologies used in large dairy herds to mitigate the effects of these physiological changes on reproductive performance. Review: The use of ovulation/estrous synchronization protocols (OSP), pre and post-ovulation hormonal treatments, and embryo transfer (ET) in the reproductive management of lactating dairy cows was reviewed. Several OSP have been developed in the past 20 years. To achieve acceptable pregnancy per artificial insemination (P/AI) OSP should result in synchronized recruitment of a new follicular wave, growth of follicles under P4 concentration > 2 ng/mL, synchronized luteolysis, and synchronized ovulation at the end of the protocol. When embryo recipient cows are submitted to OSP, these protocols must aim to tightly synchronize luteolysis and ovulation at the end of the protocol. The use of ET in lactating dairy cows in the U.S. has been limited to herds of registered animals, to mitigate the negative effects of exposure to heat stress, to improve genetics of expanding herds, and in a few herds to salvage repeat-breeders. Lactating dairy cows are sensitive to heat stress because of the high metabolic rate resulting from the increased feed intake necessary to supply nutrients for milk production. Several studies have demonstrated that lactating dairy cows exposed to heat stress that receive ET have improved reproductive performance compared with cows receiving AI. Finally, the use of hormonal treatments to increase P4 concentration during early diestrus was reviewed because several studies have demonstrated a strong association among P4 concentration and embryo development and pregnancy establishment. The effects of hormonal treatments during ovulation synchronization protocols, after AI or at ET on P4 concentration and reproductive outcomes are controversial and likely dependent on management, milk yield, and diet of the lactating dairy cows. Conclusion: The use of reproductive technologies in lactating dairy cows, particularly AI, is extremely well disseminated and has resulted in significant improvements in milk yield in the past 50 years. Recent developments in the understanding of reproductive physiology of lactating dairy cows have resulted in ovulation synchronization protocols that optimize fertility after AI or ET.

DINÂMICA TÉRMICA EM CUTIAS (Dasyprocta leporina Linnaeus, 1758) E PREÁS (Galea spixii Wagler, 1831) EM AMBIENTE SEMIÁRIDO NEOTROPICAL MOSSORÓ-RN 2016

Como a termorregulação de cutias (Dasyprocta leporina Linneus, 1758) e preás (Galea spixii Wagler, 1831) em um ambiente semiárido permanece desconhecida, o presente trabalho objetivou determinar a termólise evaporativa e a transferência de calor por radiação e convecção. Foram utilizadas 20 cutias e 28 preás em experimentos distintos. As cutias foram submetidas a oito dias de amostragem, sendo as coletas de dados realizadas em cinco horários (7h00, 9h00, 11h00, 14h00 e 16h00). Cada preá foi submetido a três dias de amostragem, com coletas de dados realizadas em intervalos de uma hora, das 6h00 às 13h00. O ambiente térmico foi monitorado em cada horário de coleta. A temperatura da superfície corporal foi mensurada por termografia infravermelha. As regiões corporais consideradas nos termogramas das cutias foram: focinho, olhos, orelhas, corpo, membros torácicos e pélvicos. Nos termogramas dos preás foram consideradas, além daquelas mencionadas para cutias, as vibrissas e as perioculares. A termólise evaporativa foi determinada por calorimetria. As orelhas (13,10±1,17 W m-2) e os membros pélvicos (11,19±1,17 W m-2) foram as principais regiões envolvidas na perda de calor por radiação em cutias, funcionando como janelas térmicas. A termólise por radiação em preás foi mais elevada nas regiões perioculares (45,23±0,81 W m-2), seguida dos olhos (41,41±0,81 W m-2), orelhas (31,56±0,80 W m-2) e vibrissas (27,03±0,80 W m-2). As temperaturas das regiões perioculares mostraram ser valorosas preditoras da temperatura retal de preás, exibindo coeficiente de correlação de 0,61. A termólise convectiva em cutias foi mais intensa no corpo e membros pélvicos em todos os horários. Nos preás, a transferência de calor por convecção foi irrisória (0,54±0,56 W m-2). A termólise evaporativa em cutias (52,53±1,64 W m-2) e preás (143,69±1,37 W m-2) foi mais intensa no horário com maior temperatura atmosférica. Assim, observamos que tanto mecanismos não-evaporativos quanto evaporativos são importantes para a manutenção da homeotermia de cutias e preás em ambiente quente. Estes roedores utilizam regiões corporais especializadas na transferência de calor, que correspondem às janelas térmicas.

Because the thermoregulation of red-rumped agouti (Dasyprocta leporina Linneus, 1758) and Spixs yellow-toothed cavy (Galea spixii Wagler, 1831) facing a semiarid environment remain unknown, this study aimed to determine the evaporative heat loss and heat exchanges by radiation and convection. Twenty red-rumped agoutis and twenty-eight Spixs yellow-toothed cavies were used in different experiments. Red-rumped agoutis were subjected to eight samplings days, and the data collection was performed in five times (7h00, 9h00, 11h00, 14h00 and 16h00). Each Spixs yellow-toothed cavy was subjected to three sampling days, with data collection performed at hourly intervals, from 6h00 to 13h00. The thermal environment was monitored in each data collection. The body surface temperature was measured by infrared thermography. The body regions considered in the thermograms of red-rumped agoutis were nose, eyes, pinna, body, fore and hindlimbs. In addition to those mentioned for agoutis, thermograms of Spixs yellow-toothed cavies considered the vibrissae and periocular regions. Evaporative heat loss was determined by calorimetry. The pinna (13.10±1.17 W m-2) and hindlimbs (11.19±1.17 W m-2) of the agoutis were the main regions involved in heat loss by radiation, working as thermal windows. The radiation was higher in the periocular regions (45.23±0.81 W m-2), followed by the eyes surface (41.41±0.81 W m-2), pinna (31.56±0.80 W m-2) and vibrissae (27.03±0.80 W m-2). The periocular temperatures proved to be a valuable predictor of rectal temperature of the cavies, showing a correlation coefficient of 0.61. The convection in agoutis was more intense in the body and hindlimbs at all day times. In cavies, the convection was insignificant (0.54±0.56 W m-2). Evaporative heat loss in agoutis (52.53±1.64 W m-2) and cavies (143.69±1.37 W m-2) was more intense when the atmospheric temperature was higher. Thus, we observe that both non-evaporative and evaporative mechanisms are important for the maintenance of homeothermy in red-rumped agouti and Spixs yellow-toothed cavy in a hot environment. These rodents use specialized body regions in the heat transfer, the thermal windows.

TRANSFERÊNCIA DE CALOR LATENTE E COMPORTAMENTO TERMORREGULATÓRIO DE VACAS LEITEIRAS EM AMBIENTE TROPICAL

Objetivou-se estimar a transferência de calor latente e verificar o tempo de exposição ao sol e a preferência na orientação do corpo em relação à direção do sol de vacas leiteiras Holandês x Gir, criadas em regime de confinamento a céu aberto, no semiárido brasileiro. Os dados foram coletados em dois grupos de vacas, cada um composto de 13 animais, sendo o primeiro de vacas com nível de produção entre 18 e 26 kg de leite/dia-1 (média de 20 kg/dia-1) e o outro de vacas que produziam entre 10 e 16 kg de leite/dia-1 (média de 14 kg/dia-1). Deste total, 8 vacas apresentavam pelame de coloração predominantemente branco e 18 preto. Para caracterização do ambiente, foram registradas, diariamente, as variáveis ambientais temperatura do ar, umidade relativa do ar, temperatura de globo negro e velocidade do vento, os quais foram utilizados para calcular o Índice de Temparatura de Globo Negro e Umidade (ITGU) e a Temperatura Média Radiante (TRM). Nos animais, foram mensuradas as variáveis frequência respiratória e temperatura do pelame. Além de observar os comportamentos de localização (sombra e sol) e orientação do animal em relação à trajetória do sol. De acordo com os resultados obtidos, conclui-se que os modelos de predição baseados na frequência respiratória e temperatura do pelame podem ser utilizados para estimar a perda de calor latente em vacas leiteiras Holandês x Gir, mantidas em condições de céu aberto. A dissipação de calor por meio do trato respiratório e superfície cutânea correspondem, em média, a 12,1% (26,31 W.m-2) e 87,9% (190,70 W.m-2), respectivamente, de vacas leiteiras criadas nas coordenadas 07° 22 45,1S, 36° 31 47,2W, sob temperatura do ar média de 27,3°C. Vacas leiteiras Holandês x Gir permanecem mais tempo na sombra que exposta ao sol. Vacas pretas permacem mais tempo em pleno sol em comparação as brancas e preferem se posicionar com o eixo do corpo formando um ângulo azimutal de 0°, quando a temperatura do ar ultrapassa os 25°C.

Objective was to estimate the latent heat transfer and check the time of sun exposure and a preference in orientation of the body relative to the direction of the sun Holstein x Gir dairy cows in confinement regime to heaven open in the brazilian semiarid region. Data were collected in two groups of cows, each consisting of 13 animals each, the first output level cows between 18 and 26 kg milk day-1 (average of 20 kg/day-1) and the other cows that produce between 10 and 16 kg milk/day-1 (average of 14 kg/day-1). Of this total, eight cows had predominantly white coloring hair coat and 18 black. To characterize the environment, were recorded daily environmental variables air temperature, relative humidity, black globe temperature and wind speed, which were used to calculate the Temparatura Index of Black Globe and Humidity (BGT) and the Average Radiant Temperature (MRT). In animals, the variables respiratory rate and temperature of the hair coat were measured. In addition to observing the behaviors of location (shade and sun) and orientation of the animal in relation to the sun's path. According to the results, it is concluded that the prediction models based on respiratory rate and temperature fur can be used to estimate the loss of latent heat in dairy cows Holstein x Gir, kept in open conditions. The heat dissipation through the respiratory tract and skin surface corresponds, on average, to 12.1% (26.31 Wm-2) and 87.9% (190.70 Wm-2), respectively, created dairy cows at coordinates 07° 22 '45.1 "S, 36° 31' 47.2" W, in average air temperature of 27.3°C. Dairy cows Holstein x Gir stay longer in shadow exposed to sunlight. Black cows longer permacem in full sunlight compared white and prefer to position with the body axis forming an azimuthal angle of 0° when the air temperature exceeds 25°C.

Tipos de lâmpadas e cor da luz para codornas japonesas nas fases de crescimento e seus efeitos na fase de produção

A coturnicultura é uma atividade avícola que vem se destacando no Brasil. As codornas durante a fase de crescimento possuem necessidades especiais, principalmente em nutrição e manejo. Algumas ações de manejo podem ser utilizadas visando à maximização do potencial produtivo, a exemplo da luz que está diretamente envolvida no desenvolvimento reprodutivo desta espécie. De baixo custo, com bons resultados e de fácil uso, as lâmpadas se tornaram grande sucesso e ainda é o método popular de iluminação. Lâmpadas incandescentes liberam a maior parte de sua energia sob a forma de fótons de luz infravermelho carregados de calor, apenas 10% da luz produzida alcançam o espectro visível e isso desperdiça muita eletricidade. Fontes de luz fria como lâmpadas fluorescentes e LEDs (Light Emitting Diode) não desperdiçam tanta energia gerando calor, emitindo assim muito mais luz visível. Objetivou-se no presente estudo avaliar o impacto da aplicação de diferentes tipos de luz nas fases de cria e recria sobre o desempenho produtivo, biometria de vísceras e qualidade de ovos em codornas japonesas. O experimento foi conduzido no Departamento de Zootecnia da Universidade Federal de Lavras. Foram utilizadas 1554 codornas japonesas fêmeas com um dia de idade e os tratamentos experimentais foram constituídos por seis diferentes comprimentos de ondas emitidos por três tipos de lâmpadas, a citar: Incandescente amarela, Fluorescente compacta branca e LEDs (azul, verde, vermelha e branca). As aves foram submetidas aos tratamentos durante a fase de crescimento (1 a 35 dias de idade), sendo avaliado nessa fase o desempenho zootécnico, o crescimento de vísceras e a viabilidade do lote. Aos 35 dias de idade as aves foram transferidas para o galpão de postura onde foi registrado o desempenho zootécnico, evolução da produção de ovos, qualidade interna e externa dos ovos e viabilidade das aves. Nas fases de crescimento utilizou-se sete repetições, sendo a parcela experimental constituída por 37 aves. No momento da transferência de instalações foram selecionadas 20 aves em cada unidade experimental, com o peso vivo próximo à média da parcela, sendo alojadas 10 aves por gaiola na fase de produção, totalizando 14 repetições com seis tratamentos para verificação do efeito residual. As médias foram submetidas à análise de variância utilizando o pacote computacional SAS, e quando significativa, os diferentes comprimento de onda, foram comparados entre si pelo teste SNK (P<0,05). Conclui-se que comprimentos de ondas específicos, usados nas fases de cria e recria, influenciam o desempenho produtivo de codorna japonesa, sendo o comprimento de onda branco o que se mostrou mais eficiente.

The quail production is a poultry activity that has been increasing in Brazil. During quails growth stage, this phase have special needs, especially regarding nutrition and handling. Some handling actions can be used in order to maximize the productive potential, as example, the light is directly involved in the reproductive development of this species. Bulbs have become very successful and are still popular lighting method, because it is low cost, easy to use and bring good results. Incandescent bulbs release most of their energy in the form of infrared light photons loaded with heat, and only 10% of light output reaches the visible spectrum and this waste a lot of electricity. Cold light sources such as fluorescent lamps and LEDs (Light Emitting Diode) do not spend so much energy generating heat, consequently emitting more visible light. In this study aimed to evaluate the impact of the application of different light types in development phase on productive performance, biometric viscera and egg quality in Japanese quail. The experiment was conducted at the Animal Science Department of Federal University of Lavras. It was used 1554 Japanese female quails with one day of age. The experimental treatments consisted of six different wavelengths emitted for three bulbs types, such as: Yellow Incandescent, White compact Fluorescent and LEDs (blue, green, red and white). The quails were submitted the treatments during the growth phase (1 to 35 days of age), this stage being evaluated zootechnical performance, viscera growth and batch viability. At 35 days of age the quails were transferred to the laying house where it was registered the zootechnical performance, evolution of egg production, internal and external egg quality, and quails viability. In the growth phase seven replicates were used and the experimental group had 37 quails. At the time of installations transfer, 20 quails were selected in each experimental unit with live weight close to the parcel average; 10 quails were housing per cage in the production phase, totaling 14 repetitions with six treatments to verify the residual effect. The averages were submitted to variance analysis using the SAS computer package, and when significant, the different wavelength were compared with each other by SNK test (P<0.05). It was concluded that specific wavelengths used in the development phases influence the productive performance of Japanese quail. The white wavelength was considered the most efficient.