Influence of temperature and humidity on rumen pH and fatty acids in dairy cows.

The aim of this study was to investigate the variations of rumen pH and fatty acids (acetic acid, propionic acid, iso-butyric acid, n-butyric acid, iso-valerianic acid, n-valerianic, caproic acid and total fatty acids) in 245 early lactating dairy cows under different temperature and humidity conditions. The animals were divided into six groups and rumen fluid was collected by rumenocentesis on 22 dairy cows in April (Group A), 33 in May (Group B), 43 in June (Group C), 48 in July (Group D), 36 in September (Group E) and 60 in October (Group F). One-way analysis of variance (ANOVA), followed by the Bonferroni’s test, showed a significant effect of environmental variations on all studied parameters (P<0.0001). Changes in studied parameters can be explained in relation to the microbial population and shift in the optima for rumen conditions associated with variations of environmental conditions. We can affirm that the microbial assemblages that underlie energy and protein supply to wild ruminant are evident especially in relation to temperature and humidity conditions.

Serum acute phase proteins in cows with SARA (Subacute Ruminal Acidosis) suspect / Proteínas séricas de fase aguda em vacas com suspeita de SARA (Subacute Ruminal Acidosis)

The aim of this study was to evaluate the variations of Acute Phase Proteins (APPs) and other blood constituents during the onset of the sub-acute ruminal acidosis (SARA) pathological status. A total of 108 cows from 12 dairy herds were randomly selected and divided into three Groups of 36 animals each. All animals were subjected to a rumenocentesis. Group A was composed by subjects with a rumen pH>5.8, Group B was composed by subjects with a rumen pH ≤5.5≤5.8 and Group C was composed by subjects with a rumen pH<5.5. Blood samples were collected by jugular venipuncture and Haptoglobin (Hp), Serum Amyloid A (SAA), Total Proteins, Albumin and White Blood Cells (WBC) were determined. One-way ANOVA showed a statistical significance on Rumen pH, Hp, SAA. SARA seems not stimulate the APPs production from liver.

O objetivo deste estudo foi avaliar as variações de Proteínas de Fase Aguda (APPs) e outros constituintes sanguíneos durante o início do status patológico de sub-acute ruminal acidosis (SARA). O total de 108 vacas de 12 rebanhos leiteiros foram aleatoriamente selecionados e divididos em três grupos com 36 animais cada. Todos os animais foram submetidos a ruminocentesis. O Grupo A foi composto por sujeitos com rumen pH>5.8, o Grupo B foi composto por sujeitos com rumen pH ≤5.5≤5.8 e o Grupo C foi composto por sujeitos com rumen pH<5.5. Amostras sanguíneas foram coletas por punção venosa jugular e Haptoglobin (Hp), Serum Amyloid A (SAA), Proteínas totais, Albumin e células brancas do sangue (WBC) foram determinadas. ANOVA em via única mostrou significância estatística em Rumen pH, Hp, SAA. SARA não parece estimular a produção de APPs pelo fígado.

Effects of housing systems on physiological and energetic parameters in comisana ewes.

The pattern of some physiological parameters (rectal temperature, respiratory rate and heart rate) and some energetic parameters (glucose, triglycerides, total cholesterol and total lipid) has been investigated with the purpose to assess the influence of shearing on thermoregulation. Thirty-six Comisana ewes were divided into two groups of 18 subjects and were allowed to two different housing systems: animals of group A were housed in an open-front barn with a paddock and animals of group B to a paddock equipped with shading net. After a period of adaptation to the experimental conditions, individual rectal temperature, respiratory and heart rates were measured. The serum concentrations of glucose, triglycerides, total cholesterol and total lipid were also assessed. All parameters were recorded, with an average interval of eleven days during 90 days, from July 15th to October 11. The statistical analysis, the ANOVA followed by the Bonferroni’s test, showed a significant effect of the time for respiratory rate, heart rate and glucose and it showed that during experimental period the type of housing system influenced glucose, triglycerides, total cholesterol and total lipid. These results confirm that different micro-environmental conditions can influence thermoregulatory mechanisms with effects on the productivity and on the welfare of ewes.

Monitoring of physiological and blood parameters during perinatal and neonatal period in calves / Monitoramento de parâmetros fisiológicos e sanguíneos de bezerros durante os períodos perinatal e neonatal

Rectal temperature, heart and respiratory rates, and the course of some blood parameters were monitored in calves during perinatal and neonatal periods. The study was carried out on eight Limousine calves. From all subjects, rectal temperature, heart rate, and respiratory rate were measured. Blood samples were taken at the same hour (9am) from the external jugular vein, and then centrifuged and stored until analyses. By means of an UV spectrophotometer, the following blood parameters were assessed for each subject: total protein, total cholesterol, triglycerides, glucose, non-esterified fatty acids (NEFA), urea, creatinine, cholinesterase, lactate dehydrogenase (LDH), hydroxybutirate, glutamate pyruvate transaminases (GPT), glutamate oxalacetate transaminases (GOT), direct and total bilirubin, magnesium, iron, potassium, phosphorus, chloride and sodium. The results showed a significant effect of days of life (P<0.05) only on total cholesterol, creatinine and GOT during the first week of life and a significant effect of days of life on rectal temperature, heart rate, respiratory rate, total cholesterol, NEFA, creatinina, and GOT during the first month of life. A correlation among individual values for postnatal age (days of life) and heart rate in calves during the first month of life was observed. In conclusion, modifications of studied parameters could be attributed to functional development of calves in neonatal period and contribute to the knowledge of adaptation processes in calf during the first week and the first month of life resulting useful for the diagnosis and treatment of any neonatal diseases.

Realizou-se o monitoramento da temperatura retal das frequências cardíaca e respiratória e de alguns parâmetros sanguíneos em oito bezerros da raça Limousine, durante o período perinatal e neonatal. Paralelamente às mensurações da temperatura retal e das frequências cardíaca e respiratória (9h), foram pesquisados, por meio de espectrofotômetro de UV, proteína total, colesterol total, triglicérides, glicose, ácidos graxos não esterificados (NEFA), ureia, creatinina, colinesterose, lactato desidrogenase (LDH), hidroxibutirato, glutamato piruvato transaminases (GOT), direta e total bilirrubina, magnésio, fósforo, cloretos e sódio. Os resultados mostraram efeito significativo dos dias de vida (P<0,05) somente sobre o colesterol total, creatinina e GOT, durante a primeira semana e um significante efeito de dias de vida sobre a temperatura retal, as frequências cardíaca e respiratória, colesterol total, NEFA, creatina e GOT durante o primeiro mês de vida. Observou-se correlação entre os valores individuais para dias de vida e frequência cardíaca durante o primeiro mês de vida. Conclui-se que as modificações desses parâmetros podem ser atribuídas ao desenvolvimento dos bezerros no período neonatal, contribuindo para o conhecimento do processo de adaptação, em bezerros, durante a primeira semana e o primeiro mês de vida.

Effect of shearing and environmental conditions on physiological mechanisms in ewes.

The aim of this study was to establish the influence of shearing in dairy sheep during summer season. Several physiological and haematological parameters, which are closely related to thermoregulatory potential, have been investigated with the purpose to assess shearing influence on thermoregulation. Forty dairy sheep, clinically healthy and well-fed, were used. They were divided into two groups of 20 subjects each. Twenty sheep were let unshorn as a control group (Group A), and twenty sheep were shorn (Group B). On each subject of group A and Group B, rectal temperature, respiration and heart rates were recorded and blood samples were collected in order to asses the following parameters: red blood cells, white blood cells, platelets, haematocrit and haemoglobin. All measurements taken on day 0 (before shearing), were repeated after 1, 15, 30, 45 and 60 days after shearing. The statistical analysis, the ANOVA followed by the Bonferroni's test, showed statistical differences between two groups for rectal temperature (F(1.90) = 5.57, p < 0.0001), respiratory rate (F(1.90) = 18.40, p < 0. 0001) and white blood cells (F(1.190) = 7.61, p < 0.0001). These results suggest that the shearing induce adaptative responses in the organism.

Nitrogenous metabolism in Thoroughbred and Arabian foals from birth to five months of age / Metabolismo do nitrogênio em potros PSI e Arabe do nascimento aos cinco meses de idade

The maturation of nitrogen metabolism was studied in six Thoroughbred and six Arabian foals. Rectal temperature, heart and respiratory rates and serum concentration of several hematochemical parameters (total protein, urea, uric acid, creatinine, and albumine) were monitored from birth to 5 months of age. In both breeds, all the parameters except albumine showed significant differences over time (P<0.05). The two breeds did not differ from each other at any time point. Statistically significant decreases in urea and creatinine concentrations were related to the growth needs of foals during this critical period of development.

A maturação do metabolismo do nitrogênio foi estudada em seis potros da raça Puro-Sangue Inglês e seis da raça Arabe. A temperatura retal, batimento cardíaco e concentração sérica de várias características hematoquímicos (proteína total, uréia, ácido úrico, creatinina e albumina) foram investigadas do nascimento aos cinco meses de idade. Em ambas as raças, todas as características, exceto a albumina, mostraram diferenças significativas ao longo da maturação (P<0,05). As duas raças não diferiram uma da outra durante os períodos de vida equivalentes. Reduções significativas das concentrações de uréia e creatinina mostraram as necessidades de crescimento dos potros durante esse período crítico de desenvolvimento.

Electrocardiographic changes induced by physical exercise in the jumper horse

The authors conducted an electrocardiographic investigation on eight jumpers of Sella Italiana breed to evaluate cardiovascular changes associated with specific competitions. Electrocardiographic recordings were carried out using an electrocardiograph with a deflection of 10 mm/mV and a paper speed of 25 mm/sec. Recordings were conducted under the following experimental conditions: at rest, after warm up, after a jumping trial, and 15 and 30 minutes after the end of the trial. Significant reductions were observed in the duration of the P wave, of the P-Q interval, and of the R-R intervals immediately after the test. Significant elevations were observed immediately after the test in the range of the T and P waves of the heart rate. The observed changes can be attributed mainly to increase of the sympathetic tone connected with increase of heart rate necessary to satisfy the elevation of the cardiac range. These results are useful to plan and monitor specific training programmes.