Fatores intervenientes no comportamento de vacas e bezerros do parto até a primeira mamada

O objetivo deste estudo foi determinar os fatores ambientais que modulam o comportamento materno-filial nas primeiras horas após o parto, período essencial para desenvolver os laços da mãe com o bezerro. Os dados foram obtidos durante sete anos de pesquisa com o rebanho da Estação Experimental de Zootecnia de Sertãozinho, SP, com quatro raças de bovinos de corte: Nelore, Guzerá, Gir e Caracu. No primeiro artigo destaca-se uma análise dos principais fatores ambientais e seus efeitos no comportamento de vaca e bezerro e a relação do comportamento do bezerro com sua sobrevivência até os 120 dias de idade. O segundo artigo mostra as diferenças nos comportamentos exibidos pelas vacas e pelos bezerros da raça Nelore em função da experiência materna e o terceiro trata da descrição de um potencial predador, o urubu (Coragyps atratus) e sua influência no comportamento materno-filial nas primeiras horas após o parto. Nessas três abordagens os principais fatores considerados foram: ano do parto, raça, número de partos da fêmea, local do parto, hora do parto, tempo que a mãe passa em contato com a cria, agilidade do bezerro e presença do predador. Os resultados sugeriram ser necessário acompanhamento mais detalhado dos partos, monitorando as causas que prejudicaram a relação vaca e bezerro e mostraram que a latência para ficar em pé pode ser utilizada como indicador de vigor do bezerro recém nascido.The objective of this study was to determine the environmental factors that modulate maternal-offspring behaviour during the first hours after parturition, period, in which, the bond between mother and calf is developed. The data were recorded during seven years at Estação Experimental de Zootecnia de Sertãozinho, located in São Paulo State, Brazil. Four breeds of beef cattle (Nelore, Guzerá, Gir and Caracu) were studied. In the first article the main environmental factors and their effects upon cow and calf behaviour is analyzed as well as he relationship between calf behaviour and its survival up to 120 days of age. The second article shows behavioural differences of Nelore cows and calves induced by the mother's experience and, finally, the third article is related to the presence the black vulture (Coragyps atratus), a potential predator, at calving site, as well as its influence upon maternal-offspring first hours after the birth. The main factors considered in these three studies were: year of birth, breed, cow's parturition number, birth site, birth time, grooming time devoted of mother to its calf, calf agility and predator presence. These results suggest the need of more detailed birth keep up, monitoring cow and calf relationship's harmful causes. Furthermore suggests that latency so stand up could be used as an indicator of calf vigour.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Influence of environmental health in the cow-calf dyad system

Health factors influence the cow-calf dyad system in the postpartum period until the first suckling. The use of maternity paddock is a recommended management to facilitate the monitoring of parturient cows and calves. However, side effects occur due to environmental health conditions of maternity paddock that can affect the behaviour of the cow and result in the separation of calf from the mother, undermining sucking and the formation of the cow-calf dyad. To improve the understanding of this complex and dynamic system we built a conceptual model using the technique of causal loop diagram, Figure 1. By hypothesis, the environmental variables that act in maternity paddock influence the variable "Sources of pathogens in maternity". Those sources present a positive effect (in the same direction) in the infection process of the calf and cow. Thus, a recommended practice is exposing the parturient cow to pathogens in maternity for sufficient period to stimulate their immune system and build disease resistance. That process contributes to improve the quality of colostrum that will be consumed by the calf during the first hours postpartum which has the function of increasing calf immunity, minimizing the occurrence of infections. In the model, sanitary environmental factors work in two Balance feedback loops (B1 and B2). The B1 cycle refers to the production of a healthy cow with a low level of infection by means of the variables: “Vaccine”, "Stimulation of cow immune system" and "Health resistance" with delay. The variable "Cow infection" has a negative influence (in the opposite direction) in the "Maternal behaviour", thus the more infected the cow, the less investment will occur in maternal behaviour. The B2 cycle refers to the calf’s health condition, which is positively influenced by “Calf infection” which, in turn, has positive influence, contributing to the increase of "Calf diseases". The increase in “Calf diseases” generates an increase in "Health care". The more health care, the lower the degree of the “Calf diseases”. However, the “Health care” requires “Separation Calf-Cow" that interferes with the stimulus needed to form the dyad, immediately after birth (imprinting). Therefore, two balance cycles act in stabilizing the health of the cow and calf to avoid undesirable influences on cow-calf dyadic behaviour. We conclude that the variable "Stimulation of cow immune system" is a leverage point in the maternity paddock system

Influência do ambiente sanitário na formação da díade no sistema vaca-bezerro

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Influência do ambiente sanitário na formação da díade no sistema vaca-bezerro

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Crescimento do pelo em bovinos tosquiados

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Growing hairs in shorn cattle

The shearing operation can provide double benefits to the cattle: they can become more heat tolerant and the tick infestation decreases. The cattle tick Rhipicephalus (Boophilus) microplus causes great losses to dairy cattle, especially to the Holstein cattle because they are very susceptible to this tick. Its control is becoming each day more difficult, owing to the increasing resistance to acaricides they are acquiring. The objective of this work was to study the growing of haircoat following shearing. We made our experiment with 17 animals, 7 females and 10 males. They were shaved on the anterior third (head, neck, dewlap, scapula and arm) of one side, at random. The work was performed in two steps: they were shorn for the first time on August 2nd 2012, with a size 10 blade in a clipper Oster model GoldenA5, which left the fur coat 2 mm long. Then we evaluated the hair length growing by collecting fortnightly three sample of hairs in the middle of the scapula, with  electric pliers, modified for this purpose, in both sides of the animals, sheared and non-sheared, until 30 days after this shearing. The three hair samples were put inside a little plastic bag per animal. Meanwhile, as we thought that the animals shearing had to be done closer to the skin, we decided to shear them again (in the same side shorn before), on October 2nd 2012. We changed our procedure using the same machine, but now with a blade size 30, which left the fur coat 1mm thick. After that, we collected again, fortnightly, samples of hairs on both sides during 2 months. The 10 longest hairs in the plastig bag were measured using a graph paper and the average per animal was calculated in each data and blade. A random design was applied for statistical analysis, the hair length of both sides, sheared and non sheared were compared by a two related samples tests – Wilcoxon, in a non parametric test, using the SPSSP 12.0 program, in each data within each blade. Using blade size 10, hair decreased from average 21.26 ± 5.72 mm to 4.50 ± 0.83 mm. On the sheared side a hair growth of 26 mm was observed during the first two weeks, increasing to 40 mm for the next two weeks and at the end of 28 days there was still a significant difference (Z= -3.195; P= 0.001) for the non sheared hair (19.42 ± 7.33 mm) and sheared hair (11.15 ± 3.23 mm). Such procedure was done by the beginning of August, still winter time. Using the blade size 30, sheared hair had an average of 4.76 ± 1.1 mm. A 24 mm hair growth was observed for the first two weeks and 20 mm for the next two weeks, decreasing its growth speed to 9 mm and after 57 days no significant difference was observed between sheared side (11.47 ± 5.61 mm) and non sheared side (14.78 ± 8.06 mm, Z= -1.915; P= 0.055). Second cut was performed by  the beginning of October, spring time, period where there is a change of hair in European cattle  from winter season (thin and long hair) to summer season (thick and short hair), starting on spring time. In this work we could observe the fast growing of hair when cut was done in winter time and the closer to the skin the better the benefits to the animals, as heat tolerance and fewer tick infestations. If shearing is done in spring time, it must be every 45-50 days

Infestação artificial com carrapato rhipicephalus (bophilus) microplus e consumo de alimentos e condição corporal em bovinos resistentes e susceptíveis

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