Navegando por Autor "BRCKO, Carolina Carvalho"

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Acesso aberto (Open Access)
Estimativas de parâmetros genéticos para a produção de leite e idade ao primeiro parto em vacas da raça pardo-suiça utilizando amostrador de Gibbs
(Universidade Federal do Pará, 2008-07-03) BRCKO, Carolina Carvalho; ARAÚJO, Cláudio Vieira de; http://lattes.cnpq.br/5049897507837031
Data from 2.981 lactations of Brown Swiss cows, from 62 herds, calving from 1980 to 2002, were used to check the influence of genetic and not genetic factors, on milk yield and age at first calving. An animal model used included the fixed effect of herds, age-season of calving and grade of cows, random effect of animal and temporary environment. For milk yield, in addition to the fixed effects described above, is also included the linear effect of lactation length and linear and quadratic effects of the age at first calving, as co-variables. Bayesian inference was used to estimate the components of (co) variance through of Gibbs sampling, the size of chain of 1,500,000 rounds and burn in 500,000 rounds. The frequency of sampling was 500 rounds. The estimated average for milk yield and age at first calving were 5347.471849.13 kg and 29,65  4,51 months respectively. The effects of herd, year of calving and lactation length, significantly influenced the production of milk (P <0.01). The age at first calving was influenced by the effects of herd, year of calving (P <0.01), beyond the end of season of calving (P <0.05). The heritability estimates obtained for the milk yield and age at first calving were e 0.23 and 0.18, respectively. The genetic correlation was -0.31. The genetic and phenotypic trend for milk yield was 1.09 kg and 115.34 kg of milk, respectively, for each year of production. For age at first calving, the values of genetic breeding have become negative from 1988, with reduction of approximately 0.05 months of each year and there was a reduction of 32 to 28 months of age at first calving. Daughters of sires with a high genetic value for milk tend to have faster growth or physiological maturity at a very early age, reducing the age at first calving.
Acesso aberto (Open Access)
Respostas termorregulatórias e comportamentais de fêmeas bubalinas criadas a pasto, em condições de ambiente do trópico úmido
(Universidade Federal do Pará, 2015-09-11) BRCKO, Carolina Carvalho; LOURENÇO JÚNIOR, José de Brito; http://lattes.cnpq.br/2919433679918544
Testing the thermoregulatory and behavior responses in buffalo in the eastern Amazon, three experiments were conducted at Embrapa Amazônia Oriental (01 ° .26'.03 "S and 48 ° .26'.03" W) in the period July 2013 to June 2014, with 24 buffaloes crossbred Murrah / Mediterranean. That were in paddocks with Brachiaria brizantha (cv. Marandu) in a rotational system with drinking water and mineral salt at will. Experiment 1 aimed to evaluate the effects of climate and the inclusion of four levels (0, 0.25, 0.5 and 1% of PV) of palm kernel cake in thermoregulation of buffaloes. Air temperature data were recorded (AT), relative humidity (RH), dew point temperature, wet bulb temperature, black globe temperature (BGT), rectal temperature (RT), temperature of the body surface (TBS), respiratory rate (RR). Daily, animals received food into individual troughs and the diet was adjusted by reweighing of animals every 28 days. It was concluded that there is no effect of palm kernel cake on thermoregulation of buffaloes. The second experiment aimed to study the exchange capacity and daily heat preservation buffaloes and lasted six days. Physiological (RT, RR and TBS by infrared thermography) and climate (TA, UR, TG) at 6:00 am, 9:00 am, 12:00, 15:00, 18:00 and 21:00. Although exposed to adverse weather conditions, the buffalo are able to return to homeostasis in the evening, indicating that the species has great adaptive capacity. Finally, the experiment 3 aimed to study the inclusion of palm kernel cake, at different levels (0, 0.25, 0.5, 1% of PV) is able to change the behavior of buffalo raised on pasture. The experiment was conducted in two seasons (wettest and less rain). Climate variables are as described in experiment 1. The behavioral analysis (grazing, ruminating, leisure and other activities) was carried out between 6:00 a.m. and 18:00 for three consecutive days in each collection campaign. 24 buffaloes were used, six for each treatment. The test diet does not influence the buffalo behavior. Despite suffering physiological and behavioral changes due to the effect of environmental variables, especially in the period with higher temperatures, buffaloes showed its ability to return to homeostasis as the temperature became milder, indicating great adaptive capacity.