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| Cunha,Daniel de Noronha Figueiredo Vieira da; Pereira,José Carlos; Campos,Oriel Fajardo de; Braga,José Luis; Silva,Fabyano Fonseca e; Martuscello,Janaina Azevedo. |
| The objective of this study was to develop and to evaluate a dynamic simulation model, with stochastic components in order to assess milk production systems. The simulation model was developed by using STELLA 9.0, ZooCalc 1.0 and electronic data sheets. The physical structure of the herd was divided into 15 interlinked modules that represented categories or subdivisions of categories. Mathematical models obtained from the literature were used to simulate the body weight of growing and lactating animals and milk production and milk composition. Electronic data sheets were used to calculate the nutritional requirements and dietary balance. After cost minimization, each feed was evaluated by using ZooCalc 1.0. Some average responses of farm size, zootechnical... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dairy cattle; Modeling. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010000400027 |
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| Cunha,Daniel de Noronha Figueiredo Vieira da; Pereira,José Carlos; Campos,Oriel Fajardo de; Gomes,Sebastião Teixeira; Braga,José Luis; Martuscello,Janaina Azevedo. |
| The objective of the study was to compare through simulation Holstein and Jersey breed herds, considering the farm size, zootechnical and economic indexes and profitability of the activity, by using different systems of bonus payment for milk price based in percentage of fat and protein in the milk. The comparisons were made, initially, disregarding the bonus payment for milk price based on the increase in the fat and protein percentage in milk. After that, the profitability of the activity was compared considering bonus payment for milk price of the Jersey breed herd, for each unit increment in fat and protein percentage in milk above those obtained with the Holstein breed herd. Finally, the profitability of the activity was compared by using the bonus... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dairy cattle; Milk fat; Milk protein modeling; Simulation. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010000400028 |
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| Cunha,Daniel de Noronha Figueiredo Vieira da; Pereira,José Carlos; Silva,Fabyano Fonseca e; Campos,Oriel Fajardo de; Braga,José Luis; Martuscello,Janaina Azevedo. |
| The objective of this study was to select models of lactation curves with a better adjustment to the observed data in models of milk production simulation systems. A data base on 6,459 recordings of daily milk production was used. These data were obtained from monthly and fortnightly controls of milk between 2004 and 2007, from 472 lactations of animals from ten different milking cow herd farms. Based on rolling averages of milk production (MP-L/day) per cow, the ten herd farms were divided into low (L < 15), medium (15 <M < 20) and high (H > 20). Data were also divided according to the lactation numbers in first, second, third or greater. Eight lactation curve models commonly used in literature were compared. The models were individually... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dairy cattle; Modeling; Non-linear model. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010000400026 |
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