- Kajang, Selangor, Malaysia
In chapter 2, the stochastic model developed to calculate the costs of rearing a young stock is described. The model includes uncertainty in young dairy calf diseases, and variation in reproduction and growth. Moreover, the model... more
In chapter 2, the stochastic model developed to calculate the costs of rearing a young stock is described. The model includes uncertainty in young dairy calf diseases, and variation in reproduction and growth. Moreover, the model calculates the different cost components separately (costs for feed, barn, labor, health, insemination, mortality, and revenues foregone).
In chapter 3, the costs of rearing young stock are calculated for 75 Dutch dairy farms. The farmers rst estimated the cost of young stock rearing and subsequently lled in an economic tool to calculate the costs. The amount of underestimation or overestimation for these speci c farms is determined. The model
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outcome on the calculated total cost of rearing in this chapter is used to validate the outcome of the stochastic model in chapter 2.
In chapter 4, the effect from lowering the FCA on the FLP is described using data from 8,454 heifers. The analysis is extended by investigating the association between the FCA and FLP and the following health and management factors: general management, healthcare, incidence of calf diseases, pre-weaned colostrum and milk feeding, housing, hygiene, and breeding.
Chapter 5 describes the average culling rate for slaughter/death of dairy cows in 1,903 Dutch farms during the period from 2007 to 2010, and the variation in culling rate. The analysis is extended by exploring the association between the average culling rate and the characteristics of the herd.
Chapter 6 investigates the decision to retain the optimal number of heifer calves at 2 weeks of age, using a stochastic model at herd level. The model uses information from chapters 2 and 5 (see Figure 1.1). The optimal number is de ned as the number of retained heifer calves for which the net cost of rearing is at its minimum. This chapter elaborates on changes in the optimal number of retained heifer calves for different scenarios and circumstances.
Finally, in chapter 7, critical points and concerns that have not been mentioned in the earlier chapters are discussed. Chapter 7 nishes with conclusions based on the work presented in this thesis.
In chapter 3, the costs of rearing young stock are calculated for 75 Dutch dairy farms. The farmers rst estimated the cost of young stock rearing and subsequently lled in an economic tool to calculate the costs. The amount of underestimation or overestimation for these speci c farms is determined. The model
12
outcome on the calculated total cost of rearing in this chapter is used to validate the outcome of the stochastic model in chapter 2.
In chapter 4, the effect from lowering the FCA on the FLP is described using data from 8,454 heifers. The analysis is extended by investigating the association between the FCA and FLP and the following health and management factors: general management, healthcare, incidence of calf diseases, pre-weaned colostrum and milk feeding, housing, hygiene, and breeding.
Chapter 5 describes the average culling rate for slaughter/death of dairy cows in 1,903 Dutch farms during the period from 2007 to 2010, and the variation in culling rate. The analysis is extended by exploring the association between the average culling rate and the characteristics of the herd.
Chapter 6 investigates the decision to retain the optimal number of heifer calves at 2 weeks of age, using a stochastic model at herd level. The model uses information from chapters 2 and 5 (see Figure 1.1). The optimal number is de ned as the number of retained heifer calves for which the net cost of rearing is at its minimum. This chapter elaborates on changes in the optimal number of retained heifer calves for different scenarios and circumstances.
Finally, in chapter 7, critical points and concerns that have not been mentioned in the earlier chapters are discussed. Chapter 7 nishes with conclusions based on the work presented in this thesis.
