Pig Growth Rates in Vietnam Article Example | Topics and Well Written Essays - 2000 words

Pig Growth Rates in Vietnam - Article Example The data of litter mortality, birth weight, farm of origin, year of birth, and weight of big after twenty one days concerning a sample of one thousand pigs were collected and recorded. The purpose of the study is to compare growth performance of these two breeds of pigs by analyzing the effect of the different factors monitored in isolation and combined on the growth of pigs represented by their average weight after twenty one days of their birth. To determine the relationship between the Day 21 average piglet weight and the various influences monitored during the experiment such as breed, farm of origin, year of birth, litter mortality and birth weight, the following Ordinary Least Squares (OLS) regression analyses were examined: The non-numerical value of Breed was coded numerically so that Breed equals one for Landrace (L) piglets and equals to zero for Yorkshire (Y). Regression analysis was applied with the numerical representation of breed as the independent variable and the dependent variable Day 21 average weight. Table 1 summarizes the results of the regression analysis. Table 1 shows adjusted R-squared of -0.00078 which means the independent variable breed predicts 0.07% of the dependent variable Day 21 average piglet weight. T-stat for this variable is 0.46674 so it is statistically insignificant. Both values indicate changes in breed do not affect the Day 21 average piglet weight. Regression analysis was applied... 0.000218 Adjust R2 -0.00078 Standard Error 0.793569 Observations 1000 Table 1 shows adjusted R-squared of -0.00078 which means the independent variable breed predicts 0.07% of the dependent variable Day 21 average piglet weight. T-stat for this variable is 0.46674 so it is statistically insignificant. Both values indicate changes in breed do not affect the Day 21 average piglet weight. 4.2 Analysis II: Relationship between Day 21 Average Piglet Weight and Farm of Origin The non-numerical value of the farm-of-origin variable is numerically encoded to allow statistical analysis of the variable using the following code shown in table 2. Table 2: Encoding of Farm of Origin into Number Farm of Origin Numerical Code A 1 B 2 C 3 D 4 E 5 F 6 G 7 Regression analysis was applied with the numerical representation of farm of origin as the independent variable and the dependent variable Day 21 average weight. Table 3 summarizes the results of the regression analysis. Table 3:Regression results for Day 21 Average Piglet Weight as a function of Farm of Origin Independent Variable Enumerated Farm of Origin Dependent variable: Day 21 Average Piglet Weight Constant 5.038045 Coefficient -0.04348 T Stat -2.87992 R2 0.008242 Adjust R2 0.007248 Standard Error 0.790379 Observations 1000 Table 3 shows adjusted R-squared of 0.007248 which means the independent variable farm of origin predicts 0.7% of the dependent variable Day 21 average piglet weight which is still a small influence but with more effect than the breed variable. T-stat for this variable is -2.87992 so it is statistically significant. Both values indicate the limited effect of breed in Day 21 average piglet weight. The Day 21 weight can be predicted to some limited extent using the equation: Day 21 Average Weight