Good day SAS friends: Well, first to thank you a lot because all you help is usefull in my current research, well here i go with the last step of my avaliation, lets begin: As you know, the growing models are very usefull in many biological ares, specially in animal nutrition, there fore, this example is the resume os a dataset of 5000 animals in average, the reason that im posting this is i will not beable to do this manually, and SAS can help very much. My example has 3 animals observed in the time, and weighted (repeated measures) several times to obtain the eficience and growing parameters of them. here is the data base: data have; input Animal age_in_days weight_in_Kilograms; cards; 1 11 10.00 1 21 10.20 1 31 10.21 1 41 10.22 1 45 10.45 1 50 10.60 2 43 11.00 2 45 11.30 2 49 11.35 2 60 11.30 2 65 12.20 2 70 12.50 2 76 12.65 2 80 13.00 2 95 14.00 2 105 16.00 3 10 11.00 3 20 11.00 3 33 11.00 3 43 11.20 4 44 11.65 4 45 12.00 4 46 13.00 4 50 13.00 4 60 13.50 ; Untill here everything is good, to evaluate the eficience in the growing rate of each animal i need to obtain a new variable called "Mean daily Weight Gain", this explains in average the the weight gained from the begining day to the next (final) day, for example: The animal number 1 began to be weighted at the 11th day of the experiment with an observed weight of ten (10) kilograms and the next measure (of the same animal) at the 21th day is about 10.20 kilograms, this means clearly that in 10 days this animal gained 200 grams, and in average 0.02 Kg each day, to find this we can asume the next formula: (Final weight - Initial weight)/(Final day - Initial day) = (10.2 - 10.0)/(21 - 11)=0.02 Kilograms As you can see, this measure offers the observed weight gained using 2 measures, but the big problem is that i need several measures to trust in this result. The way to make it posible is to obtain the weight gained for each measure, well i constructed a table in excel to visualiza better this methodology:
Animal
Age_in_days
Weight_In_Kilograms
1
11
10.000
1
21
10.200
0.020
1
31
10.210
0.011
0.001
1
41
10.220
0.007
0.001
0.001
1
45
10.450
0.013
0.010
0.017
0.057
1
50
10.600
0.015
0.014
0.021
0.042
0.030
This tables shows what i explained before, i took the age of 11 days and 21 days and their respective weights, and could be obtained de gain (IN RED). So the numbers in "bold" represent the weight gained using the next age as the initial measure, in ORANGE we can see the last measure or weight gain, taking the 45 as the inicial day and 50 as the final measure with 10.45 and 10.60 kilograms respectively, in here was obtained 0.03 Kg.
Until now, we want to obtain the weight gained using 2 measures (the initial and the final), but once obtained all the means, i could perormance and general average like this:
0.020
0.011
0.001
0.007
0.001
0.001
0.013
0.010
0.017
0.057
0.015
0.014
0.021
0.042
0.030
Total Average
0.017
Here the value os 0.017 means the total average of the complete set of means obtained en the past step. with this we can conclude that the animal 1 in 39 days, begining in the day 11 and finishing in the day 50 of the experiment, accomplished an average weght gain daily of 0.017. This we can traduce into an new table:
Animal
Animal
Avegare_Gain_by-day
1
0.017
This mus to be done for all the animals in the data set (data have) i proposed in the beginig of the post.
So i hope you to help me, i will thank you for ever.
Big regards and thank you very much
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