topic Re: Generation of parameters to fit the lactation curve in SAS Programming

Generation of parameters to fit the lactation curve

JesusBGRO — Wed, 16 Sep 2020 02:52:37 GMT

Hello guys, How do I generate the parameters k and a in SAS for the fit of the lactation curve in beef cows, using the equation proposed by Jenkins and Ferrell (1984) Yn = n / aekn.
Thank you.
A sample of the data to be analyzed are:

# cow Milk, kg days
1 7.44 40
1 7.92 68
1 9.00 96
1 6.60 124
1 3.60 152
1 2.40 180
2 3.12 105
2 3.84 155
2 3.00 183
2 2.40 248
3 2.52 61
3 2.64 96
3 1.44 124
3 1.20 159
3 0.72 194
4 1.68 44
4 2.76 72
4 3.60 100
4 0.48 128
4 1.44 156
4 0.96 184
5 5.76 86
5 2.88 121
5 2.40 149
5 3.00 184
5 2.40 219
6 3.48 56
6 2.16 88
6 2.16 112
6 1.68 140
6 0.72 164
6 2.64 196

Re: Generation of parameters to fit the lactation curve

jimbarbour — Wed, 16 Sep 2020 14:28:18 GMT

I'm not familiar with this formula, so I cannot directly help you. However, this is the Programming community which might not be the best fit for your question. Perhaps a post in one of the Analytics communities (see graphic, below) would be of greater assistance?

Jim

Re: Generation of parameters to fit the lactation curve

ballardw — Wed, 16 Sep 2020 15:20:58 GMT

@JesusBGRO wrote:

Hello guys, How do I generate the parameters k and a in SAS for the fit of the lactation curve in beef cows, using the equation proposed by Jenkins and Ferrell (1984) Yn = n / aekn.
Thank you.
A sample of the data to be analyzed are:

# cow Milk, kg days
1 7.44 40
1 7.92 68
1 9.00 96

What is an "aekn"? You are asking for a topic, lactation, that is not likely common to most of the users and need to provide details. Since you do not provide a variable "aekn" then that needs considerable explanation or at a minimum a link to where the formula is discussed and hopefully using the same variables.