Fitting multiphasic logistic functions to the lactation curves of Gir x Friesian crossbred dairy cattle in Malaysia

The data used in this study consisted of milk yield (kg) taken at approximately fortnightly intervals from Gir x Friesian crossbred dairy cattle raised at Institut Haiwan Kluang, Malaysia. The data were first edited, smoothed and then fitted with mono-, di- and triphasic logistic functions. In gener...

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Main Authors:	Majid, A.M., Shariff, A.A., Merican, A.F., Y.B., Bong
Format:	Article
Language:	English
Published:	Universiti Kebangsaan Malaysia 2014
Online Access:	http://journalarticle.ukm.my/7253/ http://journalarticle.ukm.my/7253/ http://journalarticle.ukm.my/7253/1/04_A.M._Majid.pdf

id	ukm-7253
recordtype	eprints
spelling	ukm-72532016-12-14T06:43:32Z http://journalarticle.ukm.my/7253/ Fitting multiphasic logistic functions to the lactation curves of Gir x Friesian crossbred dairy cattle in Malaysia Majid, A.M. Shariff, A.A. Merican, A.F. Y.B., Bong The data used in this study consisted of milk yield (kg) taken at approximately fortnightly intervals from Gir x Friesian crossbred dairy cattle raised at Institut Haiwan Kluang, Malaysia. The data were first edited, smoothed and then fitted with mono-, di- and triphasic logistic functions. In general, parameter estimates for the first lactation were reasonable. However, for the second lactation the estimates were erratic and unreasonable because this was the atypical lactation for which the multiphasic functions were obviously unsuitable. Residual mean squares for the di- and triphasic functions of the first lactation were very similar (0.0002 and 0.0004, respectively) and smaller for the monophasic function (0.0894). For the second lactation, residual mean squares for the triphasic function (0.001) was the lowest compared to those for the mono- and diphasic functions (0.0345 and 0.0315). For the first lactation, the monophasic function did not fit the data well because it had large residuals. The di- and triphasic functions were almost similar in fitting the lactation and had low residuals. For the second lactation, both the mono- and diphasic functions did not fit the data very well and had rather large residuals. The triphasic function was the most fitting and had small residuals. Derived functions were generally lower for the first lactation than the second lactation: initial milk yields (4.88 to 6.0 kg versus 9.9 to 11.8 kg); peak milk yields (5.8 to 9.6 kg versus 12.8 to 15.7 kg) and 305-day milk yields (1147.7 to 1328.6 kg versus 1687.4 to 2296.1 kg). Universiti Kebangsaan Malaysia 2014-07 Article PeerReviewed application/pdf en http://journalarticle.ukm.my/7253/1/04_A.M._Majid.pdf Majid, A.M. and Shariff, A.A. and Merican, A.F. and Y.B., Bong (2014) Fitting multiphasic logistic functions to the lactation curves of Gir x Friesian crossbred dairy cattle in Malaysia. Sains Malaysiana, 43 (7). pp. 987-993. ISSN 0126-6039 http://www.ukm.my/jsm/
repository_type	Digital Repository
institution_category	Local University
institution	Universiti Kebangasaan Malaysia
building	UKM Institutional Repository
collection	Online Access
language	English
description	The data used in this study consisted of milk yield (kg) taken at approximately fortnightly intervals from Gir x Friesian crossbred dairy cattle raised at Institut Haiwan Kluang, Malaysia. The data were first edited, smoothed and then fitted with mono-, di- and triphasic logistic functions. In general, parameter estimates for the first lactation were reasonable. However, for the second lactation the estimates were erratic and unreasonable because this was the atypical lactation for which the multiphasic functions were obviously unsuitable. Residual mean squares for the di- and triphasic functions of the first lactation were very similar (0.0002 and 0.0004, respectively) and smaller for the monophasic function (0.0894). For the second lactation, residual mean squares for the triphasic function (0.001) was the lowest compared to those for the mono- and diphasic functions (0.0345 and 0.0315). For the first lactation, the monophasic function did not fit the data well because it had large residuals. The di- and triphasic functions were almost similar in fitting the lactation and had low residuals. For the second lactation, both the mono- and diphasic functions did not fit the data very well and had rather large residuals. The triphasic function was the most fitting and had small residuals. Derived functions were generally lower for the first lactation than the second lactation: initial milk yields (4.88 to 6.0 kg versus 9.9 to 11.8 kg); peak milk yields (5.8 to 9.6 kg versus 12.8 to 15.7 kg) and 305-day milk yields (1147.7 to 1328.6 kg versus 1687.4 to 2296.1 kg).
format	Article
author	Majid, A.M. Shariff, A.A. Merican, A.F. Y.B., Bong
spellingShingle	Majid, A.M. Shariff, A.A. Merican, A.F. Y.B., Bong Fitting multiphasic logistic functions to the lactation curves of Gir x Friesian crossbred dairy cattle in Malaysia
author_facet	Majid, A.M. Shariff, A.A. Merican, A.F. Y.B., Bong
author_sort	Majid, A.M.
title	Fitting multiphasic logistic functions to the lactation curves of Gir x Friesian crossbred dairy cattle in Malaysia
title_short	Fitting multiphasic logistic functions to the lactation curves of Gir x Friesian crossbred dairy cattle in Malaysia
title_full	Fitting multiphasic logistic functions to the lactation curves of Gir x Friesian crossbred dairy cattle in Malaysia
title_fullStr	Fitting multiphasic logistic functions to the lactation curves of Gir x Friesian crossbred dairy cattle in Malaysia
title_full_unstemmed	Fitting multiphasic logistic functions to the lactation curves of Gir x Friesian crossbred dairy cattle in Malaysia
title_sort	fitting multiphasic logistic functions to the lactation curves of gir x friesian crossbred dairy cattle in malaysia
publisher	Universiti Kebangsaan Malaysia
publishDate	2014
url	http://journalarticle.ukm.my/7253/ http://journalarticle.ukm.my/7253/ http://journalarticle.ukm.my/7253/1/04_A.M._Majid.pdf
first_indexed	2023-09-18T19:49:10Z
last_indexed	2023-09-18T19:49:10Z
_version_	1777406103178444800

Fitting multiphasic logistic functions to the lactation curves of Gir x Friesian crossbred dairy cattle in Malaysia

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