The Effect of the Number of Test Days on Estimation Accuracy in Modeling the Lactation Curve of First-Lactation Holstein Cows

Abdullah Burak Baydur; Samet Hasan Abacı

Makale detayları

The Effect of the Number of Test Days on Estimation Accuracy in Modeling the Lactation Curve of First-Lactation Holstein Cows

Yazarlar:

Abdullah Burak Baydur | Samet Hasan Abacı

Yayıncı:

Kirsehir Ahi Evran University

Ana Başlıklar:

Zootekni | Genetik ve Biyoistatistik

Dergi:

Kırşehir Ahi Evran Üniversitesi Fen Bilimleri Enstitüsü Dergisi Vol.2 Issue 2, pp.81-89

Belge Tipi:

Makale

Yayın Tarihi:

12/2024

Belge Dili:

Türkçe

Document ID (Org No.):

2001337138

pISSN:

2979-9198

Anahtar kelimeler:

Özet:

 With lactation curve models used to accurately predict the milk production performance of animals, the amount of milk produced by animals during the lactation period can be observed graphically over time. By analyzing this process using mathematical models, it can be estimated how milk production will change in different situations. In particular, by using different test day numbers, the most appropriate number of test days can be determined, and researchers can be provided with preliminary information in terms of time and labour. Therefore, this study examined the effect of different test day numbers on the estimation accuracy in the Wood model, which researchers widely use. For this purpose, test day milk yield records TDMY of 150 Holstein cattle that completed the first lactation in a private farm in Kırşehir province and were recorded every 15 days up to 305 days were used. In the data analysis, TGSV records were used every 15 days up to 150 days, TGSV records every 30 days up to 150 days, TGSV records every 15 days up to 305 days, and TGSV records every 30 days up to 305 days. The SPSS statistical package program was used to estimate the models. In comparing the models, mean square error MSE and coefficient of determination R2 values were used. According to the results obtained for the models examined in the study, the MSE values were 12.284, 11.504, 13.790 and 13.959, respectively, and the coefficient of determination values were 0.595, 0.767, 0.545, 0.664. Accordingly, it was determined that TGSV records taken every 30 days up to 150 days, when the MSE value is the lowest, and the R2 value is the highest, can be used in modelling the lactation of Holstein cattle in the first lactation.

 With lactation curve models used to accurately predict the milk production performance of animals, the amount of milk produced by animals during the lactation period can be observed graphically over time. By analyzing this process using mathematical models, it can be estimated how milk production will change in different situations. In particular, by using different test day numbers, the most appropriate number of test days can be determined, and researchers can be provided with preliminary information in terms of time and labour. Therefore, this study examined the effect of different test day numbers on the estimation accuracy in the Wood model, which researchers widely use. For this purpose, test day milk yield records TDMY of 150 Holstein cattle that completed the first lactation in a private farm in Kırşehir province and were recorded every 15 days up to 305 days were used. In the data analysis, TGSV records were used every 15 days up to 150 days, TGSV records every 30 days up to 150 days, TGSV records every 15 days up to 305 days, and TGSV records every 30 days up to 305 days. The SPSS statistical package program was used to estimate the models. In comparing the models, mean square error MSE and coefficient of determination R2 values were used. According to the results obtained for the models examined in the study, the MSE values were 12.284, 11.504, 13.790 and 13.959, respectively, and the coefficient of determination values were 0.595, 0.767, 0.545, 0.664. Accordingly, it was determined that TGSV records taken every 30 days up to 150 days, when the MSE value is the lowest, and the R2 value is the highest, can be used in modelling the lactation of Holstein cattle in the first lactation.

 With lactation curve models used to accurately predict the milk production performance of animals, the amount of milk produced by animals during the lactation period can be observed graphically over time. By analyzing this process using mathematical models, it can be estimated how milk production will change in different situations. In particular, by using different test day numbers, the most appropriate number of test days can be determined, and researchers can be provided with preliminary information in terms of time and labour. Therefore, this study examined the effect of different test day numbers on the estimation accuracy in the Wood model, which researchers widely use. For this purpose, test day milk yield records TDMY of 150 Holstein cattle that completed the first lactation in a private farm in Kırşehir province and were recorded every 15 days up to 305 days were used. In the data analysis, TGSV records were used every 15 days up to 150 days, TGSV records every 30 days up to 150 days, TGSV records every 15 days up to 305 days, and TGSV records every 30 days up to 305 days. The SPSS statistical package program was used to estimate the models. In comparing the models, mean square error MSE and coefficient of determination R2 values were used. According to the results obtained for the models examined in the study, the MSE values were 12.284, 11.504, 13.790 and 13.959, respectively, and the coefficient of determination values were 0.595, 0.767, 0.545, 0.664. Accordingly, it was determined that TGSV records taken every 30 days up to 150 days, when the MSE value is the lowest, and the R2 value is the highest, can be used in modelling the lactation of Holstein cattle in the first lactation.

 Hayvanların süt üretim performanslarının doğru bir şekilde öngörülmesi için kullanılan laktasyon eğrisi modelleri ile hayvanların laktasyon döneminde ürettikleri süt miktarları zamana göre grafiksel olarak gözlenebilmektedir. Bu sürecin matematiksel modeller kullanılarak analiz edilmesiyle, süt üretiminin farklı durumlarda nasıl değişeceği tahmin edilebilir. Özellikle farklı test günü sayıları kullanılarak en uygun test günü sayısının belirlenmesi ile zaman ve işgücü açısından araştırmacılara önbilgi sağlanabilecektir. Bu nedenle bu çalışmada araştırmacılar tarafından yaygın olarak kullanılan Wood modelinde farklı test günü sayılarının tahmin doğruluğuna etkisi incelenmiştir. Bu amaç için Kırşehir ilindeki özel bir işletmede birinci laktasyonu tamamlayan ve 305 güne kadar 15 günde bir kaydı alınan 150 baş Holstein sığırının test günü süt verim kayıtları TGSV kullanılmıştır. Verilerin analizinde 150 güne kadar 15 günde bir TGSV kayıtları, 150 güne kadar 30 günde bir TGSV kayıtları, 305 güne kadar 15 günde bir TGSV ve 305 güne kadar 30 günde bir TGSV kayıtları kullanılmıştır. Modellerin tahmin edilmesinde SPSS istatistik paket programından yararlanılmıştır. Modellerin karşılaştırılmasında hata kareler ortalaması HKO ve belirtme katsayısı R2 değerleri kullanılmıştır. Araştırmada incelenen modeller için elde edilen sonuçlara göre HKO değerleri sırasıyla 12.284, 11.504, 13.790 ve 13.959 belirtme katsayısı değerleri ise 0.595, 0.767, 0.545, 0.664 olarak bulunmuştur. Buna göre HKO değerinin en düşük ve R2 değerinin en yüksek olduğu 150 güne kadar 30 günde bir alınan TGSV kayıtlarının birinci laktasyondaki Holstein sığırlarının laktasyonlarının modellenmesinde kullanılabileceği belirlenmiştir.

Makale detayları

The Effect of the Number of Test Days on Estimation Accuracy in Modeling the Lactation Curve of First-Lactation Holstein Cows

Yazarlar:

Abdullah Burak Baydur | Samet Hasan Abacı

Yayıncı:

Kirsehir Ahi Evran University

Ana Başlıklar:

Zootekni | Genetik ve Biyoistatistik

Dergi:

Kırşehir Ahi Evran Üniversitesi Fen Bilimleri Enstitüsü Dergisi Vol.2 Issue 2, pp.81-89

Belge Tipi:

Makale

Yayın Tarihi:

12/2024

Belge Dili:

Türkçe

Document ID (Org No.):

2001337138

pISSN:

2979-9198

Milk production performance

Estimation accuracy

Test day milk yield

ModelingSüt üretim performansı

Tahmin doğruluğu

Test günü süt verimi

Modelleme

Sayı

Makale detayları

Yazarlar: Abdullah Burak Baydur | Samet Hasan Abacı

Yayıncı: Kirsehir Ahi Evran University

Ana Başlıklar: Zootekni | Genetik ve Biyoistatistik

Dergi: Kırşehir Ahi Evran Üniversitesi Fen Bilimleri Enstitüsü Dergisi Vol.2 Issue 2, pp.81-89

Belge Tipi: Makale

Yayın Tarihi: 12/2024

Belge Dili: Türkçe

Document ID (Org No.): 2001337138

pISSN: 2979-9198

Sayı

Yazarlar:

Abdullah Burak Baydur | Samet Hasan Abacı

Yayıncı:

Kirsehir Ahi Evran University

Ana Başlıklar:

Zootekni | Genetik ve Biyoistatistik

Dergi:

Kırşehir Ahi Evran Üniversitesi Fen Bilimleri Enstitüsü Dergisi Vol.2 Issue 2, pp.81-89

Belge Tipi:

Makale

Yayın Tarihi:

12/2024

Belge Dili:

Türkçe

Document ID (Org No.):

2001337138

pISSN:

2979-9198