ManageChatDiscover
426334

THE IMPACT OF AGE AT FIRST CALVING ON PRODUCTIVITY AND PROFITABILITY IN FRIESIAN COWS UNDER EGYPTIAN CONDITIONS

Article

Last updated: 11 May 2025

OverviewSimilar Items

Subjects

-

Tags

Animal genetic and breeding

Abstract

The aim of this study was to estimate the effect of age at first calving (AFC) on first lactation traits (FLMY, FLP, FDO, FDP, and FCI), lifetime milk yield (LTMY), number of lactations complete (NLC), and profitability in Friesian cows under Egyptian conditions. Additionally, the study aimed to assess genetic parameters and breeding values to aid in genetic selection and improve dairy herd performance. Data were collected over 23 years from 1767 first lactation cows. A General Linear Model (GLM) in SAS was used to assess significant fixed effects, and restricted maximum likelihood (REML) procedures were applied to estimate genetic parameters and breeding values.
AFC significantly influenced productivity and reproductive traits. Cows with early AFC (≤25 -35 months) had higher LTMY (19881.25 ± 1248.6 kg) and NLC (4.58 ± 0.15) compared to cows with late AFC (≥46 months) (LTMY: 15343.5 ± 1430.55 kg, NLC: 2.87 ± 0.15). Profitability was highest in early AFC cows (39518.24 ± 2268.06 EGP), decreasing with delayed AFC. Heritability estimates ranged from 0.14 to 0.26 indicating potential for genetic improvement.
Breeding values were estimated for sires, cows, and dams with high accuracy. These values can guide genetic selection to enhance desired traits in Friesian cows, contributing to improved lifetime milk production and the number of lactations complete.

DOI

10.21608/ejap.2025.338429.1093

Keywords

Friesian cows, lifetime milk yield, Age at first calving, Breeding values

Authors

First Name

I.

Last Name

Abu El-Naser

MiddleName

A.

Affiliation

Department of Animal, Poultry and Fish Production, Faculty of Agriculture, Damietta University, Egypt

Email

-

City

-

Orcid

-

First Name

A.

Last Name

Abo El-Enin

MiddleName

S.

Affiliation

Animal Production Research Institute, Ministry of Agriculture, Dokki, Egypt

Email

-

City

-

Orcid

-

First Name

S.

Last Name

El-Mansy

MiddleName

A.

Affiliation

Department of Animal Production, Faculty of Agriculture, Zagazig University, Zagazig, 44519, Egypt

Email

-

City

-

Orcid

-

First Name

Abdullah

Last Name

Ghazy

MiddleName

-

Affiliation

Department of Animal Production, Faculty of Agriculture, Suez Canal University, Ismailia 41522, Egypt

Email

ghazy@agr.suez.edu.eg

City

Ismailia

Orcid

-

Volume

62

Article Issue

2

Related Issue

55578

Issue Date

2025-05-01

Receive Date

2024-11-25

Publish Date

2025-05-01

Page Start

69

Page End

77

Print ISSN

0302-4520

Online ISSN

2735-3028

Article File

EJAP_Volume 62_Issue 2_Pages 69-77.pdf

PDF . 540.1kB

Link

https://ejap.journals.ekb.eg/article_426334.html

Detail API

http://journals.ekb.eg?_action=service&article_code=426334

Order

1

Type

Original Article

Type Code

1,298

Publication Type

Journal

Publication Title

Egyptian Journal of Animal Production

Publication Link

https://ejap.journals.ekb.eg/

MainTitle

THE IMPACT OF AGE AT FIRST CALVING ON PRODUCTIVITY AND PROFITABILITY IN FRIESIAN COWS UNDER EGYPTIAN CONDITIONS

Details

Type

Article

Created At

11 May 2025