Home About Browse Search
Svenska


Genotype by environment interaction for automated and traditional fertility traits in dairy cattle

Ismael, Ahmed (2016). Genotype by environment interaction for automated and traditional fertility traits in dairy cattle. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2016:37
ISBN -
eISBN 978-91-576-8577-3
[Doctoral thesis]

[img]
Preview
PDF
463kB

Abstract

Genotype by environment interaction (G×E) is one of the issues the dairy farming industry faces due to the globalization of using artificial insemination with genetically superior bulls to improve the performance of their herds. This includes distribution of genetic material to multiple environments within countries and between countries. The major concern is that animal rank may change across the environments which mean that the best animals in one environment are not the best in another environment. In this thesis, the genetic variation and G×E effect on fertility traits was investigated in Nordic cattle. Two types of fertility traits were studied, 1) automatically recorded fertility traits based on the physical activity measuring devices and, 2) traditional fertility traits based on the AI recording.

In Paper I, genetic parameters were estimated for interval for calving to first high activity (CFHA); duration of high activity as an indicator of estrus duration (DHA); and strength of high activity as an indicator of estrus strength (SHA), all based on activity measurements from cows in commercial herds. These parameters were compared with parameter estimates for interval from calving to first insemination (CFI). It was found that CFHA shows higher heritability than CFI. Moreover, the two traits were strongly genetically correlated. Consequently, the selection criteria for fertility may be improved by including “time from calving to first high activity”, because it reflects the ability of the cow to return to reproductive cycling and heat after calving.

In Paper II, Seasonality of estrus activity traits with respect to the month of calving was investigated. It was found that the summer calving season was associated with shorter CFHA than winter, spring, and fall seasons. Moreover, there was evidence for genotype by environment interaction for CFHA with calving season. However, DHA and SHA were less affected by seasonal variation. The results might be useful for the interpretation of seasonal variation in estrus expression traits and fertility traits in Holstein cows kept in the temperate climate zone.

In Paper III, the objectives were to estimate genetic parameters of fertility traits derived from activity tags (CFHA, DHA, and SHA), and estimate the genetic correlation between the CFHA and yield of energy corrected milk at 70 days in milk (ECM70). Parameters were estimated as a function of production level, expressed as herd average yield using reaction norm model in Danish Holstein cows. Heterogeneous genetic variation was found for all traits as a function of production environment, but the genetic correlation estimate of the trait between low and high production environment showed no evidence for G×E effect. The genetic correlation between CFHA and ECM70 decreased with increasing the production level implying that the unfavorable genetic correlation between fertility and milk yield could is reduced in improved production environments.

In Paper IV, the G×E interaction effects were studied on CFI in first parity Holstein cows in Denmark and Sweden, with environments defined as calving month and geographic location (in 8 North-South location classes). It was found that that cows calving in September had the shortest CFI. Cows in the northernmost location class had the longest CFI. Furthermore, there was a G×E effect between cold and warm calving months. However, CFI genotypes showed little interaction with geographic location. The obtained results are useful for improving genetic evaluations of Holstein cow fertility using data from a wide range of geographic locations and seasons.

Authors/Creators:Ismael, Ahmed
Title:Genotype by environment interaction for automated and traditional fertility traits in dairy cattle
Series/Journal:Acta Universitatis agriculturae Sueciae (1652-6880)
Year of publishing :2016
Depositing date:2016
Volume:2016:37
Number of Pages:49
Papers/manuscripts:
NumberReferences
1.Ismael, A., E. Strandberg, M. Kargo, A. Fogh, and P. Løvendahl. 2015. Estrus traits derived from activity measurements are heritable and closely related to the time from calving to first insemination. J Dairy Sci 98: 3470-3477.
2.Ismael, A., E. Strandberg, B. Berglund, A. Fogh, and P. Løvendahl. 2016. Seasonality of fertility measured by physical activity traits in Holstein cows. J Dairy Sci 99: In press.
3.Ismael, A., E. Strandberg, B. Berglund, M. Kargo, A. Fogh, and P. Løvendahl. 2016. Genotype by environment interaction for activity based estrus traits regarding to production level for Danish Holstein. (Manuscript in preparation)
4.Ismael, A., E. Strandberg, B. Berglund, M. Kargo, A. Fogh, and P. Løvendahl. 2016. Genotype by environment interaction for the interval from calving to first insemination with regard to calving month and geographic location in Holstein cows in Denmark and Sweden. (Submitted to J Dairy Sci)
Place of Publication:Uppsala
Publisher:Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences
ISBN for printed version:-
ISBN for electronic version:978-91-576-8577-3
ISSN:1652-6880
Language:English
Additional Information:Joint PhD thesis, Swedish University of Agricultural Sciences, Uppsala, Sweden and Aarhus University, Denmark
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L10 Animal genetics and breeding
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 402 Animal and Dairy Science > Animal and Dairy Science.
Agrovoc terms:dairy cattle, breeds (animals), genotype environment interaction, genetic parameters, oestrous cycle, fertility, parturition interval, milk yield, denmark, sweden
Keywords:dairy cattle, holstein, genotype by environment interaction, fertility traits, genetic parameters
URN:NBN:urn:nbn:se:slu:epsilon-e-3340
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-3340
ID Code:13230
Faculty:VH - Faculty of Veterinary Medicine and Animal Science
Department:(VH) > Dept. of Animal Breeding and Genetics
Deposited By: Gunilla Åkerlund
Deposited On:30 Mar 2016 17:23
Metadata Last Modified:01 Apr 2016 17:40

Repository Staff Only: item control page

Downloads

Downloads per year (since September 2012)

View more statistics

Downloads
Hits