BACKGROUND This study was carried out to determine if an association exists between the shape of the lactation curve before it is influenced by the event of conception and the time from calving to conception in Norwegian dairy cattle. Lactation curves of Norwegian Red cows during 5 to 42 days in milk (DIM) were compared between cows conceiving between 43 and 93 DIM and cows conceiving after 93 ...

the main objective of the present study was to explore the feasibility of nonlinear mixed models to describe the somatic cell score (scs) lactation curves and to compare the fit of four nonlinear vs. two linear models when applied to scs lactation records in iranian holstein cows. the animal breeding center of iran provided the scc data. the data consisted of 445077 test-day observations from 6...

A total of 989,582 test-day records of 160,243 first-parity cows collected from 131 herds of Iranian Holstein dairy cows from 1995 to 2014 by the Animal Breeding and Improvement Centre of Iran, were used to determine the best model for lactation curves of fat to protein ratio (FPR) and somatic cell scores (SCS) in the first lactation. Several mathematical models including the Wood (WD), Wilmink...

Cow-calf contact (CCC) systems, although beneficial in many respects, introduce additional challenges to collect reliable data on milk production, which is important assess individual cow efficiency and dairy farm profitability. Apart from weighing calves before after each feeding, the amount of saleable lost due calf suckling practically impossible measure. Here, we 2 indirect methods for esti...

test day records of first lactation holstein cows from 1996 to 2008 were obtained from animal breeding center of iran and used in this research. data consisted of 872125 test-day milk records of 95816 cows from 59 herds. (co)variance components and genetic parameters were estimated using random regression model via gibbs sampling method. two order legendre polynomials and third coefficient of w...

Lilium species (Liliaceae) are a significant floriculture commodity and one of the three major bulb crops in the commercial market. Lilies are monocotyledonous plants that have been generally recalcitrant to molecular genetic manipulation because of limitations that restrict utilization of transformation technologies that are routinely applied to dicotyledonous plants. Cucumber mosaic virus (CM...

Modeling extended lactations for the US Holsteins is useful because a majority (>55%) of the cows in the present population produce lactations longer than 305 d. In this study, 9 empirical and mechanistic models were compared for their suitability for modeling 305-d and 999-d lactations of US Holsteins. A pooled data set of 4,266,597 test-day yields from 427,657 (305-d complete) lactation recor...

specific hybridization has reduced disease problems, increased biomass yield and sugar yield, and improved Direct screening of genomic libraries for highly expressed genes adaptability for growth under various stress conditions is an efficient way to identify promoters that confer high levels of (Roach, 1972; Srivastava et al., 1994). gene expression. To test the efficacy of this approach to is...