Test-day records of somatic cell count (SCC), milk yield, fat and protein content and six linearly scored type traits (fore udder attachment, udder depth, central ligament, rear udder height, front teat placement, teat length) of 22 613 first lactation cows from 117 herds were included in this study. SCC was log-transformed into somatic cell score (SCS). Milk yield was standardized as follows: ...

A genome scan was conducted in two US Holstein half-sib families to identify quantitative trait loci (QTL) affecting milk production and conformation traits using the granddaughter design. The sires of the two studied families were related as sire and son and had 96 and 212 sons respectively. A total of 221 microsatellite loci were scored in both families. Statistical analysis was performed usi...

correlation between breeding value of crude milk (cm) and energy-corrected milk (ecm) was studied based on a total of 774,013 test day records belongs to 88,456 first-parity holsteins dairy cattle calving during 1997-2009 in 165 herds (from six provinces). genetic analysis of the traits was carried out by a fixed regression test day model. in the model, effects of herd, calving year, production...

This research is focused on the evaluation of milk flow traits of Slovak Simmental dairy cows, using electronic mobile milk flow meters Lactocorders. All measurements were carried out on a farms located in the western Slovakia. We evaluated a total amount of 124 Simmental dairy cows. The Main group of Slovak Simmental dairy cows was divided according to parity and lactation stage respectively, ...

Applying a multiple trait random regression (MT-RR) in national level and for whole test day records of a country is a great advance in animal breeding context. Having reliable (co) variance components is a critical step in applying multiple traits genetic evaluation especially in developing countries. Genetic parameters of milk, fat and protein yields were estimated for Iranian Holstein dairy ...

The aim of this research was to estimate the influence of environmental factors, such as air temperature and milk production, on reproduction traits of primiparous Polish Holstein-Friesian cows. The following reproduction traits were considered: interval from calving to first insemination, interval from first to last insemination, interval from calving to conception, number of inseminations per...

The difficulties and costs of measuring individual feed intake in dairy cattle are the primary factors limiting the genetic study of feed intake and utilisation, and hence the potential of their subsequent industry-wide applications. However, indirect selection based on heritable, easily measurable, and genetically correlated traits, such as conformation traits, may be an alternative approach t...

In order to estimate economic values of productive traits (meat, milk and wool) in Taleshi native sheep breed of Iran, records from economic parameters and performance of local Taleshi flocks were used. The economic values of traits were used to select the maximum profit estimation also to study the sensitivity rate of the model the effects of 20 percent increase / decrease in the price of milk...

The objective was to examine the direct and correlated responses of linear type, yield traits, and somatic cell scores (SCS) to divergent selection for predicted transmitting ability for type (PTAT) in Holsteins, while maintaining selection for yield traits across lines. For four generations, one-half of the University of Nebraska research Holstein herd was bred to Holstein sires with PTAT > 1....

Breed differences and nonadditive genetic effects for milk production traits, somatic cell score (SCS), conception rate (CR), and days to first service (DFS) were estimated for Holstein × Montbéliarde and Holstein × Normande crossbreds, using an animal model adapted from the French genetic evaluation and extended to across-breed analysis. Inbreeding and breed differences were estimated from all...