Phosphodiesterase9A (PDE9A) is a cyclic guanosine monophosphate (cGMP)-specific enzyme widely expressed among the tissues, which is important in activating cGMP-dependent signaling pathways. In our previous genome-wide association study, a single nucleotide polymorphism (SNP) (BTA-55340-no-rs(b)) located in the intron 14 of PDE9A, was found to be significantly associated with protein yield. In ...

Advances in breeding and management resulted in a considerable increase of production traits in Austrian dairy cattle. Besides, low input systems were also established. Possible genotype by environment interactions (G x E) and genetic antagonisms dependent on production level might indicate the need for separate breeding programmes for dairy farms diff ering in management intensity. Th us, G x ...

Concomitant with intensive selection for increased milk yield, reproductive performance of dairy cows has declined in the last decades, in part due to an unfavourable genetic relationship between these traits. Given that the six main milk protein genes (i.e. whey proteins and caseins) are directly involved in milk production and hence have been a target of the strong selection aimed at improvin...

Data were obtained from 1980 to 1987 on animals belonging to one of three breeding systems: Hereford, small rotation, and large rotation. Differences among Angus-, Gelbvieh-, Pinzgauer-, and Tarentaise-sired calves within the small rotation system were generally not detected as significant for the preweaning traits of gestation length, calving ease, birth weight, gain to weaning, or creep feed ...

Preweaning and weaning records on 457 calves and weights and milk production of their dams were used to evaluate breed of dam effects, breed of sire effects, and individual heterosis effects. Hereford and Tarentaise dams were mated to Hereford and Tarentaise sires and calves were born from 1987 to 1991. Calf traits were birth weight, proportion calving difficulty, weaning weight, weaning height...

Using spline functions (segmented polynomials) in regression models requires the knowledge of the location of the knots. Knots are the points at which independent linear segments are connected. Optimal positions of knots for linear splines of different orders were determined in this study for different scenarios, using existing estimates of covariance functions and an optimization algorithm. Th...

lactoferrin (lf) is a bioactive protein present in all external secretions such as milk that plays important role in the innate host defense. therefore, the lf has a major role in bovine mammary gland defense during mastitis. in this study, 5’-flanking region of bovine lf gene containing three single nucleotide polymorphisms (snps) at positions −602 (t/g), −600 (a/g) and -586 (t/c) were screene...

background: the osteopontin (opn) is a highly phosphorylated glycoprotein in numbers of bovine tissues and milk. opn has been reported to be associated with milk production in cattle.objective: the genotype and allelic frequencies for opn and its association with milk production will be evaluated in iranian holstein bulls.  materials and methods: bulls dna (100) was isolated. oligo was used for...

The objective of this study was to examine the prion protein gene locus (PRNP) in Chios sheep. PRNP is linked with scrapie resistance in small ruminants. Here, its impact on milk production (test-day and total lactation yield) and reproduction (age at first lambing, conception rate at first service, and prolificacy) was assessed. Genotyping at codons 136, 154 and 171 (classical scrapie) and 141...

Recent publications indicate genetic variation in milk production traits on proximal BTA14, which cannot be explained solely with genetic variation in the DGAT1 gene. To elucidate these QTL effects, animals from a German Holstein granddaughter design (18 families, 1,291 sons) were genotyped for CYP11B1 (V30A) and DGAT1 (K232A) polymorphisms. Frequencies of alleles of maternal descent were estim...