In order to survey the behaviour of choosing the alley area instead of a cubicle as a lying place (cubicle refusal), a questionnaire was sent to the 273 dairy farms in Norway known to keep cows in cubicle housing systems. Sixty-six percent of the farmers contacted were included in the study. The median herd size was 18 cows (range 7-118). More than 85% of the herds had sheds providing one or mo...

The CIDR is an intravaginal progesterone insert, used in conjunction with other hormones to synchronize estrous in beef and dairy cows and heifers. The CIDR was developed in New Zealand and has been used for several years to advance the first pubertal estrus in heifers and the first postpartum estrus in cows. The CIDR is a “T” shaped device with flexible wings that collapse to form a rod that c...

Abstract Our objective was to evaluate the reproductive performance of Holstein nulliparous heifers carrying SLICK1 mutation and half-sisters not mutation. Heifers were born between November March 2020 two sires heterozygous for dominant allele raised in four dairy farms San Joaquin Tulare basins California Central Valley. bred from January September 2021 according farm protocols. Data obtained...

The aim of this study was to examine the effect age and dietary crude protein (CP) level on nitrogen (N) excretion in dairy heifers develop simple models predict N farm based nutrient intake parameters. Thirty-six Danish Holstein were divided into 4 groups; 8, 12, 16, 20 months old (M8, M12, M16, M20), respectively, with 9 animals per group. Heifers within groups blocked 3 according pregnancy s...

Relevance. The main direction in the improvement of dairy cattle breeds is search for ways and methods creating highly productive herds. However, successful solution these issues impossible without use modern technologies. Among them, sexed sperm a divided into Xand Y-containing spermatozoa. When using breeding, it possible to regulate receipt desired sex (heifers). effective semen will provide...

Investigations on the optimum timing of artificial insemination (AI) following automated activity monitoring (AAM) depending different types semen in heifers are limited and part show controversial results. Therefore, objective this observational study was to determine association between AI using characteristics estrus (i.e., onset, peak, end estrus) pregnancy per (P/AI) Holstein heifers. Heif...

During 3 consecutive calving seasons, calving performance, placental characteristics and endocrine profiles of total 98 pregnancies of late pregnant Swedish Red and White (SRB) and Swedish Holstein (SLB) dairy heifers and cows, were investigated. Ninety-four singleton pregnancies and 4 sets of twins were recorded. In animals with singleton pregnancy, 8 stillbirths, 7 weak calves, 3 premature pa...

Rapid body growth during the prepubertal period may be associated with reductions in mammary parenchymal growth and subsequent milk yield. The objective of this study was to test effects of dietary rumen-undegradable protein (RUP) and administration of recombinant bovine somatotropin (bST) during the prepubertal period on mammary growth and milk yield of dairy heifers. Seventy-two Holstein heif...

Our objective in this study was to determine endocrine responses and changes in ovarian structures after a single injection of a GnRH agonist in Holstein dairy heifers (n = 38). Heifers were inseminated and received (i.m.) either saline or 200 micrograms of fertirelin acetate once on d 11, 12, or 13 after estrus (d 0). Blood was collected at 15- to 30-min intervals for 6 h after the injection t...