A cross-sectional study of factors associated with birth weights of Norwegian beef calves.

A cross-sectional study was performed to evaluate factors which influence birth weights of beef suckler calves in Norway. Data were from a national beef cattle registry, and lifetime production data of cows slaughtered between January 2010 and January 2013 were included in the study population. The study population consisted of 20,541 cows and 53,819 calves.

Assessment of progesterone profiles and postpartum onset of luteal activity in spring calving Hereford beef suckler cattle.

Background: Reproduction is the single greatest factor limiting beef cattle production. Previous research on beef suckler luteal activity has largely focused on the mechanisms, and duration, of postpartum anoestrus. However, the temporal pattern of luteal activity after resumption of post-partum ovarian activity, and the impact of pattern type on days open (DO) in purebred beef suckler cows, are unknown.

Factors influencing women's acceptance of prenatal screening tests.

Objective: To determine the factors influencing a woman's acceptance of the expanded alpha-fetoprotein (AFP) test.

Methods: A population-based case-control study. All women (age < 35) who declined the expanded AFP test were identified as eligible cases.

Pregnancy incidence in Norwegian red cows using nonreturn to estrus, rectal palpation, pregnancy-associated glycoproteins, and progesterone.

The objectives of the study were to estimate pregnancy incidence and calving rate after first artificial insemination (AI) in Norwegian Red cows undergoing spontaneous estrus, to assess the relationship between pregnancy and management factors at herd or cow level, to evaluate differences between 60-d nonreturn rate (NRR60d) and pregnancy incidence, and to compare the accuracy of pregnancy diagnosis by rectal palpation and plasma pregnancy-associated glycoproteins (PAG) analysis supported by progesterone measurements. In total, 829 animals (n = 229 heifers, 234 first-lactation, 173 second-lactation, and 193 >second-lactation cows) were included. Milk samples for progesterone analysis were collected both at AI and 3 wk later.

Pregnancy associated glycoproteins (PAG) in postpartum cows, ewes, goats and their offspring.

Determination of plasma concentrations of pregnancy associated glycoproteins (PAG) has been used for early pregnancy diagnosis in cows. However, this is complicated by the presence of PAG in plasma for an extended period postpartum. The main objective of the present study was to investigate the postpartum elimination rates of pregnancy associated glycoproteins (PAG) in sheep, goats and cows in order to gain background information applicable to the use of PAG for pregnancy diagnosis in domestic ruminants.