Laure Rutter

Learn More
This study tested the hypothesis that the increased glucose requirement of lactation had effects that were independent of the suckling-dependent inhibition of postpartum endocrine function in beef cows. Mature Hereford cows were either suckled ad libitum and infused with saline iv (n = 9) from d 2 through 4 (d 0 = jugular catherization on d 32 +/- 3(More)
Discriminant analysis was used to develop equations for predicting dystocia in 2-yr-old, first-calf beef heifers. Data collected on 893 yearling heifers from 34 farms were used to derive four sets of prediction equations (Data Set 1). There was a set of equations for British x British (BRBR) heifers at prebreeding, BRBR heifers at pregnancy check,(More)
From calving through first estrus, 30 Brangus females were assigned equally to one of three diets to study the effect of postpartum nutrient intake and body condition on the ability of the pituitary to release luteinizing hormone (LH) and on the postpartum interval to estrus (PPI). The postpartum diets were calculated to achieve a 1) low [90% of the(More)
Four experiments assessed changes in serum IGF-I under various physiologic conditions in postpartum cows. In Exp. 1, anestrous suckled cows (n = 25) were infused for 6 d with either saline or glucose at two different infusion rates. In Exp. 2, anestrous cows (n = 29) received either a saline (weaned and suckled controls) or 3 g/d phlorizin (weaned(More)
Anestrous postpartum (PP) Hereford cows (n = 41) were used to compare corpora lutea (CL) from gonadotropin-releasing hormone (GnRH)-induced ovulation with CL from cycling cows. Postpartum cows were injected i.m. daily with 100 mg progesterone (P4) or oil on Days 25 through 28 PP and then given 200 micrograms GnRH i.m. on Day 30 PP. Corpora lutea were(More)
Three methods for predicting difficult births were tested on 4,140 yearling heifers measured before breeding and(or) at pregnancy check approximately 6 mo later. These heifers were from 115 beef herds in Alberta and British Columbia. The overall incidence of dystocia for normal presentations was 26.5%, which included 17.2% easy assists, 7.7% hard pulls, and(More)
The effect of dietary monensin on the luteinizing hormone (LH) surge following estradiol-17 beta (E2) injection was investigated in prepuberal Simmental X Brahman-Hereford heifers. Ten heifers, weighing approximately 260 kg and approximately 10 mo of age, were equally divided by age and weight into two groups: control (C) heifers each received 1.8 kg/d of a(More)
Corpus luteum (CL) function following spontaneous or prostaglandin F2 alpha-induced estrus was studied in 27 Brahman cows and 16 Brahman heifers. Females received one injection of 0, .38, .75 or 2.25 mg alfaprostol (PGF)/100 kg body weight at 12 +/- .1 d post-estrus. Serum progesterone (P4) during CL formation, following the subsequent estrus, increased(More)
Each of 12 prepuberal Brangus heifers (8 to 10 mo of age; 167 to 196 kg) was fitted with an abomasal cannula and assigned to one of two infusion treatments (six heifers/treatment): 1,150 ml of water/d (C) or 200 g of propionate (9% of digestible energy) plus 950 ml of water (P). The heifers were individually fed twice daily 4.50 kg of a diet consisting of(More)
The frequency of occurrence of behavioral estrus without subsequent development of functional luteal tissue (termed nonpuberal estrus, NPE), was determined in 43 Simmental X Hereford-Brahman heifers. Blood samples were collected weekly from the start of the study to first behavioral estrus and then daily from d 1 (d 0 = estrus) through d 14 following first(More)