The objectives of this study were 1) to compare temperament assessments, using multiple techniques and over repeated observations, gauge the long-term 2) evaluate relationship appraisals with serum concentrations cortisol (CS). Measures gathered 3 observations (60-d interval) yearling, fall-born Brahman bulls (initial BW = 320 +/- 4 kg; n 66). Temperament assessments included exit velocity (EV), which was rate at exited squeeze chute traversed a fixed distance (1.83 m); pen scores (PEN; 1...

The detrimental effects caused by stressors encountered animals during routine handling can pose economic problems for the livestock industry due to increased costs ultimately borne producer and consumer. Stress adversely affects key physiological processes of reproductive immune systems. In recent years stress responsiveness has been associated with cattle behavior, specifically temperament. Cattle more excitable temperaments, as measured chute score, pen exit velocity (flight speed),...

From calving through first estrus, 30 Brangus females were assigned equally to one of three diets study the effect postpartum nutrient intake and body condition on ability pituitary release luteinizing hormone (LH) interval estrus (PPI). The calculated achieve a 1) low [90% National Research Council (NRC) recommendations], 2) maintenance (100% NRC recommendations), or 3) high (110% recommendations) level intake. group-fed within treatment calves allowed suckle ad libitum. Cow weight, score...

The objective of this study conducted in tropical Brazil was to characterize some physiological and histological responses heat stress imported Bos taurus, native indicus cattle. Imported Simmental (n = 107), 99), cattle 121) (42 80 mo age) were evaluated. Animals walked 7 km at 37°C 60 65% relative humidity during midday. Rectal temperatures respiration rates taken before after the walk. A .01-cm2 sample cutaneous tissue from lateral cervical region obtained each animal. Slices stained with...

Ovarian characteristics, daily serum progesterone (P4) and estradiol-17β (E2) concentrations (d 7 through 17) uterine luminal secretory protein components histological variables were evaluated in parous Bos taurus (Angus, n=20) indicus (Brahman, n=19) cows. Cows slaughtered on d 17 (estrus = 0) for measurement of ovarian structures, flushing uteri removal tissue evaluation. placed into one three reproductive categories: nonpregnant, remnant (flushings contained remnants embryonic tissue) or...

Thirty-five Brahman × Hereford F-1 first-calf heifers were assigned to two treatment groups: normal suckling (16 heifers) and once-daily (30 min of time, once daily; 19 heifers). Once-daily began at 30 days postcalving was continued until each heifer reached first postpartum estrus. After a estrus, she allowed rear her calf normally weaning. Seven pairs cows, one cow from group, selected for milking on the bases calving date sex calf. Body weights not affected by before estrus but greater...

OVARIAN follicles may rupture and corpora lutea (CL) form after calving without prior evidence of estrus in milked cows. Among studies reported, the average period to first ovarian follicle (ovulation) ranged from 14 35 days only 35% cows showed at beginning cycle (Casida Wisnicky, 1950; Menge et al., 1962; Morrow 1966; Saiduddin 1968; Marion Gier, Wagner Hansel, 1969). Growth persistence CL be subnormal time second ovulation averages about 15 as compared 21 third (Morrow 1968). These...

Background/Objectives: The experience of prenatal stress results in various physiological disorders due to an alteration offspring's methylome and transcriptome. objective this study was determine whether PNS affects DNA methylation (DNAm) gene expression the axis tissues mature Brahman cows. Methods: Samples were collected from paraventricular nucleus (PVN), anterior pituitary (PIT), adrenal cortex (AC) 5-year-old cows that prenatally exposed either transportation (PNS, n = 6) or not...

Ovarian and gonadotropin responses to insulin energy restriction were investigated in a 2 × factorial experiment using 2-yr-old Brangus heifers. Thirty heifers paired by weight body condition, then assigned treatment groups receiving 75 (LE) or 180% (HE) of NRC recommendations for dietary maintenance. Diets adjusted weekly maintain daily .25 .5 kg loss 0 gain, respectively. On d 10 the first estrous cycle subsequent initial 45 feeding, within each group allocated receive twice infusions...

Thirty-nine Hereford (H), 32 Brahman (B) and 113 BxH (F-l) heifers were randomly allotted to one of 3 Experiments (E): I. Continuous grazing (wheat-oats-ryegrass); II. Part-time (wheat-oats-ryegrass 4 hr daily, days a week for 59 followed by part-time daily); III. Drylot confinement. E groups divided into subgroups which respectively received 200 mg or 0 monensin in .91 kg range cubes per head daily. At scheduled times the measured weight (W), height (Ht), length (L), heart girth (C),...

IN equations for predicting levels of plasma progesterone, partial regressions estradiol-17β were significant during the first 42 days pregnancy (Randel et al., 1971c) and 1 to 19 estrous cycle cows (Garverick 1971). The latter authors also reported a negative regression in an equation corticosterone. Also, progesterone LH negatively significantly correlated luteolytic phase 1971) from 0 12 after estrus pregnant nonpregnant sows (Tillson, Erb Niswender, 1970). Rates excretion estrone...

Brahman cows were used to evaluate dietary fat (3.74% [control] and 5.20% [treated]) effects on blood hormone lipid concentrations, follicular populations, in vitro steroidogenesis. Cows fed ovaries monitored by ultrasound from d 1 of the first estrous cycle (EC) until follicle second EC reached 8 mm, at which time harvested. Follicular fluid (FF) was collected large- medium-sized follicles assayed for progesterone (P4), estradiol-17β (E2), testosterone, cholesterol, triglycerides. The...

This study was designed to determine the influence of temperament on endotoxin-induced changes in body temperature, sickness behavior, and stress hormone concentrations cattle. Brahman bulls were selected based score measured 28 d prior weaning. In dwelling recording devices used monitor rectal jugular catheters collect blood samples cortisol epinephrine before after LPS administration (0.5 μg/kg weight). Temperamental had lowest peak temperature behavior scores relative Calm Intermediate...