The effects of different feeding strategies providing different levels of vitamin A on animal performance, carcass traits, and the conversion rate of subcutaneous fat color in cull-cows.

Cull cows represent a significant percentage of revenue received from the U.S. beef industry; however, cull cows are heavily price discounted at time of slaughter. This experiment's objective is to evaluate different feeding strategies and their effects on body condition score, subcutaneous fat color, and carcass yield and quality traits in cull cows. The central hypothesis is feeding a high-energy diet, with low levels of vitamin A, for 56 d will improve animal performance, carcass yield, and quality traits in addition to capturing the point (rate) of the conversion of yellow to white subcutaneous fat. In the present experiment 98 Angus crossbreed cows were utilized. Cows were fed either low vitamin A (LVA) diet consisting of whole shelled corn, soybean hulls, soybean meal, and a mineral-vitamin supplement or high vitamin A (HVA) diet, formulated using whole shelled corn, fescue hay, dry distiller grains with soluble, and a mineral-vitamin supplement for 56 d. During the 56 d feeding period, body weights and condition scores, and subcutaneous adipose samples were collected every 14 d. On day 56, cattle were slaughtered; 48 h postmortem carcass characteristics and objective color scores (subcutaneous adipose tissue) were recorded and a sample of the longissimus dorsi lumborum was collected. Subcutaneous adipose tissue samples were utilized to record subjective color scores and then ground to be analyzed for ß-carotene concentration. The longissimus dorsi lumborum samples (2.54 cm slices) were removed for Warner-Bratzler shear force (WBSF) and pH testing. Data were analyzed using the MIXED procedure of SAS. Feeding cull cows LVA resulted in differences in subcutaneous carcass fat color (P = 0.01) as well as b* values (P < 0.01) on day 56 compared with HVA. Subjective fat color scores were not different (P > 0.10) on day 0 or 14 but were different (P ≤ 0.05) on days 28, 42, and 56. Additionally, 9-cis-ß-carotene concentration on day 56 were different (P = 0.05) between treatments. A trend was noticed for all-trans-ß-carotene concentration (P = 0.10) on day 56 as well. Cull cow body weights were greater (P ≤ 0.04) when fed the LVA diet starting on days 14, 28, and 42; and a trend was noticed on day 56 (P = 0.09). Overall, cows fed the LVA treatment for 56 d exhibited decreased adipose yellowness and ß-carotene concentrations as well as increased live weights.

Genetic parameter estimates for serum insulin-like growth factor-I concentration and ultrasound measurements of backfat thickness and longissimus muscle area in Angus beef cattle.

A divergent selection experiment for serum IGF-I concentration began at the Eastern Ohio Resource Development Center in 1989 using 100 spring-calving (50 high line and 50 low line) and 100 fall-calving (50 high line and 50 low line) purebred Angus cows. Following weaning, bull and heifer calves were fed in drylot for a 140-d period. Real-time ultrasound measurements of backfat thickness and longissimus muscle area were taken on d 56 and 140 of the postweaning test. Only ultrasound data from calves born from fall 1995 through spring 1999 were included in the analysis. At the time of this study, IGF-I measurements were available for 1,521 bull and heifer calves, and ultrasound data were available for 636 bull and heifer calves. Data were analyzed by multiple-trait, derivative-free, restricted maximum likelihood methods. Estimates of direct heritability for IGF-I concentration at d 28, 42, and 56 of the postweaning period, and for mean IGF-I concentration were 0.26 +/- 0.07, 0.32 +/- 0.08, 0.26 +/- 0.07, and 0.32 +/- 0.08, respectively. Direct heritabilities for ultrasound estimates of backfat thickness ranged from 0.17 +/- 0.11 to 0.28 +/- 0.12, whereas direct heritabilities for longissimus muscle area ranged from 0.20 +/- 0.10 to 0.36 +/- 0.12, depending on the time of measurement and the covariate used for adjustment (age vs. weight). Direct genetic correlations of IGF-I concentrations with backfat thickness at d 56 and 140 and with longissiumus muscle area at d 56 and 140 averaged 0.02, 0.20, -0.08, and 0.23, respectively, when age was used as the covariate for both IGF-I and ultrasound measurements. Corresponding genetic correlations when age was used as the covariate for IGF-I and weight was used as the covariate for ultrasound measurements were 0.05, -0.07, -0.22, and -0.04, respectively. Therefore, the positive associations of serum IGF-I concentration with backfat thickness and longissimus muscle area at d 140 seem to have been partially mediated by weight. Results of this study do not indicate strong associations of serum IGF-I concentration with fat thickness or muscling of bulls and heifers during the postweaning feedlot period.

Life event stress and the association with spontaneous abortion in gravid women at an urban emergency department.

In this study, the authors hypothesized that life event stress is associated with an increased risk of spontaneous abortion. Using a nested case-control design in an emergency department (N = 970), stress was measured using a life event inventory and a sample drawn from R. B. Ness et al.'s (1999) Early Pregnancy Study. Gestational age at time of fetal loss served as a marker of chromosomal status. Women experiencing more than one life event used more alcohol and public assistance. Spontaneous abortion at 11 weeks or greater was associated with more life event stress (adjusted odds ratio 2.9, 95% confidence interval 1.4-6.2), whereas spontaneous abortion at any gestational age was not, implying that life event stress increases the risk of chromosomally normal spontaneous abortion. An analysis of confounders showed tobacco use was associated with an increased risk of spontaneous abortion, whereas prenatal care was only associated with fetal loss at 11 weeks or greater.

Experiences and attitudes of residents and students influence voluntary service with homeless populations.

OBJECTIVE: To assess the impact of two programs at the University of Pittsburgh, one that requires and one that encourages volunteer activity. In the program that requires primary care interns to spend 15 hours in a homeless clinic, we measured volunteer service after the requirement was fulfilled. In the program that encourages and provides the structure for first- and second-year medical students to volunteer, we assessed correlates of volunteering. MEASUREMENTS AND MAIN RESULTS: When primary care interns were required to spend time at homeless clinics, all (13/13) volunteered to work at the same clinic in subsequent years. Categorical interns without this requirement were less likely to volunteer (24/51; chi2 = 12.7, p >. 001). Medical students who volunteered were more likely to be first-year students, have previously volunteered in a similar setting, have positive attitudes toward caring for indigent patients, and have fewer factors that discouraged them from volunteering (p <. 01 for all) than students who did not volunteer. CONCLUSIONS: Volunteering with underserved communities during medical school and residency is influenced by previous experiences and, among medical students, year in school. Medical schools and residency programs have the opportunity to promote volunteerism and social responsibility through mentoring and curricular initiatives.

Is universal better than selective immunization in developing world? Vaccines (HBV).

PIP: Rumi et al. conducted a study to estimate the economic rationale for introducing routine prenatal hepatitis B surface antigen (HBsAg) screening and prescribing combined passive-active immunization to at-risk babies in Bangladesh. They concluded that universal hepatitis B virus (HBV) immunization may be more cost-effective than selective immunization in developing countries such as Bangladesh and India, and have therefore called for the replacement of selective vaccination with universal vaccination in Bangladesh. Given the limited available facilities in Bangladesh for antenatal checkup and laboratory tests, the universal vaccination of newborns is the more simple logistical option to control HBV infection. The Global Advisory Group of the Expanded Program on Immunization and World Health Assembly has recommended that countries with higher than a 2% prevalence of HBV carriers add hepatitis B vaccine to their routine infant immunization schedules. In the Southeast Asian region, however, only Indonesia, Mongolia, Thailand, and the Maldives have begun such routine hepatitis B immunization. Economic constraints have prevented other countries in the region from following suit.^ieng

WHO calls on South African officials to speak out.

PIP: World Health Organization (WHO) officials have suggested that President Nelson Mandela should declare a national health emergency with regard to the tuberculosis epidemic in South Africa. In July 1996, WHO announced that South Africa had about 350 cases of tuberculosis per 100,000 population, the worst in the world. The incidence of multi-drug resistance is also rising. In an article published in the New York Times on October 13, 1996, unnamed WHO officials were quoted as saying that President Mandela and Archbishop Desmond Tutu should speak about their experiences with the disease in order to increase public awareness. The article stated that a rise in drug use and the spread of human immunodeficiency virus (HIV), both of which depress the immune system and create vulnerability to tuberculosis, had occurred in South Africa with the renewal of international contacts after the lifting of sanctions imposed on the apartheid government. The South African health system currently spends about 20% of its tuberculosis budget on hospitalizing the 2% of patients with drug-resistant tuberculosis. Experts and WHO officials question the government's commitment; health administrators new to their jobs, tight budgets, and a calculated shift of power from Pretoria to the provinces are permitting the disease to go unchecked.^ieng

Day care setting ideal place for vaccination. Pediatrics (HAV).

PIP: Hepatitis A is highly endemic in developing countries. For example, in Sao Paulo, Brazil, 100% and 40.3% of lower and middle socioeconomic level children aged 2-11 years, respectively, have antibodies to hepatitis A. 90.4% of voluntary middle class adult blood donors are infected with the virus. Day care centers represent an important source of hepatitis A in several communities. Richtmann et al. investigated the immunogenicity and safety of the hepatitis A virus (HAV) strain GBM vaccine among 40 children attending a day care center in Sao Paulo. The children received three times 0.5 and 1.0 ml of the vaccine, the second and third dose one and six months after the first dose, respectively. All of the subjects had protective levels of antibodies in serum after two inoculations, with no serious adverse reactions observed. During the 8th month of follow-up, an outbreak of hepatitis A occurred in the day care center. Nine of the 27 control subjects developed either high titers of IgM class anti-HAV or acute hepatitis, but none of the vaccinated subjects developed signs or symptoms of hepatitis. This killed HAV vaccine was therefore found to be safe and effective in this area of high prevalence hepatitis A infection. Vaccination clearly benefits children in high-risk areas and should also be considered in areas of lower risk where day care centers are nonetheless important in facilitating the spread of HAV.^ieng

In vitro assessment of variables affecting the efficiency and efficacy of adenovirus-mediated gene transfer to cystic fibrosis airway epithelia.

Primary cultures of airway epithelia were used to evaluate variables pertinent to adenovirus (Ad)-mediated gene transfer efficiency and efficacy including: (i) Ad-vectors with different promoters, (ii) the duration of vector incubation with cells, (iii) the concentration and depth of vector-containing medium at constant multiplicity of infection (moi) (10(3)), and (iv) the relative sensitivity of reverse transcription polymerase chain reaction (RT-PCR) versus functional analysis for the detection of transduced cystic fibrosis transmembrane conductance regulator (CFTR). An Ad5-lacZ vector with a cytomegalovirus (CMV) enhancer/promoter transduced the greatest amount of beta-galactosidase (beta-Gal) activity, while an Ad2-lacZ vector with an E1a enhancer/promoter transduced the least. Ad5-lacZ vectors with the Rous sarcoma virus (RSV), E1a/RSV, or CMV enhancer/beta-actin (CB) promoters transduced intermediate levels of beta-Gal. Optimal gene transfer efficiency was detected with a 4-8 hr incubation of Ad5-CMVlacZ with cells, although optimal CFTR Cl-transport function was detectable after only a 30 min incubation of Ad5-CBCFTR with cells, consistent with correction of > or = 6-10% of cells in the epithelial sheet. Ad5-CBCFTR transduction of CF airway epithelial cells (moi = 10(3)) was optimal when higher concentrations, lower volumes, or smaller depths of vector-containing medium were utilized. RT-PCR was at least 100-fold more sensitive for the detection of transduced CFTR than functional analysis, and could detect as few as 0.001% Ad5-CBCFTR-infected CF cells admixed with uninfected CF cells. In summary, the variables studied clearly affect the efficiency of Ad-mediated gene transfer in vitro and potentially in vivo. They also suggest that RT-PCR is a poor marker of gene transfer efficiency and efficacy.

Decline in HIV reported among young males in Thailand.

PIP: Because of the dramatic rise in human immunodeficiency virus (HIV) infections in Thailand, the Thai Ministry of Public Health (MOPH) started a biannual sentinel surveillance program of intravenous drug users, blood donors, pregnant women, and commercial sex workers (CSWs) in 1989. The Royal Thai Army (RTA) also began screening young men, who had been conscripted by lottery, for HIV-1 that year. The results of both programs indicated that the epidemic had spread beyond the traditional high risk groups into the general population. Since heterosexual transmission, particularly through CSWs, had been the principal source of HIV transmission, the government initiated a 100% condom use campaign and condom distribution program among CSWs and their clients. Condom use in men visiting CSWs increased from 50% in 1989 to 90% in June 1992, and the rates of sexually transmitted disease (STD) reported from public clinics declined. The RTA screening program screened 311,108 young men between November 1989 and November 1994; demographic data were collected between November 1991 and May 1993, and in November 1994. The prevalence of HIV-1 among conscripts nationwide increased from 0.5% in 1989 to 3.5% in 1992; it reached 3.7% in 1993, but decreased to 3.0% in 1994. Although decreases were observed among men of all educational levels, from all regions, the greatest decrease occurred among those from the upper North (from 12.4% in 1992 to 7.9% in 1994) where the prevalence had been the highest. This information needs to be considered when planning HIV-1 vaccine efficacy trials.^ieng

STD treatment reduces HIV in rural Tanzania.

PIP: Improved sexually transmitted disease (STD) treatment reduced HIV infection by about 40% in a rural population in Tanzania. The objectives of the trial were to establish a program for the improved diagnosis and treatment of STDs within the Tanzanian primary health care system in the general population, and to measure the impact of this intervention on the incidence of HIV infection and on the prevalence and incidence of STDs. The study was conducted in the rural Mwanza region of Tanzania. HIV incidence was compared in 6 intervention communities and 6 pair-matched comparison communities. A random cohort of about 1000 adults 15-54 years old from each community was surveyed at baseline and at follow-up 2 years later. Intervention consisted of establishment of an STD reference clinic, staff training, regular supply of drugs, regular supervisory visits to health facilities, and health education about STDs. A total of 12,537 persons were recruited for the study. Baseline HIV prevalences were 3.8% and 4.4% in the intervention and comparison communities, respectively. At follow-up 8845 (71%) of the cohort were seen. Of those initially seronegative, the proportions seroconverting over 2 years were 48 of 4149 (1.2%) in the intervention communities and 82 of 4400 (1.9%) in the comparison communities. HIV incidence was consistently lower in the intervention communities in all 6 matched pairs. Allowing for the community-randomized design and the effects of confounding factors, the estimated risk rate was 0.58. No change in reported sexual behavior was observed in either group. The improved STD treatment reduced HIV incidence by about 40% in this rural population. The demonstration that HIV incidence can be almost halved by a modest intervention in one of the world's most disadvantaged countries should provide a message of hope.^ieng

Beef Quality Assurance education via satellite videoconference.

A 1.5-h satellite video program was developed for a statewide Beef Quality Assurance (BQA) producer education activity. Twenty-seven downlink sites were identified across the state, and additional known downlink sites included one each in Minnesota, Indiana, and Monterrey, Mexico. The videoconference was formally evaluated by viewers and resource people at each site. Program participants included representatives of the Ohio and National Cattlemen's Associations and two producers currently implementing BQA programs. A toll-free telephone number was available for viewer's questions during the last 15 min of air time and following the video program. A demographic data form and pre- and postconference evaluations were completed by 368 participants. Twenty-seven percent of the respondents were age 56 or older; 76% were age 36 or older. A one to five scale (strongly disagree to strongly agree) was used for evaluation. Beef Quality Assurance was considered by viewers to be an important consideration for the future in pre- (mean = 4.5, SD = .99) and post-evaluations (mean = 4.6, SD = .83). The mean response to the question regarding using more videoconferencing for agriculture programming was 3.9 (SD = .91). Four percent of participants indicated less or no videoconferencing should be used, 24% were neutral, and 72% felt more videoconferencing should be done. Comments were neutral with regard to the length of the conference (mean = 3.5, SD = .86) and the complexity of the subject matter (mean = 3.1, SD = .64). More than 88% of the participants agreed or strongly agreed that they intended to examine their overall production strategies to see where they could improve the quality of beef they produce (mean = 4.3, SD = .85). After the videoconference, 2.6% of respondents still strongly believed that BQA was not an important consideration for the future of the beef industry. The cost of all activities associated with this satellite video program was $13,000.

Objective testing of vergence ranges.

BACKGROUND: Testing of vergence ranges is a routine clinical procedure providing valuable information about the patient's binocular status. Unfortunately, obtaining this information from non-verbal or very young patients has proven difficult or impossible in many situations, due to lack of subjective response. This study explored a new prism bar technique for obtaining vergence ranges using an objective procedure in a randomized, modified examiner-masked routine that allows for vergence measurement without a verbal response. METHODS: In the first of two experiments, subjective and objective vergence ranges at 40 cm were obtained using a nonluminous target (printed picture of dog's head) from 29 adult subjects. The second experiment compared a self-illuminated target (transilluminator) to that of the nonluminous target in subjective and objective vergence range measurements using nine subjects from the first experiment. RESULTS: The results of both of these experiments suggest that, at least in the adult population, the vergence range values obtained objectively compare favorably with those obtained subjectively. However, the transilluminator yielded greater variance for all measures and, for one variable, base-out to break, did yield statistically different results between objective and subjective findings. CONCLUSIONS: Objective and subjective vergence range measurements appear to yield consistently comparable results in the adult population. The use of a non-luminous target appears to yield more consistent results, most likely due to the poor accommodative nature of a self-illuminated target (transilluminator).

Normalization of raised sodium absorption and raised calcium-mediated chloride secretion by adenovirus-mediated expression of cystic fibrosis transmembrane conductance regulator in primary human cystic fibrosis airway epithelial cells.

Cystic fibrosis airway epithelia exhibit a spectrum of ion transport properties that differ from normal, including not only defective cAMP-mediated Cl- secretion, but also increased Na+ absorption and increased Ca(2+)-mediated Cl- secretion. In the present study, we examined whether adenovirus-mediated (Ad5) transduction of CFTR can correct all of these CF ion transport abnormalities. Polarized primary cultures of human CF and normal nasal epithelial cells were infected with Ad5-CBCFTR at an moi (10(4)) which transduced virtually all cells or Ad5-CMV lacZ as a control. Consistent with previous reports, Ad5-CBCFTR, but not Ad5-CMV lacZ, corrected defective CF cAMP-mediated Cl- secretion. Basal Na+ transport rates (basal Ieq) in CF airway epithelial sheets (-78.5 +/- 9.8 microA/cm2) were reduced to levels measured in normal epithelial sheets (-30.0 +/- 2.0 microA/cm2) by Ad5-CBCFTR (-36.9 +/- 4.8 microA/cm2), but not Ad5-CMV lacZ (-65.8 +/- 6.1 microA/cm2). Surprisingly, a significant reduction in delta Ieq in response to ionomycin, a measure of Ca(2+)-mediated Cl- secretion, was observed in CFTR-expressing (corrected) CF epithelial sheets (-6.9 +/- 11.8 microA/cm2) when compared to uninfected CF epithelial sheets (-76.2 +/- 15.1 microA/cm2). Dose response effects of Ad5-CBCFTR on basal Na+ transport rates and Ca(2+)-mediated Cl- secretion suggest that the mechanism of regulation of these two ion transport functions by CFTR may be different. In conclusion, efficient transduction of CFTR corrects hyperabsorption of Na+ in primary CF airway epithelial cells and restores Ca(2+)-mediated Cl- secretion to levels observed in normal airway epithelial cells. Moreover, assessment of these ion transport abnormalities may represent important endpoints for testing the efficacy of gene therapy for cystic fibrosis.

Weight gain and reproductive performance of spring-born beef heifer calves intraruminally administered oxfendazole.

The effect of oxfendazole (Synanthic) on weight gain and reproductive performance of spring-born heifer calves was evaluated at five locations (IL, IN, MI, MO, ND). Three hundred thirty-eight mixed-breed beef heifers (293.4 kg) blocked by weight and age were randomly allotted to one of two treatments. Treatment 1 heifers were dewormed via intraruminal injection of oxfendazole. Treatment 2 heifers served as a control. Heifers were comingled during the winter phase in semi-confinement during the period from late January to late May (winter phase). Heifers were sorted by treatment at the beginning of the grazing season (approximately May 24, 1991) and remained separate until the end of the study (approximately July 31, 1991; summer phase). Dewormed heifers received oxfendazole (4.5 mg/kg BW) in late January and again 28 and 56 d after the beginning of the grazing season. Fecal samples were taken every 21 d from January through September and assayed for gastrointestinal parasite eggs. Fecal egg counts were similar across treatments at the beginning of the trial (P = .34). Deworming decreased fecal egg counts throughout the trial. Twenty-eight days after initial deworming a significant treatment effect on fecal egg counts was observed (P < .01). Winter ADG was significantly higher (P < .01) for dewormed heifers than for controls (.60 vs .52 kg, respectively). Summer ADG was not different between treatments. Dewormed heifers were 7.4 kg heavier than controls (P < .05) at the end of the trial. Age of puberty was not affected by treatment (P = .64). First-service conception and final pregnancy rates were not different between treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Crambe meal is equivalent to soybean meal for backgrounding and finishing beef steers.

Growth, feed efficiency, and carcass characteristics of 70 crossbred steers fed one of four diets were compared. The four diets differed in source of protein supplementation: 100% soybean meal (SB), 67% SB and 33% crambe meal (CM), 33% SB and 67% CM, and 100% CM. All supplements were fed in isonitrogenous amounts. Steers were fed backgrounding diets (12.9% CP) for 84 d and finishing diets (11.2% CP) for 96 d. Average initial weight was 303.4 kg. Backgrounding gains ranged from 1.38 to 1.41 kg/d (P = .92). Finishing gains ranged from 1.43 to 1.47 kg/d (P = .86). Range in entire-experiment gains was 1.41 to 1.46 kg/d (P = .85). Feed efficiencies were equal; entire-experiment efficiencies averaged .144 (P = .96). Growth and efficiency patterns were the same for all four treatments. No overall treatment differences were detected for the seven carcass variables (P = .26 to .96). Average fat depth, longissimus muscle area, yield grade, and dressing percentage were .95 cm, 84.0 cm2, 2.45, and 61%, respectively. At the protein percentage levels of these diets, CM substituted equally for SB for growth rate, feed efficiency, and carcass characteristics.

Social networks of residents in supportive housing.

One goal of supportive housing is to enlarge and improve the functioning of the social support networks of residents. The networks of a convenience sample of 42 residents were assessed using scales developed by Barrera. The size of the networks (11.5) was no larger than that reported for similar clients living in other types of community settings but the composition differed. Staff and co-residents appear to partially replace rather than add to family and friends. This is of concern because friends are uniquely important determinants of satisfaction. An association between perceived need for support and network size was also found. These findings suggest some positive influences but also raise questions about unintended negative consequences of living in artificially constructed social environments.

Supportive housing: a consumer evaluation study.

The current debate about how to provide housing for persons with persistent psychiatric disabilities should be informed by empirical information from a variety of sources. Data from a study of 17 residents discharged from Regeneration House Inc., illustrates the value of consumer perceptions in the evaluation of supportive housing. Extensive exploration of the positive and negative aspects of living in a group home from the perspective of experienced residents provides useful input for programme planning. The implications of the findings for the individual programme and the wider field are discussed.

Feedlot performance of Brahman x Angus versus Angus steers during cold weather.

Ten Angus and 10 Brahman x Angus F1 steers were used in a 184-d trial to compare feedlot performance during cold weather (-9 to 26 degrees C). Both groups of steers were exposed to the same environment for the same amount of time. All steers were fed for the same number of days regardless of frame score to avoid frame score x environment interactions. Brahman x Angus steers were 30.7 kg heavier (P less than .05) than Angus steers at the start of the trial. Differences in age (Brahman x Angus 40 d younger) for the two breed groups did not affect final live weight or carcass weight. Brahman x Angus steers consumed .2% less feed (P less than .05) as a percentage of BW than Angus steers; however, there was no difference in overall feed efficiency. Angus steers had a higher yield grade, more fat at the 12th rib (P less than .05), and graded 90% Choice; only 10% of the Brahman x Angus were graded Choice. Brahman x Angus steers were taller at the hip (P less than .05) and longer from first rib to aitch bone (P less than .05) and from thoracic vertebrae (T12/T13) to point of hock (P less than .05). Hide thickness determined at the neck, belly, and rump was found to be similar (7.7 mm) between the two groups. Sample hair weight and diameter did not differ between groups. Fiber, fat, protein, and DM digestibility coefficients were similar between groups but Brahman x Angus feces had a higher DM content.(ABSTRACT TRUNCATED AT 250 WORDS)

Synchronization of estrus in beef cows and heifers with prostaglandin F(2alpha) and estradiol benzoate.

An experiment was conducted to study an estrous synchronization regimen that involved the use of prostaglandin F(2alpha) (PGF(2alpha)) alone or in combination with estradiol benzoate (EB) and appointment breeding. Fifty-three registered Angus yearling heifers and 167 registered Angus cows (3 to 9 yr of age) were given two injections of PGF(2alpha) 11 d apart. Forty-eight hours after the second injection of PGF(2alpha') a random sample consisting of 117 cows and heifers was injected with EB in sesame seed oil. All females in the herd were artificially inseminated 80 h after the second injection of PGF(2alpha). Nearly equal percentages (25.1 vs 25.6%; P = 0.93) of treated (EB) and control (no EB) females conceived at the appointment breeding. Use of EB tended to reduce (P = 0.06) natural service conception rate (83.4 vs 93.1% for EB and control groups, respectively). Estrous synchronization treatment did not affect interval from Day 1 of the breeding season to calving.

Shipping suppresses lymphocyte blastogenic responses in Angus and Brahman X Angus feeder calves.

An experiment using 40 Angus or Brahman X Angus preconditioned feeder calves was conducted to evaluate the influence of shipping on cellular immune reactivity. Steers were allotted on the basis of weight and breed to a control or shipped group. Shipped steers were trucked 700 km to a feedlot; control steers remained at the ranch of origin. Total and differential leukocyte counts, phytohemagglutinin skin-test responses, lymphocyte blastogenic responses, monocyte phagocytic function, packed cell volumes and concentrations of plasma cortisol were determined before, immediately after and 1 wk after shipment. At unloading, total leukocytes were increased (P less than .05) in shipped Angus steers. Shipped steers also had higher (P less than .01) numbers of neutrophils. Skin-test responses to phytohemagglutinin were higher (P less than .05) in Angus than in Brahman X Angus steers, but shipping did not influence the reaction. Lymphocyte blastogenic responses were lower (P less than .05) in shipped steers; however, cortisol levels in plasma were not elevated (P greater than .10) in shipped calves. Monocyte phagocytosis and packed cell volume were not influenced by shipping. These data suggest that shipped steers have suppressed lymphocyte blastogenic responses.