Effect of presence of clinical and subclinical endometritis at the initiation of Presynch-Ovsynch program on the first service pregnancy in dairy cows.

The present study examined the effect of presence of clinical or subclinical endometritis at the initiation of Presynch-Ovsynch estrous synchronization program on the first service pregnancy rate in dairy cows. Lactating Holstein cows (N=275) were given a thorough reproductive examination at 32-38 days in milk, 3 days prior to the scheduled start of Presynch-Ovsynch program. Based on the reproductive exam findings the cows were diagnosed and classified into three groups as clinical endometritis, subclinical endometritis and normal. All cows received two set-up injections of 25mg PGF(2alpha) (Lutalyse((R)), Pfizer Animal Health, New York, NY, USA) i.m., 14 days apart starting at 35-42 days in milk (DIM). All cows received 75microg of GnRH (Cystorelin, Merial, Iselin, NJ, USA) i.m. 14 days after the second pre-synchronization injection of PGF(2alpha), followed by a third injection of 25mg PGF(2alpha) i.m. 7 days later. Cows received a second injection of 75microg of GnRH i.m. 54h after the third PGF(2alpha), and received timed artificial insemination at the time of the second GnRH injection or 24h later. Multivariate logistic regression was used to analyze the odds of pregnancy at the first service. Variables included in the model were endometritis status (clinical endometritis, subclinical endometritis and normal), farm (two), presence of corpus luteum (CL, yes or no), timing of second GnRH in relation to AI (0 or 24h), sire fertility (bulls with greater compared with lesser estimated relative conception rates), parity (primiparous and multiparous) and their interactions. Of all variable included in the model, cows with corpus letuem (OR=1.83 versus OR=1.00; P=0.05) 3 days prior to the scheduled start of Presynch-Ovsynch program and primiparous cows (OR=1.00 versus OR=0.55; P=0.04) had increased odds of becoming pregnant at the first service. No differences were found in the odds of first service pregnancy among clinical, subclinical endometritis and normal cows (P>0.1). In summary, presence of clinical or subclinical endometritis at the initiation of Presynch-Ovsynch estrous synchronization program does not harm the first service pregnancy rate in dairy cows.

Effect of sire fertility and timing of artificial insemination in a Presynch + Ovsynch protocol on first-service pregnancy rates.

Sire fertility may influence pregnancy rate (PR) by differences in sperm survival in the female reproductive system and time required for capacitation and transport of sperm to site of fertilization. A predicted fertility index, Estimated Relative Conception Rate, was used to select 3 high-fertility artificial insemination (AI) sires (+3) and 3 average AI sires (-1). Ovulation can be predicted to occur at approximately 28 h following GnRH administration when used in an Ovsynch protocol. The objective of this study was to determine if AI at 2 times, 0 or 24 h after GnRH administration, in a Presynch + Ovsynch protocol resulted in different first-service PR when average or high-fertility sires were used. Lactating Holstein cows (n = 1,457) from 2 dairy herds located in the Piedmont region of North Carolina were utilized for 12 mo. Timing of AI did not affect first AI PR and no interaction of sire-fertility group and timing of AI was detected. First AI PR did not differ between sire-fertility groups (23.2 vs. 29.4%) for average and high-fertility groups, respectively. First-lactation cows were 53% more likely to conceive than older cows, and cows bred during April through June were 66% less likely to become pregnant compared with cows bred from October through January. No interactions were detected among parity, season, sire-fertility group, or time of AI. Using only 3 sires per group based on Estimated Relative Conception Rate estimates resulted in large variability of sire conception within groups, although group averages differed by 6 points.

Fertility following fixed-time AI or insemination at observed estrus in Ovsynch and Heatsynch programs in lactating dairy cows.

The objective of this study was to compare the conception rate for fixed-timed artificial insemination (FTAI) and observed heat artificial insemination (HAI) prior to the scheduled FTAI in Ovsynch and Heatsynch synchronization protocols. In Experiment 1, lactating dairy cows (n=535) received two set-up injections of 25mg prostaglandin F(2alpha) (PGF(2alpha)) i.m., 14 days apart starting at 36+/-3 days in milk (DIM). Cows were blocked by parity and were randomly allocated to either Ovsynch or Heatsynch groups. All cows received 100 microg of GnRH i.m. 14 days after the second set-up injection of PGF(2alpha), followed by a third injection of 25mg PGF(2alpha) i.m., 7 days later. In the Ovsynch group, HAI cows (n=29) were bred on standing estrus after the third PGF(2alpha) before the scheduled second GnRH, whereas FTAI cows (n=218) that were not observed in estrus, received a second injection of 100 microg of GnRH i.m., 48 h after the third PGF(2alpha) and received TAI 8 h after the second GnRH. In the Heatsynch group, all cows (n=288) received 0.5 mg of estradiol cypionate (ECP) 24 h after third PGF(2alpha) and HAI cows (n=172) were bred on standing estrus and FTAI cows (n=116) that were not observed in estrus, received TAI 72 h after the third PGF(2alpha). In Experiment 2, repeat breeder cows (n=186) were randomly assigned to either Ovsynch or Heatsynch groups. The FTAI and HAI cows were inseminated similar to Experiment 1. All cows were observed for estrus three times daily. The associations with the conception rate were modeled with logistic regression separately for Experiments 1 and 2. Of all the variables included in the model in Experiment 1, type of AI (HAI versus FTAI, P=0.0003) and parity (primiparous versus multiparous, P=0.05) influenced the first service conception rate. Over-all conception rate and first service conception rate for HAI cows were higher compared to FTAI cows (33.8% versus 21.3%, and 35.3% versus 21.0%; P=0.001). In the Heatsynch group, cows that received HAI had significantly higher over-all conception rate and first service conception rate compared to FTAI (35.2% versus 17.3% and 36.0% versus 15.5%; P=0.0001). The conception rates in repeat breeder cows for HAI and FTAI (30.1% versus 22.3%) were not different (P>0.1). In conclusion, it was recommended to include AI at observed estrus and fixed-time AI for cows not observed in estrus in order to improve the conception rate in synchronization protocols.

Gender differences in the learning status of diabetic children.

The learning status of 95 diabetic boys and girls and 97 matched controls was evaluated using the Wechsler Intelligence Scale for Children--Revised IQ factors and school histories. Of interest was whether diabetic boys would evidence more learning difficulties. Results indicated that diabetic boys had significantly lower Freedom From Distractibility scores compared with scores of diabetic girls and control Ss and lower Perceptual Organization scores compared with scores of control boys. Although group scores were still within the average range of functioning, a significantly high percentage of diabetic boys (40%) compared with diabetic girls (16%) had learning problems that warranted either special instructional services or grade retention. Diabetic children experienced more learning difficulties (24%) than controls (13%), supporting research findings that diabetes is associated with increased risk of learning problems.

Pink triangles: antecedents and consequences of perceived workplace discrimination against gay and lesbian employees.

A model of perceived sexual orientation discrimination was tested in a national sample of 534 gay and lesbian employees. The effects of legislation, organizational policies and practices, and work group composition on perceived sexual orientation discrimination were examined, as well as the attitudinal and organizational outcomes associated with discrimination. Gay employees were more likely to report discrimination when employed in groups that were primarily heterosexual and in organizations that lacked supportive policies and were not covered by protective legislation. Disclosure of sexual orientation at work was related to discrimination and antecedent variables. Perceived discrimination was associated with negative work attitudes and fewer promotions. Organizational policies and practices had the strongest impact on perceived discrimination and were directly related to outcomes.

Odor recognition and identification: effect of labels over time.

The effect of labels on recognition and identification of odors over time was assessed. 30 men and 30 women were presented 20 odors; half of the participants were also told a name for the odor as a label. Five min. and 60 min. later, all participants were given 20 odors (10 from the original set, 10 new) and asked whether each odor was new or old (odor recognition). The group given labels was also asked to recall the label provided (odor identification). Analysis indicated a significant effect of time on recognition. Significantly more odors were recognized at 5 min. than 60 min. The effect of label was also significant, with recognition being better for the Label condition than the No-Label condition. As for odor identification, women identified more labels than did men. Overall, odor recognition was better with labels soon after exposure, and the women were better at remembering the labels than the men.

Factor Analysis of Ipsative Measures.

lpsative measures are multiple measures, where the data are collected, or are modified, in such a way that all subject totals across the measures are equal. Much has been written about factor analysis with such data, however, no clear consensus has been reached regarding the suitability of ipsative measures for factor analysis. The purpose of the present article is to show analytically the fundamental problems that ipsative measures impose for factor analysis. The expected value of the correlation between ipsative measures is shown to equal - 1/ ( k - I), where k is the number of measures. The rank of the resulting correlation matrix is reduced by one to k - 1, and ipsativity alone produces k - 1 artifactual bipolar factors, which will obscure any actual interrelations among the measures. If the data are known to be ipsative or if the tell-tale signs of ipsativity are seen, factor analysis should not be done.

Limited Information Parameter Estimates for Latent or Mixed Manifest and Latent Variable Models.

We argue for separate analyses of the measurement and structural portions of latent or mixed manifest and latent variable models. We present limited information (single equation) procedures for estimating parameters in the structural portion of these models. These include parameter estimation procedures for recursive or nonrecursive relations, and procedures for testing zero-effect hypotheses. We then compare full and limited information estimates in a Monte Carlo analysis of sample correlation matrices that contained structural model misspecifications. Both full and limited information estimates identified misspecified nonzero effects reasonably well. However, limited information estimates were far superior in detecting misspecified zero-effect hypotheses. We recommend limited information parameter estimation procedures over full information techniques for (a) testing specific causal hypotheses and (b) locating specific structural model misspecifications.