Effect of housing system and boar exposure on estrus expression in weaned sows.

Reproductive efficiency depends on detection of estrus, which may be influenced by housing and boar exposure. This experiment investigated the effects of housing system and boar contact on measures of estrus in weaned sows. Mixed-parity sows were randomly assigned to be weaned into gestation crates away from boars (AWC, n = 45), into pens away from boars (AWP, n = 42), or into pens adjacent to a mature boar (ADJ, n = 46). Estrus detection was initiated at approximately 0700 (0 h) and again at 0.25-, 0.5-, 1-, 2-, 4-, and 8-h intervals beginning on d 4 and continuing through d 7 following weaning. Estrus detection involved observation of the standing response after application of nose-to-nose boar exposure, backpressure, and side rubbing. For the AWC sows, a mature boar was moved to the front of the crates for a 10-min period and then removed. Sows housed in AWP were moved approximately 15 m to an empty pen adjacent to a mature boar for a 10-min period, and then returned to their pen. Sows housed ADJ were not moved and estrus detection was performed in their home pen for a 10-min period. The proportion of sows expressing estrus within 7 d from weaning was lowest for ADJ (80%, 37/46) compared with AWP (98%, 41/42) and AWC (96%, 43/45; P < 0.05). There was an effect of interval from weaning to estrus on the percentage of sows expressing estrus, but there was no interaction with treatment. Sows in AWC and AWP (4.7 d) had decreased (P = 0.01) intervals from weaning to estrus compared with ADJ (5.2 d). The duration of estrus was also shorter (P < 0.001) for ADJ (45 h) compared with AWC (58 h) or AWP (62 h). There was a treatment x interval x day of estrus effect for the percentage of sows expressing estrus. After detection of the first standing response on the first day of estrus, only 62 to 82% of sows were detected standing over the next 2 h for all treatments. However, at 4 to 8 h, this increased to 85 to 98% for the AWC and AWP sows, but <73% of the ADJ sows were detected during this period. On the second day of estrus, estrus expression was not influenced by interval for the AWC and AWP sows and was between 90 to 100% during the 8-h period, whereas ADJ sow detection rates were between 68 to 88%. These data suggest that housing sows adjacent to boars negatively affects estrus expression and detection. In addition, refractory behavior occurs in approximately 30 to 40% of sows and is influenced by housing relative to the boar, day of estrus, and interval from last boar exposure.

Now you see it, now you don't: explicit versus implicit measures of the personal/group discrimination discrepancy.

When making explicit self-report ratings, members of status- and racial-minority groups report less personal experience with discrimination than that encountered by their group--a phenomenon called the personal/group discrimination discrepancy (PGDD). This study provides evidence, for the first time, that the PGDD may be, in part, a product of the procedure used to measure it. White women and men completed explicit and implicit measures of personal and group discrimination based on sex. The PGDD surfaced among women in the explicit measures, but not in the implicit measures. These findings suggest that explicit and implicit measures might provide different assessments of experience with discrimination.

Less pain and more to gain: why high-status group members blame their failure on discrimination.

Members of high-status groups are more likely than members of low-status groups to blame their failure on discrimination and are less likely to blame it on themselves. This tendency was demonstrated in 3 experiments comparing men and women, White and Black students, and members of experimentally created high- and low-status groups. Results also showed that when making an attribution to discrimination, high-status group members were less likely to experience a threat to their social state self-esteem, performance perceived control, and social perceived control and were more likely to protect their performance state self-esteem. These findings help to explain why high-status group members are more willing to blame their failure on discrimination by showing that it is less harmful for them than for low-status group members.

Why minority group members perceive or do not perceive the discrimination that confronts them: the role of self-esteem and perceived control.

Self-esteem and perceived control were examined to explain why minority group members sometimes perceive discrimination but, more often, minimize the discrimination. Women (Study 1), and Asians and Blacks (Study 2) reacted to negative feedback after information about the probability for discrimination. Minority group members tended to minimize discrimination and attributed their failure to themselves. By perceiving discrimination as a reason for failure, minority group members protected their performance state self-esteem. In contrast, by minimizing discrimination, they protected their social state self-esteem and maintained the perception of control in the performance and social domains. Results suggest that minority group members minimize discrimination because the consequences of doing so are psychologically beneficial.