Similarity to the self influences memory for social targets.

The construct of the self is important in the domain of memory research. Recent work has shown that person memory is influenced by similarity of social targets to the self. The current experiments investigate self-similarity as defined by traits and political ideology to better understand how memory for social targets is organised. Across three experiments, participants formed positive or negative impressions based on each target's picture, a trait-implying behavior (Experiments 1 & 2), and/or political ideology (conservative/liberal label in Experiment 2; political-ideological belief statements in Experiment 3) followed by a memory test. Results showed a self-similarity effect dependent on valence in Experiment 1, but not in Experiments 2 or 3 when participants processed ideological information associated with targets. These results suggest that self-similarity has an effect on memory for social targets, but that ideological information disrupts self-focused processing of others, suggesting that ideological information also has a powerful influence on what people remember about others (i.e. social targets).

Effects of winter growing program on visceral organ mass, composition, and oxygen consumption of beef steers during growing and finishing.

The purpose of this experiment was to investigate the effects of winter growing program on organ mass, composition, and oxygen consumption in beef steers. A total of 46 steers were used for the experiment. Four steers were randomly selected as an initial slaughter group. Remaining steers were randomly allotted to 1 of 4 treatment groups: 1) fed a high-concentrate diet for ad libitum intake (CF); 2) grazed on wheat pasture (WP); 3) fed a sorghum silage-based growing diet (SF); or 4) program fed a high-concentrate diet (PF). Steers in the WP, SF, and PF groups were managed to achieve approximately equal rates of BW gain during the growing phase. After the growing phase (112 d), steers in the WP, SF, and PF treatments were adapted to a high-concentrate diet for finishing. Steers from all treatments were slaughtered at a fat thickness of 1.27 cm as estimated by ultrasound. In addition, 6 steers from each treatment were randomly selected for slaughter at the end of the growing phase. Weights of all individual organs were measured and tissue samples of duodenum and liver collected. At the end of the growing phase, WP steers had greater (P < 0.05) small intestine, liver, and kidney mass than SF and PF steers. In contrast, mesenteric fat mass and total visceral fat content were greatest (P < 0.01) for PF, intermediate for SF, and least for WP steers. Mass of total viscera and total splanchnic tissues (TST) did not differ (P > 0.10) among treatments. At final slaughter, mass of mesenteric fat, total viscera, and TST were similar among treatments, but liver weights remained greatest (g/kg of empty BW; P < 0.01) for WP steers. There were no differences in oxygen consumption of duodenum or liver tissue on an equal weight basis (microL.min(-1.)g(-1)) at the end of either period. Growing program affected mass of components of the TST at the end of the growing phase, which contributed to differences in rate of splanchnic organ growth during finishing. We conclude that program feeding a high-concentrate diet during the growing phase may result in greater ADG and G:F during the subsequent finishing period compared with forage-based diets due to less accretion of visceral organ mass resulting in reduced maintenance energy requirements during finishing.

Effects of winter growing programs on subsequent feedlot performance, carcass characteristics, body composition, and energy requirements of beef steers.

The purpose of this study was to investigate the effects of winter growing program on subsequent finishing performance, carcass merit, and body composition of beef steers. Four steers were slaughtered to determine initial body composition. Remaining steers (n = 256) were blocked by BW and randomly allotted to 1 of 4 treatment groups: 1) ad libitum fed a high-concentrate diet (CF), 2) grazed on wheat pasture (WP), 3) fed a sorghum silage-based diet (SF), or 4) program fed a high-concentrate diet (PF). Steers in the WP, SF, and PF groups were managed to achieve approximately equal rates of BW gain. After the growing phase (112 d), 6 steers were randomly selected from the WP, SF, and PF treatments for determination of body composition. Remaining steers were adapted to a high-concentrate diet for finishing and slaughtered at 1.27 cm of 12th-rib fat. Six steers from each treatment were used to determine carcass, offal, and empty body composition. During the growing phase, WP, SF, and PF steers gained 1.15, 1.10, and 1.18 kg/d, respectively, and ME intake did not differ (P = 0.50) among treatments. Program-fed and SF steers had greater (P < 0.05) offal and empty body fat content than WP steers. Gain in offal and empty body fat was greatest (P < 0.05) for PF steers, intermediate for SF steers, and least for WP steers. During the finishing phase (123, 104, 104, 196 d for WP, SF, PF, and CF, respectively) DMI was greater (P < 0.01) for SF steers (10.9 kg/d) than for PF steers (10.1 kg/d); WP steers were intermediate (10.4 kg/d). Daily BW gain was greatest (P < 0.05) for SF steers (2.02 kg/d), intermediate for PF steers (1.85 kg/d), and least for WP and CF steers (1.64 and 1.63 kg/d, respectively). Accretion (kg/d) of carcass and empty body mass was less (P < 0.05) for WP and CF steers compared with PF and SF steers. Calf-fed steers had greater (P < 0.05) fat content of offal than SF and PF steers; WP steers were intermediate. Gain in empty body and carcass energy (Mcal/d) was greater (P < 0.05) for PF steers than CF steers with SF and WP steers being intermediate. At slaughter, SF steers had reduced (P < 0.01) yield grades and greater marbling scores compared with CF and WP steers; PF steers were intermediate. In conclusion, growing programs that increase fat composition of feeder calves did not negatively affect subsequent finishing performance. Finishing steers as calves may reduce retained energy of carcass tissues and increase internal fat during high-grain feeding compared with steers that previously underwent a growing program.

An upper limit for caloric density of finishing diets.

This review assessed the relationships between dietary energy density and animal performance in an effort to evaluate a possible upper limit for energy density in finishing diets for cattle. Data were combined from 49 experiments (69 trials; 243 treatment observations) in which the dietary ME concentration (Mcal/kg of DM) was varied by level of concentrate, grain source, grain processing, and level of supplemental fat. Dietary concentrations of ME were determined using 1) NRC values of ME from diet ingredients; or 2) values derived from the literature, in which ingredient ME had been calculated from animal performance. Procedures for pooling data from multiple studies were used. The dependent variable was fit to a model that included a random slope and intercept clustered by trial. Trial-adjusted dependent variables (animal performance and carcass characteristics) were regressed on the independent variable (dietary ME concentration). Models were fit to cubic equations, and then reduced from cubic to quadratic to linear equations when the cubic and quadratic terms were not significant at P > 0.10. When NRC values were used, the relationship of DMI (% of BW) to dietary ME was linear (DMI decreased as ME increased; R2 = 0.631). However, the slope of ME intake (Mcal/kg of BW(0.75)) vs. dietary ME content did not differ (P > 0.25) from zero, supporting the concept that ruminants on high-grain diets (2.7 to 3.3 Mcal of ME/kg of DM) eat to maintain constant energy intake. Quadratic relationships were observed (P < 0.05) when ADG and G:F vs. dietary ME concentration were analyzed. Gain:feed was maximized with 3.46 (NRC) to 3.65 (calculated) Mcal/kg of ME from the total diet, 2.99 (NRC) to 3.40 (calculated) Mcal/kg of ME from grain, and 0.43 (NRC) to 0.53 (calculated) Mcal/kg of ME from supplemental fat. Most relationships of carcass traits to dietary ME were not significant (P > 0.10). Increased 12th-rib fat at greater ME and increasing KPH suggests greater fat deposition with increasing caloric density. Assuming that NRC ME values for ingredients commonly used in finishing diets are correct, the upper caloric limit for maximizing ADG and G:F was 3.16 and 3.45 Mcal/kg of DM, respectively. Reaching the upper caloric limit for G:F would require most grains to be processed or fed in high-moisture form. Whether maximizing G:F results in the most desirable carcass composition and yield of retail cuts should be determined.