Genetic parameter estimation for beef bull semen attributes.

Improvements in bull reproductive performance are necessary to optimize the efficiency of cattle production. Female fertility has been enhanced through assisted reproductive technologies as well as genetic selection; however, improving beef bull fertility has been largely ignored. Phenotypes routinely collected at bull semen collection facilities are believed to affect fertility and provide the phenotypes necessary for a genetic evaluation. The first objective of this study was to determine the significant fixed effects for modeling beef bull fertility using data from bull semen collection facilities. The second objective was to estimate variance components, heritabilities, repeatabilities, and correlations between beef bull semen attributes. Beef bull fertility phenotypes including volume (VOL), concentration (CONC), number of spermatozoa (NSP), initial motility (IMot), post-thaw motility (PTMot), 3-h post-thaw motility (3HRPTMot), percentage of normal spermatozoa (%NORM), primary abnormalities (PRIM), and secondary abnormalities (SEC) were obtained from two bull semen collection facilities. A total of 1,819 Angus bulls with 50,624 collection records were analyzed. Of the fixed class and covariate effects tested, the significant class effects were collection location and collection day within year and the significant covariate effects included age at collection, days since previous collection, and cumulative comprehensive climate index (CCI). For this study, the CCI was calculated for a 75-d period including the 61-d spermatogenesis cycle and 14-d epididymal transit time. The 75 d prior to collection accounted for the environmental stress a bull may have experienced over the course of development of the spermatozoa, which was more significant than the CCI calculated for collection day or spermatogenesis start date. Pre-thaw beef bull semen traits had low heritability estimates of 0.11 ± 0.02 (VOL), 0.09 ± 0.02 (CONC), 0.08 ± 0.02 (NSP), and 0.12 ± 0.03 (IMot). Heritabilities of post-thaw beef bull semen attributes were more variable at 0.10 ± 0.02 (PTMot), 0.05 ± 0.04 (3HRPTMot), 0.10 ± 0.04 (%NORM), 0.03 ± 0.03 (PRIM), and 0.18 ± 0.04 (SEC). Correlations of breeding values for these traits with scrotal circumference (SC) expected progeny difference (EPD) are low. The low to moderate heritability estimates indicate that genetic improvement can be made in beef bull semen quality traits if new tools are developed to augment the scrotal circumference EPD that are currently available within the industry.

Evaluation of different blends of medium-chain fatty acids, lactic acid, and monolaurin on nursery pig growth performance.

A total of 710 pigs (Line 400 × 200, DNA, Columbus, net energy (NE)) were used in two experiments (Exp. 1: initially, 6.3 ± 0.05 kg; Exp. 2: initially, 6.8 ± 0.05 kg) to evaluate the effects of two medium-chain fatty acid (MCFA) based products on nursery pig growth performance. Following their arrival at the nursery facility, pigs were randomized to pens (five pigs per pen) and allowed a 4-d acclimation period. Thereafter, pens of pigs were blocked by initial weight and randomized to dietary treatment. In Exp. 1, the dietary treatments were a dose titration of: 0%, 0.5%, 1.0%, or 2.0% MCFA-based additive, as well as a diet including 1.0% MCFA from a 1:1:1 blend of C6:0, C8:0, and C10:0. In Exp.2, dietary treatments consisted of a basal diet containing no MCFA (control), the control diet with a 1.0% inclusion of four different blends of MCFA, lactic acid, and monolaurin or a diet with 1.0% added MCFA (a 1:1:1 blend of C6:0, C8:0, and C10:0). The four blends consisted of 50% C6:0, 20% lactic acid, and increasing levels of monolaurin (0%, 10%, 20%, and 30%) at the expense of C12:0 (30%, 20%, 10%, and 0%). Treatment diets were formulated and manufactured in two dietary phases. Data were analyzed as a randomized complete block design with pen as the experimental unit. In Exp. 1, overall (days 0-34), increasing CaptiSURE increased (linear, P ≤ 0.014) average daily gain (ADG) and average daily feed intake (ADFI). Feed efficiency improved (quadratic, P = 0.002) with increasing CaptiSURE up to 1.0% of the diet with no benefit thereafter. There was no evidence for differences between pigs fed 1.0% CaptiSURE and pigs fed the 1.0% MCFA blend of C6:0, C8:0, and C10:0. In Exp. 2, overall (days 0-35), pigs fed the 1.0% 1:1:1 MCFA blend had increased (P < 0.034) ADFI and ADG resulting in 0.9 kg greater final weight (P = 0.014) compared with the control group. There was no evidence that the mean performance of pigs fed the four blends of MCFA, lactic acid, and monolaurin were different from the pigs fed the control diet. In summary, the addition of a 1.0% 1:1:1 blend of C6:0, C8:0, and C10:0 in nursery pig diets improved ADG, ADFI, and gain to feed ratio (G:F) compared with pigs fed the control diet. In addition, providing nursery pigs with the MCFA product CaptiSURE, up to 2% of the diet, resulted in linear improvements in ADG and ADFI. Altering the C12:0 to monolaurin ratio and adding lactic acid did not improve growth performance compared with pigs fed the control diet.

Assessing viewer-centered and stimulus-centered spatial bias: The 3s spreadsheet test version 1.

The 3s Spreadsheet Test (3S Test) is a cancellation test with high stimulus density and low target-to-distractor ratio, to assess stimulus-centered and viewer-centered spatial neglect. Twenty-five stroke survivors with left-sided neglect and 68 age-matched healthy controls took the 3S Test. Patients also took the Apples Test, a validated cancellation test. No patient's accuracy on the 3S Test was in the normal range. A total of 91.7% of the patients had an abnormal start; 52.6% of the patients took abnormally long time to complete the 3S Test. The 3S and Apples Tests agreed poorly on both the viewer-centered and stimulus-centered neglect classifications (κ = .25 and .05, respectively), but consistently identified 8 of the 25 patients (32%) as having both forms of neglect while each isolated form of neglect was present in one patient (4%). Lesion data were consistent with previous studies. These findings suggest that the 3S Test is a sensitive cancellation test for assessing viewer-centered and stimulus-centered spatial neglect. We are currently developing the 3S Test version 2 to refine the test stimuli and the scoring procedure.

Not enough familiarity for fluency: definitional encoding increases familiarity but does not lead to fluency attribution in associative recognition.

Five experiments were conducted to test whether encoding manipulations thought to encourage unitization would affect fluency attribution in associative recognition memory. Experiments 1a and 1b, which utilized a speeded recognition memory test, demonstrated that definitional encoding increased reliance on familiarity during the recognition memory test. Experiments 2a, 2b, and 3, however, replicated previous research that had shown that fluency is unlikely to be attributed as evidence of previous occurrence in associative recognition (Westerman, Journal of Experimental Psychology: Learning, Memory, and Cognition 27:723-732, 2001). The results put limits on the degree to which fluency can influence recognition memory judgments, even in cases of enhanced familiarity, and are consistent with previous work suggesting that participants have preexperimental expectations about fluency that are difficult to change (e.g., Miller, Lloyd, & Westerman, Journal of Memory and Language 58:1080-1094, 2008), as well as with work suggesting that fluency has less of an influence on recognition memory decisions that are conceptual in nature (Parks, Journal of Experimental Psychology: Learning, Memory, and Cognition 39:1280-1286, 2013).

Global processing training to improve visuospatial memory deficits after right-brain stroke.

Visuospatial stimuli are normally perceived from the global structure to local details. A right-brain stroke often disrupts this perceptual organization, resulting in piecemeal encoding and thus poor visuospatial memory. Using a randomized controlled design, the present study examined whether promoting the global-to-local encoding improves retrieval accuracy in right-brain-damaged stroke survivors with visuospatial memory deficits. Eleven participants received a single session of the Global Processing Training (global-to-local encoding) or the Rote Repetition Training (no encoding strategy) to learn the Rey-Osterrieth Complex Figure. The result demonstrated that the Global Processing Training significantly improved visuospatial memory deficits after a right-brain stroke. On the other hand, rote practice without a step-by-step guidance limited the degree of memory improvement. The treatment effect was observed both immediately after the training procedure and 24 h post-training. Overall, the present findings are consistent with the long-standing principle in cognitive rehabilitation that an effective treatment is based on specific training aimed at improving specific neurocognitive deficits. Importantly, visuospatial memory deficits after a right-brain stroke may improve with treatments that promote global processing at encoding.