Bloom Time Effect Depends on Muscle Type and May Determine the Results of pH and Color Instrumental Evaluation.

The aim of this study was to determine the effect of 30 min bloom time and the type of muscle on pH and color parameters together with the possibility of estimating these measurements. The research material consisted of 270 samples from 6 muscle types: LD-Longissimus dorsi, LL-Longissimus lumborum, IL-Iliacus, SEM-Semimembranosus, CT-Cutaneous trunci, LTD-Latissimus dorsi. Measurements included pH and color of fresh pork at 0 min, and after 30 min bloom time. Bloom time influenced all analyzed parameters, although to a varying effect, depending on the muscle type. The lowest pH values were noted for dorsal-located muscles (LD, LL), then in the ham area (IL, SEM), and the highest values of the location on the side surface of the carcass (CT, LTD). The large increase in the proportion of L* and a* was observed for CT muscle (20-30%, the highest of all observed) and LTD (20-25%); for LD and LL the largest growth changes were observed for parameters b* (15-20%) and H* (20-30%). The lowest number of strong correlations was noted for LD and CT muscles, and the largest for SEM. A very good fit (R2 > 0.90) of regression equations was achieved in 7 cases. The presented results are an important contribution to the rapid and precise instrumental evaluation of pH and color.

Pork ham and belly quality can be estimated from loin quality measurements?

The aim of the study was to determine the relationships between the quality evaluation of loin and the quality evaluation of ham and belly from the same carcasses for trying to predict the quality parameters of ham and belly based on measurements made on the loin. The research material consisted of 105 pork carcasses, from which three elements were cut and marked: loin, ham and belly. Quality evaluation included: pH, color, water holding capacity (WHC), cooking loss (CL), and sensory analysis. All designated quadratic equations were characterized by low R2 values from 0.06 to 0.43 for ham and from 0.00 to 0.28 for belly. However, it is possible to predict the quality parameters of ham or belly with different levels of accuracy (R2 from 0.50 to 0.92 - depending on the measurement and the element), using measurements selected from all those tested on the loin. Those loin quality measurements most frequently used in equations were chewiness and CL.

Analysis of the lifetime and culling reasons for AI boars.

BACKGROUND: The aim of the study was to analyze the lifetime and culling reasons for boars used in insemination centers (AI centers). METHODS: The data collected from 355 culled boars from 1998 to 2013 included: age at start of semen collection, boar herd life, culling reason, daily gain and lean meat content, and number of ejaculates not meeting sales requirements after dilution. Culling reasons were divided into 7 groups: low semen value (LSV), low or lack of libido (LL), leg problems (LP), infectious diseases (ID), old age (OA), reduced demand for semen from the given boar (RD), and others (OT). RESULTS: The most common culling reasons for boars were LSV (23.7%) and RD (22.5%). It was observed that the lowest daily gains were noted in boars culled due to OA. Boars culled due to OA and RD were maintained in production for the longest time (over 1000 d), for LSV and ID retention was about 700 d, and due to LL below 400 d. The survival probability was over 0.9 until 1.5 yr, and just over 0.2 until 4 yr. The highest relative frequency was observed in the 36th and 42nd mo of life (over 16%). Hazard risk analysis revealed a more than 10 times higher risk of culling in the case of LL, ID or OT, in comparison to OA. CONCLUSIONS: The results can be used as a direct point of reference for the identification of emerging problems in AI boar exploitation and the development of an appropriate culling policy in AI centers.

Boar genotype as a factor shaping age-related changes in semen parameters and reproduction longevity simulations.

The aim of this study was a detailed analysis of the boar genotypes used in AI stations with an indication of their production capacity, including age and a precise analysis of their culling time and reason. The study included 334 boars: 81 Polish Large White (PLW), 108 Polish Landrace (PL), 49 Pietrain (P), 56 Duroc × Pietrain (D × P) and 40 Hampshire × Pietrain (H × P). Semen volume, spermatozoa concentration, total number of spermatozoa, number of motile spermatozoa, and number of insemination doses were analyzed. Quadratic regression was used to illustrate the selected sperm parameters at specific ages. Among all the studied boars the lowest motilities of spermatozoa were identified in white breeds PLW and PL, and the difference between motility extremes was 3.53% (P ≤ 0.01). The highest number of insemination doses were produced from D × P crossbreed boars: about 0.7 portions more compared to PL, 1.13 to PLW, 1.18 to H × P and 1.8 to P (all differences P ≤ 0.01). It has been shown in the case of ejaculate volume that for PLW and H × P boars the culling moment was far too early in terms of production capacity and differences were, respectively, 16.35 ml for PLW and 12.61 ml for H × P. Based on the developed regression equations, the earliest maximum number of motile sperm (73.82 × 109) was obtained by H × P crossbreed boars as early as at age 24 months. The highest values for this parameter were achieved, however, by other D × P crossbreed boars: 74.30 × 109 at the later age of 32 months. A consequence of the high number of motile sperm in young H × P boars was that the theoretical maximum value of the number of AI doses was produced as early as the 14th month (25.59 portions). Curves of similar shape were obtained for PL and D × P boars; the difference in maximal values was 0.54 portions in favor of crossbreeds, at a later age of 7 months. It was noted that for PLW and D × P boars the highest number of cullings were due to reduced demand (24.47% and even 31.19%, respectively). Other boars - PL, P and H × P - were most frequently culled because of low semen values. Regardless of the genotype, high survival probabilities (over 0.96) were noted for the age of 12 months. The highest probabilities (still over 0.96) were noted in the longest time period (up to 18 months) for P boars. The results of our study can be used in AI stations as reference points for the exploitation and culling of boars with different genotypes.

The use of oxytocin in liquid semen doses to reduce seasonal fluctuations in the reproductive performance of sows and improve litter parameters--a 2-year study.

The objective of the present research was to eliminate seasonal fluctuations in year-round reproductive performance of sows and to improve litter parameters by administration of oxytocin into liquid semen insemination doses. A 2-year experiment was performed on crossbreed sows, Polish Large White × Polish Landrace, which were partitioned into two groups: control, insemination without any modification with 100 mL semen doses and oxytocin, insemination with 100 mL semen doses to which 5 IU of oxytocin was added just before insemination. A total of 10,486 inseminations were made. The farrowing rate and obtained litter parameters, including the effect of season, were analyzed. For each litter, the following factors were defined: average litter size, percentage of fetal death and mummified piglets, average piglet birth weight, percentage of piglet mortality, fecundity index, average number of piglets weaned, weaned piglet weight, and daily gain. Sows presented a positive reaction to the experimental factor. A statistically higher farrowing rate for oxytocin group in summer and autumn seasons was confirmed (P ≤ 0.01). Regardless of the season, a higher average litter size was observed in the oxytocin group with the most evident differences for winter, spring (P ≤ 0.01), and summer (P ≤ 0.05). The effect of oxytocin on the percentage of fetal death and mummified piglets born was not confirmed statistically except for winter. Analyzing the fecundity index, higher values were obtained for the oxytocin group in all seasons (P ≤ 0.01), including the lowest difference between groups for winter (51.43) and the highest for summer (100.61). A higher average birth piglet weight and weaned piglet weight were recorded for the oxytocin group in all seasons. The highest differences in birth piglet weight between groups were noted for spring (0.22 kg; P ≤ 0.01) and winter (0.17 kg; P ≤ 0.05) and in weaned piglet weight for winter and spring (0.58 kg and 0.52 kg; for both, P ≤ 0.01). The greatest daily gains were observed in the winter season (P ≤ 0.05) in favor of oxytocin. On the basis of the presented results, it should be noted that the use of oxytocin into insemination doses improves the farrowing rate and other parameters of the reproductive performance of sows. In the absence of negative effects, year-round insemination with oxytocin addition into seminal doses is recommended, which effectively improves the production performance and reduces the problem of seasonality in reproduction.