Influence of dietary -arginine supplementation of sows during late pregnancy on piglet birth weight and sow and litter performance during lactation.

Two experiments were conducted to determine the effect of feeding supplemental -Arg during late pregnancy on piglet birth weight and preweaning performance. In Exp. 1, 97 gilts and sows were allotted (gestation d 93) to receive a control diet (CON; 19.8 g standardized ileal digestible [SID] Arg/d) or the CON + 1.0% -Arg (ARG; 46.6 g SID Arg/d). Gilts and sows were weighed on gestation d 93 and 110, 48 h after farrowing, and at weaning. Data, including number born alive, number weaned, individual birth and weaning weight, and placenta weight, were recorded. Blood samples were collected on d 93 and 110 and analyzed for plasma IGF-1, insulin, and blood urea nitrogen concentration. In a second experiment, 383 sows in a commercial research farm were allotted to receive CON or ARG. An -Arg premix was provided daily by top dress beginning at gestation d 81 (±0.1 d) and fed for an average of 35 d (±0.2 d). Sows received 2.73 kg feed/d with CON sows provided 17 g SID Arg/d and ARG sows receiving a total of 44 g SID Arg/d. Litter birth weight was recorded and average birth weight was computed. In a subset of 82 sows, individual birth weights were recorded. In Exp. 1, there was a tendency for greater late pregnancy maternal BW gain ( = 0.06) in ARG compared with CON. A tendency for a parity × treatment interaction was observed for late pregnancy BW gain, with first litter sows fed ARG gaining the most, gilts fed ARG intermediate, and all other treatments gaining the least ( = 0.10). No differences between treatment groups were observed for maternal plasma IGF-1, insulin, and urea nitrogen and in progeny performance to weaning ( > 0.28). In Exp. 2, piglet birth weight was more effectively tested because of the large number of multiparous sows involved. There was a tendency for individual birth weight to decline in ARG compared with CON ( < 0.08), but birth weight distribution between <0.80 and >2.8 kg was similar. No other differences were observed ( > 0.18). In conclusion, late pregnancy supplementation with -Arg had no effect on number of pigs born alive, piglet birth weight, or lactation performance.

Effects of salt, BHA/BHT, and differing phosphate types on quality and sensory characteristics of beef longissimus muscles.

USDA Select striploins (n = 20) were cut into thirds (anterior, medial, and posterior) and randomly assigned to 1 of 6 treatments. Treatments included: (1) control (C); (2) 0.006% BHA (butylated hydroxyl anisole)/BHT (butylated hydroxytoluene) (70%/30%) (BB); (3) 0.4% trisodiumphosphate (CT); (4) 0.4% sodiumtripolyphosphate with 0.5% salt (BH); (5) sodiumtripolyphosphate, 0.5% salt, and 0.006% BHA/BHT (70%/30%) (SB); (6) 0.2% sodiumtripolyphosphate, 0.2% trisodiumphosphate, and 0.5% salt (STB). Muscle sections were injected to 110% (10% pump) of their weight with their respective treatments. Inclusion of BHA/BHT allowed for lower mean oxidation values. Regardless of phosphate type, muscles treated with both phosphate and salt had lower retail purge (P < 0.05). Sensory panelists rated (P < 0.05) STB, SB, and BH to be juicier than all other treatments. These data suggest that inclusion of both salt and phosphate can enhance palatability, lower cook loss, and retail purge.

Effectiveness evaluation of several cattle anthelmintics via the fecal egg count reduction test.

Utilizing groups of cograzed, naturally infected beef-type heifers, three fecal egg count reduction tests were conducted in the later months of 2007 at the University of Arkansas. Each test was 28 days in length consisting of individual animal fecal nematode egg counts and coprocultures. Both original and generic ivermectin injectable formulations were used in two of the tests at 0.2 mg/kg BW, with FECR percentages never exceeding 90% in either test. Oral fenbendazole was evaluated at 5 and 10 mg/kg BW, with FECR%'s exceeding 90% on all occasions, but with a precipitous drop when recently treated animals were treated at the lower dose. Evaluated in one test, injectable moxidectin given at 0.2 mg/kg BW resulted in egg count reductions of 96-92% (days 7 to 28). Also evaluated in one test, albendazole delivered orally at 10 mg/kg BW was 98% and 97% effective at 17 and 28 days post-treatment. For all tests, coprocultures conducted post-treatment contained only Cooperia spp. larvae (benzimidazole use), relatively unmodified percentages of Cooperia spp. and Haemonchus spp. larvae (ivermectin use), and primarily Cooperia spp. larvae with a small percentage of Haemonchus spp. larvae (moxidectin use).

Effects of conjugated linoleic acid, salt, and sodium tripolyphosphate on physical, sensory, and instrumental color characteristics of beef striploins.

USDA Select striploins (IMPS 180; n= 24) were cut into thirds (anterior, medial, and posterior) and assigned to 1 of 8 treatments utilizing a randomized incomplete block design. Treatments included (1) control (C); (2) 1.5% conjugated linoleic acid (conjugated linoleic acid = CLA) (CGA); (3) 0.4% sodium tripolyphosphate (PHO); (4) 0.5% salt (SAL); (5) 0.4% sodium tripolyphosphate, 0.5% salt (SPH); (6) 0.4% sodium tripolyphosphate, 1.5% CLA (PCL); (7) 0.5% salt, 1.5% CLA (SCL); and (8) 0.4% sodium tripolyphosphate, 0.5% salt, 1.5% CLA (SPC). Treatments were injected with solutions to 110% (10% pump) of their original weight. Treatments with CLA had higher (P < 0.05) marbling scores than treatments that did not. Not including SAL, treatments with salt, or phosphate or a combination of the two had higher tenderness values when sampled by panelists. Fresh steaks with inclusion of CLA had greater amounts (P < 0.05) of the CLA isomers than steaks not having CLA. Cooked steaks having CLA also had greater amounts (P < 0.05) of CLA, except for SCL, which were not different (P > 0.05) from the non-CLA treatments. Day was a significant source of variability for a*, b*, and saturation index. Treatment x day interactions were significant (P < 0.05) for hue angle and L* values. These data suggest that inclusion of CLA can increase amounts of CLA isomers without major deleterious effects to instrumental, physical, and quality characteristics of beef striploin steaks.

Fresh and cooked color of dark-cutting beef can be altered by post-rigor enhancement with lactic acid.

Fresh and cooked color of dark-cutting (DC) beef strip loins (mean pH=6.56) enhanced with 0.25, 0.50, 0.75 or 1.00% lactic acid (LA) were compared to non-enhanced DC and normal pH (NpH; mean pH=5.43) strip loins. Even though NpH steaks received the most (P<0.05) desirable fresh color scores, color scores for steaks from DC sections enhanced with 0.25% LA approached those of NpH steaks after the first day of retail display. Discoloration scores were also similar (P>0.05) among NpH and 0.25% LA-enhanced DC steaks throughout the 5 d of display. Fresh steaks from NpH strip loins were redder, as evidenced by greater (P<0.05) a(∗) values and lower (P<0.05) hue angles, than DC steaks and DC steaks enhanced with LA, regardless of concentration. However, cooked color scores and proportions of denatured myoglobin were similar (P>0.05) between untreated NpH steaks and DC steaks enhanced with 0.25% LA. Results from this study indicate that enhancing DC beef with LA may lead to the brightening of the fresh color and prevention of the persistent red cooked color, approaching that of NpH beef.

Interactive effect of ractopamine and dietary fat source on pork quality characteristics of fresh pork chops during simulated retail display.

Crossbred pigs (n = 216) were used to test the interactive effect, if any, of ractopamine (RAC) and dietary fat source on the performance of finishing pigs, pork carcass characteristics, and quality of LM chops during 5 d of simulated retail display (2.6 degrees C and 1,600 lx warm-white fluorescent lighting). Pigs were blocked by BW and allotted randomly to pens (6 pigs/pen), and, after receiving a common diet devoid of RAC for 2 wk, pens within blocks were assigned randomly to 1 of 4 diets in a 2 x 2 factorial arrangement, with 5% fat [beef tallow (BT) vs. soybean oil (SBO)] and RAC (0 vs. 10 mg/kg). Diets were formulated to contain 3.1 g of lysine/Mcal of ME and 3.48 Mcal/kg of ME. Across the entire 35-d trial, pigs fed RAC had greater (P < 0.01) ADG and G:F, but RAC did not affect (P = 0.09) ADFI; however, performance was not affected (P >or= 0.07) by dietary fat source. Carcass weight, LM depth, and lean muscle yield were increased (P < 0.01), whereas fat depth was decreased (P = 0.01), in carcasses from RAC-fed pigs; however, carcass composition measures were similar (P >or= 0.27) between fat sources. Feeding 10 mg/kg of RAC reduced (P

A regional evaluation of the effect of fiber type in gestation diets on sow reproductive performance.

A cooperative regional research study using 194 sows, from which data were collected from 381 litters, was conducted at 3 research stations to determine the effects of added psyllium (a concentrated fiber source) or soybean hulls to gestation diets on reproductive performance of sows and preweaning performance of their pigs. Primiparous and multiparous sows were allotted to the 3 treatments of control (corn and soybean meal-based), 0.30% psyllium, or 20% soybean hulls. Sows fed the control and 0.30% psyllium diets were provided 1.82 kg/d, and sows fed the 20% soybean hulls diet were provided 2.0 kg/d to equalize ME, Lys, Ca, P, and vitamin and trace mineral intake. Treatments 1 to 3 had 130, 130, and 121 litters per treatment from 64, 64, and 63 sows, respectively. Gestating sows fed psyllium had a greater (P < 0.01 to 0.10) d 110 gestation, farrowing, weaning, and 17 d postpartum BW and gestation ADG compared with sows fed soybean hulls. Sows fed psyllium also had a greater (P < 0.10 and 0.08) d 110 gestation BW and gestation ADG than the control sows. Sows fed soybean hulls had a reduced (P < 0.06) farrowing BW compared with the control sows. Sows fed psyllium weaned lighter (P < 0.09) pigs than sows fed the control diet. Litter size was not affected (P > 0.10) by diet. Sows fed psyllium had a reduced (P < 0.03) feed intake compared with sows fed soybean hulls for d 5 to 7 postpartum, and sows fed the control diet were intermediate. Fecal scores (1 to 5 with 1 = dry and 5 = watery) were greater (P < 0.001) and DM content was less (P < 0.001 to 0.01) in the feces of sows fed soybean hulls compared with sows fed psyllium or the control diet on d 112 of gestation and d 4 postpartum. Fecal scores were greater (P < 0.10) and fecal DM content was less (P < 0.02) in sows fed psyllium compared with sows fed the control diet only on d 4 postpartum. In summary, sows fed soybean hulls during gestation had reduced BW compared with sows fed the control diets. In contrast, sows fed psyllium had an increased BW.

Effect of a Bacillus-based direct-fed microbial feed supplement on growth performance and pen cleaning characteristics of growing-finishing pigs.

A direct-fed microbial (DFM) based on a combination of Bacillus organisms specifically selected to increase the manure decomposition process was evaluated to determine its efficacy for improving growth performance and manure dissolution time. Three experiments involving 336 crossbred barrows and gilts were conducted to determine the effect of the Bacillus-based direct-fed microbial on growth performance and pen cleaning time. In each experiment, 2 dietary treatments (0 and 0.05% DFM) were fed during the growing-finishing period throughout the experiment, such that the DFM provided 1.47 x 10(8) cfu of Bacillus organisms per gram of supplement. Data from the 3 experiments were combined for analysis, such that there were 28 pens representing each of the 2 treatments. Pigs were weighed and feed intake was determined at the initiation and termination of each phase (starter, grower, and finisher). At the end of Exp. 1 and 3, pen cleaning time was determined by measuring the time required for each pen to be scraped and washed with a high-pressure sprayer. Additionally, 2 solid manure mat samples weighing approximately 4 g each were collected from solid manure buildup in each pen (16 pens/treatment), and the time required to completely disperse each manure mat sample was determined. Gain:feed improved (P < 0.05) in pigs fed Bacillus compared with the control diet during the finisher phase and throughout the combined growing-finishing period. The time required to dissolve the manure mat was reduced (P < 0.01) in samples collected from pens containing pigs fed Bacillus compared with samples from control pens. An additional evaluation was conducted in a commercial swine production facility using statistical process control analysis. Statistical process control analysis determined that supplementation with Bacillus increased the expected mean for ADG and decreased the expected mean for death loss percentage. Supplementation with a DFM composed of specifically selected Bacillus organisms improved G:F and decreased the time required to disperse a swine manure mat sample in a controlled study conducted at swine research facilities. Furthermore, when evaluated in a commercial swine production facility, the Bacillus-based DFM improved ADG and reduced mortality of pigs during the growing-finishing period.

The impact of lactic acid concentration and sodium chloride on pH, water-holding capacity, and cooked color of injection-enhanced dark-cutting beef.

The objectives of this study were to evaluate the effect of enhancement with 0.5%, 1.0%, 1.5%, or 2.0% lactic acid (LA), with or without 0.5% salt (NaCl), on pH, water-holding capacity, and resultant cooked color of dark-cutting (DC) beef. The pH of DC sections treated with LA decreased (P<0.05), whereas water-holding capacity (WHC) increased (P<0.05) with increasing concentrations of LA. Sensory panelists noted an increase (P<0.05) in the degree of doneness (less pink internal color), whereas, a(∗) and chroma values were lower (P<0.05), and hue angles were greater (P<0.05), indicating the internal color of LA-treated DC sections was less red and appeared more well-done. Also, 630:580nm reflectance ratios were similar (P>0.05) among DC steaks treated with 0.5% and 1.0% LA and normal pH (NDC) steaks, likely caused by an increase (P<0.05) in myoglobin denaturation in LA-enhanced DC steaks. These results indicate that the use of LA can reduce postmortem muscle pH and alter the cooked color of DC beef, ultimately resulting in a deletion of the persistent pinking condition.

Influence of vacuum-aging period on bloom development of the beef gluteus medius from top sirloin butts.

The gluteus medius (GM) from USDA Select beef carcasses was used to test the effect of aging period on bloom development. Top sirloin butts (IMPS #184) were randomly allocated to 0, 7, 14, 21, 28, and 35d vacuum-aging at 2°C (n=10/aging period). Each week, aged top sirloin butts were faced before two 2.5-cm-thick, non-adjacent steaks were cut and instrumental color (L(∗), a(∗), and b(∗)) of the GM was measured at 10-min intervals for 2h after cutting. Steaks aged for 7 and 14d were a more vivid (greater chroma values; P<0.05), redder (greater a(∗) values; P<0.05), and more yellow (greater b(∗) values; P<0.05) color than steaks from the other aging periods. Change in total color (ΔE) was greater (P<0.05) for steaks from top sirloin butts aged 7, 14, and 21d than steaks from top butts aged 28 and 35d, whereas oxymyoglobin percentages for steaks from top butts aged 7 and 14 days were greater (P<0.05) than those from top sirloin butts aged 28 and 35d. As much as 90% of the total increase (P<0.05) in a(∗), b(∗), and chroma values, as well as hue angles and oxymyoglobin percentages, was achieved during the first 60min after cutting.

Influence of wet-aging on bloom development in the longissimus thoracis.

The longissimus thoracis (LT) from USDA Select beef carcasses was used to test the effect of aging period (0, 7, 14, 21, 28, or 35d) on bloom development (n=10/aging period). After aging, two 2.54-cm-thick, non-adjacent steaks were cut and instrumental color of the LT was measured at 10-min intervals for 2h. All instrumental color parameters increased (P<0.05) over 40% during the first 10min; however, asymptotic points indicated that color plateaued sometime after 120min. Although aging did not (P⩾0.05) affect the values where color development plateaued, rate of oxymyoglobin formation tended to be the slowest (P=0.06) in LT steaks aged 7d compared to steaks aged 0, 14, 28 and 35d. Results indicated that as much as 90% of the total increase (P<0.05) in instrumental color and oxymyoglobin percentages was achieved during the first 60min after cutting, but aging period had no impact on bloom development.

Interactive effect of ractopamine and dietary fat source on quality characteristics of fresh pork bellies.

Crossbred pigs (n = 216) were used to test the interaction, if any, of ractopamine (RAC) and dietary fat source on the characteristics of fresh pork bellies. Pigs were blocked by BW (77.6 +/- 6.5 kg) and allotted randomly to pens (6 pigs/pen). After receiving a common diet devoid of RAC for 2 wk, pens within blocks were assigned randomly to 1 of 4 treatments arranged in a 2 x 2 factorial design, with 5% fat (beef tallow vs. soybean oil) and RAC (0 vs. 10 mg/kg). At the conclusion of the 35-d feeding period, pigs were slaughtered at a commercial pork packing plant (average BW of 108.8 +/- 0.6 kg), and fresh bellies were captured during carcass fabrication. Neither RAC (P = 0.362) nor fat source (P = 0.247) affected belly thickness. Subjective (bar-suspension) or objective (compression test) measures of belly firmness were not (P > or = 0.148) affected by the inclusion of RAC in the diet; however, bellies from pigs fed soybean oil (SBO) were softer than those from pigs fed beef tallow (BT), as indicated by perpendicular (P < or = 0.005) and parallel (P < 0.001) suspensions. Moreover, bellies from BT-fed pigs required more (P = 0.096) force to compress 50% of their thickness than bellies from SBO-fed pigs (52.29 vs. 43.51 kg). Color (L*, a*, and b* values) of the belly lean and fat was not (P > or = 0.131) affected by RAC, and lean color was similar (P > or = 0.262) between fat sources; however, belly fat from BT-fed pigs was lighter (P = 0.030) and redder (P = 0.013) in color than belly fat from SBO-fed pigs. Bellies of SBO-fed pigs had greater (P < 0.001) proportions of PUFA and lower (P < 0.001) proportions of SFA and MUFA than belly fat from pigs fed BT. Regardless of the RAC inclusion level, PUFA:SFA and iodine values were lower in belly fat from pigs fed BT than SBO; however, within SBO-fed pigs, PUFA:SFA and iodine values were further increased by feeding RAC (RAC x fat source, P < 0.001). As expected, dietary fat source altered the fatty acid composition of fresh pork bellies, which subsequently impacted fresh belly firmness. Interestingly, including RAC in swine finishing diets exacerbated the effect of feeding SBO on pork fat polyunsaturation.

Injection of conjugated linoleic acid into beef strip loins.

Beef strip loins (IMPS 180; n=15) were sectioned in thirds and sections (n=45) were left untreated (CNT) or injected with either a commercial powder conjugated linoleic acid (CLA) source (Powder) or a commercial oil CLA source (Oil), whose major isomers were 18:2cis-9, trans-11 and 18:2trans-10, cis-12 CLA isomers. Fresh Oil steaks had 3.20 and 3.15, Powder steaks had 4.67 and 4.62, and CNT steaks had 0.19 and 0.02mg/g muscle tissue (wet basis) of the cis-9, trans-11 and trans-10, cis-12 CLA isomers, respectively. TBARS were similar (Oil) and lower (Powder), compared to CNT. Powder steaks had similar instrumental color, and beef and off flavor characteristics as CNT. Artificial marbling was created with Oil steaks having USDA Small(79) and Powder steaks having USDA Modest(86) marbling scores, while CNT steaks had USDA Slight(94) marbling scores. Injection of CLA can be effective in significantly increasing CLA and potentially creating artificial marbling.

Lateral and longitudinal characterization of color stability, instrumental tenderness, and sensory characteristics in the beef semimembranosus.

The objectives of this study were to evaluate longitudinal and lateral variations in color stability and sensory characteristics of the semimembranosus from each muscle location (dorsal=D, medial=M, ventral=V), and within each steak subsequently divided into four regions (caudal-distal=CaD, cranial-distal=CrD, caudal-proximal=CaP, cranial-proximal=CrP). Instrumental color assessment indicated that L(∗) (lightness) values tended to be lower for the CaD and CrD regions of all muscle locations, with higher L(∗) values recorded for the CrP regions of muscle sections. Instrumental tenderness measurements for Meullenet-Owens razor and Warner-Bratzler shear force values were generally lower for the CaD region of the D section, whereas regions within the V section were tougher and required greater shear force. Sensory panelists perceived lower amounts of connective tissue in the CaD of the D section, which tended to be more tender, whereas higher levels of connective tissue and greater toughness occurred in the CaP and CrP regions of the M and V sections. These results provide a detailed muscle profile of the quality variation within the semimembranosus, and may be used to further enhance the fabrication and marketability of this beef subprimal cut.

The influence of different management systems and age on intestinal morphology, immune cell numbers and mucin production from goblet cells in post-weaning pigs.

At time of weaning, the immune system in piglets is not fully mature resulting in reduced growth and increased mortality. Early-weaned pigs transported to a segregated early weaning (SEW) facility have enhanced performance and gut development compared to conventional (CONV) pigs which may be due, in part, to decreased pathogen challenge. To gain further insight into SEW enhanced performance and gut development, gut samples from pigs weaned at 19+/-2 days were assessed during the post-weaning (PW) period. The numbers of cells expressing CD2, CD4, CD8, and CD172 (the 74-22-15 (SWC3) antibody is now known to be specific for CD172), MHC class II, and CD25 were quantified using immunohistochemistry. Additionally, samples of duodenum, jejunum, and ileum were evaluated for the production of neutral, acidic, and sulfuric mucins from goblet cells and morphological measurements were also made. No effects due to the management systems alone were observed for any of the parameters. However, there were interactive effects of age/time post-weaning and management system on the immune cells as well as on the mucin secreting goblet cells. There were no differences in gut morphology between SEW and CONV reared pigs.

Ontogeny of T lymphocytes and intestinal morphological characteristics in neonatal pigs at different ages in the postnatal period.

To evaluate morphological characteristics and development of the immune system at different ages in neonatal pigs, 4 piglets were euthanized at 7, 14, and 18 d of age for collection of blood, bile, and intestinal tissue for morphological measurements. Blood was collected for differential cell counts, lymphocyte blastogenesis, immunoglobulin (Ig) concentrations, cytokine concentrations, and flow cytometric analysis. Bile was collected for quantification of Ig-A and Ig-M. Villus width and crypt depth from duodenum sections, as well as ileum crypt depth, were reduced (P < or = 0.08) in 18-d-old pigs compared with 7-d-old pigs. No age-related differences (P > or = 0.11) were observed in the number of goblet cells with neutral and acidic mucins, serum or enteric Ig concentrations, IL-2, IL-4, spontaneous lymphocyte proliferation, or leukocyte concentrations. When measured as counts per minute (cpm) and as a stimulation index (SI), lymphocyte proliferation responses to phytohaemagglutinin increased (P = 0.05) between 7 and 14 d of age; no changes (P = 0.10) occurred at 18 d of age. No age-related changes (P = 0.39) were observed in response to pokeweed mitogen (PWM) when measured as cpm; however, the SI from PWM-induced lymphocytes decreased (P = 0.04) 4-fold between 7 and 18 d of age. The CD4+:CD8+ and populations of lymphocytes expressing CD2+CD4+CD8- (T helper cells) and CD25+CD4+CD8- (activated T helper cells) were greater (P > or = 0.04) at 7 d of age than at 14 and 18 d. Populations of T lymphocytes, cytotoxic T cells (CD2+CD4-CD8+), activated lymphocytes (CD25+), and activated cytotoxic T cells (CD25+CD4-CD8+) were greater (P > or = 0.02) in 18-d-old pigs compared with 7-d-old pigs, whereas CD2+CD4-CD8- [double negative cells] were lower (P = 0.08) in 18-d-old pigs compared with 14-d-old pigs. The percentage of CD2+ T cells was 8.4% at 7 d of age, and by the time the pigs reached 18 d of age, the percentage of CD2+ T cells was 33.8%. Moreover, the percentage of gammadelta T cells was greater (P = 0.02) in 18-d-old pigs than in 7-d-old pigs (74.8 vs. 46.1%, respectively). Results indicate that the porcine immune system and gut are continuously changing as the young pig matures. Changes occurred in lymphocyte phenotypic expression and functional capabilities, as well as morphology and mucin production, and their role may be to further protect the neonate from antigenic challenge as protection from passive immunity declines.

Effect of weaning age and commingling after the nursery phase of pigs in a wean-to-finish facility on growth, and humoral and behavioral indicators of well-being.

Pigs from one farrowing group in which gilts were bred to farrow pigs that would be either 14 or 21 d of age at weaning, were divided into older and younger age groups (108 pigs per group) and penned 12 pigs per pen in a wean-to-finish facility. At the end of the nursery phase, half the pigs in each age group were removed, rerandomized, and commingled for the finishing phase. The other half remained in their original pens. Pigs were fed common Phase 1 (d 0 to 14) and Phase 2 (d 14 to 35) nursery diets, and a common 4-phase program diet during growing/finishing, with transitions at 45, 68, and 90 kg of BW. The study ended when the lightest weight block averaged 107 kg. Blood was obtained on d 0, 2, 10, 27, 37, 44, and 65 after weaning to determine leukocyte concentrations. In addition, behavior was monitored during the nursery period at weaning (d 0), on d 7, 14, and 27 after weaning, and during the growing/finishing phase on d 35 (after commingling following the nursery phase), 38, 44, and 65 after weaning. Older pigs were heavier (P < 0.001) throughout the nursery period, and the BW difference between younger and older pigs increased from 2 to 6.5 kg at the start and end of the nursery period, respectively. Older pigs had a greater concentration of white blood cells (P < 0.05) and lymphocytes (P < 0.10) on d 0, 2, and 10 after weaning than younger pigs. Younger pigs spent less (P < 0.05) time resting on the day of weaning, and more (P < 0.05) time active during the overall nursery phase. During Phase 3 and in the overall finishing phase, younger pigs had greater (P < 0.01) ADG and G:F than older pigs. Moreover, during Phase 3, ADFI (as fed) decreased (P < 0.05) when older pigs were commingled compared with older pigs that were not commingled. There was no difference in ADFI of younger pigs, regardless of commingling (interaction; P < 0.10). Results of this study indicate that weaning age affects growth performance in a wean-to-finish facility, as well as behavioral and immunological responses to weaning and commingling after the nursery phase. Management strategies should be further explored to optimize these benefits without the detrimental effects on health observed during the nursery period in this study.

Fatty acid and sensory characteristics of beef from three biological types of cattle grazing cool-season forages supplemented with soyhulls.

Over two consecutive years, the effects of allocating divergent biological types of cattle (n=107) to fescue pasture without supplementation, or fescue or orchardgrass pasture with soyhull supplementation on chemical, fatty acid and sensory characteristics were investigated. Cattle from the two supplemented treatments produced beef that had increased (P<0.05) percentage lipid and decreased (P<0.05) polyunsaturated and n-3 fatty acids compared to the control. However, the n-6 to n-3 ratio was still less than four in beef from the supplemented cattle. Additionally, supplementation did not decrease (P>0.05) the CLA present in the longissimus, which can commonly occur when forage-fed cattle are supplemented concentrates. Although supplementation did not impact (P>0.05) Warner-Bratzler shear force or tenderness, supplementation of soyhulls reduced (P<0.05) the grassy flavor intensity of rib steaks when compared to the control. Biological type did not have a significant influence on most traits analyzed in this study. These results suggest that supplementation of soyhulls to cattle grazing forage can reduce grassy flavor intensity without decreasing CLA proportions, but can reduce the n-3 fatty acid proportions present in the longissimus.

Enhancement with varying phosphate types, concentrations, and pump rates, without sodium chloride on beef biceps femoris quality and sensory characteristics.

Beef biceps femoris muscles (n=45) were used to evaluate the effect of enhancement with solutions containing sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), or tetrasodium pyrophosphate (TSPP) at either 0.2% or 0.4% of product weight, without sodium chloride. All solutions were injected into muscle samples at either 112% (12% pump) or 118% (18% pump) of raw product weight. Muscles enhanced with STPP or TSPP had a higher (P<0.05) pH than SHMP or untreated muscles (CNT), whereas there was no difference (P>0.05) in pH between SHMP and CNT. Muscles enhanced with STPP had less (P<0.05) free water than CNT, whereas SHMP and TSPP did not differ from CNT. However, direct comparison of phosphate types revealed no difference (P>0.05) in free water. Steaks enhanced with SHMP had greater (P<0.05) cooking losses than CNT, whereas steaks treated with STPP or TSPP did not differ (P>0.05) from CNT. Phosphate inclusion at 0.2% allowed for greater (P<0.05) cooking losses than CNT, whereas 0.4% phosphate inclusion exhibited similar (P>0.05) cooking losses as CNT. Although there were no differences (P>0.05) in cooking loss between pump rates, steaks enhanced at an 18% pump rate had greater (P<0.05) cooking losses than CNT, whereas those enhanced at 12% had similar (P>0.05) cooking losses as CNT. Enhancement with any of the three phosphate types or either concentration did not improve (P>0.05) sensory tenderness or juiciness characteristics compared to CNT, but enhancement at an 18% pump rate allowed for improved (P<0.05) overall tenderness, compared to a 12% pump rate. These results suggest that while phosphate enhancement independent of sodium chloride generally did not improve water retention, cooked yields and palatability compared to untreated samples, utilizing higher phosphate concentrations or utilizing STPP or TSPP effectively retained the additional water associated with solution enhancement, allowing for similar free water and cook yields as untreated samples.

Effects of enhancement with differing phosphate types, concentrations, and pump rates, without sodium chloride, on beef biceps femoris instrumental color characteristics.

Enhancement of beef biceps femoris muscles (n=45) with solutions comprising sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), or tetrasodium pyrophosphate (TSPP) at either 0.2% or 0.4% of product weight, with the exclusion of sodium chloride, was performed to observe the independent phosphate effects on instrumental color during simulated retail display. All solutions were injected into muscle samples at either 112% (12% pump) or 118% (18% pump) of raw product weight. All three phosphate types maintained higher (P<0.05) L* values than untreated steaks (CNT) through 5 days-of-display, and SHMP had higher (P<0.05) L* values than STPP and TSPP through 7 days-of-display. Additionally, steaks with 0.2% phosphate inclusion were lighter (L*; P<0.05) than CNT throughout display, and were lighter (P<0.05) than steaks enhanced with 0.4% phosphates through 7 days of display. Steaks enhanced with TSPP had higher (P<0.05) a* values than CNT on days 5 and 7 of display, whereas SHMP- or STPP-enhanced steaks generally had similar (P>0.05) a* values as CNT after 3d of display. Direct comparison of phosphate concentrations revealed no differences (P>0.05) in a* values. Only steaks enhanced with TSPP were more vivid (P<0.05) and had higher (P<0.05) proportions of oxymyoglobin than CNT on days 5 and 7 of display. However, direct comparison of phosphate types indicated that TSPP- and STPP-enhanced steaks had similar (P>0.05) oxymyoglobin proportions during display. Phosphate inclusion at 0.4% maintained higher (P<0.05) oxymyoglobin proportions than 0.2% phosphate inclusion through 5 days-of-display. These results indicate that while 0.2% phosphate concentrations maintain lighter color, 0.4% concentrations can more effectively retain oxymyoglobin during display. Additionally, only steaks enhanced with TSPP were redder, more vivid, and had higher oxymyoglobin proportions than untreated steaks during the latter stages of display.