Nonlinear analysis of heart rate variability for evaluating the growing pig stress response to an acute heat episode.

Heart rate variability (HRV) is a proxy measure of autonomic function and can be used as an indicator of swine stress. While traditional linear measures are used to distinguish between stressed and unstressed treatments, inclusion of nonlinear HRV measures that evaluate data structure and organization shows promise for improving HRV interpretation. The objective of this study was to evaluate the inclusion of nonlinear HRV measures in response to an acute heat episode. Twenty 12- to 14-week-old growing pigs were individually housed for 7 days and acclimated to thermoneutral conditions (20.35°C ± 0.01°C; 67.6% ± 0.2% RH) before undergoing one of the two treatments: (1) thermoneutral control (TN; n = 10 pigs) or (2) acute heat stress (HS; n = 10 pigs; 32.6°C ± 0.1°C; 26.2% ± 0.1% RH). In Phase 1 of the experimental procedure (P1; 60 min), pigs underwent a baseline HRV measurement period in thermoneutral conditions before treatment [Phase 2; P2; 60 min once gastrointestinal temperature (Tg) reached 40.6°C], where HS pigs were exposed to heated conditions and TN pigs remained in thermoneutral conditions. After P2, all pigs were moved back to thermoneutral conditions (Phase 3; P3; 60 min). During each phase, Tg data were collected every 5 min and behavioural data were collected to evaluate the amount of time each pig spent in an active posture. Additionally, linear (time and frequency domain) and nonlinear [sample entropy (SampEn), de-trended fluctuation analysis, percentage recurrence, percentage determinism (%DET), mean diagonal line length in a recurrence plot] HRV measures were quantified. Heat stressed pigs exhibited greater Tg (P = 0.002) and spent less time in an active posture compared to TN pigs during P2 (P = 0.0003). Additionally, low frequency to high frequency ratio was greater in HS pigs during P3 compared to TN pigs (P = 0.02). SampEn was reduced in HS pigs during P2 (P = 0.01) and P3 (P = 0.03) compared to TN pigs. Heat stressed pigs exhibited greater %DET during P3 (P = 0.03) and tended to have greater %DET (P = 0.09) during P2 than TN pigs. No differences between treatments were detected for the remaining HRV measures. In conclusion, linear HRV measures were largely unchanged during P2. However, changes to SampEn and %DET suggest increased heat stress as a result of the acute heat episode. Future work should continue to evaluate the benefits of including nonlinear HRV measures in HRV analysis of swine heat stress.

Short communication: Assessment of disbudding pain in dairy calves using nonlinear measures of heart rate variability.

The purpose of this study was to evaluate whether pain-related stress caused by disbudding could be detected using nonlinear measures of heart rate variability (HRV). Twenty-five female Holstein calves (4-7 wk of age) were randomly assigned to 1 of 3 treatments: (1) sham disbud (SHAM; n = 9), (2) disbud with lidocaine-meloxicam pain mitigation (MED; n = 8), or (3) disbud without pain mitigation (NoMED; n = 8). Heart rate variability (sample entropy, percentage determinism, percentage recurrence, or mean length of diagonal lines in a recurrence plot) was recorded on d -1, 0, 1, 3, and 5 relative to the experimental procedure, with disbudding taking place on d 0. The short-term detrended fluctuation analysis scaling exponent was greater in MED calves than in SHAM calves, indicating a greater stress response to the disbudding procedure regardless of pain mitigation. These results indicate that calves in the MED group may have experienced pain-related stress as a result of the disbudding procedure. The remaining nonlinear HRV measures did not differ by treatment. Future research on this topic should address additional potential confounding factors, such as the effect of pain-mitigating drugs on autonomic function or the influence of the autonomic nervous system on wound healing, that may prohibit HRV measurement as an indicator of disbudding pain severity.

Short communication: Effect of age at group housing on behavior, cortisol, health, and leukocyte differential counts of neonatal bull dairy calves.

To determine the effect of age at grouping on behavior, health, and production of dairy bull calves, 90 Holstein-Friesian bull calves were housed in individual pens until moved to 1 of 3 treatments. Calves were housed in groups of 3 calves at 3 d old (GH3), 7 d old (GH7), or 14 d old (GH14) until 7 wk of age. Ten groups of 3 calves for each treatment were used, with 5 pens/treatment in each of 2 replications (10 pens/treatment, 3 treatments, 3 calves/treatment; 90 calves total). Direct behavioral observations using instantaneous scan sampling every 10 min were conducted twice per week for 7 wk. At the same times, video data were recorded for continuous observations at feeding time to observe the overall activity of group-housed calves. Hip height, heart girth, and health scores were recorded weekly and body weight was recorded at the start and end of the study. Calves in GH3 spent more time playing and but more time cross-sucking and displacing other calves from milk bottles. Calves engaged in social interaction as early as 3 d of age, and social interactions between 3 to 6 wk of age increased markedly. Calves housed in GH14 vocalized more than did calves in GH7 and GH3. No difference was found between treatments in growth performance. Calf fecal, cough, and nasal and ocular discharge scores, differential leukocyte counts, and plasma cortisol concentrations were not affected by age at grouping. However, during the first week of grouping, when calves were moved from individual pens to group pens, some calves were unable to find their milk bottles and required guidance. In conclusion, these data show no adverse effects on health or performance and some benefits on social behavior for early (d 3) grouping of calves.

Feed withdrawal and transportation effects on Salmonella enterica levels in market-weight pigs.

Feed withdrawal and transport commonly occur together in pigs. Objectives of this study were to determine if these preslaughter stressors, feed withdrawal and transportation, affect the levels of , stress hormone concentrations, and immune functions in infected market pigs. A 2 × 2 factorial analysis of a randomized complete block design with feed withdrawal and transport as fixed effects was used. Sixty market-weight pigs were individually inoculated with serovar Typhimurium. The experiment was replicated 3 times (blocking factor) with 20 pigs per replicate. Three days after inoculation, the pigs were randomly assigned to 1 of 4 treatments (5 pigs per treatment in each/replicate), including 1) control (Control; or no stress), 2) feed withdrawal for 12 h (FW), 3) transportation for 2 h (T), and 4) feed withdrawal for 12 h followed by transportation for 2 h (FWT). Feed withdrawal by itself or followed by transportation caused an increase of levels in ileal contents ( < 0.05), whereas only FWT caused an increase of levels in cecal contents ( < 0.05). Rectal contents (feces) consistently contained very low levels of , with no difference among treatments ( > 0.10). Cortisol increased in pigs from all 3 stress treatments ( < 0.001), with T and FWT pigs having greater concentrations than Control pigs ( < 0.05), although total white blood cell counts were lower for FWT pigs compared with Controls ( > 0.03). Each granulocyte percentage (neutrophil, eosinophils, and basophils) increased ( < 0.05) following transport but was attenuated ( > 0.05) by feed withdrawal with transport. Lymphocytes were suppressed ( < 0.05) by all stressors, and the greatest suppression occurred when pigs were transported (T and FWT). However, monocytes were suppressed ( < 0.05) compared with Controls only by FWT. Expression of IL-1 (produced by monocytes/macrophages) from the spleen cells increased ( < 0.05) with FW compared with Controls, whereas its receptor antagonist was suppressed by FWT ( < 0.05). It is concluded that some typical preslaughter practices, such as feed withdrawal and transportation, lead to greater intestinal levels and gut-associated lymphoid tissue markers of inflammation in market pigs and, consequently, to an increased food safety risk.

Effect of threonine on secretory immune system using a chicken intestinal ex vivo model with lipopolysaccharide challenge.

Secretory IgA (sIgA) and its transcytosis receptor, polymeric immunoglobulin receptor (pIgR), along with mucus, form the first lines of intestinal defense. Threonine (Thr) is a major component of intestinal mucins and IgA, which are highly secreted under lipopolysaccharide (LPS) induced inflammation. In the current study, the effect of Thr on the secretory immune system was determined in an ex vivo chicken ileal explant model. Results showed that a 2-hour Thr-deprivation of culture medium induced a compensatory increase in the mRNA expression of interleukin-8 (IL-8), mucin 2 (MUC2), and IgA during LPS challenge, and this increase was suppressed with Thr addition to the media (P ≤ 0.05), suggesting that Thr was required for mucin and IgA production after exposure to LPS. Similarly, a 2-hour culture of explants from birds fed a Thr adequate diet showed an increase in the mRNA abundance of IL-8, MUC2, and IgA with LPS treatment (P ≤ 0.003), which had a trend to be attenuated with Thr supplementation in the media (P ≤ 0.10). In contrast, explants from birds fed a Thr deficient diet had no response to LPS treatment. These results indicated that in vivo Thr deficiency induced impaired inflammatory and secretory immune responses in broiler chicks. Furthermore, our results revealed that induction of MUC2 and pIgR gene expression required nuclear factor-κB (NF-κB) activation. Additionally, IgA transcytosis may be dependent on extracellular-regulated protein kinase (ERK) activation, which may indirectly impact pIgR gene expression.

Acute brief heat stress in late gestation alters neonatal calf innate immune functions.

Heat stress, as one of the environmental stressors affecting the dairy industry, compromises the cow milk production, immune function, and reproductive system. However, few studies have looked at how prenatal heat stress (HS) affects the offspring. The objective of this study was to evaluate the effect of HS during late gestation on calf immunity. Calves were born to cows exposed to evaporative cooling (CT) or HS (cyclic 23-35°C) for 1 wk at 3 wk before calving. Both bull and heifer calves (CT, n=10; HS, n=10) were housed in similar environmental temperatures after birth. Both CT and HS calves received 3.78 L of pooled colostrum within 12 h after birth and were fed the same diet throughout the study. In addition to tumor necrosis factor α, IL-1ß, IL-1 receptor antagonist (IL-1RA), and toll-like receptor (TLR)2, and TLR4 mRNA expression, the expression of CD14(+) and CD18(+) cells, and DEC205(+) dendritic cells were determined in whole blood samples at d 0, 3, 7, 14, 21, and 28. The neutrophil to lymphocyte ratio, differential cell counts, and the hematocrit were also determined. During late gestation, the HS cows had greater respiration rates, rectal temperatures, and tended to spend more time standing compared with the CT cows. The HS calves had less expression of tumor necrosis factor-α and TLR2 and greater levels of IL-1ß, IL-1RA, and TLR4 compared with CT calves. The HS calves also had a greater percentage of CD18(+) cells compared with the CT calves. Additionally, a greater percentage of neutrophils and lesser percentage of lymphocytes were in the HS calves compared with the CT calves. The results indicate that biomarkers of calves' immunity are affected in the first several weeks after birth by HS in the dam during late gestation.

Acute phase cytokines, TAC1, and toll-like receptor4 mRNA expression and health associated with group size in veal calves.

Chronic stressors are a major health and well-being issue in animals. Immune status of animals under chronic stress is compromised, thus reducing disease resistance and compromising well-being of the animal. The objective of this study was to determine the influence of group size of veal calves on immune status and leukocyte mRNA expression of acute phase cytokines, toll-like receptor 4 (TLR4) and tachykinin 1 (TAC1) over a five-month finishing period. Holstein bull calves (n=168), 44±3 days of age were assigned to one of three treatments; 2, 4, or 8 calves/pen (pen space allowance of 1.82m(2)/calf). Jugular blood samples were collected at the day of grouping and then monthly for 4 months. The differential leukocyte counts were determined and mRNA was extracted from the leukocytes. Reverse transcription-qPCR was used to measure the gene expression of interleukin-1 (IL-1ß), IL-1 receptor antagonist (IL-1Ra), tumor necrosis factor (TNF-α), TLR4, and TAC1 in leukocytes. Health was evaluated before grouping and monthly for 4 months. On the 1st month after grouping, veal calves that were housed in groups of 8 have greater expression of IL-1ß mRNA than calves housed in groups of 4 or 2 (treatment×month, P=0.04). Also at 1 month, groups of 8 had greater TAC1 expression (P<0.05) than calves housed in groups of 4 or 2. However, the expression of IL-1Ra, TNF-α, and TLR4 were not influenced by group size. In the first month of the trial, calves in groups of 8 coughed more (P<0.05) than calves in groups of 2 and coughed more than calves in groups of 4 and 2 during the 2nd month (treatment×month, P=0.03). Calves housed in groups of 8 tended to have greater neutrophil percentage (P=0.09), neutrophil to lymphocyte ratio (P=0.06), and had lower lymphocyte percentage (P=0.06) than those housed in groups of 4 or 2. In conclusion, the number of veal calves in a group, given the same space during the finishing period did not alter IL-1Ra, TNF-α, and TLR4 mRNA expression. However, housing of calves in groups of 8 was associated with greater expression of IL-1ß and TAC1 mRNA in peripheral blood leukocytes, and coughing during the first 2 months after grouping. Therefore, housing of veal calves in larger groups may lead to greater susceptibility to respiratory disease and stress.

Group space allowance has little effect on sow health, productivity, or welfare in a free-access stall system.

Free-access stalls allow sows to choose the protection of a stall or use of a shared group space. This study investigated the effect of group space width, 0.91 (SS), 2.13 (IS), and 3.05 (LS) m, on the health, production, behavior, and welfare of gestating sows. Nine replications of 21 (N = 189) gestating sows were used. At gestational d 35.4 ± 2.3, the pregnant sows were distributed into 3 pens of 7 sows, where they remained until 104.6 ± 3.5 d. Each treatment pen had 7 free-access stalls and a group space that together provided 1.93 (SS), 2.68 (IS), or 3.24 (LS) m(2)/sow. Baseline measurements were obtained before mixing. Back fat depth, BW, BCS, and lameness were measured monthly, and skin lesions were scored weekly. Blood was collected monthly for hematological, immunological, and cortisol analyses. Sow behavior was video recorded continuously during the initial 4 d of treatment and 24 h every other week thereafter. Behavior was analyzed for location, posture, pen investigation, social contact, and aggression. Skin response to the mitogen concanavalin A (Con A) was tested at mean gestational d 106. Litter characteristics including size and weight were collected at birth and weaning. The data were analyzed using a mixed model. Multiple comparisons were adjusted with the Tukey-Kramer and Bejamini-Hochberg methods. Group space allowance had no effect on any measure of sow health, physiology, or production (P ≥ 0.10). Sows in the SS, IS, and LS pens spent 77.88% ± 3.88%, 66.02% ± 3.87%, and 63.64% ± 3.91%, respectively, of their time in the free-access stalls (P = 0.12). However, SS sows used the group space less than IS and LS sows (P = 0.01). Overall, pen investigatory behavior was not affected by group space allowance (P = 0.91). Sows in the LS pens spent more time in a social group than SS sows (P = 0.02), whereas sows in IS pens were intermediate to, but not different from, the other treatments (P ≥ 0.10). The size of the social groups was also affected by the group space allowance (P = 0.03), with SS sows forming smaller groups than LS sows; again, IS sows were intermediate to, but not different from, the other treatments. Although the group space allowance had no measurable impact on the health, physiology, or productivity of the sows, the lower group space use and social contact of the SS sows reduced the behavioral diversity benefits of group housing and may indicate an avoidance of social stressors or a lack of physical comfort in the smallest pens.

Growth and reproductive development of male piglets are more vulnerable to midgestation maternal stress than that of female piglets.

In many mammalian species, prenatal stress masculinizes female and feminizes male offspring impairing their reproductive capacity. Regrouping gestating sows is a common, stressful production practice, but its impact on the developing pigs of the sow is not fully known. This study examined the effects of regrouping gestating sows and the administration of exogenous glucocorticoids on the growth and external reproductive morphology of pigs. At 37.2 ± 0.26 d of gestation, 6 cohorts of 18 sows (N = 108) were placed in 1 of 3 treatments: socially stable (Stable), hydrocortisone acetate (HCA), or mixed (Mixed). The HCA sows were administered 70 mg HCA, a synthetic glucocorticoid, twice daily during the 21 d experimental period. Each Mixed sow was penned with 2 companion sows (Companion) and regrouped on d 7 and 14 with 2 different Companion sows in a new pen. Stable and HCA sows were penned in treatment groups of 3 sows. Sow social rank was assessed weekly during feeding. After the 21 d experimental period, all sows were housed in gestation stalls for the duration of pregnancy. During the 21 d, Companion sows gained more weight than HCA and Mixed sows (P < 0.05) with Stable sows intermediate. High ranked sows gained more weight than middle and low ranked sows (P < 0.05). Mixed sows had greater head lesion scores than Stable and HCA sows (P < 0.05) with Companion sows intermediate. Head lesions increased with lower social rank (P < 0.001). Sow treatment did not affect farrowing rate, litter size, or sex ratio (P > 0.10). Social rank also had no effect on farrowing rate (P > 0.10), but affected total litter size (P = 0.03). High ranked sows bore and weaned more live females than low ranked sows (P < 0.05), in part due to differential preweaning mortality among female pigs (P = 0.01). Only male pigs were affected by sow treatment. Preweaning mortality was higher among male pigs from HCA than from Mixed sows (P = 0.04) with other treatments intermediate. Despite no weight differences in the preweaning period, at 160 d of age males from HCA sows weighed more than males from Stable sows (P = 0.01) with other treatments intermediate. Males born to Companion sows had longer relative anogenital distances, a marker of fetal testosterone exposure, than males from Mixed sows (P = 0.03) with other treatments intermediate. The prenatal environment affected the pigs in a sex-specific manner altering the growth and reproductive morphology of the males more than that of the females.

Repeated mixing and isolation: measuring chronic, intermittent stress in Holstein calves.

Objectives of this study were to determine the physiological effects of psychological stress applied to dairy calves and to test if molasses consumption could be used to validate that a stressed condition was achieved. Twenty male calves (3 wk old) received jugular catheters and were randomly assigned to control (CTR; n = 4 pens of 1 calf per pen) or social stress treatments (STR; n = 4 pens of 4 calves per pen). The STR treatment included 5 cycles of 24-h isolation followed by regrouping with unfamiliar animals for 48 h (over 15 d). An ACTH challenge (0.1 IU/kg of body weight) was used to determine adrenal fatigue. Peak and total cortisol concentrations were greater for STR calves until the ACTH challenge. After the ACTH challenge, CTR calf cortisol increased and STR calf cortisol continued to decrease, suggesting adrenal fatigue. The number of calves that became positive for fecal shedding of Salmonella after the acute stress of being moved and the number of calves that were positive after the move decreased with each move. Fifty-six percent of STR calves changed from negative to positive for shedding after the first move compared with 18.75% of STR calves remaining negative after the third move. Difference in fecal shedding of Enterobacteriaceae from samples taken before and after moving calves on d 6 was less than that on d 2, 3, and 5. Leukocyte counts were not different, but trends for day effects were detected for neutrophil and monocyte percentages. Molasses consumption was greater for STR calves on d 2 and 11, as was total consumption. Latency to lie after eating also increased as the study progressed; STR calves required more time to lie after eating on d 12 than on d 3, and latency to lie was greater for STR than CTR on d 4, 8, 12, and 14. The STR calves also stood more than the CTR calves in the 4-h afternoon period on d 4, 5, 7, and 14. However, during the 4-h morning observations on d 14 (ACTH challenge), CTR calves stood more than STR calves. This model induced chronic stress, as characterized by adrenal fatigue, which was confirmed by molasses consumption and behavior changes. Therefore, molasses consumption could be used to confirm social stress in experimental models.

Effect of group size on behavior, health, production, and welfare of veal calves.

The objective of this study was to investigate the effect of group size on behavior, growth, health, and welfare of veal calves. Holstein-Friesian bull calves (n=168; 44±3 d of age) were assigned randomly to 1 of 3 treatments of group housing with 2, 4, or 8 calves per pen. The pens used for housing were 3 by 1.20 m (2 calves per pen), 3 by 2.40 m (4 calves per pen), and 3 by 4.80 m (8 calves per pen), supplying a total pen space allowance of 1.82 m2/calf, regardless of pen size. Behavior was recorded from video data throughout the day from 0700 to 1900 h during a single day each month for 5 mo using scan sampling every 5 min within 30-min observation sessions. On d 0, 1, 5, 14, 42, and 70 after grouping, continuous focal sampling around feeding time (30-min intervals before, during, and after feeding) focused on oral and aggressive behaviors. Calves housed in large groups (4 or 8 calves per pen) showed more (P≤0.001) conspecific contact, walking, and standing and less (P<0.001) manipulation of objects, self-licking, and lying when compared to calves housed in small groups (2 calves per pen). Group size had no effect on play behavior (P=0.11) throughout the experiment. During feeding times group size had no (P≥0.07) effect on any behavioral patterns except for duration of conspecific contact (P<0.01). Aggression at feeding time was not (P>0.23) affected by treatment. Group size treatments were similar for hip height change (P=0.41) and heart girth change (P=0.18) over the duration of the experiment; however, both hip height and heart girth increased (P=0.001) with calf age. During mo 1, calves in groups of 8 or 4 coughed more than calves in groups of 2 whereas calves in groups of 8 coughed more than calves in groups of 4 or 2 in mo 2 (treatment×month, P=0.03). Furthermore, during mo 4, calves in groups of 8 had less nasal discharge than calves in groups of 2 or 4 (treatment×month, P=0.02). Ocular discharge, ears, and fecal scores did not differ (P≥0.05) among treatments. Plasma cortisol was not (P≥0.37) affected by group size. The number of veal calves in a group when given the same space did not affect production and physiological indicators of welfare but had a transient effect on health during the 5-mo finishing period. If increased play and social contact and decreased aggression are considered as primary indicators of welfare, group size did not alter calf welfare.

Effects of rubber flooring during the first 2 lactations on production, locomotion, hoof health, immune functions, and stress.

Some housing systems on dairy farms can result in long-term chronic pain. The effects of acute pain on immunity have been explored, but chronic pain's influence on immune responses is still poorly understood. Therefore, the objective of this research was to determine chronic effects of flooring on immune responses and production in freestall housing for dairy cows. Thirty heifers were studied from before calving as first-calf heifers until d 180 of their second lactation. Treatments were rubber (Kraiburg; Agromatic Inc., Fond du Lac, WI) flooring or concrete with diamond grooves in a freestall barn, each in 2 quadrants of the barn. Heifers entered the treatments after calving, so the system was dynamic and each cow was considered an experimental unit. At the end of the first lactation, cows were housed in a bedded pack barn with pasture access until calving was imminent. At that time, they returned to their assigned treatment, but not necessarily into the same quadrant. Production, reproduction, cortisol, acute-phase proteins, and health data were recorded throughout lactation 1, locomotion was scored weekly, and hoof scoring and care was conducted on d 60 and 180 of lactations 1 and 2, and quantitative real-time-PCR of blood leukocytes was analyzed in mid lactation of lactation 1. Mature-equivalent milk fat, milk protein, and protein percentages during the first lactation were greater for cows on the rubber flooring. Hoof and leg therapy treatments per cow were fewer for rubber floor-housed cows. Locomotion scores were less for cows housed on rubber during the second lactation. White blood cell counts were less for cows housed on rubber, and caused by greater lymphocyte counts for cows housed on concrete. The possibility of chronic inflammation was substantiated by less IL-1ß and more IL-1 receptor antagonists for cows housed on rubber at d 150 in the second lactation. Cortisol and acute-phase proteins did not differ between the treatments. Interferon-γ, IL-12, the modulator of tissue reconstruction (B-cell-transforming growth factor 1), and pain-modulating neurokinin (tachykinin 1) were not different at d 105. These data show indicators of chronic inflammation for cows housed on the concrete flooring compared with those housed on rubber. Implications for the use of rubber flooring in freestall barns are broader than just lameness and may affect many aspects of cow physiology and production.

Feeding behaviors of transition dairy cows fed glycerol as a replacement for corn.

Feed sorting is a natural behavior of dairy cows that can result in inconsistencies in the nutritive value of a total mixed ration (TMR). The objective of this study was to determine the effects of replacing high-moisture corn with glycerol on feed sorting and the feed intake pattern of transition dairy cows. Multiparous Holstein cows (n=26) were paired by expected calving date, housed in individual tie stalls, and fed diets containing either glycerol or high-moisture corn once daily from d -28 to +56 relative to calving. Glycerol was included at 11.5 and 10.8% of the ration dry matter for the pre- and postpartum diets, respectively. The feed consumption pattern was determined by measuring TMR disappearance during the intervals from 0 to 4 h, 4 to 8 h, 8 to 12 h, and 12 to 24 h relative to feed delivery. Feed sorting was determined on d -16, -9, 9, 16, and 51 relative to calving at 4, 8, 12 and 24 h after feeding. The TMR particle size profile was determined at feed delivery and at 4, 8, 12, and 24 after feed delivery by using the Penn State Particle Separator (Nasco, Fort Atkinson, WI) to yield long (>19 mm), medium (<19 mm, >8 mm), short (<8 mm, >1.18 mm), and fine (<1.18 mm) particles. Overall feed intake did not differ between diets and was 14.7±0.4 and 20.2±0.5 kg/d for the pre- and postpartum intervals, respectively. During the prepartum period, glycerol decreased the amount of feed consumed during the first 4h after feed delivery (7.22 vs. 5.59±0.35 kg; control vs. glycerol, respectively) but increased feed consumed from 12 through 24 h after feed delivery (2.22 vs. 3.82±0.35 kg; control vs. glycerol, respectively). Similar effects on the feed consumption pattern were observed after calving. During the prepartum period, cows fed the control diet sorted against long particles, whereas cows fed glycerol did not sort against long particles (77.2 vs. 101.5±3.50% of expected intake for control vs. glycerol; significant treatment effect). The data indicate that addition of glycerol to the TMR alters the feed consumption pattern to increase feed consumption late in the day at the expense of feed consumed immediately after feeding, and it reduces sorting behavior against long particles. Together, these may reduce diurnal variations in the rumen environment to promote greater rumen health in transition cows.

Behavioral changes in neonatal swine after an 8-hour rest during prolonged transportation.

Long distance transportation of weaned piglets (Sus scrofa) is increasingly common in the united states and may result in delayed eating, drinking, or normal social behaviors. A potential solution is a mid-journey rest (lairage). The objective of this study was to determine if a lairage altered behavior after a 16-h transport. Pigs that weighed approximately 18 kg each (n = 894) were housed in 16 pens with 8 pens per treatment. Lairaged pigs were transported for 8 h and given an 8-h rest with food and water, whereas control pigs were transported continuously for 16 h. The heaviest, the lightest, and 2 average-BW pigs relative to the average weight of the pen were observed by video recording for 24 h immediately before and after transport, and during d 6 and 13 after transport. Postures (lying, sitting, and standing) were recorded using 10-min-interval scan sampling, and behavioral categories included inactivity, activities (eating, drinking, alert, manipulating pen, rooting, and walking) and social interactions (aggression, belly nosing, playing, tail biting, and positive social behaviors). In both treatments, sitting occurred most before transport (P < 0.01) than at other times, but did not differ between treatments. Standing increased (time effect; P < 0.01) for both treatments immediately after transport through d 6, but returned to pre-transport values by d 13. In contrast, lying decreased (time effect; P < 0.01) after transport, but returned to above pre-transport values by d 13. Time effects were evident for activity (P < 0.01), pen manipulation (P = 0.05), rooting (P < 0.01), initiation of belly-nosing (P = 0.01), and receiving belly-nosing (P = 0.03); however, initiation of aggression did not differ for day (P = 0.19) or treatment (P = 0.56). Lairaged pigs initiated more (P = 0.05) play than continuously transported pigs, but no differences (P = 0.84) were seen in receipt of play behavior. Pigs that were to be transported for 16 h continuously walked less pre-transport, walked more post-transport (treatment × time interaction; P = 0.02), and drank less pre-transport, but drank more on all days post-transport compared with the lairage group (treatment × time interaction; P = 0.001). This study indicated that extended transport without lairage alters some swine behaviors relevant to production (water consumption) and demonstrated that a long-duration transport, regardless of the mid-journey lairage treatment, affects a number of behaviors up to 13 d after transportation.

Genetic variations alter physiological responses following heat stress in 2 strains of laying hens.

Heat stress (HS) is a major problem experienced by the poultry industry during high-temperature conditions. The ability to manage the detrimental effects of HS can be attributed to multiple factors, including genetic background of flocks. The objective of the present study was to determine the genetic variation in HS effects on laying hens' physiological homeostasis. Ninety 28-wk-old White Leghorn hens of 2 strains were used: a commercial line of individually selected hens for high egg production, DeKalb XL (DXL), and a line of group-selected hens for high productivity and survivability, named kind gentle bird (KGB). Hens were randomly paired by strain and assigned to hot or control treatment for 14 d. Physical and physiological parameters were analyzed at d 8 and 14 posttreatment. Compared with controls, HS increased hen's core body temperature (P < 0.05) and decreased BW (P < 0.05) at d 8 and 14. Heat shock protein 70 concentrations in the liver were greater in hens exposed to HS (P < 0.05). Compared with DXL hens, KGB hens had higher heat shock protein 70 concentrations (P < 0.05). The hens' liver weight decreased following HS, with less of a response in the KGB line (P < 0.05). The data indicate HS has detrimental effects on the physiology of laying hens due to genetic variations. These data provide evidence that is valuable for determining genetic interventions for laying hens under HS.

Effects of increasing dietary concentrations of corn naturally contaminated with deoxynivalenol on broiler and turkey poult performance and response to lipopolysaccharide.

In this study, 2 experiments determined the effects of increasing dietary concentrations of deoxynivalenol (DON) on performance, intestinal morphology, and measures of innate immunity in broilers and turkeys. For experiment 1, the 3-wk study used 5 concentrations of DON (up to 18 or 10 mg of DON/kg of feed in broilers or turkeys, respectively) from naturally contaminated corn. The BW gains were cubically or quadratically affected by the increasing dietary concentrations of DON for broilers and turkeys, respectively; however, feed consumption was not affected. For experiment 2, the birds were subsequently injected or not injected with lipopolysaccharide (LPS) 24 h before tissue and blood sample collection. Dietary DON had no effect on intestinal crypt depth, but linearly increased the mid-ileal villus height in broilers (P = 0.04). An interaction was observed between the LPS challenge and the dietary DON with regards to heterophil to lymphocyte ratio (P < 0.05) in broilers, but not in turkeys. The cecal tonsil cell phagocytosis of microbeads was not affected by the dietary concentration of DON either with or without the subsequent LPS challenge for both broilers and turkeys. Conversely, the phagocytic capacity of cecal tonsil cells to engulf killed Staphylococcus aureus was significantly reduced (over 2.5-fold) when broilers were fed the highest concentration of dietary DON (non-LPS-challenged; P < 0.05). However, diets containing DON showed no effects on broilers when they were challenged with LPS. Antibody-dependent phagocytosis (S. aureus) was not affected in turkeys fed DON. Overall, corn naturally contaminated with up to 18 or 10 mg/kg of DON (broiler or turkey, respectively) reduced bird BW gain at 21 d of age, reduced antibody-dependent phagocytosis of previously killed S. aureus by cecal tonsil cells in non-LPS-challenged broilers, and greatly decreased heterophil to lymphocyte ratios in LPS-challenged broilers.

ß-Glucan plus ascorbic acid in neonatal calves modulates immune functions with and without Salmonella enterica serovar Dublin.

To determine if ß-glucan plus ascorbic acid affects adherence and pathogenicity of Salmonella Dublin and innate immune response in neonatal calves, 20 calves were fed control or supplemented diets (ß-glucan, 0.9 g/d, plus ascorbic acid, 500 mg/d) until d 23. On d 21, 5 calves per treatment received 2.4 × 10(8)CFU of S. Dublin orally. S. Dublin spread through intestinal tissues into mesenteric lymph nodes (MLN), spleen, and lung tissues within 48 h. All supplemented calves had less mRNA expression of IL-1 receptor antagonist in liver. Leukocyte cell surface markers changed in lung cells, but not in blood, MLN, or spleen. CD14 in lungs was greatest for calves receiving supplement and challenge, but CD18 in lungs was greater for challenged than control calves. Lung DEC205 was greatest for challenged calves with and without supplement compared to controls, but more lung cells expressed CD14 for all treated groups compared to controls. These data show that S. Dublin briefly inhabited the intestinal tract, moving quickly to spleen, MLN, and lung tissues. Lung tissue was modulated by S. Dublin, but supplement alone increased CD14 expressing cells. The supplement appears not to attenuate invasiness but modified some lung cell populations by 48h.

Yeast culture supplement during nursing and transport affects immunity and intestinal microbial ecology of weanling pigs.

The objectives of this study were to determine the influence of a Saccharomyces cerevisiae fermentation product on innate immunity and intestinal microbial ecology after weaning and transport stress. In a randomized complete block design, before weaning and in a split-plot analysis of a 2 × 2 factorial arrangement of yeast culture (YY) and transport (TT) after weaning, 3-d-old pigs (n = 108) were randomly assigned within litter (block) to either a control (NY, milk only) or yeast culture diet (YY; delivered in milk to provide 0.1 g of yeast culture product/kg of BW) from d 4 to 21. At weaning (d 21), randomly, one-half of the NY and YY pigs were assigned to a 6-h transport (NY-TT and YY-TT) before being moved to nursery housing, and the other one-half were moved directly to nursery housing (NY-NT and YY-NT, where NT is no transport). The yeast treatment was a 0.2% S. cerevisiae fermentation product and the control treatment was a 0.2% grain blank in feed for 2 wk. On d 1 before transport and on d 1, 4, 7, and 14 after transport, blood was collected for leukocyte assays, and mesenteric lymph node, jejunal, and ileal tissue, and jejunal, ileal, and cecal contents were collected for Toll-like receptor expression (TLR); enumeration of Escherichia coli, total coliforms, and lactobacilli; detection of Salmonella; and microbial analysis. After weaning, a yeast × transport interaction for ADG was seen (P = 0.05). Transport affected (P = 0.09) ADFI after weaning. Yeast treatment decreased hematocrit (P = 0.04). A yeast × transport interaction was found for counts of white blood cells (P = 0.01) and neutrophils (P = 0.02) and for the neutrophil-to-lymphocyte ratio (P = 0.02). Monocyte counts revealed a transport (P = 0.01) effect. Interactions of yeast × transport (P = 0.001) and yeast × transport × day (P = 0.09) for TLR2 and yeast × transport (P = 0.08) for TLR4 expression in the mesenteric lymph node were detected. Day affected lactobacilli, total coliform, and E. coli counts. More pigs were positive for Salmonella on d 7 and 14 than on d 4, and more YY-TT pigs were positive (P = 0.07) on d 4. The number of bands for microbial amplicons in the ileum was greater for pigs in the control treatment than in the yeast treatment on d 0, and this number tended to decrease (P = 0.066) between d 1 and 14 for all pigs. Similarity coefficients for jejunal contents were greater (P = 0.03) for pigs fed NY than for those fed YY, but pigs fed YY had greater similarity coefficients for ileal (P = 0.001) and cecal (P = 0.058) contents. The number of yeast × transport × day interactions demonstrates the complexity of the stress and dietary relationship.

Effects of maternal natural (RRR alpha-tocopherol acetate) or synthetic (all-rac alpha-tocopherol acetate) vitamin E supplementation on suckling calf performance, colostrum immunoglobulin G, and immune function.

The objective of this study was to determine the effects of maternally supplemented natural- or synthetic-source vitamin E on suckling calf performance and immune response. In a 2-yr study, one hundred fifty-two 2- and 3-yr-old, spring-calving, Angus-cross beef cows were blocked by age, BW, and BCS into 1 of 3 isocaloric, corn-based dietary supplements containing 1) no additional vitamin E (CON), 2) 1,000 IU/d of synthetic-source vitamin E (SYN), or 3) 1,000 IU/d of natural-source vitamin E (NAT). Maternal supplementation began approximately 6 wk prepartum and continued until the breeding season. Colostrum from cows and blood from calves was collected 24 h postpartum for analysis of IgG concentration as an indicator of passive transfer and circulating alpha-tocopherol concentration. At 19 d of age, blood was collected from calves to determine the expression of CD14 and CD18 molecules on leukocytes. At 21 and 35 d of age, humoral immune response was measured by a subcutaneous injection, in the neck, with ovalbumin (20 mg; OVA) and blood samples collected weekly until d 63 of age to determine antibodies produced against OVA. At d 63 of age, calves were administered an intradermal injection of OVA (1 mg) in the neck to assess cell-mediated immunity, which was determined on d 65 of age by measuring nodule size with calipers. Circulating alpha-tocopherol concentrations were increased at both 24 h (P = 0.001) and at the day of initial OVA challenge (P < 0.001) in SYN and NAT compared with CON calves. No differences were detected (P > 0.05) for calf birth BW, ADG, or weaning BW. There were no differences (P > 0.05) in calf serum total IgG or cow colostrum total IgG at 24 h or presence of CD14 and CD18 receptors at d 19 of age. The NAT calves had a greater antigen response to OVA at d 63 than SYN calves (P = 0.01; treatment x day interaction). As an indicator of cell-mediated immunity to OVA, nodule size at 65 d of age was not affected (P = 0.92) by maternal dietary supplementation. In conclusion, calves suckling cows supplemented with natural- and synthetic-source vitamin E had increased circulating concentrations of alpha-tocopherol at 24 h, which appeared to continue throughout maternal supplementation; however, calf immune function and performance were not affected.

Yeast cell-wall products containing beta-glucan plus ascorbic acid affect neonatal Bos taurus calf leukocytes and growth after a transport stressor.

The objectives were to ascertain whether a yeast cell-wall derivative that was 1.8% beta-glucan in combination with ascorbyl-2-polyphosphate could improve innate immunity and mediate transportation stress in neonatal calves, and to compare the 1.8% beta-glucan yeast cell-wall derivative with a more purified yeast cell-wall derivative (70% beta-glucan). Treatments were 1) an unsupplemented control (CNT); 2) 113 g of a 1.8% (approximately 2%) beta-glucan derivative of yeast cell walls plus 250 mg of l-ascorbic acid phosphate (BG2); or 3) 150 mg of a purified beta-glucan fraction from yeast cell walls (approximately 70% beta-glucan) plus 250 mg/feeding of l-ascorbic acid phosphate (BG70). Calves (n = 39) were transported for 4 h, placed in outdoor hutches, and randomly assigned to treatments. Treatments (mixed with a milk replacer) were individually fed twice daily for 28 d. Calves were offered calf starter, free choice, throughout the study. Weekly starter intake and BW were measured, and fecal samples were collected for Salmonella Typhimurium and Escherichia coli O157:H7 PCR analysis. Blood was collected immediately before transport (d 0) and on d 3, 7, 10, 14, 21, and 28 after transport. Starter intake and DMI were less (P < 0.05) at d 28 for the BG2 and BG70 treatments compared with the CNT treatment. Hematocrit percentages increased (P = 0.002) throughout the experiment. White blood cell counts (treatment x time interaction, P = 0.066) were less for the calves supplemented with BG70 than for those supplemented with BG2 (P = 0.01) or for CNT calves (P = 0.04) on d 28. Granulocyte counts changed (P = 0.04) throughout the experiment. A trend (P = 0.077) for a treatment x time interaction was detected for peripheral blood mononuclear cell counts (PBMC). Counts of PBMC were greater (P = 0.006) for the BG2 treatment compared with the CNT treatment on d 3. Calves given the BG70 supplement had fewer PBMC than those given the BG2 supplement on d 21 (P = 0.03) and 28 (P = 0.05). Fibrinogen concentrations were affected only by time (P = 0.002). Time effects were detected for phagocytosis (P = 0.005), oxidative burst (P < 0.001), expression of cluster of differentiation 18 (P = 0.001), and increased cluster of differentiation 18 (P = 0.006). Phagocytosis was less (P = 0.05) for calves in the BG70 group than for those in the CNT group. Percentage of calves positive for E. coli O157:H7 was greatest (P