Antibiotic use and ammonia (NH3) emissions during animal production are two environmental issues of worldwide concern. However, the role of antibiotics on NH3 emissions is still unknown. This study ...evaluated the effects of rearing pigs without antibiotics on NH3 emissions from a swine experimental building starting with 657 piglets during a wean-to-finish production cycle of 154 days. Pigs were reared in two groups of 10 rooms that were divided into five 2-room pairs (P1–P5) and fed in nine dietary phases. Each pair consisted of one room without antibiotics (no antibiotics in the diet, water, or injectable) and another room as a positive control. Control animals were fed diets containing carbadox-10 (phases 1–4), chlortetracycline (CTC, phase 5), lincomix (phases 6–7), and tylan 40 (phases 8–9). Temperatures in the pig living space and the under-floor manure pit headspace were continuously measured. Ventilation rates at all wall fans and pit fans were obtained by continuous monitoring. Ammonia concentrations in the wall and pit fan exhaust air, and in room inlet air were measured with two multi-gas monitors. Only days that contained at least 18 h of data each day were validated and used. The study generated 1337 room-days of valid data of NH3 emission rates, with a data completeness of 88.6%. Daily mean NH3 emission patterns demonstrated large variations between the paired rooms and among different pairs. Within the individual 2-room pairs, no NH3 emission differences were found in P1 (rooms 1 and 2, p = 0.34) and P2 (rooms 3 and 4, p = 0.44). Significant differences were found in P3–P5 (p < 0.01). The antibiotic-free rooms emitted more NH3 from P3 and P4, but less NH3 from P5. However, the combined cycle mean NH3 emissions from the group of five antibiotic-free rooms and the group of five control rooms were 41.6 ± 10.5 and 39.4 ± 10.6 g d−1 AU−1 (mean ± standard deviation. AU = 500 kg live body weight), respectively. Therefore, there was no statistical difference in combined cycle mean NH3 emissions from rearing pigs with or without antibiotics (p = 0.78). This study also revealed that experiments with multiple replicates and long NH3 monitoring durations were necessary to avoid potential misinterpretation of experimental results.
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•Ammonia emissions from 10 swine rooms (5 pairs) were studied for 154 days.•Different pairs showed different effects of antibiotics on ammonia emissions.•Overall, antibiotic-free pig rearing did not increase ammonia emissions (p = 0.78).•Multi-replicate and long-monitoring studies could avoid result misinterpretation.
The study objective was to evaluate the interaction between corticotrophin releasing factor (
CRF
) receptor signaling and prophylactic antibiotic administration on intestinal physiology in newly ...weaned and transported pigs. Pigs (n = 56; 5.70 ± 1.05 kg) were weaned (20.49 ± 0.64 d), a blood sample was taken, and then pigs were given an intraperitoneal injection of saline (
SAL
; n = 28 pigs) or a CRF receptor antagonist (
CRFA
; n = 28 pigs; 30 μg/kg body weight; Astressin B), and then were transported in a livestock trailer for 12 h and 49 min. A second and third intraperitoneal injection was given at 4 h 42 min and 11 h 36 min into the transport process, respectively. Following transport, 4 SAL and 4 CRFA pigs were blood sampled and euthanized. The remaining 48 pigs were individually housed and given dietary antibiotics
AB
; n = 12 SAL and 12 CRFA pigs; chlortetracycline (441 ppm) + tiamulin (38.6 ppm) or no dietary antibiotics (
NAB
; n = 12 SAL and 12 CRFA pigs) for 14 d post-transport. Blood was collected at 12 h and on d 3, 7, and 14, and then pigs were euthanized on d 7 (n = 24) and d 14 (n = 24) post-weaning and transport. Circulating cortisol was reduced (
p
= 0.05) in CRFA pigs when compared to SAL pigs post-weaning and transport. On d 7, jejunal villus height and crypt depth was greater overall (
p
< 0.05) in AB-fed pigs versus NAB-fed pigs. On d 14, ileal crypt depth was reduced (
p
= 0.02) in CRFA pigs when compared to SAL pigs. Jejunal CRF mRNA abundance tended to be reduced (
p
= 0.09) on d 7 in CRFA pigs versus SAL pigs. On d 14, jejunal tumor necrosis factor-alpha was reduced (
p
= 0.01) in AB-fed pigs versus NAB-fed pigs. On d 7, change in glucose short-circuit current tended to be increased (
p
= 0.07) in CRFA pigs fed the AB diet when compared to CRFA pigs fed the NAB diet. In conclusion, CRFA pigs and pigs fed AB had some similar biological intestinal function measures post-weaning and transport.
In utero heat stress alters postnatal physiological and behavioral stress responses in pigs. However, the mechanisms underlying these alterations have not been determined. The study objective was to ...characterize the postnatal hypothalamic-pituitary-adrenal axis response of in utero heat-stressed pigs. Pigs were subjected to a dexamethasone suppression test followed by a corticotrophin releasing hormone challenge at 10 and 15 weeks of age. Following the challenge, hypothalamic, pituitary, and adrenal tissues were collected from all pigs for mRNA abundance analyses. At 10 weeks of age, in utero heat-stressed pigs had a reduced (P < 0.05) cortisol response to the corticotrophin releasing hormone challenge versus controls. Additionally, the cortisol response tended to be greater overall (P < 0.10) in 15 versus 10-week-old pigs in response to the dexamethasone suppression test. The cortisol response tended to be reduced overall (P < 0.10) in 15 versus 10-week-old pigs in response to the corticotrophin releasing hormone challenge. Hypothalamic corticotropin releasing hormone mRNA abundance tended to be greater (P < 0.10) in in utero heat-stressed versus control pigs at 15-weeks of age. In summary, in utero heat stress altered some aspects of the hypothalamic-pituitary-adrenal axis related to corticotropin releasing hormone signaling, and age influenced this response.
Parabolic trough collectors are so far the most successful and mature concentrating solar power technology on the market. Recent development towards higher performance and significant cost reductions ...leads to further improvements in competitiveness. FLABEG GmbH started its development of the ULTIMATE TROUGH® (UT) collector in 2010, jointly with sbp sonne gmbh, and with scientific support from the German Aerospace Center (DLR) and Fraunhofer Institute for Material Flow and Logistics (FhG-IML). With the successful installation of an indoor prototype in 2011, the assembly concept and optical performance was validated. In the second half of 2012, a demonstration loop consisting of two collectors with 3,400 m2 total aperture area, has been assembled and integrated into a commercial plant in the US. The loop is in operation since January 2013.
The present paper presents the first experiences and especially the very promising performance results of the demonstration loop. Cost savings and related reduction of levelized costs of electricity (LCOE) are illustrated.
While the positive effect of raising turbine inlet temperature to increase overall plant efficiency is often quoted and discussed, another figure is mentioned to a much lesser extent: The HTF outlet ...temperature at the steam generator exit, which also has a profound influence on cycle efficiency due to the fact that allowing higher temperatures allows moving to much higher evaporator pressures and, thus, higher cycle efficiencies.
This paper aims at evaluating potential benefits of increasing the lower HTF temperature in molten salt parabolic trough power plants based on an evaluation of its influence on LCOE.
Abstract
Zinc (Zn) supplementation has proved to mitigate the effects of heat stress with varying effects evident with Zn source during acute heat events. However, the effects of Zn supplementation ...during long-term summer weather patterns have yet to be explored. Therefore, the objective of this study was to identify the effects of supplementation source and level of Zn to mitigate the negative effects of long-term, cyclic heat stress in finishing swine. Six hundred cross-bred pigs were housed under thermoneutral (TN) or cyclic heat (HS) conditions simulating summer heat with acute 3-d heat waves for a 70-d study. Thermoneutral conditions were 16.7 to 18.9 °C throughout the study. HS pigs were housed at the same temperature as TN from days 0 to 18, then 28 °C/24 °C for 12 h/12 h on days 18 to 21, followed by 30 °C/26.7 °C for 12 h/12 h on days 24 to 70, except during acute heat (32 to 33 °C/29 to 30 °C, 12 h/12 h) on days 21 to 24, 42 to 45, and 63 to 66. Treatments were arranged in a 2 × 6 factorial with main effects of environment (HS vs. TN) and dietary available Zn supplementation: (1) 50 mg/kg zinc oxide (ZnO), (2) 130 mg/kg ZnO, (3) 50 mg/kg of organic Zn (Availa Zn), (4) 50 mg/kg ZnO + 40 mg/kg organic Zn, (5) 50 mg/kg ZnO + 60 mg/kg organic Zn, and (6) 50 mg/kg ZnO + 80 mg/kg organic Zn. Pigs (5 pigs/pen) were blocked by initial body weight (72.2 kg) and randomly allotted to 1 of 12 temperature and diet treatment combinations across 10 replicates. Body weight and feed intake were determined at the beginning and end of each acute heat event. All pigs were ultrasonically scanned at the 10th rib (TR) to predict loin muscle area (LMA), backfat (BF), and percent lean. Data were analyzed by the MIXED procedure in SAS with pen as the experimental unit. At day 63, HS pigs were lighter (P < 0.05), had lower overall average daily gain (ADG; P < 0.05) and average daily feed intake (P < 0.05). A diet-by-environment interaction was observed for overall ADG (P < 0.05) with diet 5 HS pigs having a 3.9% reduction in ADG whereas diet 6 had 14.4% reduction in ADG, while under TN temperatures diet 6 had the greatest overall ADG of all treatments. Other diets were intermediate in their ADG under both HS and TN conditions. Pigs under HS had less BF at the TR (P < 0.05) and a smaller LMA (P < 0.05), and a greater calculated percent lean (P < 0.05). Our results indicate that a blend of supplemental Zn sources at 50/60 mg/kg may mitigate the reduction in growth performance due to HS. While not directly contrasted, the NRC requirement of 50 mg/kg Zn may be too low to optimize finishing pig growth performance under both TN and HS conditions.
Feeding a blend of 50 inorganic 60 organic mg/kg Zn to finishing swine prevents the loss of growth performance under summer weather pattern simulation.
Lay Summary
Heat stress is a condition where excessive heat exposure leads to dysregulation of core body temperature, reduced feed intake, growth, and carcass characteristics in swine. Nutritional mitigation techniques such as zinc (Zn) supplementation can be used to lessen the effects of heat stress. However, Zn supplementation during cyclic summer weather patterns has yet to be explored. In addition, Zn can come in different forms (inorganic vs. organic) where organic is more easily absorbed by the animal. Therefore, the objective of this study was to identify the optimal form and level of Zn to mitigate the effects of long-term, cyclic heat stress in finishing swine. Six hundred cross-bred pigs were housed under thermoneutral or cyclic heat (HS) conditions simulating summer heat with acute 3-d heat waves for a 70-d study. There was a total of six diets varying in Zn level and form, each increasing in a stepwise manner in the amount of Zn included. At the conclusion of the study, pigs supplemented with 50 inorganic and 60 organic mg/kg Zn blend under HS conditions were affected the least by the summer heat simulation therefore indicating this blend may be helpful to prevent loss in growth performance in finishing swine.
Relative predominance of each of five probiotic strains was investigated in the ileum of weaned pigs, compared with that in feces, when administered in combination at c. 5 x 10⁹ CFU day⁻¹ for 28 ...days. Probiotic was excreted at 10⁶-10⁹ CFU g⁻¹ feces, while ileal survival ranged from 10² to 10⁶ CFU g⁻¹ digesta. In contrast to the feces, where Lactobacillus murinus DPC6002 predominated, the bacteriocin-producing Lactobacillus salivarus DPC6005 dominated over coadministered strains both in the ileum digesta and in mucosa. Probiotic administration did not alter counts of culturable fecal Lactobacillus or Enterobacteriaceae but higher ileal Enterobacteriaceae were observed in the ileal digesta of probiotic-fed pigs (P<0.05). We observed decreased CD25 induction on T cells and monocytes (P<0.01) and decreased CTLA-4 induction (P<0.05) by the mitogen phytohemagglutinin on CD4 T cells from the probiotic group. Probiotic treatment also increased the proportion of CD4+ CD8+ T cells within the peripheral T-cell population and increased ileal IL-8 mRNA expression (P<0.05). In conclusion, superior ileal survival of L. salivarius compared with the other coadministered probiotics may be due to a competitive advantage conferred by its bacteriocin. The findings also suggest that the five-strain combination may function as a probiotic, at least in part, via immunomodulation.
Managing stressors is essential for optimizing pig growth performance. To determine the effects of temperature and space allocation on growth performance and carcass characteristics, pigs were housed ...within their thermoneutral zone, at 23.9°C, or above their thermoneutral zone, at 32.2°C, and were provided either 0.66 or 0.93 m²/pig for the final 35 d of the grow-finish period. Individual BW were recorded on d 1, 10, 20, and 30. At slaughter, carcass measurements and samples of backfat and belly fat were collected. Final BW was decreased (P <= 0.05) from 113 to 103 kg for pigs housed at 32.2°C. The ADG was reduced (P < 0.05) for pigs housed at 32.2°C (0.89 vs. 0.54 kg/d), as was G:F (0.28 vs. 0.24). Housing at 0.66 m²/pig resulted in pigs that were lighter (P <= 0.05), at 106 compared with 110 kg, as a result of decreased (P <= 0.05) ADG (0.78 to 0.65 kg/d) and decreased (P <= 0.05) G:F (0.275 to 0.255) compared with pigs housed at 0.93 m²/pig. Pigs housed at a greater spatial allocation had elevated (P <= 0.05) ADFI. The interaction of housing at 32.2°C and decreasing spatial allocation increased (P <= 0.05) the adipose iodine value from 66.8 to 70.4, decreased (P <= 0.05) the saturated:unsaturated fatty acids ratio from 0.59 to 0.56, and increased (P <= 0.05) the n-6:n-3 from 23.56 to 25.27. Decreased spatial allocation resulted in decreased (P <= 0.05) belly weights. Although increased temperature did not affect belly weight, the 32.2°C pigs had decreased (P <= 0.05) raw and cooked slice weights, increased (P <= 0.05) percentage lean of bacon, increased (P <= 0.05) lean:fat ratio of bacon slices, increased (P <= 0.05) raw slice scores, and increased (P <= 0.05) quantity of collagen in belly fat. Some of these changes may have resulted from changes in lipid metabolism. Increasing spatial allocation in the 32.2°C pigs decreased fatty acid synthase (P = 0.03) and stearoyl-CoA desaturase- 1 (P = 0.08) mRNA expression in adipose tissue. The results from this study demonstrated decreased growth, carcass lipid quality, and bacon quality in pigs housed at temperatures above the thermoneutral zone; however, increasing the spacial allocation for housing may be a means to ameliorate the negative effects of temperature stress.
Alternative feed supplements have shown promising effects in terms of performance, but their effects on welfare have had little evaluation. In the present study, we aimed at evaluating the effect of ...diet supplementation on welfare indicators. A total of 246 piglets were weaned and transported for 12 h. After transport, they were assigned to one of 3 diets for a 14-day period: A-an antibiotic diet including chlortetracycline and tiamulin, NA-a control diet without any antibiotic or feed supplement, GLN-a diet including 0.20% L-glutamine. After the 14-day period, all piglets were fed the same diet. Tear staining was measured 11 times post-weaning (from d0 to 147). Skin lesions were counted before and after weaning (d-2, 2, and 36). Novel object tests (NOT) were done in groups 4 times post-weaning (d17, 47, 85, 111). Samples for 16S rRNA gene composition were collected prior to transport (d0), following the 14-day period (d14) and at the conclusion of the nursery phase (d34). The NA pigs appeared less interested in novel objects. On d17, they avoided the object less than A pigs (
< 0.05). They spent less time exploring the object on d85 and took longer to interact with the object on d111 than A and GLN pigs (
< 0.05). NA pigs also appeared more sensitive to environment and management. They had larger tear stains than GLN pigs on d84 and 110 (
< 0.05). On d2, NA pigs had more lesions than A and GLN (
< 0.01). In terms of microbiota composition, GLN had higher α-diversity than A and NA (
< 0.001). Differences between dietary treatments were absent at d0, were demonstrated at d14 and disappeared at d34. Pearson correlations between aggression, stress and anxiety indicators and bacterial populations were medium to high from 0.31 to 0.69. The results demonstrate that short-term feeding strategy can have both short- and long-term effects on behavior and welfare, that may partly be explained by changes in gut microbiota composition. Supplementation with GLN appears to confer similar benefits to dietary antibiotics and thus could be a viable alternative.
An 8-wk study of the effects of CLA, rendered animal fats, and ractopamine, and their interactive effects on growth, fatty acid composition, and carcass quality of genetically lean pigs was ...conducted. Gilts (n = 228; initial BW of 59.1 kg) were assigned to a 2 x 2 x 3 factorial arrangement consisting of CLA, ractopamine, and fat treatments. The CLA treatment consisted of 1% CLA oil (CLA-60) or 1% soybean oil. Ractopamine levels were either 0 or 10 ppm. Fat treatments consisted of 0% added fat, 5% choice white grease (CWG), or 5% beef tallow (BT). The CLA and fat treatments were initiated at 59.1 kg of BW, 4 wk before the ractopamine treatments. The ractopamine treatments were imposed when the gilts reached a BW of 85.7 kg and lasted for the duration of the final 4 wk until carcass data were collected. Lipids from the belly, outer and inner layers of backfat, and LM were extracted and analyzed for fatty acid composition from 6 pigs per treatment at wk 4 and 8. Feeding CLA increased (P < 0.02) G:F during the final 4 wk. Pigs fed added fat as either CWG or BT exhibited decreased (P < 0.05) ADFI and increased (P < 0.01) G:F. Adding ractopamine to the diet increased (P < 0.01) ADG, G:F, and final BW. The predicted carcass lean percentage was increased (P < 0.05) in pigs fed CLA or ractopamine. Feeding either 5% fat or ractopamine increased (P < 0.05) carcass weight. Adding fat to the diets increased (P < 0.05) the 10th rib backfat depth but did not affect predicted percent lean. Bellies of gilts fed CLA were subjectively and objectively firmer (P < 0.01). Dietary CLA increased (P < 0.01) the concentration of saturated fatty acids and decreased (P < 0.01) the concentration of unsaturated fatty acids of the belly fat, both layers of backfat, and LM. Ractopamine decreased (P < 0.01) the i.m. fat content of the LM but had relatively little effect on the fatty acid profiles of the tissues compared with CLA. These results indicate that CLA, added fat, and ractopamine work mainly in an additive fashion to enhance pig growth and carcass quality. Furthermore, these results indicate that CLA results in more saturated fat throughout the carcass.
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