scholarly journals 236 Effects of mitoquinol during acute heat stress exposure in growing pigs

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 118-118
Author(s):  
Edith J Mayorga ◽  
Erin A Horst ◽  
Brady M Goetz ◽  
Sonia Rodríguez-Jiménez ◽  
Megan A Abeyta ◽  
...  

Abstract Objectives were to determine the effects of mitoquinol (MitoQ) on performance, metabolism, and inflammation during acute heat stress (HS) in growing pigs. Crossbred barrows (n=32; 59±1 kg BW) where blocked by BW and randomly assigned to 1 of 4 therapeutic-environmental treatments: 1) thermoneutral (TN) control (n=8; TNCtl), 2) TN and MitoQ (n=8; TNMitoQ), 3) HS control (n=8; HSCtl), or 4) HS and MitoQ (n=8; HSMitoQ). The trial consisted of two experimental periods (P). During P1 (2d), pigs were fed ad libitum and housed in TN conditions (20.6±0.1°C). During P2 (24h), HSCtl and HSMitoQ pigs were exposed to continuous HS (35.2±0.03°C); while TNCtl and TNMitoQ remained in TN conditions. Mitoquinol was orally administered twice daily (0700 and 1800 h; 40 mg/d) during P1 and P2. Pigs exposed to HS had increased rectal temperature, skin temperature, and respiration rate (1.46°C, 6.79°C, and 101 bpm, respectively; P< 0.01) compared to their TN counterparts. Acute HS markedly decreased feed intake (67%; P< 0.01). Additionally, HS pigs lost BW compared to their TN counterparts (-4.7 vs. +1.6 kg, respectively; P< 0.01); however, the reduction in BW was less severe in HSMitoQ compared to HSCtl pigs (-3.85 vs. -5.50 kg, respectively; P< 0.01). Circulating glucose increased in HSMitoQ relative to HSCtl pigs (15%; P=0.04). Non-esterified fatty acid (NEFA) concentrations were increased in HS compared to TN pigs (P< 0.01), although this difference was influenced by increased NEFA in HSCtl relative to HSMitoQ pigs (251 vs. 142 μEq/L; P< 0.01). Insulin:feed intake tended to increase in HS relative to TN pigs (P=0.09). Overall, no differences in blood urea nitrogen or cell blood counts were observed across treatments (P >0.10). In conclusion, acute HS exposure negatively altered animal performance and metabolism; however, administering MitoQ appeared to ameliorate the HS response.

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 117-117
Author(s):  
Edith J Mayorga ◽  
Erin A Horst ◽  
Brady M Goetz ◽  
Sonia Rodríguez-Jiménez ◽  
Megan A Abeyta ◽  
...  

Abstract Objectives were to determine the effects of rapamycin on biomarkers of metabolism and inflammation during acute heat stress (HS) in growing pigs. Crossbred barrows (n=32; 63.5±0.8 BW) where blocked by BW and randomly assigned to 1 of 4 therapeutic-environmental treatments: 1) thermoneutral (TN) control (n=8; TNCtl), 2) TN and rapamycin (n=8; TNRapa), 3) HS control (n=8; HSCtl), or 4) HS and rapamycin (n=8; HSRapa). The trial consisted of 2 experimental periods (P). During P1 (10d), pigs were fed ad libitum and housed in TN conditions (21.3±0.01°C). During P2 (24h), HSCtl and HSRapa pigs were exposed to constant HS (35.5±0.1°C); while TNCtl and TNRapa remained in TN conditions. Rapamycin (0.15 mg/kg BW) was orally administered twice daily (0700 and 1800 h) during P1 and P2. HS increased rectal temperature, skin temperature, and respiration rate compared to TN counterparts (1.28°C, 8.68°C, and 87 bpm, respectively; P< 0.01). Feed intake (FI) markedly decreased in HS relative to TN treatments (64%; P< 0.01). Additionally, pigs exposed to HS lost BW (4 kg; P< 0.01), while TN pigs gained BW (0.7 kg; P< 0.01). Overall, circulating white blood cells decreased in HS compared to TN pigs (19%; P=0.01). Circulating neutrophils did not differ across treatments; however, lymphocytes, monocytes, and basophils decreased in HS relative to TN pigs (23, 33, and 38%, respectively; P≤0.07). Despite marked changes in phenotypic parameters, circulating glucose and blood urea nitrogen did not differ among treatments (P >0.10). However, insulin:FI increased in HS relative to TN treatments (P=0.04). Plasma non-esterified fatty acids (NEFA) increased in HS relative to TN treatments; although this difference was driven by increased NEFA in HSCtl compared to TN and HSRapa pigs (P< 0.01). In summary, pigs exposed to HS had altered phenotypic, metabolic, and leukocyte responses; however, rapamycin administration had little to no effect on any of the variables measured.


2018 ◽  
Vol 315 (6) ◽  
pp. R1096-R1106 ◽  
Author(s):  
Lidan Zhao ◽  
Ryan P. McMillan ◽  
Guohao Xie ◽  
Samantha G. L. W. Giridhar ◽  
Lance H. Baumgard ◽  
...  

Heat-stressed pigs experience metabolic alterations, including altered insulin profiles, reduced lipid mobilization, and compromised intestinal integrity. This is bioenergetically distinct from thermal neutral pigs on a similar nutritional plane. To delineate differences in substrate preferences between direct and indirect (via reduced feed intake) heat stress effects, skeletal muscle fuel metabolism was assessed. Pigs (35.3 ± 0.8 kg) were randomly assigned to three treatments: thermal neutral fed ad libitum (TN; 21°C, n = 8), heat stress fed ad libitum (HS; 35°C, n = 8), and TN, pair-fed/HS intake (PF; n = 8) for 7 days. Body temperature (TB) and feed intake (FI) were recorded daily. Longissimus dorsi muscle was biopsied for metabolic assays on days −2, 3, and 7 relative to initiation of environmental treatments. Heat stress increased TBand decreased FI ( P < 0.05). Heat stress inhibited incomplete fatty acid oxidation and glucose oxidation ( P < 0.05). Metabolic flexibility decreased in HS pigs compared with TN and PF controls ( P < 0.05). Both phosphofructokinase and pyruvate dehydrogenase (PDH) activities increased in PF ( P < 0.05); however, TN and HS did not differ. Heat stress inhibited citrate synthase and β-hydroxyacyl-CoA dehydrogenase (β-HAD) activities ( P < 0.05). Heat stress did not alter PDH phosphorylation or carnitine palmitoyltransferase 1 abundance but reduced acetyl-CoA carboxylase 1 (ACC1) protein abundance ( P < 0.05). In conclusion, HS decreased skeletal muscle fatty acid oxidation and metabolic flexibility, likely involving β-HAD and ACC regulation.


2017 ◽  
Vol 1 (1) ◽  
pp. 116-125 ◽  
Author(s):  
F. Liu ◽  
J. J. Cottrell ◽  
U. Wijesiriwardana ◽  
F. W. Kelly ◽  
S. S. Chauhan ◽  
...  

Abstract Improving insulin sensitivity may reduce impacts of heat stress (HS) in pigs by facilitating heat dissipation. Chromium (Cr) has been reported to improve insulin sensitivity in pigs. Therefore, the aim of this experiment was to investigate whether Cr supplementation can mitigate HS in growing pigs. Thirty-six gilts were randomly assigned to 2 diets containing 0 (control) or 400 ppb Cr. After 14 d the supplemented pigs were allocated to either 8 d thermoneutral (20°C constant; TN) or cyclic HS (35°C, 0900 h to 1700 h) conditions and continued their respective diet (n = 9 per group). Growth performance was recorded during the 14-d supplementation period. The physiological responses to HS were monitored by measuring respiration rate, rectal temperature, blood gas chemistry, and feed intake during thermal exposure. Kinetics of plasma glucose, insulin and NEFA were studied by intravenous glucose tolerance test (IVGTT) on d 8 of thermal treatment. Results showed Cr alleviated the HS-increased rectal temperature (P &lt; 0.05) and respiration rate (P &lt; 0.01) at 1300 h and 1600 h during thermal exposure. However, Cr did not mitigate the reduction in average daily feed intake which was reduced by 35% during HS or the HS-induced respiratory alkalosis. Chromium tended to increase average daily gain (0.86 vs. 0.95 kg, P = 0.070) during the 14-d supplementation under TN conditions before thermal exposure, which might be associated with the potential of Cr in improving overall insulin sensitivity, as evidenced by a reduced insulin resistance index calculated by Homeostatic Model Assessment (HOMA-IR; 0.65 vs. 0.51, P = 0.013) and a tendency of reduced fasting plasma insulin concentration (1.97 vs. 1.67 μU/mL, P = 0.094). Heat stress decreased the acute insulin releasing rate (P = 0.012) and consequently slowed glucose clearance rate (P = 0.035) during IVGTT. Besides, HS enlarged the values of area under the curve of NEFA during IVGTT (P &lt; 0.01), indicating a reduced lipid mobilization. In conclusion, HS reduced insulin response to IVGTT. Chromium supplementation exhibited a potential in improving insulin sensitivity and mitigating HS symptoms in growing pigs.


1971 ◽  
Vol 13 (1) ◽  
pp. 51-57 ◽  
Author(s):  
S. R. Morrison ◽  
L. E. Mount

SUMMARYPigs fed ad libitum were exposed to changes from 22 to 33°C and from 33 to 20°C. Responses were investigated in two groups of animals kept for three successive periods of four weeks at 22°, 33° and finally 20°C.Twenty-four hr after the first change, from 22 to 33°C, there was a decline in body weight; after the second change, from 33 to 20°C, there was a large increase. After the change to 33°C, feed intake by the second day and growth rate for the first week were about the same as at the end of the four weeks, but about 12 days were required for water intake, rectal temperature and respiratory rate to reach steady values.After the change from 33 to 20°C, steady values for respiratory rate and rectal temperature were reached in one and 12 days respectively. The rate of gain in weight increased to reach a peak nine days following the temperature change and then declined.


Animals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 359 ◽  
Author(s):  
Wei Fang ◽  
Xiaobin Wen ◽  
Qingshi Meng ◽  
Lei Liu ◽  
Jingjing Xie ◽  
...  

Heat stress influences lipid metabolism independently of nutrient intake. It is not well understood how cholesterol and bile acid (BA) metabolism are affected by heat stress. To investigate the alterations of cholesterol and bile acids when pigs are exposed to short term heat stress, 24 Large White pigs (63.2 ± 9.5 kg body weight, BW) were distributed into one of three environmental treatments: control conditions (CON, 23 °C with ad libitum intake; n = 8), heat stress conditions (HS, 33 °C with ad libitum intake; n = 8), or pair-fed conditions (PF, 23 °C with the same amount to the feed consumed by the HS; n = 8) for three days. Compared with CON pigs, HS pigs reduced the average daily feed intake and average daily gain by 55% and 124%, respectively, and significantly increased rectal temperatures by 0.9 °C and respiration rates more than three-fold. The serum total cholesterol (TC), low-density lipoprotein-cholesterol, and triglycerides (TG) increased (p < 0.05), while hepatic TC, TG, and mRNA of 3-hydroxy-3-methylglutaryl-CoA reductase were reduced on day 3. Furthermore, liver taurine-conjugated BAs (TCBAs), including taurolithocholic acid, taurochenodeoxycholic acid (TCDCA), tauroursodeoxycholic acid, taurohyodeoxycholic acid, and taurocholic acid were elevated in HS pigs compared to CON and PF pigs (p < 0.05), and the level of chenodeoxycholic acid was more significant in the PF group than in the CON and HS groups. The concentration of ursodeoxycholic acid in the serum was higher in HS pigs than CON and PF pigs (p < 0.05), and TCDCA was increased in HS pigs compared with PF pigs (p < 0.05). Altogether, short-term HS reduced hepatic cholesterol levels by decreasing cholesterol synthesis, promoting cholesterol to TCBAs conversion, and cholesterol release to serum in growing pigs. This independently reduced feed intake might serve as a mechanism to protect cells from damage during the early period.


2014 ◽  
Vol 54 (3) ◽  
pp. 319 ◽  
Author(s):  
Ronald E. Newman ◽  
Jeffery A. Downing ◽  
Peter C. Thomson ◽  
Cherie L. Collins ◽  
David J. Henman ◽  
...  

Three studies investigated the effect of feeding strategy on production performance and endocrine status of growing pigs. For Experiment 1, 20 entire male pigs (70.0 ± 4.6 kg) were allocated randomly to individual pens in one of four climate-controlled rooms. Pigs were fed for 23 days either ad libitum or entrained to feed bi-phasically for two 90-min periods. For Experiment 2, 20 entire male pigs (41.2 ± 3.5 kg) were housed as per Experiment 1. Pigs were fed for 49 days either ad libitum or fed bi-phasically for two 60-min periods. For Experiment 3, 100 female pigs (66.1 ± 3.5 kg) were randomly allocated to individual pens within a commercial piggery and fed for 42 days either ad libitum or bi-phasically for two 60-min periods. Ear vein catheters were inserted into 10 pigs from each group and hourly blood samples were collected for 24 h in Experiments 1 and 2 and for 11 h in Experiment 3. Plasma insulin, non-esterified fatty acid and glucose concentrations were determined in Experiments 1 and 2, and glucose and insulin concentrations in Experiment 3. Feed intake and performance were recorded in all experiments and carcass composition was assessed by computed tomography for Experiment 2. There were no differences in final liveweight between the two treatment groups for all experiments. Pigs fed for two 90-min periods (Experiment 1) showed no difference in feed intake when compared with feeding ad libitum. Pigs in Experiment 2 fed for two 60-min intervals consumed 2.49 kg/pig.day compared with those fed ad libitum that consumed 2.68 kg/day (P = 0.057). In Experiment 3, pigs fed twice daily consumed 2.82 kg/pig.day compared with 2.91 kg/pig.day in ad libitum-fed pigs (P = 0.051). Bi-phasic fed pigs in Experiment 2 had improved (P < 0.05) feed conversion efficiency compared with pigs fed ad libitum. For all experiments, there was no difference in plasma glucose concentrations between the two treatments. In all three experiments, the circulating insulin concentrations for pigs fed ad libitum remained at a constant level throughout the sampling period. However, plasma insulin concentrations for the bi-phasic fed pigs significantly increased ~1 h after both feeding periods during all three experiments. Insulin secretion of pigs fed for two 90-min periods differed from that of pigs fed for two 60-min periods. Plasma insulin concentration increased five-fold following feeding for 60 min, compared with that in pigs fed for 90 min, which increased two-fold. Bi-phasic-fed pigs from Experiment 2 had reduced (P < 0.05) total carcass fat and significantly increased muscle when compared with pigs fed ad libitum. The data showed that feeding pigs at two succinct periods aligned insulin secretion to the time of feeding. Pigs fed for 60 min, unlike those fed for 90-min intervals, had reduced feed intake in comparison to those fed ad libitum. This may suggest that the duration of the feeding bout is important for this response and this may in turn influence both energy balance and the way energy is partitioned.


Author(s):  
Joyce Barcellos ◽  
Warley Júnior Alves ◽  
Pedro Riguetti Arnaut ◽  
Lucimauro Fonseca ◽  
Jorge Cunha Lima Muniz ◽  
...  

Abstract To evaluate the effect of an E. coli lipopolysaccharide (LPS) challenge on the digestible lysine (Lys) requirement for growing pigs, a nitrogen (N) balance assay was performed. Seventy-two castrated male pigs [19 ± 1.49 kg body weight (BW)] were allocated in a 2 x 6 factorial design composed of two immune activation states (control and LPS-challenged) and 6 dietary treatments with N levels of 0.94, 1.69, 2.09, 3.04, 3.23 and 3.97% N, as fed, where Lys was limiting, with six replicates and one pig per unit. The challenge consisted of an initial LPS dose of 30 μg/kg BW via intramuscular (IM) injection and a subsequent dose of 33.6 μg/kg BW after 48 h. The experimental period lasted 11 days and was composed of a 7-day adaptation and a subsequent 4-day sampling period in which N intake (NI), N excretion (NEX) and N deposition (ND) were evaluated. Inflammatory mediators and rectal temperature were assessed during the 4-day collection period. A 3-way interaction (N levels × LPS challenge × time, P &lt; 0.05) for IgG was observed. Additionally, 2-way interactions (challenge × time, P &lt; 0.05) were verified for IgA, ceruloplasmin, transferrin, haptoglobin, α-1-acid glycoprotein, total protein, and rectal temperature; and (N levels × time, P &lt; 0.05) for transferrin, albumin, haptoglobin, total protein and rectal temperature. LPS-challenged pigs showed lower (P &lt; 0.05) feed intake. A 2-way interaction (N levels × LPS challenge, P &lt; 0.05) was observed for NI, NEX and ND, with a clear dose-response (P &lt; 0.05). LPS-challenged pigs showed lower NI and ND at 2.09% N and 1.69 to 3.97% N (P &lt; 0.05), respectively, and higher NEX at 3.23% N (P &lt; 0.05). The parameters obtained by a nonlinear model (N maintenance requirement, NMR and theoretical maximum N deposition, NDmaxT) were 152.9 and 197.1 mg/BWkg  0.75/d for NMR, and 3,524.7 and 2,077.8 mg/BWkg  0.75/d for NDmaxT, for control and LPS-challenged pigs, respectively. The estimated digestible Lys requirements were 1,994.83 and 949.16 mg/BWkg  0.75/d for control and LPS-challenged pigs, respectively. The daily digestible Lys intakes required to achieve 0.68 and 0.54 times the NRmaxT value were 18.12 and 8.62 g/d, respectively, and the optimal dietary digestible Lys concentration may change depending on the feed intake levels. Based on the derived model parameters obtained in the N balance trial with lower cost and time, it was possible to differentiate the digestible Lys requirement for swine under challenging conditions.


Author(s):  
A.L. Lightfoot ◽  
A.W. Armsby ◽  
C.F. Widdows

An experiment was carried out to determine which feeding method maximised feed intake of growing pigs and to record growth rates, feed conversion efficiency and backfat measurements. There is an increasing tendency for dry fed pigs to be fed ad libitum or to appetite in order to increase growth rates and throughput of building.Limited information is available on how the modern genetically improved pig will respond to high levels of feeding and whether ad libitum feeding will encourage higher feed intake than feeding to appetite either wet or dry.


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