scholarly journals 232 Reduced growth performance during viral challenge primarily results from disease hypophagia

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 118-118
Author(s):  
Blaire Todd ◽  
Larissa Becker ◽  
Nicholas Gabler

Abstract Reductions in voluntary feed intake during disease, or disease hypophagia, is a common phenotype observed in nearly all species. However, the extent to which disease hypophagia explains attenuated pig performance during disease is poorly defined. The objective of this study was to describe the extent to which hypophagia explains pig performance during a Porcine Reproductive and Respiratory Syndrome (PRRS) virus challenge. Twenty-four PRRS naïve barrows (12.8 ± 0.73 kg BW; Landrace x Large White, PIC) were selected, blocked by body weight, and allotted across three treatments (n=8/trt): 1) PRRS-naïve, ad libitum fed (Ad), 2) PRRS-inoculated, ad libitum fed (PRRS), and 3) PRRS-naïve, pair-fed daily to the PRRS pigs (PF) to mimic disease feed intake. All pigs were individually penned and after a 4-day acclimation, on days post inoculation (dpi) 0, PRRS pigs were inoculated with PRRS virus. Over 7 dpi, daily feed intake and body temperatures (BT), and 7 day ADG, ADFI, and G:F were assessed. Over the 7-day challenge period, a treatment x time interaction (P < 0.0001) was reported for ADFI in which PRRS and PF pigs’ ADFI was reduced by 51% compared with Ad pigs. Compared with Ad pigs, PRRS and PF pigs end BW was reduced by 23% (P = 0.004). The Ad pigs had greater ADG compared with PF and PRRS pigs (0.64, 0.12, -0.04 g/d, respectively, P < 0.0001). Overall G:F was reduced by 112% and 53% in the PRRS and PF pigs, respectively, compared with Ad pigs (P < 0.0001). A treatment x dpi effect was reported in core BT, in which PF pigs; BTs reduced over time compared with Ad and PRRS pigs (38.7, 39.4, 39.6 °C, respectively, P = 0.001). In summary, disease hypophagia explains much of the reduced growth observed during PRRS challenge.

2020 ◽  
Vol 98 (4) ◽  
Author(s):  
Jessica E Jasper ◽  
Omarh F Mendoza ◽  
Caleb M Shull ◽  
Wesley P Schweer ◽  
Kent J Schwartz ◽  
...  

Abstract Porcine reproductive and respiratory syndrome virus (PRRSV) compromises pig performance. However, increasing standardized ileal digestible Lys per Mcal metabolizable energy (SID Lys:ME) above requirement has been shown to mitigate reduced performance seen during a porcine reproductive and respiratory syndrome (PRRS) virus challenge. The objective of this study was to evaluate the effects of increasing the dietary SID Lys:ME from 100% National Research Council (NRC) requirement to 120% of the requirement in vaccinated (vac+; modified live vaccine Ingelvac PRRS) and non-vaccinated (vac−; no PRRS vaccine) grower pigs subjected to a PRRSV challenge. In addition, the dietary formulation approach to achieve the 120% ratio by increasing Lys relative to energy (HL) or diluting energy in relation to Lys (LE) was evaluated. This allowed us to test the hypothesis that pigs undergoing a health challenge would have the ability to eat to their energy needs. Within vaccine status, 195 mixed-sex pigs, vac+ (35.2 ± 0.60 kg body weight [BW]) and vac− (35.2 ± 0.65 kg BW) were randomly allotted to one of three dietary treatments (2.67, 3.23, or 3.22 g SID Lys:ME) for a 42-d PRRS virus challenge study representing 100%, 120%, and 120% of NRC requirement, respectively. Pigs were randomly allotted across two barns, each containing 24 pens with 7 to 10 pigs per pen (8 pens per diet per vaccine status). On day post-inoculation 0, both barns were inoculated with PRRSV and started on experimental diets. Within vaccine status, weekly and overall challenge period pig performance were assessed. In both vac+ (P < 0.05) and vac− (P < 0.05) pigs, the HL and LE diets increased end BW and overall average daily gain (ADG) ADG compared with pigs fed the control diet (P < 0.05). Overall, average daily feed intake (ADFI) during the challenge period was greater (P < 0.05) for pigs fed the LE diet compared with pigs fed control and HL treatments, regardless of vaccine status (20% and 17% higher ADFI than the control in vac+ and vac− pigs, respectively). The HL vac+ pigs had the greatest gain to feed (G:F) compared with the control and LE pigs (0.438 vs. 0.394 and 0.391 kg/kg, respectively; P < 0.01). Feed efficiency was not impacted (P > 0.10) by treatment in the vac− pigs. In summary, PRRSV-challenged grower pigs consumed feed to meet their energy needs as indicated by the increase in ADFI when energy was diluted in the (LE) diet, compared with control pigs. In both PRRS vac+ and vac− pigs subsequently challenged with PRRSV, regardless of formulation approach, fed 120% SID Lys:ME diets resulted in enhanced overall growth performance.


1998 ◽  
Vol 1998 ◽  
pp. 131-131
Author(s):  
J. J. Hyslop ◽  
A. Bayley ◽  
A. L. Tomlinson ◽  
D. Cuddeford

De-hydrated forages are often fed to equids in the UK in place of more traditional grass hay, particularly where individual animals are known to have a sensitivity to dusty, mouldy hay which may play a part inducing respiratory problems such as chronic obstructive pulmonary disease (COPD). One such alternative forage is short-chop de-hydrated grass. However, there is very little information available on voluntary feed intake (VFI), apparent digestibility and nutrient intake parameters when de-hydrated grass is offered to equids compared with traditional grass hay. This study examines the VFI and apparent digestibility in vivo of a short-chop de-hydrated grass compared with a traditional grass hay and determines their ability to meet the predicted energy and protein needs of mature ponies.Six mature Welsh-cross pony geldings with a mean liveweight (LW) of 281 kg (s.e.d. 0.89) were individually housed and offered ad libitum access to either short-chop de-hydrated grass (DHG) or traditional grass hay (HAY) plus 60 g/h/d minerals. The DHG and HAY were made from the same 2nd cut perennial ryegrass sward cut on the same day.


1967 ◽  
Vol 9 (4) ◽  
pp. 463-470 ◽  
Author(s):  
M. J. Ulyatt ◽  
K. L. Blaxter ◽  
I. McDonald

Three sheep with permanent fistulas of the rumen were each given dried grass and two hays, each in three different amounts, and the apparent digesti-bility of the roughages in the rumen and distal to the rumen was determined. A lignin ratio method was used to measure digestibility.With increase in the amount of the poorest hay given, the proportion digested in the rumen fell and that distal to the rumen increased. With the second hay this effect was also noted but was not statistically significant. The voluntary intakes ofdry matter varied from 1·94 kg/day for the dried grass to 1·28 for the poorest hay. The volumes of distribution of polyethylene glycol in the rumen when feed was offered ad libitum, however, were the same, irrespective of the type of feed, at between 14·1 and 15·2 litres. These observations were confirmed at slaughter. The results support the hypothesis that sheep voluntarily consume roughages of different qualities to achieve constant fill of their rumens, and that little regulation of voluntary intake can be attributed to distension of the hind gut.


2019 ◽  
Vol 97 (8) ◽  
pp. 3213-3227 ◽  
Author(s):  
Emma T Helm ◽  
Shelby M Curry ◽  
Carson M De Mille ◽  
Wesley P Schweer ◽  
Eric R Burrough ◽  
...  

Abstract Porcine reproductive and respiratory syndrome (PRRS) virus is one of the most economically significant pig pathogens worldwide. However, the metabolic explanation for reductions in tissue accretion observed in growing pigs remains poorly defined. Additionally, PRRS virus challenge is often accompanied by reduced feed intake, making it difficult to discern which effects are virus vs. feed intake driven. To account for this, a pair-fed model was employed to examine the effects of PRRS challenge and nutrient restriction on skeletal muscle and liver metabolism. Forty-eight pigs were randomly selected (13.1 ± 1.97 kg BW) and allotted to 1 of 3 treatments (n = 16 pigs/treatment): 1) PRRS naïve, ad libitum fed (Ad), 2) PRRS-inoculated, ad libitum fed (PRRS+), and 3) PRRS naïve, pair-fed to the PRRS-inoculated pigs’ daily feed intake (PF). At days postinoculation (dpi) 10 and 17, 8 pigs per treatment were euthanized and tissues collected. Tissues were assayed for markers of proteolysis (LM only), protein synthesis (LM only), oxidative stress (LM only), gluconeogenesis (liver), and glycogen concentrations (LM and liver). Growth performance, feed intake, and feed efficiency were all reduced in both PRRS+ and PF pigs compared with Ad pigs (P < 0.001). Furthermore, growth performance and feed efficiency were additionally reduced in PRRS+ pigs compared with PF pigs (P < 0.05). Activity of most markers of LM proteolysis (μ-calpain, 20S proteasome, and caspase 3/7) was not increased (P > 0.10) in PRRS+ pigs compared with Ad pigs, although activity of m-calpain was increased in PRRS+ pigs compared with Ad pigs (P = 0.025) at dpi 17. Muscle reactive oxygen species production was not increased (P > 0.10) in PRRS+ pigs compared with Ad pigs. However, phosphorylation of protein synthesis markers was decreased in PRRS+ pigs compared with both Ad (P < 0.05) and PF (P < 0.05) pigs. Liver gluconeogenesis was not increased as a result of PRRS; however, liver glycogen was decreased (P < 0.01) in PRRS+ pigs compared with Ad and PF pigs at both time points. Taken together, this work demonstrates the differential impact a viral challenge and nutrient restriction have on metabolism of growing pigs. Although markers of skeletal muscle proteolysis showed limited evidence of increase, markers of skeletal muscle synthesis were reduced during PRRS viral challenge. Furthermore, liver glycogenolysis seems to provide PRRS+ pigs with glucose needed to fuel the immune response during viral challenge.


1998 ◽  
Vol 1998 ◽  
pp. 130-130 ◽  
Author(s):  
J. J. Hyslop ◽  
A. L. Tomlinson ◽  
A. Bayley ◽  
D. Cuddeford

Many mature, non-pregnant, non-lactating equids are often kept in circumstances where they are expected to perform only light physical work or activity eg: a childs pony. Consequently their maintenance energy and protein needs can often be met at very restricted feed intake levels. Conversely, when they are housed during the winter months it is believed desirable to manage such animals on unrestricted ad libitum feeding regimes in order to allow the animals to exhibit their natural feed intake pattern and consume forage on a little and often basis throughout the daily feeding period. However, ad libitum access to the diet may lead to such animals becoming excessively fat. These conflicting needs of low energy and protein requirement coupled with the desirability of unrestricted access to the diet could both be met, at least in part, if a low quality forage is available ad libitum. This study examines the voluntary feed intake and apparent digestibility in vivo of a mature threshed grass hay offered ad libitum and determines its ability to meet the predicted energy and protein needs of mature ponies.


1994 ◽  
Vol 45 (2) ◽  
pp. 355
Author(s):  
SW Walkden-Brown ◽  
BW Norton ◽  
BJ Restall

The effects of season and diet quality on voluntary feed intake and growth were examined in mature cashmere bucks over a 16 month period at Wollongbar (29�S., 153� E.). Three-year-old bucks were individually housed under natural photoperiod and fed ad libitum diets of High (pelleted lucerne, CP 17.6%, ME 8.3 MJ/kg) or Low (pasture hay; CP 6.9%, ME 6.6 mJ/kg) quality, between July 1988 and Oct. 1989 (n = 6/treatment). Bucks on both diets exhibited a seasonal pattern in voluntary feed intake with maximal intakes during spring and summer, and minimal intakes during autumn. The pattern appeared to be circannual with high intakes during spring of both years. Liveweight also varied with season peaking in mid to late summer and reaching a seasonal nadir in late autumn or early winter. Change in liveweight was closely associated with digestible energy intake ( r = 0-87, P < 0.001) resulting in a growth cycle closely resembling that of voluntary feed intake. In both treatments, bucks lost weight throughout autumn, while growth rates were maximal between mid-winter and mid-spring. Diet quality did not alter the magnitude of the autumnal decline in liveweight with bucks losing 7.6% (Low) and 7.8% (High) of liveweight during this period. However, bucks on the high quality diet exhibited significantly elevated growth rates between mid-winter and mid-spring. We conclude that mature cashmere bucks exhibit an annual growth cycle with weight loss during autumn and maximal weight gains between mid-winter and mid-spring; that the growth cycle is driven primarily by changes in voluntary feed intake; and that increasing diet quality does not reduce the autumnal decline in liveweight but significantly increases liveweight gain during the seasonal peak in growth.


1973 ◽  
Vol 17 (3) ◽  
pp. 281-285 ◽  
Author(s):  
J. D. Wood

SUMMARYThe fatty acid composition of backfat from Pietrain and Large White pigs was examined. Both the inner and outer layers of Pietrain backfat had higher concentrations of unsaturated fatty acids and lower concentrations of saturated fatty acids. Pietrains consequently had relatively soft fat.A pair-feeding experiment was conducted with Large White and Pietrain pigs to determine whether these differences could be explained by the lower voluntary feed intake of Pietrains. The results showed that the Large Whites continued to accumulate relatively saturated fatty acids even at the lower level of feeding. It was concluded that the differences in the fatty acid composition of backfat reflect genetic differences in the capacity for fat deposition between the two breeds.


2009 ◽  
Vol 49 (12) ◽  
pp. 1093 ◽  
Author(s):  
V. J. Strickland ◽  
J. S. Fisher ◽  
W. T. Potts ◽  
G. W. Hepworth

With the increased incidence of parasite resistance to chemical anthelmintics worldwide novel approaches to manage parasite infection, such as medicinal plants and their extracts, are being investigated by the scientific community. The current study tested the effect of three rates of garlic (0.9, 1.8 and 3.6%) in a pelleted ration on Haemonchus contortus in sheep. Thirty-nine Merino wether lambs aged 6 months were divided into five treatment groups, including three garlic dose rates and two control groups that received no garlic. All animals were infected with 4000 L3 H. contortus larvae 3 weeks after allocation to treatments. A positive control group was drenched with abamectin 28 days after infection. The synthetic drench was effective in controlling the parasites, but there was no reduction in either worm egg counts (WEC) or total worm count due to the garlic. The 3.6% garlic treatment had significantly lower (P < 0.05) liveweight, feed intake, body condition score and feed conversion ratio than any of the other treatment groups, suggesting that this level of garlic had a low level of anti-nutritional properties. There was an interaction between faecal WEC and voluntary feed intake over time, with the animals with higher voluntary feed intake having lower WEC over time.


2002 ◽  
Vol 2002 ◽  
pp. 155-155
Author(s):  
J. J. Hyslop ◽  
B. A. Hedley ◽  
R. Keatinge ◽  
D. G. Chapple

An understanding of the dry matter intake (DMI) capacity of suckler cows is crucial to the provision of adequate nutrition during lactation. However, quantitative data on the likely feed intake patterns of modern continental x dairy suckler cow genotypes is scarce. The objective of the current experiment was to determine voluntary DMI in Simmental x Holstein/Friesian (SIM) and Belgian Blue x Holstein/Friesian (BB) autumn calving suckler cows offered a grass silage based diet ad libitum.


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