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.

Nutritional strategies to enhance intestinal development, caloric intake, and hydration are advantageous to newborn and weaned pigs by aiding in growth performance and survivability. However, the lifetime benefit of such strategies in commercial pigs has been poorly elucidated. Therefore, the objective of this study was to evaluate the effect of an isotonic electrolyte supplementation on lifetime pig performance. Three hundred ninety-three piglets (Duroc sires by Yorkshire-Landrace F1 females; 1.63 ± 0.38 kg birthweight) born from 40 sows were allotted to one of two treatments: 1) supplementation of TonistyPx (TON+) or 2) no supplementation of TonisityPx (CON). TON+ pigs were given a liquid solution from d 2 to 8 (500 mL/litter/d). All pigs were weaned and shipped to a wean-to-finish site, and randomly allotted by litter/supplemental treatment across two barns with identical configuration (12 pens/treatment; 15-17 pigs/pen). Once allocated, TON+ pens were given a liquid solution (5.68 L/pen/d) on the day of placement and a gruel solution on day 2 and 3 post placement. Individual pig BW was recorded at birth, weaning, end of nursery and end of finishing period. From birth to weaning CON pigs tended to have increased weaning BW compared to TON+ pigs (5.63 vs. 5.38, P < 0.10). At the end of the 42d nursery in which all pigs were fed the same common diets with supplementation from d 0 to 3 post-weaning, no differences in BW were reported between CON and TON+ pigs (25.62 vs. 25.43 kg, P >0.05). However, at the end of the grow-finish period the TON+ pigs were 4.63% heavier compared to CON pigs (P < 0.01). No numerical differences in mortality were reported in nursery or grow-finish periods. In summary, isotonic electrolyte supplementation to newborn and weaned pigs resulted in a 5.87 kg heavier BW at the end of the finisher period.

Crossbred pigs (Fast Genetics 276 × PIC 800; n = 2,332; initial BW = 24.5 ± 1.6 kg) were used in two, 84-d growth trials to evaluate effects of an additional water source (fixed double nipple waterer) to a wet/dry feeder on growing-finishing pig performance. Pigs were assigned randomly to 1 of 2 treatments with 27 to 30 pigs per pen and 40 pens per treatment. Pens were equipped with a wet/dry feeder (SDI, drop shelf wet/dry feeder) or with a wet/dry feeder in combination with the additional water source. Marketing began on d 84 of each trial so the highest pig demands on feeders and waterers were assumed to occur from d 0 to 84 when all pigs were present in each pen. Growth data were analyzed using the GLIMMIX procedure of SAS and removals, mortalities, and total removals were analyzed using a Chi-square test in SAS version 9.4 (SAS Institute Inc., Cary, NC). No significant interactions between trial and water treatment were observed, thus data were combined using water treatment as a fixed effect and trial as a random effect. No differences were observed for body weight on d 84, average market weight, or number of removals, mortalities, or total pigs removed (Table). Similarly, no evidence for differences in overall average daily gain, average daily feed intake, or gain efficiency were observed regardless of an additional water source. However, pigs given access to a supplemental water source displayed a numeric increase in water disappearance per pig compared to pigs in pens with only wet/dry feeders. In conclusion, addition of a fixed double nipple waterer to wet/dry feeders did not influence growth performance of growing-finishing pigs.

The objective was to evaluate the effects of increasing the dietary g SID Lys:ME from 100% (NRC requirement) to 120% of the requirement of grower pigs, in vaccinated (vac+; MLV Ingelvac PRRS®) and non-vaccinated [vac-; no vaccination for Porcine Reproductive and Respiratory Syndrome (PRRS)] pigs that were then challenged with a PRRS virus. Secondly, we evaluated two diet formulation approach to achieve a 120% SID Lys:ME ratio by either increasing Lys relative to energy or diluting energy relative to Lys. Within vaccine status, 195 mixed-sex pigs vac+ (35.2 ± 0.60 kg BW) and vac- (35.2 ± 0.65 kg BW) were randomly allotted to one of three dietary treatments: The treatments (g SID Lys:ME) were 2.67 (100%, control), 3.23 (120%, increased SID Lys), and 3.22 (120S%, dilution of ME via dietary inclusion of sand). Pigs were randomly allotted, within vaccine status, to 24 pens (7-10 pigs/pen; n=8). All pigs were inoculated with a PRRS virus and started on experimental diets on d 0. Over a 42 d challenge period, BW, ADG, ADFI and G:F were determined and all data was analyzed within vaccination status. In vac+ pigs compared to control, end BW increased in 120% and 120S% fed pigs (10% and 9% respectively; P < 0.05) and ADG increased by 20% and 17% respectively (P < 0.05). Similarly, in vac- pigs a 9% and 20% improvement in end BW and ADG was observed respectively compared to control (P < 0.05). Overall, ADFI increased by 20% in the 120S% vac+ pigs (P = 0.003) and by 17% in vac- pigs (P = 0.001) compared to control. The 120% vac+ pigs had the greatest G:F compared to control and 120S% pigs (P < 0.01). In summary, increasing SID Lys:ME by either increasing Lys or decreasing ME improved growth performance of PRRSV challenged pigs.

Porcine reproductive and respiratory syndrome (PRRS) virus is an economically significant pathogen that antagonizes production in all stages of the swine industry. In nursery pigs, it increases the risk of mortality and reduces growth performance parameters. Thus, the objective of this study was to further understand how PRRS virus infection and its associated viremia and serology levels related to febrile response and performance in nursery pigs. Over two replicates, 37 three-week post-weaned PRRS naïve gilts (11.2 ± 2.56 kg BW) were randomly assigned to one of two treatments: Control (CON, n = 16) or PRRS virus-inoculated (PRRS+, n = 21). All pigs were housed individually in a BSL2 facility for the 21 d test period. PRRS serology, BW, ADG, ADFI, and G:F were determined at 0, 7, 14 and 21 days post inoculation (dpi). Core body temperatures were collected daily using a biosensor microchip. Data was analyzed using mixed procedure of SAS with dpi as a repeated effect and CON or PRRS+ as a treatment effect. Treatment, dpi and their interactions were assessed. As expected, viremia and antibody titers in PRRS+ pigs were significantly different compared to CON pigs, which remained negative (P < 0.001). The lowest PRRS Ct was observed at dpi 7, while antibody titers were highest between dpi 14 to 21 (P < 0.001). Compared with the CON, PRRS+ reduced BW gains by 17, 33 and 42% at dpi 7, 14 and 21 respectively (P < 0.001). The PRRS challenge also reduced ADFI by 30, 67 and 68% at dpi 7, 14 and 21 respectively, compared to CON (P < 0.001). The febrile response in the PRRS+ pigs peaked between dpi 7 and 14 then returned to CON baseline level by dpi 21 (P < 0.001). Overall, PRRS virus challenge induced a sustained febrile response that contributes to the attenuated performance of nursery pigs.