Post-weaning Performance Research Articles

PSIX-27 Ultrasound scanning of carcass traits in Katahdin lambs for predictive breeding value and marketing premium

Abstract Ultrasound scanning (USS) technique has been routinely used in performance testing of meat animals, such as swine and beef cattle. This study is to evaluate USS application in organic lamb production, selection, and the accuracy of carcass traits and market value prediction. Ewes (n = 60) were bred, pregnancy diagnosed at 40 d post-mating, and their suckling lambs were assigned to two groups, a non-creep feeding (control) and creep feeding (treatment) group. Each group was balanced with sexes and litter size when allocated into groups at 30-d of age. All lambs had unrestricted suckled their dams during pasture grazing or grazing with creep feeding supplementation until weaning. There were 28 control and 32 treatment group lambs presented at weaning 90 d of age. Lambs were continued to graze as two groups on fescue-based pasture or grazing with creep feeding supplementation till marketing at 120 d. Weaning body weight (BW), average daily gain (ADG), and post-weaning growth weight were significantly (P < 0.05) greater than control 24.0 kg, 226 g/d, and 28.0 kg for treatment group compared with control group at 21.3 kg, 196 g/d, and 25.3 kg, respectively. However, AGD was not significantly increased during the post-weaning creep supplementary feeding period. The ultrasound scanned carcass traits increase in creep feeding over control lambs at weaning and post-weaning measurements (Figure 1). The average ultrasound scanned back fat depth, loineye muscle depth, muscle width, and loineye muscle area were 2.2 mm, 17.9 mm, 45.6 mm and 5.8 cm2 at weaning age of 90 d; and 2.6 mm, 20.9 mm, 48.0 mm, and 7.0 cm2 at 120 d, respectively. The correlative associations (Table 1) between carcass traits and lamb BW, such as loineye muscle depth (LED), loineye muscle width (LEW), loineye muscle depth (LED) and loineye muscle area (LEA), and LEA were significantly improved (P < 0.05) with increased BW. However, there was no difference in these traits due to treatment except backfat depth, which was significantly higher for treatment and females. Creep supplementary feeding lambs during pre-weaning has increased ADG and weaning weight; therefore, will enhance market values of organically raised lambs. The results indicate that USS technique is worthy of application in meat lamb selection, post-weaning performance and market premium prediction.

255 Awardee Talk: Nutritional management to optimize cow-calf production in Southeast

Abstract Nearly one-half of beef cows in the United States are located in southern states where cow-calf operations predominate. Grazing management in cow-calf systems can be affected by environmental and seasonal conditions, often leading to nutrient deficiency, particularly during late gestation of beef females. Maternal nutrition during the last trimester of gestation can influence offspring development and health, and can be explored to optimize maternal and progeny performance. The objective of this presentation is to share nutritional and management strategies for pregnant beef cows and their long-term effects on offspring growth and physiology. Study 1 investigated the effects of timing of maternal protein supplementation during all last trimester of gestation (LATE84), only the first 42 d of last trimester of gestation (LATE42), or no prepartum supplementation (NOSUP) on offspring pre- and post-weaning performance. At weaning, LATE84 calves were the heaviest, followed by LATE42, and NOSUP (P ≤ 0.05). Steer serum parainfluenza-3 titers were greater (P = 0.03) for LATE42 vs. NOSUP and tended to be greater for LATE84 (P = 0.10) vs. NOSUP steers. Marbling and the proportion of steers grading choice were greater (P ≤ 0.04) for LATE42 vs. NOSUP, and intermediate for LATE84. Study 2 evaluated the effects of frequency of maternal protein supplementation on offspring pre-weaning growth. Cows received the same weekly amount of supplement (7 kg·cow⁻¹·wk⁻¹) but with different frequencies: once a week (1X), three times per week (3X), every day (7X), or no prepartum supplementation (NOSUP) during the last 80 d of gestation. At weaning, calves born from 7X cows were the heaviest (P ≤ 0.05), followed by 3X and 1X, which did not differ between them (P = 0.54), and NOSUP calves were the lightest (P ≤ 0.05). Study 3 evaluated the use of monensin supplementation during the last 77 d of gestation and its impacts on offspring performance. Treatments consisted of no prepartum supplementation (NOSUP), supplementation of dried distillers grains at 1 kg·cow⁻¹·d⁻¹ added with 0 (SUP) or 200 mg/d of monensin (SUPMO). At weaning, SUPMO calves were the heaviest (P ≤ 0.05), SUP intermediate, and NOSUP were the lightest. Experiment 4 consisted of pregnant heifers receiving the supplementation of 1 kg/d of soybean hulls dry matter added (BAC) or not (CON) with a Bacillus-based DFM mixture during late gestation (d 0 to 139) and early lactation (d 139 to 242). Post-weaning body weight gain and indicators of humoral immune response post-vaccination were greater for BAC vs. CON calves (P ≤ 0.05). Therefore, changing the time and frequency of supplementation, and the use of additives and probiotics during late gestation of beef females are effective alternatives to improve offspring pre- and post-weaning growth and immune response.

490 Lifetime growth performance and carcass composition of offspring when inactivated Saccharomyces cerevisiae was included in gestating and lactating gilt diets and/or offspring nursery diets

Abstract Gilts [n = 90; initial body weight (BW) = 189.1 ± 3.9 kg] were used to determine the effect of feeding a yeast additive (Saccharomyces cerevisiae inactivated through hydrolyzation; HY) to gestating and lactating gilts and/or the offspring during the nursery period on lifetime offspring growth performance. Gilts were randomly assigned to one of three dietary treatments (n = 30/treatment): standard gestation and lactation diets (GHY0) or supplemented with 0.25% (GHY0.25) or 1% (GHY1.0) HY. Diets were fed between d 85 of gestation until weaning at d 21 (2.6 kg/d in gestation, ad libitum in lactation). At weaning, 8 piglets/litter were placed in nursery pens and pens were randomly assigned to a control (NO) or a HY-supplemented diet (NHY), apart from GHY1.0 offspring who were only provided NO during the nursery period (n = 12). In nursery phases 1, 2 and 3, HY was included at 0.75, 0.50, and 0.25% respectively. Thereafter, pigs received standard grower and finisher rations until slaughter (160 d of age). Data were analyzed in SAS using GLIMMIX with gilt treatment as the main effect (pre-weaning); post-weaning performance used gilt and nursery treatments as the main effects, and interactive effects were tested separately due to the incomplete 3 × 2 factorial design. Mean comparisons were conducted using the Tukey-Kramer test to separate LSmeans. Gilt BW was unaffected by gilt treatment, but gilts fed GHY1.0 had greater total lactation feed intake versus GHY0.25 (128.6 vs. 109.4 ± 7.7 kg; P < 0.01). At birth, GHY0.25 offspring were 70 g heavier than pigs from GHY0 (P < 0.001) with GHY1.0 intermediate. At weaning, GHY0.25 and GHY1.0 offspring were heavier than GHY0 offspring (5.9 vs. 5.6 kg; P < 0.001). After weaning, neither gilt nor nursery diet influenced offspring BW. Pigs fed GHY1.0-NO had greater ADFI versus all other treatments in the nursery (interaction; P < 0.001), GHY0.25-NHY had greater ADFI than GHY0.25-NO and GHY1.0-NO in the grower (interaction; P = 0.005), and NHY consumed more feed than NO in the finisher phase (main effect; P < 0.001). In the nursery, NHY had less average daily feed intake (ADFI) than NO (main effect; P < 0.05), but in grower and finisher, NHY had greater ADFI than NO pigs (main effect; P < 0.001). In the nursery, gain to feed (G:F) was greater for GHY0-NHY versus GHY0.25-NHY and GHY1.0-NO, and greater for GHY0-NO versus GHY0.25-NHY with all other treatments intermediate (interaction; P < 0.05). In the grower phase, G:F was unaffected by maternal or nursery diet, but in the finisher phase, G:F was less for pigs fed NHY versus NO during the nursery phase (main effect; P < 0.05). Slaughter BW, hot carcass weight, and fat and lean percents were not influenced by gilt or nursery diet. Therefore, HY provided to gilts during gestation and lactation, improved pre-weaning offspring growth, but HY supplemented to pigs during the nursery period had greater positive effects on lifetime growth performance.

238 Boosting post-weaning performance of piglets and uniformity with yeast extract supplementation

Abstract The yeast extract, derived from 100% natural and pure Saccharomyces cerevisiae, boasts a high digestibility coefficient (> 95%). It is an excellent source of vitamins, minerals, and amino acids, particularly aspartic and glutamic acids, and is noted for its exceptional palatability (Figure 1). This study aimed to assess the impact of dietary yeast extract supplementation on the performance of nursery-phase piglets. Mixed-sex piglets (n = 1,360) were allocated across 18 pens, with 75 animals per pen, and subjected to two treatments (9 replicates each) on a commercial farm in Minas Gerais, Brazil. The treatment groups included a positive control (PC) group, receiving a phase-specific standard diet, and a yeast extract (YE) group, supplemented with 1% yeast extract on top. Initially, all piglets were fed a commercial diet for the first 7 d (from 21 to 27 d old), followed by a farm-specific diet (PC and YE). The YE was administered as a liquid via an oil-injection system at the feed mill. Performance metrics evaluated included body weight gain (BWG) and feed conversion ratio (FCR), with feed intake (FI) being constant due to automated feeding. Data analysis employed ANOVA at a 90% confidence level, with mean differences assessed using the F-test. Piglets in the YE group demonstrated significantly greater BWG from wk 1 post-supplementation, maintaining statistical differences throughout the study (Table 1). The final BWG difference favored the YE group by 1.560 kg (PC = 15.106 kg; YE = 16.666 kg; P-value = 0.05). Notably, animal uniformity within each treatment was superior in the YE group, exhibiting a 49% reduction in variance across the study period compared with the PC group (Figure 2). This improvement in BWG was accompanied by enhanced batch uniformity relative to the PC group. FCR differences were statistically significant from wk 1 of supplementation, concluding with a final FCR of 1.49 for the PC group and 1.39 for the YE group (P-value = 0.02; Table 2). Given the fixed FI across phases, this FCR improvement primarily reflects the observed weight gain differences. These findings indicate that YE supplementation can enhance performance parameters and piglet uniformity in the nursery phase, offering nutritional benefits throughout this critical growth stage.

423 Comparative post-weaning performance characteristics of four breeds of rabbit in hot humid climate of Nigeria

Abstract Rabbits are one of the most popular livestock breeds raised for their meat, fur, and companionship. Rabbit meat is fast gaining prominence as a healthier meat compared with beef, mutton, pork and chevon, which are mostly consumed in Nigeria. This study investigated breed differences in mortality, survival rates and post-weaning growth rate of rabbits reared under inimical environmental conditions. The animals were fed commercially compounded feed with 18% crude protein and 2300Kcal metabolizable energy with intermittent feeding of Panicum sp and Tridax sp. The study area, located at latitude 6.5867° N and longitude 3.9700° E, had an average daily temperature of 35°C and relative humidity of 64%, which negatively impacted the adaptation, survival rates and growth performance of the rabbits. A total of 48 weaner rabbits 8 wk of age, comprising 12 each (9 does and 3 bucks) of Checkered, Chestnut, Dutch and Hyla breeds were reared for 10 wk post-weaning. Mortality was recorded across the breeds and the body weights (BW) of the rabbits were also recorded on a weekly basis for the entire 10-wk period. The study evaluated survival rates across breeds and sex and BW gain. Statistical analyses were conducted using the Minitab software for Chi Squared test of independence for counts and descriptive statistics and general linear model analysis of variance for bodyweight gain. The statistical model describing the analysis was Yijk = µ + αi + (α:β)ij + eijk where αi is the ith fixed effect of breed and βj is the jth fixed effect of sex. The model accounted for 67.03% variation in total weight gain. Further mean separation was done using the Tukey’s multiple comparison procedure. Mortality rates across breeds on the average was 56.25%, with Checkered, Chestnut, Dutch and Hyla respectively recording 66.67%, 41.67%, 50.00% and 66.67% mortality, respectively. Mortality rate across sexes was 63.89% for does and 33.33% for bucks; however, mortality rates were independent (P > 0.05) of both breed and sex with a Chi-Squared value of 2.285 and 3.41, respectively, despite the numerical differences in mortality rates across breeds and sexes. Average total BW gain during the study period across the breeds and within breeds is as presented in Table 1. The nesting of sex within breed revealed that the only significant (P > 0.05) difference was noticed between the Hyla buck and Chestnut doe, while other means were not statistically different (P > 0.05). The Chestnut breed with the least BW gain adapted well in the environment with greatest survival rate, while the Hyla breed had the greatest BW gain and least survival rate throughout the study. This study indicated a negative relationship between survival rates and BW gain, that lighter breeds of rabbit tend to have greater survival rates than the heavier breeds.

363 Effects of supplementation of vitamin B complex on the performance of beef calves during a 42-d preconditioning program

Abstract The objective of this study was to evaluate the effects of supplementation of vitamin B complex on post-weaning performance of beef calves. The study was conducted during fall of 2023 at Eastern Oregon Agriculture Research Center (EOARC; Burns, OR). At weaning (d 0), 63 calves [Angus × Hereford; body weight (BW) = 252 ± 3.6 kg] were randomly assigned to 1 of 3 treatments: 1) Control, 2) VitB1, or 3) VitB2. Calves assigned to Control treatment served as a negative control and were not supplemented with vitamin B complex. Calves assigned to treatment VitB1 were supplemented at 1g/calf daily, while calves assigned to VitB2 treatment were supplemented at 2g/calf daily of vitamin B complex during the 42 d of preconditioning. Upon weaning processing, calves were allocated to 21 pens (3 calves/pen) and treatments were allocated to each pen (7 pens/treatment). Vitamin B complex [Vivalto, pantothenic acid (B5; 40,000 mg/kg), pyridoxine (B6; 20,000 mg/kg), folic acid (B9; 3,200 mg/kg), biotin (B7; 3,200,000 mcg/kg), cobalamin (B12; 320,000 mcg/kg); Selko USA, Indianapolis, IN] supplementation was offered at pen level beginning on d 1 and until the end of the preconditioning phase (d 42). Vitamin B complex was offered to calves assigned to vitamin B complex treatment mixed with 1.3 kg of dried distiller’s grains. Additionally, calves had free access to chopped alfalfa-grass hay mix and whole corn. Pen intake was recorded daily. On d 0, BW and blood samples were collected from all calves. Additional blood and BW were collected on d 1, 3, 7, 14, 21, 42 post-weaning. Body weights were used to calculate calf average daily gain (ADG) and blood samples were assayed for acute phase proteins (ceruloplasmin and haptoglobin). Additional blood samples will be analyzed for cortisol and vitamin B concentrations. Variables were analyzed considering pen as the experimental unit and pen(treatment) as a random effect. Blood variables were evaluated as repeated measures and effects of treatment, day, and treatment the interactions were analyzed with the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC). Significance was set at P ≤ 0.05. No treatment effects (P = 0.98) were observed for final BW (283, 283, and 284 kg respectively for Control, Vit1, and Vit2) or for ADG (P = 0.53; 0.735, 0.795, and 0.747 kg/d respectively for Control, Vit1, and Vit2). Similarly, no treatment effects were observed for the acute phase proteins analyzed, ceruloplasmin (P = 0.66; 27, 30, and 33 µg/dL respectively for Control, Vit1, and Vit2) and haptoglobin (P = 0.41; 0.55, 0.62, and 0.59 mg/mL, respectively for Control, Vit1, and Vit2). Supplementation of vitamin B complex to beef calves post-weaning does not seem to affect calf performance, regardless of the level of supplementation.

NETWORK PERSPECTIVE: BENEFITS OF INTERNATIONAL SCIENTIFIC COLLABORATION

In 2010 Freeman suggested that "the globalization of scientific and engineering knowledge is the most potent aspect of modern globalization". International research collaboration is an activity that is widely pushed globally, at the level of research institutes and universities. Academic world is increasingly interconnected, fostering such international partnerships that represents the globalization of science from the scientific collaboration perspective. These collaborations extend beyond sharing resources. Main goal of those activities is exchanging ideas, cultures, and visions to address complex global challenges. It is evident that from partnering with institutions and researchers worldwide, National Agricultural and Food Centre (NPPC) can be exposed to diverse pools of knowledge and expertise that significantly enhance the academic quality and reputation of our NPPC. This global exchange of ideas leads to more innovative, comprehensive, and impactful research outcomes. Additionally, as the institute's reputation improves, the research centre will attract more funding, students and talented researchers, achieve globalization, creating a cycle of excellence and improvement. In conclusion, the importance and benefits of international co-research agreements are multiple and profound. Collaboration's activities are pivotal in enhancing academic quality, broadening research horizons, preparing young researcher for global challenges, addressing international issues and policy makers, and fostering cultural understanding and global networks. In the second Editorial article of 2024, I am going to introduce the contents of the articles collected and published in the second issue of 2024 year. Atteh reviewed the effects of fiber on nutrition and reproduction in pigs. Author concluded that the reduction of dietary fiber's hemicellulose in a sow's lactation diet can improve the low-birth-weight piglets' health, post-weaning performance and milk composition. While exogenous enzymes and the extrusion of fibrous feedstuffs enhanced nutrient digestibility and utilisation, other processing methods, including fermentation and extrusion, decreased the dietary fiber components and had a beneficial impact on the performance of the pigs. Agro-industrial residues have enormous potential to improve reproductive efficiency and serving as an economically viable dietary fiber feeding strategy in the pig industry. Awodoyin et al. investigated the dietary supplementation of coffee arabica seed powder on performance and meat quality of broiler chicken. Authors ended up that low pathogenic gut microorganisms and total volatile nitrogen base coupled with high sensory acceptability of meat confirm the antioxidant potential of black coffee in broiler chicken diet. Ngige et al. performed a study aimed at screening the internal and external bacteria found in farmed Nile tilapia and African Catfish. According to microbiological investigation, the presence of the microorganisms, some of which are pathogens (Salmonella enteritidis, Enterobacter aerogenes, Klebsiella oxytoca) to humans, is an indication that undercooked fish may pose health risks to susceptible human and an impediment to the rapid intensification of aquaculture because of mortality of fingerings. Busanello reviewed the most common traffic systems in barns for lactating dairy cows milked in automatic milking systems. The study describes the advantages and disadvantages of free, milk-first and feed-first traffic and the differences between forced and guided cow traffic designs. Some research data are also shown to emphasize the theoretical concepts included in this document. Author concluded that guided traffic designs emerge as the most efficient, milking more cows throughout the day while reducing the need to fetch cows and overall labour. When operating at full cow capacity, guided cow traffic designs are recommended. Sudik conducted a study with the aim to determine the nutritional composition of roselle seed cake (Hibiscus sabdarica L.) and its effect on broiler chickens. Author concluded that roselle seed cake is rich in proteins and energy and it can be included up to 50 % in the diet of broilers without negative effects on growth rate and carcass performance. Rajsky et al. described the flexible duodenal monocannula of the National Agricultural and Food Centre design for the determination of intestinal nutrient digestibility in cattle. The innovativeness of the technical design of the NPPC cannula lies in the fact that the cannula is made of one piece of a straight tube with an inner diameter of 22 mm. As a result, the life of cannulated animals can be extended without age limitation. Editorial Team looks forward to evaluating your submitted contributions and providing all necessary support to Authors in order to best serve animal science and the scientific community, with commitment to research integrity and the highest publishing ethics. Enjoy reading!

FIBRE EFFECTS ON NUTRITION AND REPRODUCTION IN PIGS

Dietary fibre (DF) is an indigestible carbohydrate in the form of a non-starch polysaccharide that is a major problem in the use of inexpensive agro-wastes by pigs such as brewer's dry grains, cassava peel, palm kernel cake, rice bran, sorghum spent grain and wheat offal. The DF in a pig's diet can be classified by its solubility as soluble dietary fibre and insoluble dietary fibre, and chemically − as neutral detergent fibre and acid detergent fibre. High DF levels reduced nutrient utilization, growth rate, in terms of pork production and reproductive performance. Pigs' reproductive cycles at different stages and lactation were both greatly impacted by increased DF intake. High DF decreased the number of stillborn piglets at birth and the farrowing duration by sow, while improving colostrum intake in piglets and colostrum yield in sows. On the other hand, reducing the quantity of DF's hemicellulose in a sow's lactation diet can improve the low-birth-weight piglets' health, post-weaning performance and milk composition. While exogenous enzymes and the extrusion of fibrous feedstuffs enhanced nutrient digestibility and utilisation, other processing methods, including fermentation and extrusion, decreased the DF components and had a beneficial impact on the performance of the pigs. Agro-industrial residues have enormous potential to improve reproductive efficiency and serving as an economically viable DF feeding strategy in the pig industry.

PSV-19 Impact of precision feeding and bump feeding strategy during gestation on the performance of post-weaning pigs

Abstract The objective of this study was to evaluate the post-weaning growth performance of piglets from sows of parities 1 to 3 fed with 4 different feeding programs during gestation; Flat feeding (FF, constant concentration and feed intake), Bump feeding (BF, constant concentration and variable feed intake), precision feeding by parity (PFP, variable concentration and variable feed intake using the average weight per parity), individual precision feeding (PFI, variable concentration and variable feed intake using the weight of each sow at breeding). At weaning of each parity, five litters from each of the dietary treatments were selected and five average piglets from each of these litters were transferred to a nursery building with 20 pens. All pens received the same feeding program in 3 phases of 14 d each. Piglets were weighed at the beginning and end of each feeding phase. The quantity of feed was noted for each phase. At the end of phases 1 and 3, one piglet per pen was scanned on the DXA to assess its body lean, fat, and bone mineral composition. During phase 1, average daily gain (ADG) was greater for piglets from parity 1 sows than those from parity 2 and 3 while average daily feed intake (ADFI) and feed conversion (FC) were greater for piglets from parity 3 sows (P < 0.05; Table). Dietary treatments during gestation did not affect performances in phase 1. In phase 2, ADG and ADFI were greater while FC was decreased for piglets from sows of parity 2 and 3 (P< 0.001). Piglets from FF treatment had a greater ADG and a lesser FC (P < 0.05) than piglets from BF, piglets from PFP and PFI being intermediate. In phase 3, piglets from parity 2 sows and those from FF treatment had greater ADG and ADFI than piglets from PFI treatment, piglets from PFP and BF treatments being intermediate (P < 0.005). For all post-weaning period, piglets from parity 2 sows had greater ADG, ADFI and body weight at 42 d (P < 0.001) while piglets from the FF treatment had better ADG and weight at 42 d (P < 0.05) than those from BF and PFI (P < 0.05), PFP being intermediate. The lean ADG was greater for piglets from FF treatment (P < 0.021) than piglets from PFI, piglets from BF and PFP being intermediate. Piglets from sows of parity 2 and 3 had also greater lean ADG (P < 0.001). Fat ADG was also higher for piglets from parity 2 sows (P < 0.010) than piglets from parity 1 sows, piglets from parity 3 sows being intermediate. Piglets from parity 2 sows clearly had better post-weaning performances. The FF treatment during gestation led to better post-weaning performance, suggesting that energy or nutrient intake in early gestation affects offspring growth and development in post-weaning period.

Transition from one commercial porcine reproductive and respiratory syndrome modified-live virus vaccine to another in a breeding herd and impact on productivity

Porcine reproductive and respiratory syndrome (PRRS) continues to represent a significant cost to the swine industry and efforts are focused on prevention and mitigation of losses across production phases. Herein describes a PRRS modified-live virus (MLV) vaccinated breeding herd that changed commercial MLV vaccines to improve post-weaning performance. Two whole-herd vaccinations with a new PRRS MLV vaccine, administered 4 weeks apart, occurred without breeding herd production disruptions and with limited changes in diagnostic results. Replacement gilts tested PRRS virus negative 10 weeks post vaccination with the new MLV vaccine. Diagnostics were intermittently positive in the breeding herd and early nursery.

17. The impact of pellet size and moisture level of creep feed on post-weaning performance of pigs

17. The impact of pellet size and moisture level of creep feed on post-weaning performance of pigs

187 Effect of Piglet Weaning Weight on Wean-to-Finish Growth Performance and Ultrasound Carcass Measures

Abstract The objective of this study was to evaluate the impact of variation in piglet weaning weight (WW) resulting from interventions during lactation on post-weaning performance. A split-split plot design was used with a 2 x 2 x 2 factorial arrangement of treatments: 1) Liquid milk replacer [MR; main plot; No Supplement (NS) vs. Supplement (SU)]; 2) Litter size [LS; sub-plot; LOW (4 pigs less than functional teat number) vs. HIGH (2 pigs greater than functional teat number)]; 3) WW [sub-sub-plot; LIGHT (2 lightest barrows and 2 lightest gilts within each litter) vs. HEAVY (2 heaviest barrows and 2 heaviest gilts within each litter)]. Each MR feeder was available to 2 litters, one on the LOW and one on the HIGH LS treatment. Cross-fostering was carried out at 24 h after birth to create LS treatment litters; MR treatment was applied from 24 h after birth until weaning (20 days of age). The study involved 256 pigs housed in mixed-sex pens of 4 pigs (2 barrows; 2 gilts) and was carried out from weaning to a fixed pen weight (130.0 ± 2.27 kg). Pigs were weighed at start and end of the study when ultrasound scans were collected (at the 10th rib) to measure backfat depth (BF) and Longissimus muscle area (LMA). Data were analyzed using PROC MIXED of SAS; the model accounted for fixed effects of MR, LS, WW, and all interactions, and random effects of replicate, replicate by MR interaction and replicate by MR by LS interaction. There were no treatment interactions (P > 0.05) for any measurements (Table 1). The MR treatment had no effect (P > 0.05) on WW; the SU treatment had greater (P ≤ 0.05) ADFI but had no effect (P > 0.05) on other measurements compared with the NS treatment (Table 1). Compared with the LOW LS treatment, the HIGH LS treatment had lighter WW (1.7 kg; P ≤ 0.05), and greater days on test (4 days; P ≤ 0.05); however, there were no differences (P > 0.05) for other measurements. Compared with the LIGHT WW treatment, HEAVY pigs had greater WW (1.7 kg; P ≤ 0.05), fewer days on test (7.9 days; P ≤ 0.05), greater (P ≤ 0.05) overall ADG (38 g) and ADFI (78 g), less BF (0.17 cm; P ≤ 0.05) and greater LMA (1.37 cm2; P ≤ 0.05). In conclusion, providing MR during lactation had little effect on post-weaning performance. However, increasing LS above sow functional teat number reduced WW and increased the time to reach harvest weight with no effect on post-weaning growth performance. In addition, HEAVY WW piglets had improved post-weaning growth performance and carcass lean measurements compared with LIGHT WW piglets.

PSI-15 Impact of Dietary Zinc Source on Post-Weaning Performance and Livability

Abstract Zinc (Zn) is a key trace element involved in protein synthesis and immune development, which makes it a pivotal nutrient for the newly weaned pig. The objective was to investigate the effects of dietary Zn source on pig performance and livability in a commercial nursery setting. A total of 1,296 weaned pigs [5.67 ± 0.15 kg initial body weight (BW)] were randomly assigned to dietary treatments consisting of Zn Sulfate (ZSF), Zn amino acid complex (AVL), or glycinate-bound Zn (GMT), all supplying 120 ppm of Zn to the diets and fed in a three-phase (Ph) feeding system [Ph1: d 0-14; Ph2: d 14-28; Ph3: d 28-42]. Pigs had ad libitum access to pelleted feed and water throughout the study. Performance and feed intake were measured on d 14, 28, and 42 of the study. All pigs removed from test were recorded and weighed. During the first week of the study, there was an outbreak of Escherichia coli, and pigs were all administered water-soluble Zn via water lines and potato starch in pans. Pigs fed GMT had decreased (P < 0.05) average daily feed intake (ADFI, kg/d) during Phase 1 (0.082, SEM = 0.005), 2 (0.628, SEM = 0.002), and overall (0.526, SEM = 0.005) compared with AVL [Phase 1 (0.097, SEM = 0.005), 2 (0.651, SEM = 0.002), and overall (0.552, SEM = 0.005)], and ZSF [Phase 1 (0.107, SEM = 0.005), 2 (0.640, SEM = 0.002), and overall (0.547, SEM = 0.005)]. Moreover, pigs fed GMT had greater (P < 0.05, SEM = 0.710) overall mortality (4.60%) compared with AVL (1.89%) and ZSF (2.53%). Our results indicate that there are differences in feed intake and mortality when post-weaning pigs are fed different sources of Zn, and further work is needed in other health status flows.

PSII-3 Effect of Room Temperature Regimen on Growth Performance and Mortality of Newly-Weaned Pigs

Abstract Current recommended room temperatures for newly weaned pigs are based on historical research carried out several years ago. Since that time, major changes have occurred in the genotype of the pigs and in the management and the housing environment. This study was carried out to determine if a temperature regimen based on the choice of temperature of the pigs would improve post-weaning performance of pigs of different weaning weights. This study was carried out over the first 4 weeks after weaning (21 ± 1 d) using a split-plot design with 2 treatments: 1) Room Temperature Regimen (RT; main plot; Preferred vs. Control); 2) Weaning Weight (WW; subplot; Light vs. Heavy). Room temperatures for the Preferred treatment were 32, 32, 30, and 28℃ for wk 1, 2, 3, and 4 of the study, respectively. Room temperatures for the Control treatment (based on current recommendations) were 28, 26, 24, and 22℃ for week 1, 2, 3, and 4 of the study, respectively. The WW treatments were based on the lightest and heaviest pigs, respectively, from each litter. Four identical rooms of a wean-to-finish facility were used (2 rooms/RT treatment); 256 newly weaned pigs were housed in mixed-sex pens of 8 (16 pens/RT treatment) at a floor space of 0.78 m2/pig. Growth performance (ADG, ADFI, G:F) and mortality were measured over the 4-wk study period. The average start and end weight was 4.6 ± 0.32 kg and 12.7 ± 0.89 kg, respectively, for the Light WW treatment and was 6.4 ± 0.40 kg and 15.8 ± 1.47 kg, respectively for the Heavy WW treatment. There were no interactions (P > 0.05) between RT and WW for growth performance measures. There was no effect (P > 0.05) of RT on overall growth performance. Light WW pigs had less (P < 0.05) overall ADG (0.29 vs. 0.34 kg; SEM 0.009) and ADFI (0.40 vs. 0.46 kg; SEM 0.010) but similar G:F (0.733 vs. 0.739 kg; SEM 0.0115) compared with Heavy WW pigs. There was an interaction (P < 0.05) between the RT and WW treatments for overall mortality. There was no effect (P > 0.05) of RT for Heavy WW pigs (3.1 vs. 1.6 % for the Preferred and Control treatments, respectively; SEM = 1.89); however, mortality was less (P < 0.05) for Light pigs on the Preferred than on the Control treatment (1.6 vs. 7.8 %, respectively; SEM 1.89). In conclusion, the Preferred RT treatment did not impact growth performance in the first 4 weeks after weaning but reduced mortality of pigs of light, but not heavy weaning weight. This finding warrants verification under commercial conditions.

293 The Effect of Creep Feed and Nursery Diet Flavoring on Piglet Lactation and Nursery Performance

Abstract Larger litter sizes in swine production systems and potential milk limitations for piglets have given new opportunities to incorporating creep feeding as a management strategy. Sows (n = 51) and their litters were used to test the effects of creep feed and nursery diets on piglet lactation and nursery growth performance. Ten days before weaning, litters were assigned to one of three creep feeding treatments: 1) Control diet: 2) Control+Flavoring (50 ppm Allium XL, Pancosma): 3) No creep feed. Creep feed was delivered twice/day via one bowl creep feeder/litter. Sows and litters (17/treatment) were allotted to equalize parity (average = 2.8), genetics, number of piglets (average = 10.9), and weaning age (average = 19.1). Litter weights and creep feed intake were recorded on d 0, 4, and 10 (weaning). Post-weaning pigs were allotted to Control or Flavoring (50 ppm Allium XL) diets in a 3x2 factorial arrangement. During nursery there were 10 pens/treatment with 7 or 8 pigs/pen, blocked by initial BW within creep treatment. Nursery treatments were fed in phase 1 (1.13 kg/pig) and 2 (2.27 kg/pig) diets followed by common phase 3 (6.8 kg/pig) and 4 (ad lib to d 35) diets. Weekly pig BW and feed intake were used to calculate nursery pen ADG, ADFI, and G:F. Data were analyzed using GLM procedure of SAS 9.4. Creep feeding treatment during lactation did not affect litter or piglet BW gain pre-weaning. Flavoring did not affect total creep feed intake (control = 114 g/pig vs. flavoring = 110 g/pig). Providing creep feed during lactation increased ADFI on days 2, 3, and 4 post-weaning (P < 0.013). Pigs fed either creep feed increased week 1 nursery ADFI (8.8%; P< 0.02), numerically increased ADG (5.2%), and greater d ay7 BW (P = 0.055). Week 3 ADG (P < 0.05) and ADFI (P < 0.05) were greater for the no creep pigs than pigs fed the control creep feed, flavored creep feed pigs were intermediate. For week 4, ADG, and week 4 and 5 ADFI, pigs previously fed control creep had greater growth performance than pigs previously fed flavored creep with pigs fed no creep being intermediate (P< 0.05). Overall (days 0-35), pigs fed control creep had greater ADG ( P< 0.05) and ADFI (P < 0.05) than flavored creep fed pigs with no creep pigs being intermediate in ADG and greater ADFI than flavored creep fed pigs. Final BW (P < 0.05) was greater for control creep fed pigs than flavored creep fed pigs with no creep pigs being intermediate (23.5 kg, 23.0 kg, 23.3 kg, respectively). Nursery dietary flavoring treatment did not affect post-weaning ADG, ADFI, or G:F at any point during the study (P > 0.12). Lactation creep feeding significantly increases ADFI and ADG during the first week post-weaning, which could improve post-weaning performance and reduce the rate of pigs failing to thrive post-weaning.

A Systematic Review and Meta-Analysis of Creep Feeding Effects on Piglet Pre- and Post-Weaning Performance.

In the present systematic review and meta-analysis, we evaluated the effects of providing piglets with creep feed during lactation on piglet pre- and post-weaning performance. A total of 20 articles met the inclusion criteria. Creep feeding in lactation improved pre-weaning piglet performance in 46% of the studies selected, while 58% of the included studies reported that creep feeding in lactation improved piglet performance during the nursery phase. Creep feeding increased the average piglet body weight (creep = 7.23 ± 0.30, no creep = 6.96 ± 0.31; p = 0.03) and litter weight (creep = 81.2 ± 4.18, no creep = 76.4 ± 4.22; p < 0.001) at weaning. The average piglet body weight and litter weight were positively associated (p < 0.001 and p < 0.001, respectively) with total creep feed intake. Creep feeding of piglets for more than 14 days increased (p = 0.003) the litter weight at weaning compared to litters not provided or provided for shorter periods with creep feed. The present work strengthened the notion that creep feeding during lactation presents opportunities for improving weaning weights and post-weaning piglet performance compared to litters not provided or provided for shorter periods with creep feed.

Citrullinemia is a suitable biomarker for post weaning performance in piglets under intensive farming

To describe citrullinemia profiles during the weaning transition and correlate citrulline production with stress and growth in a commercial pig farm. 240 healthy piglets of homogenous weight, weaned from second and third parity sows, were selected at weaning and subjected to the farm's routine management practices in May to July 2020 and May to July 2021. Piglets were weighed at weaning, then 15 and 49 days later in order to calculate daily weight gain during the first 15 and 49 days after weaning. Blood samples were collected from each piglet to determine citrulline and cortisol profiles during the early postweaning period. Citrullinemia decreased dramatically during the first week postweaning and then increased progressively to reach preweaning values by 15 days postweaning. Citrulline production during the first 2 weeks postweaning was negatively correlated with cortisol production (r: -0.2949) and positively correlated with mean daily weight gain during the first 15 (ρ: 0.5450) and 49 (ρ: 0.6603) days postweaning. Citrullinemia profile of piglets during the early postweaning period showed a temporal negative impact of stress (assessed by plasmatic cortisol levels) on intestinal enterocytes' mass and function, which resulted in a lower average daily weight gain. We demonstrated that a single biomarker, plasmatic citrulline, is useful to describe intestinal metabolism during the early postweaning period and that the greater the citrulline production during the first days after weaning, the higher the weight gain during the entire postweaning period.

Linking the sow diet to piglet nutrition via sensory imprinting improves piglet performance postweaning

The influence of the sow diet on piglet feeding behavior is a relatively new topic of research in pig nutrition. The use of a flavour to link the taste of the sow and the weaner diet can benefit the sow by improving voluntary feed intake during lactation and provide a familiar taste to the young piglets that can encourage early consumption of feed at weaning. This study aimed to evaluate the impact of the supplementation of feed with a flavour in diets for sows during lactation and evaluate a possible carry-on effect via sensory imprinting on the post-weaning performance of piglets receiving the same flavour. A total of 200 mixed-parity sows were allocated to one of two treatments during lactation; a control diet or a diet with the inclusion a feed flavour. After weaning, 1,680 piglets were distributed in a 2 × 2 factorial experimental design (sow treatment and piglet flavour exposure via starter feed). The feed flavour influenced voluntary feed intake, with the flavour fed sows having a higher intake than control fed sows (6.15 vs. 5.32 kg/d, respectively). The lactation body weight (BW) variation was influenced by treatments with flavour sows having a higher BW loss (5.22 vs. 0.51 kg, respectively). There was an effect of the treatment on litter daily gain where litters from flavour sows showed a higher daily gain when compared to the control (2.36 vs. 2.06 kg/d respectively). Consequently, flavour fed sows weaned heavier litters (71.85 vs. 64.92 kg, respectively for flavour and control), and the average weaning weight was also higher for piglets from flavour sows when compared to control (5.62 vs. 5.07 kg, respectively). Average daily milk production was higher in the flavour sows when compared with the control fed sows (12.18 vs. 10.67 kg/d respectively). An interaction of the effects of previous exposure to the flavour during the lactation phase and the use of the sow-flavour during nursery was observered. Whereas, piglets receving the sow-flavour showed a higher intake than control piglets. As a consequence of the higher feed intake, the treatments influenced piglet average weight gain and final weight, with a higher total weight gain for sow-flavour fed piglets. Feed conversion ratio was also influenced by the treatments with the sow-flavour fed piglets having the lowest values. In conclusion, the use of a flavour can be an important tool to establish a link between the ingredients that make up the sows' diet and the establishment of the piglets' sensory memory. The imprinting effect can improve voluntary feed intake of the piglet during the first week post-weaning, all of which can help reduce the negative effects of the challenges of the weaning process.

Decreasing the level of hemicelluloses in sow’s lactation diet affects the milk composition and post-weaning performance of low birthweight piglets

Hemicelluloses (HC) are polysaccharides constituents of the cell walls of plants. They are fermented in the gut to produce volatile fatty acids (VFA). The present study investigated the effects of decreasing HC level in a sow’s lactation diet on sow performances, offspring development and milk composition. From 110 days (d) of gestation until weaning (26 ± 0.4 d post-farrowing), 40 Swiss Large White sows were assigned to one of the four dietary treatments: (1) T13 (HC: 127 g/kg), (2) T11 (HC: 114 g/kg), (3) T9 (HC: 94 g/kg) and (4) T8 (HC: 80 g/kg). Milk was collected at 3 and 17d of lactation. At birth, piglets were divided into two groups according to their birthweight (BtW): normal (N-BtW; BtW >1.20 kg) or low (L-BtW; BtW ≤1.20 kg). Decreased HC levels in the maternal diet linearly increased (p ≤ .05) the body weight of L-BtW piglets at two weeks post-weaning and linearly decreased (p ≤ .05) diarrhoea incidence and duration in this category. The concentrations of copper, threonine and VFA, as well as the proportion of butyrate, in milk linearly increased (p ≤ .05), whereas lactose content linearly decreased (p ≤ .05) with decreased HC in the maternal diet. The present study provides evidence that decreasing HC level in a sow’s lactation diet can positively affect the composition and VFA profile of milk and ultimately favour the growth and health of L-BtW piglets. Highlights The results of this study showed that decreasing the level of hemicelluloses in a sow’s lactation diet modified milk composition and had positive effects on the post-weaning performance of low birthweight piglets. This study highlighted the role of dietary fibres in the maternal diet to alleviate body weight variations at two weeks post-weaning. Nevertheless, before advising pig producers, further research should elucidate the optimal level of hemicelluloses for lactating sows.

Effect of the supplementation with a combination of plant extracts on sow and piglet performance and physiology during lactation and around weaning.

Weaning is a critical period for pigs. Some plant extracts showing antioxidant, anti-inflammatory or antibacterial properties, provided to piglets and/or their dam, may improve piglets' robustness at weaning, thus reducing the need for antobiotics. This study investigated the effects of a maternal and/or a direct supplementation of piglets with a combination of plant extracts on sow and piglet performance and their metabolic, immune, inflammatory, and oxidative status during lactation and around weaning. Sixty-four sows were assigned to the control or treated group. Treated sows were supplemented with a powdered plant extracts supplement daily top-dressed on feed from day of gestation (DG) 106 to day of lactation (DL) 28 and a liquid solution top-dressed on feed on DG109. Within each sow group, litters were divided into two groups: a control piglet group and a treated piglet group. A single dose of a liquid solution was orally given to piglets in the treated piglet group. Piglets were weaned on DL28. Blood samples were collected from sows on DG94, DG112, and DL26 and from 2 piglets per litter on DL3, DL14, DL25, and 5 d postweaning to analyze indicators of metabolic, immune, inflammatory, and oxidative status. Colostrum and milk samples were collected at farrowing, DL6, and 26. Maternal supplementation had no effect on sow metabolic, immune, inflammatory, and oxidative status except for fewer lymphocytes on DG112 (P < 0.05) and a lower plasma concentration of non-esterified fatty acids on DL26 (P < 0.05). Maternal supplementation tended to decrease dry matter and gross energy (P < 0.10) and reduced fat and haptoglobin concentrations (P < 0.01) in milk on DL26. Maternal supplementation had no effect on piglets' growth performance and blood indicators during lactation and around weaning. On DL25, the direct supplementation of piglets decreased their neutrophils proportion (P < 0.05), increased the expression of genes encoding pro- and anti-inflammatory cytokines in whole blood culture in response to lipopolysaccharide (P < 0.05) and tended to decrease the oxidative stress index (P = 0.06). After weaning, these beneficial effects were no longer observed but the supplementation improved piglets' growth performance during the postweaning period (P < 0.05). Plant extract supplementation could thus modify the composition of mammary secretions and improve postweaning performance of piglets potentially related to the modification of their immune and oxidative status before weaning.