Post-weaning Growth Performance Research Articles

234 Evaluation of a phytogenic blend on post-weaning growth performance, health, and sera metabolite responses during the initial 56 d feedlot receiving period in newly weaned steers

Abstract The objective of this study was to determine if a blend of capsicum oleoresin, clove essential oil, and garlic essential oil (CCG; Fytera Advance - Selko USA, Indianapolis IN) influences measures of cattle performance during the initial 56-d feedlot receiving phase. Newly weaned Charolais × Angus steers [n = 256; initial shrunk body weight (BW) = 273 ± 26 kg) were used in 56-d receiving phase experiment. Steers were transported 513 km to the Ruminant Nutrition Center in Brookings, SD on the day of weaning. Steers were individually weighed and allotted to 1 of 32 pens (n = 8 steers; 8 pens/treatment) in a randomized complete block design and randomly assigned to 1 of 4 treatments: control diet with no test product (CON); CCG at 125 mg/steer daily (CCG1); CCG at 250 mg/steer daily (CCG2); or CCG at 500 mg/steer daily (CCG3). Steers were fed twice daily, and bunks were managed using a slick bunk system from d 14 to 56; feed deliveries during the first 14 d were managed by feedlot personnel to adapt cattle to a targeted dry matter intake (DMI). The basal diet provided: 13.8% CP, 1.74 Mcal/kg NEm, and 1.07 Mcal/kg NEg. Monensin sodium was fed to all steers at a rate of 25 g/907 kg (DM basis). Steers were individually weighed on d -1, 1, 14, 35, and 56. Daily dry matter intake (DMI) was influenced by dietary treatment (quadratic effect; P = 0.01) in which steers that were fed with CON or CCG3 had greater DMI than those subjected to CCG1 and CCG2 dietary regimens. However, CCG supplementation did not result in improvements in average daily gain nor gain to feed ratio (P ≥ 0.15). A tendency for a treatment × day interaction was noted for sera non-esterified fatty acids (NEFA; P = 0.06), on d 14, steers from CCG3 had greater NEFA compared with CON and steers from CCG1 and CCG2 were intermediate (P ≤ 0.05). Dietary treatment influenced (P = 0.04) circulating concentrations of ceruloplasmin (CPL), where steers from CCG2 and CCG3 resulted in decreased circulating concentrations of CPL compared with CON and CCG1, indicating less inflammation. In conclusion, steers supplemented CCG3 had greater DMI and decreased ceruloplasmin suggesting an overall improvement in health status. Steers from CCG3 had increased NEFA on d 14, which could imply a catabolic state; However, sera NEFA decreased over time compared with the other treatments. More research is necessary to determine the consistency of the performance responses and better understand the correct dosage of CCG fed to newly weaned beef calves.

49 Effects of xylanase or a stimbiotic on growth performance and total tract digestibility of nutrients by pigs weaned from sows fed a lactation diet without or with xylanase

Abstract Two hypotheses were tested 1) the offspring of sows fed xylanase in lactation have greater growth performance after weaning than offspring of sows fed no xylanase, and 2) xylanase and a stimbiotic (i.e., xylanase in combination with xylo-oligosaccharides) improve growth performance, apparent total tract digestibility (ATTD) of gross energy (GE) and total dietary fiber (TDF), and digestible energy (DE) of diets for weanling pigs. A total of 120 newly weaned pigs from sows fed a lactation diet without xylanase and 120 pigs from sows fed a lactation diet containing 16,000 beechwood xylanase units (BXU) per kg of an exogenous xylanase were used [initial body weight (BW) = 5.81 ± 0.50 kg]. Pigs were allotted to a 2 × 3 factorial with two sow groups (lactation diet without or with xylanase) and three dietary treatments (i.e., control, control plus 100 g/t of xylanase, or control plus 100 g/t of stimbiotic). The xylanase (Econase XT) and the stimbiotic (Signis) were procured from AB Vista, Marlborough, UK. Pigs were weaned in 4 blocks and allotted to 12 pens per block, with 5 pigs per pen for a total of 8 replicate pens per treatment. Pigs were fed phase 1 diets from d 1 to 14, phase 2 diets from d 15 to 28, and phase 3 diets from d 29 to 42 post-weaning. Average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F) were calculated. Fecal samples were collected at the end of phases 2 and 3. Data were analyzed using the MIXED procedure of SAS. Sow group, diet, and the interaction between sow group and diet were fixed effects, and block and replicate within block were random effects. Results indicated that for the overall experiment, there were no interactions between sow group and diet, and sow lactation diet treatment did not impact any post-weaning growth or digestibility parameters in the weaned pigs (Table 1). However, weaned pigs had greater (P < 0.05) ADG, G:F, ATTD of GE and TDF, and DE in phase 2 if fed the diet with stimbiotic than if fed the xylanase diet or the control diet, but pigs fed the xylanase diet had greater (P < 0.05) ADG, G:F, ATTD of GE and TDF, and DE than pigs fed the control diet (Table 2). In phase 3, pigs fed the diet with xylanase or stimbiotic had greater (P < 0.05) ADG, ATTD of GE and TDF, and DE than pigs fed the control diet. In conclusion, pigs fed diets containing xylanase or stimbiotic had greater nutrient digestibility and DE, resulting in greater overall ADG, G:F, and final body weight on d 42 post-weaning, but feeding sows xylanase in lactation did not influence post-weaning growth performance.

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.

Effects of maternal calcium propionate supplementation on offspring productivity and meat metabolomic profile in sheep.

This study determined the effect of dietary calcium propionate (CaPr) as a source of energy supplementation during the First Half of Gestation (FMG), the Second Half of Gestation (SMG), and during All Gestation (AG), on offspring post-weaning growth performance, meat quality, and meat metabolomic profile. Thirty-one pregnant ewes were assigned to one of four treatments: a) supplementation of 30 gd-1 of CaPr during the first half of gestation (day 1 to day 75, n = 8) (FMG); b) supplementation of 30 gd-1 of CaPr during the second half of gestation (day 76 to day 150, n = 8) (SMG); c) supplementation of 30 gd-1 of CaPr during all gestation (AG, n = 8); d) no CaPr supplementation (control; CS, n = 7). The ewes were ad libitum fed a basal diet based on oat hay and corn silage. Ewes were distributed in a completely randomized unbalanced design to four treatments. The FMG group had lower (P ≤ 0.05) birth weight and weaning weight than the CS group. However, the average daily gain was similar across all treatments. Empty body weight and FMG had lower values (P ≤ 0.05) than the other groups. Both FMG and AG had lower hot carcass weight (P ≤ 0.05) compared to CS, while CaPr treatments resulted in reduced hot carcass yield (P ≤ 0.05). Meat color and texture were similar among treatments. A principal component analysis between gestation stages showed a trend for separating CS and FMG from SMG and AG, and that was explained by 93.7% of the data variability (PC1 = 87.9% and PC2 = 5.8%). Regarding meat metabolomic profile, 23 compounds were positively correlated between all treatments. Only 2 were negatively correlated (eicosane and naphthalene 1,2,3); but tetradecanoic acid, hexadecane, undecane 5-methyl, (-)-alpha, hexadecenoic acid, octadecanoic acid, and octadecane had a highly significant correlation (P ≤ 0.05). Overall, dam supplementation with CaPr during different periods of gestation provoked changes in meat metabolites related to the biosynthesis of fatty acids in lambs without negative changes in lamb's growth performance and carcass quality.

257 Effects of Prebiotic Galactooligosaccharide (GOS) on Hindgut Microbial Composition of Pigs During the Peri-Weaning Period

Abstract Galactooligosaccharide (GOS) is a prebiotic containing beta-linked galactose oligomers of 2 to 8 units. Previously, GOS positively impacted post-weaning growth performance and altered jejunal morphology. In this study, GOS-enriched whey permeate (Milk Specialties Global, Eden Prairie MN) was supplemented to piglets in farrowing and nursery phases. To maximize pre-weaning GOS intake, novel gruel creep feeders were used. Piglets from 24 litters received either no creep feed (NC), creep without GOS (CG-) or creep with 5.0% GOS (CG+) followed by a phase 1 nursery diet without (NG-) or with 3.8% GOS (NG+). At d 22 (pre-weaning) and d 31 (post-weaning), 6 pigs per treatment were euthanized for sample collection. DNA was extracted from cecal and rectal swabs for downstream 16S rRNA sequencing via Illumina MiSeq (Zymo Research Corp, Irvine CA). An amplicon sequence variant (ASV) table was created using the DADA2 pipeline in R and taxonomy assignment was performed using the SILVA database. Average sequencing depth after filtering was 138,323 and low sequencing counts were discarded based on 20% prevalence. Data were analyzed using the lmer and adonis procedures in RStudio ver. 4.2.2. Analysis of 16S rRNA genes did not detect pre- or post-weaning GOS effects on Chao1, Simpson, or Shannon alpha diversity measures (P > 0.1). Similarly, no pre-weaning GOS effects were detected in Principal Coordinates Analysis (PCoA) beta diversity plots (P > 0.1); however, pigs fed GOS post-weaning segregated from controls (P < 0.01). The relative abundance of several genera including Fusicatenbacter and Collinsella increased by 2.0 and 1.3-fold, respectively, in the cecum of NG+ pigs, whereas, Bacteroides decreased by 3.8-fold (FDR, P < 0.05). In the rectum, relative abundance of Corprococcus decreased by 2.0-fold and Fusicatenbacter increased by 1.5-fold in NG+ pigs compared with NG- pigs (FDR, P < 0.05). Collectively, these genera in the cecum and rectum comprise of less than 3% of the total community. In contrast, lactobacillus in the cecum (33%) and rectum (21%) had a large relative abundance but was unaffected by treatment. We conclude that supplementation of GOS in the post-weaning phase 1 nursery diet alters the hindgut microbial community and may contribute to improvements in growth performance.

PSV-16 The Effects of Bodyweight-Basis Iron Injection to Newborn Piglets on Pre-And Post-Weaning Growth Performance and Hematological Parameters

Abstract The objective of this study was to evaluate the effects of iron injection to newborn pigs based on birth weight on pre- and post-weaning growth performance and hematological variables. At d 1-3 of age (d 0 of experiment), a total of 24 piglets (initial body weight: 1.55 ± 0.11 kg) from 4 litters were allotted into 3 treatments within litter based on body weight and sex as follows: 1) Fe100: 100 mg iron at d 0 of experiment, 2) Fe200: 200 mg Fe at d 0 of experiment, and 3) FeBW: 125 mg Fe per kg body weight at d 0 of experiment. The iron-dextran was injected intramuscularly at the assigned levels based on treatments. The pigs were housed by litter in the suckling and nursery periods with a common corn-soybean meal-based diet during the entire nursery period. Body weight, hemoglobin concentrations and hematocrit were measured at d 0, 10, 17, 24 (weaning), 31 and 38 after the iron injection. There was no difference in pre- and post-weaning growth performance (10.91, 11.53, and 10.90 kg body weight at d 38 of experiment for the Fe100, Fe200, and FeBW treatments, respectively). Compared with the control treatment, the hemoglobin concentrations were greater in the Fe200 and FeBW treatments (P < 0.06) at d 17, 24, and 31 (12.43, 13.99, and 14.65 g/dL for the Fe100, Fe200, and FeBW treatments, respectively) of experiment with greater values in the FeBW treatment than the Fe200 treatment (P = 0.08; tendency) at d 31 of experiment. Hematocrit levels were greater in the Fe200 and FeBW treatments than the control treatment at d 10 (P = 0.09) and 31 of experiment (P < 0.05; 30.97, 35.57, and 37.07% for the Fe100, Fe200, and FeBW, respectively) and tended to be greater (P < 0.10) in the FeBW treatment than the control treatment at d 17 (31.71, 33.81, and 38.44% for the Fe100, Fe200, and FeBW, respectively) and 24 of experiment. However, there were no differences in hemoglobin concentrations and hematocrit at d 38 of experiment. In conclusion, there was no beneficial effect of iron injection based on body weight in pre- and post-weaning growth performance whereas it had a potential to slightly increase hemoglobin concentrations and hematocrit when the iron was injected based on body weight of newborn piglets.

PSIV-15 Effect of Secondary Iron Injection Timing to Suckling Pigs on Pre- and Post-Weaning Growth Performance and Hematological Parameters

Abstract The objective of this study was to evaluate the effects of secondary iron injection timing to suckling pigs on pre- and post-weaning growth performance and hematological variables. A total of 22 pigs (initial body weight: 1.62 ± 0.12 kg) from 4 litters were allotted into 3 treatments within litter based on body weight and sex at d 1-3 of age (d 0 of experiment) as follows: 1) Control: intramuscular injection of 150 mg iron-dextran at d 0 of experiment only, 2) Iron14: intramuscular injection of 150 mg iron-dextran at d 0 of experiment and 100 mg iron-dextran at d 10 of experiment (14 d before weaning), and 3) Iron7: intramuscular injection of 150 mg iron-dextran at d 0 of experiment and 100 mg iron-dextran at d 17 of experiment (7 d before weaning). The pigs were housed by litter in the suckling and nursery periods with a common corn-soybean meal-based diet during the nursery period. Body weight, hemoglobin concentrations and hematocrit were measured at d 0, 10, 17, 24 (weaning), 31 and 38 of experiment. The Iron14 treatment tended to have greater final weight at d 38 of experiment than the control treatment (P = 0.07; 10.97 vs. 9.38 kg) and the Iron7 treatment had intermediate value (10.15 kg). The ADG in d 24-31 postweaning tended to be greater in the Iron14 treatment than the control and Iron7 treatments (P = 0.08; 82.6, 151.8, and 53.5 g/d for the control, Iron14, and Iron7 treatments, respectively). In hemoglobin concentrations, the Iron14 treatment had greater levels than the control treatment at d 17 (P = 0.06; 12.24, 13.51, and 11.66 g/dL, respectively), 24, and 31 (P < 0.05; 10.72, 12.74, and 12.77 g/dL, respectively) of experiment whereas the Iron7 treatment had greater concentrations than the control treatment at d 24, 31, and 38 (P< 0.05; 9.46, 10.60, and 11.21 g/dL, respectively) of experiment and less than Iron14 treatment at d 17 and 24 (P < 0.05; 10.63, 12.95, 11.91 g/dL, respectively) of experiment. Hematocrit showed similar response to hemoglobin concentrations in which the Iron 14 treatment had greater hematocrit than the control treatment at d 17, 24, 31 (P < 0.05) and 38 (P = 0.10) of experiment while the Iron7 treatment had greater hematocrit levels than the control treatment at d 24, 31, and 38 (P < 0.05) of experiment. Hematocrit levels only at d 17 of experiment was greater in the Iron14 treatment than the Iron7 treatment (P < 0.05). In conclusion, the secondary iron injection to suckling piglets could improve early postweaning growth when the pigs were injected with iron at 14 d before weaning and increase hemoglobin concentrations and hematocrit regardless of timing, but the differences in hemoglobin and hematocrit values varied depending on the timing of secondary iron injection.

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.

Post-Weaning Growth Performance of Belgian Blue Crossed with Brahman Cross

This study was conducted to observe the post-weaning growth performance of Belgian Blue-Crossed (BB-crossed) and Brahman Cross (BX) calves. This study used a total of eighteen calves (BB-crossed = 6 heads and BX = 12 heads) aged 6 months. Calves were reared for six months under the same conditions and management. Calves were observed and measured their growth performance (body weight, body length, heart girth, and withers height). Data were analyzed using One-Way Anova, and for body weight gain and body size gain were analyzed by Ancova with initial body weight and initial body size as covariates. BB-crossed calves in this study had a body weight and body size greater than BX calves (P<0.05). BB-crossed calves also had increasing in body weight (BB-crossed 0.87±0.06 vs BX 0.63±0.04 kg/day) and body length (BB-crossed 0.23±0.01 vs BX 0.12± 0.01 cm/day) was greater (P<0.05) than BX calves, while the increasing in body height (BB-crossed 0.09±0.01 vs BX 0.07±0.01 cm/day) and heart girth (BB-crossed 0.16±0.02 vs BX 0.18±0.01 cm/day) did not differ. In conclusion, BB-crossed calve had post-weaning growth performances greather than BX calves, except increasing in withers height and heart girth. Thus, crosses with Belgian Blue cattle can improve post-weaning growth performance of BX calves.

Effects of Acacia Albida leaf Supplementation on Post-Weaning Growth Performance and Carcass Characteristics of Young Arab Lambs

Effects of Acacia Albida leaf Supplementation on Post-Weaning Growth Performance and Carcass Characteristics of Young Arab Lambs

Case study: effects of low-stress weaning on calf growth performance and carcass characteristics.

The objective of this study was to compare the influence of two low-stress weaning methods with conventional weaning on post-weaning performance and carcass characteristics of beef steers. Single-sourced steer calves (n = 89) were stratified by body weight (BW) and dam age into three groups in a completely randomized design (n = 29 or 30 steers/treatment): ABRUPT (calves isolated from dams on the day of weaning), FENCE (calves separated from dams via a fence for 7 d prior to completely weaning), and NOSE (nose-flap inserted and calves remained with dams for 7 d prior to completely weaning). At day +7 post-weaning, calves were transported to a commercial feedlot where they received standard step-up and finishing rations typical for a Northern Plains feedlot. BWs were recorded in study day -7 (PreTreat), 0 (Weaning), 7 (PostWean), 26 (Receiving), 175 (Ultrasound), and 238 or 268 (Final), and average daily gains (ADG) were calculated for each time period. Blood samples were collected via coccygeal venipuncture at d -7 (PreTreat), 0 (Weaning), and +7 (PostWean) from a subsample of calves (n = 10 per treatment) and analyzed for haptoglobin (acute-phase stress protein) concentrations using a bovine haptoglobin ELISA kit. On day 175, ultrasound fat thickness and intramuscular fat were determined and utilized to project marketing dates when steers reached 1.27 cm of backfat (day 238 or 268). Carcass measurements were recorded at the time of harvest. The weaning method interacted (P < 0.01) with a time period for ADG and BW. Calf ADG was greater (P < 0.01) in the NOSE treatment during PreTreat to Weaning than ABRUPT or FENCE. In the Weaning to PostWean period, the FENCE calves had greater (P < 0.01) ADG than ABRUPT and NOSE. During the Postwean to Receiving period ADG was greater (P < 0.04) for ABRUPT compared to FENCE and NOSE. Calf ADG was similar (P > 0.05) among treatments for the remainder of the feeding period. Calf BW did not differ among treatments (P > 0.05) at all times of weighing. Haptoglobin was undetectable in all samples except two samples collected on day -7. The weaning method did not influence (P > 0.05) carcass measurements. Collectively these data suggest low-stress weaning methods do not significantly improve post-weaning growth performance or carcass characteristics compared to using conventional methods despite minor, short-term alterations in ADG during the weaning period.

Effects of providing sensory attractants to suckling pigs during lactation and after weaning on post-weaning growth performance.

Three experiments were conducted to determine the effect of sensory attractants pre- and post-weaning on the growth performance of pigs after weaning. For each experiment, treatments were arranged as a 2 × 2 × 2 factorial with main effects of pre-weaning application (without or with), post-weaning application (without or with), and body weight category (representing the lightest or heaviest 50% of the population). In Exp. 1, 356 nursery pigs (initially 5.7 kg) were used in a 28-d trial with enrichment cubes used as the sensory attractant. A greater percentage of heavy pigs (P = 0.007) or pigs offered enrichment cubes pre-weaning (P = 0.044) lost BW from weaning to d 3 compared to light pigs or pigs not offered enrichment cubes pre-weaning. From weaning to d 7, a greater percentage of pigs lost weight when not offered cubes post-weaning (P = 0.002) compared to pigs offered cubes post-weaning. In Exp. 2, 355 nursery pigs (initially 5.6 kg) were used in a 29-d trial with a powder used as the sensory attractant. Providing a powder attractant both pre- and post-weaning reduced the percentage of pigs that lost weight from weaning to d 3 as compared with providing a powder either pre- or post-weaning only (interaction, P < 0.05). In Exp. 3, 355 nursery pigs (initially 5.9 kg) were used in a 24-d trial with a liquid spray used as the sensory attractant. A greater percentage of heavy pigs that did not receive liquid attractant lost weight from weaning to d 3, whereas a greater percentage of light pigs lost weight when they received liquid attractant only pre-weaning (three-way interaction; P = 0.016). Across all three experiments, sensory attractant application had limited effects on the growth performance of pigs after weaning; however, varying responses were observed for the percentage of pigs that lost weight in the first 3 to 7 d immediately post-weaning. In summary, environmental enrichment with cubes (Exp. 1) appears to have the greatest effect when applied post-weaning whereas flavor attractants (Exp. 2 and 3) appear to have the greatest effect when applied both pre- and post-weaning.

Consequences of Selection for Post-weaning Growth Performance Traits on Fat Partition Traits in Rabbits

Genetic and phenotypic parameters, using multi-trait animal model, for weaning weight (WW), slaughter weight (SW) and daily gain (DG) from weaning to slaughter were applied on 218 New Zealand White rabbits to improve post-weaning growth traits using selection indices. The specific objective was to improve profitability of rabbit producers through increasing body weight at slaughter and daily gain from weaning to slaughter. Expected impacts of selection for post-weaning growth traits on fat partition traits were also investigated. The fat partition traits included weights of subcutaneous fat (SF) and intermuscular fat (IF) as carcass components and heart fat (HF), kidneys fat (KF), mesenteric fat (MF) and caul fat (CF) as offal components. Growth traits showed low to moderate heritability estimates (h2,0.03 to 0.37), while fat partition traits had higher h2 estimates (0.72 to 0.93), except for SF (h2=0.27). Application of the reduced index considering WW and DG was as efficient as full index in terms of accuracy of selection (rTI=0.66); it provided higher improvement in aggregate genotype represented in SW (+170.72gm) and DG (+2.41gm/day) for each round of selection. This improvement in post-weaning traits was accompanied by unfavorable expected impact in fat traits SF, HF, MF and CF (+45.32, +12.77, +56.50 and +12.25%, respectively) and favorable expected impact on IF and KF (-32.16 and -59.47gm, respectively). The single trait selection index (I6) with SW was found to be useful for rabbit meat consumers, as it decreased the undesirable fat gain in fat depots compared to the other indices, with some reduction in accuracy. In conclusion, it is possible to improve the post-weaning growth traits through selection programs, taking into consideration the undesirable changes in fat partition traits of New Zealand White rabbits.

Selenium-Enriched Mushroom Powder Enhances Intestinal Health and Growth Performance in the Absence of Zinc Oxide in Post-Weaned Pig Diets.

Simple SummaryThe imminent ban on zinc oxide in pig diets within the European Union is a major challenge facing the swine industry. Commercial weaning is associated with abrupt dietary, environmental and social changes resulting in stress, reduced feed intake and gut developmental issues in the post-weaned pig. Mushrooms are rich in natural bioactives and have long been regarded as a health-promoting food due to their immunomodulatory and antioxidant effects and their ability to modulate the gut microbiota. Mushrooms can become abundant in organic selenium when grown under certain conditions. The present study aimed to determine the optimum Se level, using Se-enriched mushrooms and selenite, in weaned pig diets to enhance intestinal health, performance and antioxidant capacity. Our study demonstrated that 0.3 ppm selenium inclusion, using selenium-enriched mushroom powder, led to positive effects on faecal scores and had similar pig performance compared to zinc oxide during the first 21 days post-weaning. The selenium inclusion level of 0.6 ppm, using selenium-enriched mushroom powder and selenite, enhanced pig performance and aspects of gastrointestinal health during days 21 and 39 post-weaning.This study was conducted to examine the effects of varying selenium (Se) inclusion levels, in the form of Se-enriched mushroom powder (SeMP) and selenite, on post-weaning growth performance (Period 1; day 1–21), intestinal health and antioxidant capacity (Period 2; day 21–39). Weaned pigs were blocked according to live weight, sex and litter of origin and randomly assigned to the following experimental groups: basal (basal + selenite (0.3 ppm Se)); ZnO (basal + ZnO + selenite (0.3 ppm Se)); 0.15 SeMP (basal + SeMP (0.15 ppm Se)); 0.3 SeMP (basal + SeMP (0.3 ppm Se)) and 0.6 SeMP/Sel (basal + SeMP (0.3 ppm Se) + selenite (Sel) (0.3 ppm Se)) with eight replicates/experimental group. After 21 days, the ZnO experimental group was removed from the experiment and the remaining pigs continued on their respective diet until day 39 post-weaning (Period 2). In Period 1, 0.15 SeMP supplementation reduced (p < 0.05) average daily gain (ADG), average daily feed intake (ADFI) and day 21 body weight, and increased (p < 0.05) faecal scores compared to the ZnO group. Supplementation with 0.3 SeMP and 0.6 SeMP/Sel during Period 1 resulted in similar (p > 0.05) ADG, ADFI, gain-to-feed ratio (G:F) and body weight compared to the ZnO group. However, 0.6 SeMP/Sel supplementation increased (p < 0.05) faecal scores compared to the ZnO group. In Period 2, 0.6 SeMP/Sel increased (p < 0.05) ADG, feed efficiency and day 39 body weight compared to the basal group. Supplementation with Se-enriched mushroom powder, at all inclusion levels, increased (p < 0.05) the abundance of Prevotellaceae and Prevotella, decreased (p < 0.05) the abundance of Sporobacter and increased (p < 0.05) the expression of SELENOP in the jejunum compared to the basal group. Lactobacillaceae and Lactobacillus was increased (p < 0.05) in 0.15 SeMP and 0.3 SeMP pigs compared to the basal group. Selenium deposition in muscle and liver tissue increased (p < 0.001) as a function of inclusion level while pigs supplemented with 0.3 ppm organic Se (0.3 SeMP) had an increase (p < 0.05) in total Se in the muscle compared to pigs supplemented with 0.3 ppm inorganic Se (basal). In conclusion, 0.3 SeMP supplementation led to positive effects on faecal scores and had similar pig performance compared to ZnO in Period 1, while the addition of 0.3 ppm selenite to 0.3 SeMP (0.6 SeMP/Sel) in Period 2 led to enhanced pig performance and aspects of gastrointestinal health.

P185. A synergistic blend of organic acids in drinking water of piglets supports post-weaning growth performance – a meta-analysis

P185. A synergistic blend of organic acids in drinking water of piglets supports post-weaning growth performance – a meta-analysis

PSVIII-3 Evaluation of the Metal Corrosiveness and Pelleting Stability of Formic Acid-Based Organic Acid Blend and the Effects of the Blend on Post-Weaning Growth Performance

Abstract Studies were conducted to evaluate the metal corrosiveness and pelleting stability of a formic acid-based organic acid blend, which is a free-flowing powder with silica as inert carrier. Under experimental conditions, results suggested the blend has minimal metal corrosiveness and is stable during the pelleting process (conditioning temperature = 1950 F). An animal trial was conducted to evaluate the effects of the blend on post-weaning growth performance. A total of 1,320 post-weaning piglets (~21 d of age, 6.9 kg BW) were assigned to 5 dietary treatments (22 pigs/pen, n = 12) and fed for 42 d in 4 dietary phases (12, 10, 13 and 7 d, respectively). Treatments were 1) NC, basal diet without antibiotics or acidifier; 2) PC, basal diet with antibiotics but without an acidifier; 3) PC+A, product A is a blend of organic and inorganic acids; 4) PC+B, product B is a blend of organic acids and derivatives; 5) PC+C, product C is the formic acid-based organic acid blend. For treatments 3, 4, and 5, products A, B and C were added to the PC diet respectively at 0.3% in Phase 1, 0.15% in Phase 2 and 0% in Phase 3 and 4. Data were analyzed with ANOVA and differences considered significant at P &amp;lt; 0.05. During Phase 1, 2 and 3, PC+C treatment showed the greatest BW, ADG and ADFI, which were greater compared with NC (P &amp;lt; 0.05) and numerically greater comparing with PC, PC+A and PC+B treatments. In Phase 1, PC+C treatment showed less FCR than the other groups. There were no significant differences for ADG, ADFI and FCR among all treatments during Phase 4. Overall, PC+C treatment showed greater final BW, ADG and ADFI, which were significantly greater than NC (P &amp;lt; 0.05) and numerically higher than PC, PC+A and PC+B groups.

150. The effect of rearing environment and the provision of zinc oxide post-weaning on pre- and post-weaning growth performance in pigs

150. The effect of rearing environment and the provision of zinc oxide post-weaning on pre- and post-weaning growth performance in pigs

PSXIII-23 Influence of reproductive technologies on post weaning calf performance and carcass characteristics

Abstract The experiment objective was to evaluate the impact of assisted reproductive technologies on post weaning calf performance. Calves born following various reproductive treatments (synchronized natural service and synchronized AI) in 10 herds over 2 years were fed to reach a target backfat (BF) of 1.27 cm, sent to harvest, and carcass data collected. Calves were classified into calving groups as natural service born early (NS-Early, n = 189), natural service born late (NS-Late, n = 203), or AI sired born early (AI-Early, n = 116). Data were analyzed using the MIXED procedure in SAS with calving group, year and calf gender in the model. Weaning weights were similar between AI-Early and NS-Early; however, earlier born calves (AI-Early and NS-Early) were heavier (P &amp;lt; 0.0001) than NS-Late. AI-Early calves had heavier finished bodyweight (622.2 kg: P = 0.0024) compared to NS-Early (601.4 kg) and heavier HCW compared to both NS-Early and NS-Late (P &amp;lt; 0.01). NS-Early calves reached 1.27 cm BF in fewer days than AI-Early (261 d and 275 d, respectively; P &amp;lt; 0.01) with NS-late requiring the most days on feed to reach the same endpoint (296 d, P &amp;lt; 0.01). No differences in Quality Grade, Yield Grade, REA, marbling, or BF were detected between AI-Early, NS-Early, and NS-Late, or between early- and late-born calves (P &amp;gt; 0.38). Late-born calves required 29 more days on feed (P &amp;lt; 0.001) to reach 1.27 cm BF resulting in greater final bodyweight compared to early-born calves (625.5 kg and 612.8 kg, respectively; P = 0.04); however, hot carcass weights were similar between early- and late-born calves. Reproductive technologies that increase the number of calves born early in the calving season increased weaning weight and post weaning growth performance, but compared to high quality natural service sires, AI did not improve carcass characteristics.

291 Weaned Holstein Calves Fed an Experimental Botanical Extract Alone or in Combination with an Eubiotic Product

Abstract A botanical extract (BE; garlic oil, anise oil, cinnamaldehyde, rosemary, and thyme blend) has been shown to enhance dry matter intake (DMI) and gut health, while eubiotics (EU; lactobacillus acidophilus fermentation product), has been shown to improve gut health and growth performance of growing Holstein calves. The hypothesis was the combination BE and EU could be synergistic to post-weaning neonatal calf growth performance. Seventy-seven (77) Holstein bull calves from a previous milk replacer trial were randomly assigned to 1 of 4 treatments using a 3 wk experimental period. Treatments were: 1) Control: Calf starter (CS) without BE or EU; 2) BE: CS with 275.6 g/ton of an experimental BE (Adisseo North America, Alpharetta, GA); 3) EU: CS with 0.22% EU (RumaCell DF 5G; Pacer Technology, Murtaugh, ID); and 4) BE&amp;EU: CS with added BE and EU. The 22% crude protein CS was a mini-pellet and fed for ad-libitum consumption with amounts fed and orts recorded daily. Calves fed EU demonstrated greater (P &amp;lt; 0.05) body weight (BW; 81.3, 80.8, 84.8, and 84.2 kg for Control, BE, EU, and BE&amp;EU, respectively) compared with calves fed Control and BE with calves fed BE&amp;EU being intermediate and similar (P &amp;gt; 0.10). Calves fed BE demonstrated greater (P &amp;lt; 0.05) average daily gains (ADG; 965.5, 984.3, 1052.8 and 989.1 g/d) compared with calves fed Control with calves fed BE and BE&amp;EU being intermediate and similar (P &amp;gt; 0.10). The DMI (2.19, 2.18, 2.31, and 2.14 kg/d) and feed conversions (0.45, 0.46, 0.45, and 0.45 kg BW gain/kg DMI) were similar (P &amp;gt; 0.10) among calves fed all treatments. Blood urea nitrogen concentrations (14.7, 14.6, 14.9, and 13.4 mg/dL) were similar (P &amp;gt; 0.10) among calves fed all treatments. Feeding a EU improved BW of weaned growing Holstein bull calves, but the BE and EU combination was not beneficial for enhancing growth performance.

The effect of creep feed composition and form on pre- and post-weaning growth performance of pigs and the utilization of low-complexity nursery diets.

Fifty-six litters from first-parity sows standardized to 12 piglets were used to determine the effects of creep feed composition and form on pre- and post-weaning pig growth performance and the utilization of low-complexity nursery diets. At 5 days of age, litters (initial body weight [BW] 2.31 ± 0.61 kg) were assigned to one of four creep feeding regimens (n = 14): 1) pelleted commercial creep feed (COM), 2) liquid milk replacer (LMR), 3) pelleted milk replacer (PMR), or 4) no creep feed (NO); creep feeds contained 1.0% brilliant blue as a fecal marker. Individual piglet BW and fecal swabs were collected every 3 ± 1 days during the creep-feeding period. The latter was to identify piglets that regularly consumed creep feed via the visual appearance of blue dye in the feces. At weaning (21 ± 2 days of age), six pigs per litter with median BW that consumed creep feed were placed on either a HIGH− (contained highly digestible animal proteins) or LOW− (contained corn and soybean meal as the main protein sources) complexity nursery diet (n = 7) in a three-phase feeding program over 39 days. On day 8, two pigs per pen were sacrificed to collect organ weights and digesta. The LMR disappeared at the greatest rate (average 37.7 g/pig/d; dry matter-basis) versus COM and PMR (10.6 and 10.3 ± 1.5 g/pig/d, respectively; P < 0.001). Litters that received LMR had the greatest proportion of pigs with blue fecal swabs throughout the creep feeding period (85.0 vs. 54.9 and 63.0% ± 0.4% for COM and PMR, respectively; P < 0.05) and LMR piglets had greater BW at weaning versus all other treatments (6.32 vs. 6.02, 5.92, and 5.67 ± 0.14 kg, for LMR, COM, NO, and PMR, respectively; P < 0.001). Overall, pigs given LOW (vs. HIGH) diets in the nursery period had reduced average daily gain (25.1 vs. 27.7 ± 0.4 g/kg BW; P < 0.001), gain:feed (0.75 vs. 0.81 ± 0.02; P < 0.001), and exit BW (21.2 vs. 24.4 ± 0.6 kg; P < 0.001); no carryover effects of creep feeding program were observed. Creep feed regimen had limited effects on nutrient digestibility of nursery diets but the apparent ileal digestibility of organic matter tended to be less at 28 days of age for pigs that received the LOW nursery diet (64.2 vs. 68.8% ± 2.5%; P = 0.076). Providing supplemental nutrition during the suckling period via LMR improved piglet BW at weaning, which did not correspond to improved post-weaning growth performance, regardless of nursery diet complexity.