Growth Performance Variables Research Articles

PSLBI-21 Interactive effects of dietary betaine supplementation and soybean hulls inclusion on growth performance and carcass composition of young growing pigs

Abstract Growing barrow pigs [n = 24; Large White x Landrace x Duroc; 29.51 ± 3.24 kg initial body weight (BW)] were assigned to 4 treatments in a 2 x 2 factorial design to evaluate the synergistic effects of dietary levels of betaine (BET; 0 and 0.1%) and soybean hulls (SBH; 0 and 15%) on growth performance and carcass composition. Pigs were blocked by initial BW and housed in individual pens with ad libitum access to feed and water for a 28-d feeding period. Pigs were weighed and feed intake was recorded at 14-d intervals. Real-time ultrasonic (RTU) measurements of the 10th-rib longissimus dorsi muscle area (LMA) and off-midline backfat thickness (BF) were obtained initially and on d 28 for all pigs. Prediction equations were used to estimate total fat tissue (TOFAT) and fat-free total lean (FFTOLN) from the measurements. All data were analyzed using the MIXED procedure of the SAS software. Growth performance data were analyzed as repeated measures on time and carcass data were analyzed as single measures with the respective baseline values used as covariate in the statistical model. There were no SBH x BET interactions for growth response variables. Pig growth was not affected by dietary BET supplementation. During the first 14 d of the study, pigs fed 15% SBH had decreased average daily gain (ADG; P = 0.01), average daily feed intake (ADFI; P = 0.02), and feed efficiency [gain:fee; (G:F;P = 0.04)] when compared with pigs fed diets without SBH. From d 15 to 28, dietary addition of 15% SBH reduced ADFI (P = 0.01), whereas no significant effects on the other growth performance variables were observed. Overall, when compared with pigs fed diets without SBH, pigs fed diets with 15% SBH had reduced feed intake (P = 0.01) and ADG (P = 0.04), which resulted in lighter pigs (P = 0.03) at the completion of the feeding trial. A SBH x BET interaction (P = 0.04) was observed for LMA, with decreased values (P < 0.05) detected for BET-supplemented pigs only when SBH was not included in the diet. No additional carcass composition traits were altered by BET supplementation. Including 15% SBH to the diet decreased BF (P = 0.05) and TOFAT (P = 0.04) in growing pigs. Neither BET supplementation nor SBH inclusion affected FFTOLN. In conclusion, adding supplemental BET to diets with SBH did not synergistically alter nutrient partitioning of young growing pigs. Although no beneficial effects of BET supplementation on growth and carcass composition traits were observed, feeding pigs diets containing 15% SBH resulted in slower growth rates with less fat deposition.

PSLBI-9 The growth performance and total tract starch digestibility of finishing Nelore bulls fed flint corn-based diets are improved by the corn processing method and urea source

Abstract The aim of this study was to evaluate the flint corn processing method (CPM) and urea source for finishing Nellore bulls fed corn-based diets. In this study, 80 Nellore bulls [initial body weight (BW) = 388 ± 45.7 kg] were allocated into 28 pens (7 pens/treatment; 6 pens with 3 bulls + 1 pen with 2 bulls). A completely randomized design with a 2 × 2 factorial arrangement of treatments was used to test two CPMs: dry ground corn (DGC) and reconstituted and ensiled corn (REC), and two US: feed-grade urea (FGU) and post-ruminal release urea (PRU). Dietary inclusion (% DM) of flint corn (vitreousness = 86.0%) was 61.3% (DGC or REC), and urea source addition was 0.5% as non-protein nitrogen (NPN; as FGU or PRU). The PRU source (Trouw Nutrition, Netherlands) contained 82% urea on a DM basis. In an in vitro assay, 27% of this urea was released into the rumen. Experimental period lasted 100 d (with 14 d of adaptation). Fecal samples from each bull were collected in two periods of three consecutive days (d 44 to 46 and 94 to 96) at different time (0600, 1200, and 1800 h). Samples were composited by pen and analyzed for fecal starch (FS) and indigestible NDF as markers for fecal excretion. At the end of the experiment, bulls were slaughtered and the jejunum and pancreas were sampled from one bull per pen. Interaction effects were not found (P ≥ 0.31) for any feedlot growth performance variables (Table 1). Final BW, average daily gain, and feed efficiency (gain to feed; G:F) were greater for bulls fed REC and PRU than for those fed DGC and FGU (P < 0.02), respectively. As a result, observed dietary net energy (NE) for maintenance and BW gain were about 7.0% and 9.0% greater for bulls fed REC diets, and 4.3% and 5.6% greater for bulls fed PRU diets, respectively. Bulls fed DGC had 2.2 times greater FS compared with bulls fed REC, resulting in lower fecal pH and total tract starch digestibility (TSD) for bulls fed DGC compared with those fed REC (P < 0.01). Interestingly, a similar trend was observed in bulls fed PRU compared with those fed diets with FGU (P < 0.06). Jejunal gene expression of SLC5A1 was not affected by treatments (P > 0.14). Nevertheless, bulls fed diets with PRU presented greater jejunal α-amylase activity (P = 0.02). Pancreatic α-amylase activity was less when bulls were fed DGC + PRU diet. In conclusion, REC markedly improved TSD and growth performance compared with DGC. Additionally, independent of CPM, PRU inclusion as NPN source increased G:F and dietary NE concentration due to the positive effects on jejunal amylase activity and TSD.

Piglets performance, nutrient digestibility and gut health in response to feeding Ulva lactuca seaweed supplemented with a recombinant ulvan lyase or a commercial carbohydrase mixture.

Ulva lactuca, a green seaweed, may be an alternative source of nutrients and bioactive compounds for weaned piglets. However, it has a recalcitrant cell wall rich in a sulphated polysaccharide - ulvan - that is indigestible to monogastrics. The objective of this study was to evaluate the effect of dietary incorporation of 7% U. lactuca, combined with carbohydrases supplementation (commercial carbohydrase mixture or recombinant ulvan lyase), on growth performance, nutrient digestibility and gut health parameters (morphology and microbiota) of weaned piglets. The experiment was conducted over 14 days using 40 weaned piglets randomly allocated to one of four experimental diets: a control diet based on wheat-maize-soybean meal, a diet with 7% U. lactuca replacing the control diet (UL), a diet with UL supplemented with 0.005% Rovabio® Excel AP, and a diet with UL supplemented with 0.01% of a recombinant ulvan lyase. The dietary treatments had no major effects on growth performance, nitrogen balance and gut content variables, as well as histological measurements. Contrarily, dry matter and organic matter digestibility decreased with dietary seaweed inclusion, while hemicellulose digestibility increased, suggesting a high fermentability of this cell wall fraction independently of carbohydrases supplementation. Some beneficial microbial populations increased as a consequence of enzymatic supplementation (e.g., Prevotella), while seaweed diets as a whole led to an increased abundance of Shuttleworthia, Anaeroplasma and Lachnospiraceae_NK3A20_group, all related with a healthier gut. It also decreased Lactobacillus when compared to controls, which is possibly related to increased bioavailability of seaweed zinc. This study indicates that, under these experimental conditions, up to 7% dietary U. lactuca has no detrimental effect on piglet growth, despite decreasing acid detergent fibre digestibility. Carbohydrases supplementation of Ulva diets is not required at this incorporation level.

Reduction of methyltestosterone concentration in feed during masculinization of Nile tilapia (Oreochromis niloticus) in biofloc system

Most larviculture of Nile tilapia is carried out in ponds with a large presence of live food, with temperature variations throughout the day and year, and feed leftoovers due to dissipation in the water. As a consequence, the masculinization process needs to be done with a high concentration of 17α-methyltestosterone (MT) in the diet. Production in closed systems, such as biofloc technology (BFT), allows controlling the water temperature, uses a smaller volume of water and generates less effluent, being an alternative system for the masculinization process. This study evaluated the masculinization rates of Nile tilapia in the BFT, with a controlled temperature (∼28 °C), using concentrations of MT in the feed lower than those recommended for masculinization in ponds and BFT (60 mg ∙ Kg−1 of feed). Tilapia larvae (post yolk sac absorption) were raised in BFT (2 larvae ∙ L−1 or 100 larvae ∙ tank−1) and submitted to different concentrations of MT in the diet (0, 30, 40, 50 and 60 mg ∙ Kg−1 of feed), which was offered five times a day for a period of 28 days. The experimental design was entirely randomized. After the hormonal treatment, the water in the tanks was completely replaced with new water, free of hormonal residues, where the fry remained until they reached a viable size for sexing. It was also tested to maintain the original water used during the hormonal treatment period, during the post-experimental period, where 30 mg ∙ Kg−1 of feed was used. The water quality variables (temperature, pH, dissolved oxygen, settleable solids, total suspended solids, alkalinity, nitrogen compounds, salinity, phosphate and organic carbon) and growth performance variables (final body weight and length, specific growth rate, condition factor and survival) did not differ between MT concentration in the diet (p > .05). The treatment without hormone (control) presented 73.6% of males and the treatments that received hormone showed masculinization rates >99%, significantly higher than control (p < .05), but did not differ from each other (p > .05). The percentage of male individuals in the control treatment was high and this may have occurred because of the temperature of 28 °C throughout the experiment. However, this percentage of males is not considered high enough for production, which requires higher rates close to 100% as possible. The MT was not detected in the water 12 h after the last feeding with feed containing hormone. Thus, it is feasible to use a lower concentration (30 mg of MT ∙ Kg−1 of feed) in BFT. Our study has a direct impact on the global tilapia production scenario, offering a new environmentally sustainable masculinization protocol, using less water and hormones in the process and avoiding the release of hormonal residues.

PSII-16 Effect of iron injection levels and second iron injection on preweaning growth performance and hematological variables

Abstract This study was conducted to evaluate the effect of intramuscular iron-dextran injection to suckling pigs at either a high level or with two doses on preweaning growth performance and hematological variables. At d 1 of age, a total of 36 pigs (body weight = 1.56 ± 0.13 kg) from 6 sow litters with litter size greater than 10 pigs were selected, and six piglets per litter were assigned to 3 treatments based on body weight and sex. Treatments were: 1) NC: 200 mg intramuscular iron injection at d 1 of age, 2) PC: 400 mg intramuscular iron injection at d 1 of age, 3) NC+IRON: 200 mg intramuscular iron injection at d 1 of age and 200 mg iron injection at d 7 of age. The body weight, hemoglobin, and hematocrit concentrations were measured at d 1 (before initial iron injection for all treatments), 3, 7 (second dose for the NC+IRON treatment), 9, 12, and 19 (weaning) of age. A repeated measures ANOVA was used to analyze body weight, hemoglobin, and hematocrit results. There were no significant differences in body weight, hemoglobin, and hematocrit concentrations among iron injection treatments (P &amp;gt; 0.89) and no interactions between iron injection treatment and day of age (P &amp;gt; 0.64) from d 1 to 19 of age, although hemoglobin and hematocrit concentrations were numerically greater in the PC and NC+IRON treatments at d 19 of age (129.2, 133.4, and 133.82 g/dL hemoglobin for the NC, PC, and NC+IRON treatments, respectively). Hemoglobin and hematocrit concentrations declined (P &amp;lt; 0.01) from d 1 to 3 of age regardless of iron injection and then increased until weaning (d 19 of age; 86.9, 78.1, 87.6, 94.0, 105.7, and 132.1 g/dL hemoglobin for d 1, 3, 7, 9, 12, and 19 of age, respectively), where the hemoglobin concentrations were similar between d 1 and 7 of age (P &amp;gt; 0.76) whereas the hematocrit concentrations were greater at d 7 of age compared with d 1 of age (P &amp;lt; 0.05; 31.8% vs. 29.1%). Hemoglobin concentrations were significantly correlated with hematocrit concentrations (P &amp;lt; 0.01), and the correlation coefficients were greatest at d 1 and 3 of age and weaning (d 19 of age; r &amp;gt; 0.92). In conclusion, increased hemoglobin and hematocrit concentrations were observed in all treatments, resulting in no significant difference in the preweaning growth performance of piglets. Although the iron injection was performed at d 1 of age, hemoglobin and hematocrit concentrations decreased in the first few days of life and then increased. Hemoglobin and hematocrit values are positively correlated from birth to weaning.

57 Effect of diet mixing strategies on growth performance and carcass characteristic in feedlot steer

Abstract Our objective was to determine the effects of a feeding management strategy on growth and carcass quality and characteristics on finishing feedlot beef cattle. Angus-Simmental steers (n = 60), blocked by body weight (BW), were housed in individual pens and randomly assigned to treatments. Treatments were total mixed ration (TMR) or a non-mixed diet (Split). The diet contained 67.5% of dry rolled corn, 18% of distiller grains with soluble, 2.5% soybean meal, 7% hay, and 5% of mineral and vitamin mixed. The diet composition for both treatments was similar, the only difference was the use of a TMR or that the concentrate was fed separately from the hay on the Split treated calves. Feed intake was monitored through slick bunk management in both treatments. For the Split assigned calves, if any hay or concentrate was left in the bunk on two consecutive days, the total feed was decreased by 5%; maintaining always the 93% concentrate and 7% forage ratio. Steers were weighed monthly and feed samples were collected for nutrient composition analysis semimonthly. Monthly weights and intakes were used to calculate average daily gain (ADG) and gain to feed ratio (G:F). Steers were slaughtered per block when the average weight of the block reached 555 kg. Carcasses were evaluated 48 h post slaughter. Carcass yield and quality factors were evaluated at the 12th/13th rib interface. Data were analyzed as randomized complete block design. Considering the fixed effect of the feeding strategy and the random effect of block. We did not observe differences (P &amp;gt; 0.17) in growth performance or carcass characteristics variables due to management strategy (Table 1). The lack of observed differences due to treatment might be because the ratio of concentrate and forage intake was similar for both groups, in addition to the slick bunk management in both treatments, which forced steers to eat all their ration, independent of the treatment, to continue to receive the same amount of feed.

Effects of soyhulls with different particle size on the growth performance, blood indices and gut microbiota of yellow feather broilers

ABSTRACT 1. The objective of this study was to determine the effects of soyhulls with different particle sizes on the growth performance, blood indices and gut microbiota of yellow feather broilers. 2. Total of 240 healthy, one-day-old, yellow feather broilers were randomly divided into four groups, with six pen replicates within each group and ten birds per pen. The control group birds were fed the basal diet (Control). For the treatment groups, 5% soyhulls with different particle sizes were included in the basal diet. The particle size geometric mean diameters (d gw) of the soyhulls in the three treatment groups were 299.69 μm (LowPS), 489.85 μm (MediumPS) and 734.83 μm (HighPS) with geometric standard deviation (S gw) 1.75 μm, 1.62 μm and 1.67 μm, respectively. 3. Results showed that the growth performance variables and organ indices were not different among the four groups. The MediumPS group had increased TG, T-CHO, ALT, HDL-C, and GSH-PX levels and decreased T-AOC levels, whereas LowPS and HighPS groups had increased HDL-C and GSH-PX levels (p < 0.05). Microbial diversity analysis showed that the intestinal microbiota of yellow feather broilers mainly included Firmicutes and Bacteroidetes. Inclusion of 5% soyhulls with different particle size had no effect on alpha diversity indices of caecal microbiota. The HighPS group had significantly higher relative abundance of Firmicutes spp. and lower Bacteroidetes spp. compared with the LowPS and MediumPS group but this was not different from the Control group. The relative abundance of Cyanobacteria spp. was significantly higher in the HighPS group than the other three groups. LEfSe analysis showed that there were more enriched biomarker taxa in the groups with soyhulls than the control group. 4. Overall, the inclusion of soyhulls with different particle sizes had limited effects on growth performance, blood indices and caecal microbiota composition of yellow feather broilers.

Growth performances, body composition, and blood variables of Nile tilapia (Oreochromis niloticus) juveniles grown in a recirculating aquaculture system under different water salinity levels

ABSTRACT Nile tilapia (Oreochromis niloticus) can tolerate brackish water conditions besides their ability to grow under intensive farming systems. This study tested the growth performance, body composition, and blood variables of Nile tilapia juveniles cultivated in RAS with brackish water. Fish were allocated in 16 plastic tanks (1000 L) at 200 fish per tank with an average weight of 14.34 ± 0.47 g/fish, subdivided into four groups where each group was replicated in four tanks. Nile tilapia juveniles in the four groups were kept at different levels of salinities (0, 5, 10, and 15 ppt). After 70 days, the growth performance and feed efficiency ratio were significantly lower in Nile tilapia grown at 15 ppt than those reared at 0, 5, and 10 ppt (P < .05). The Nile tilapia reared at 15 ppt had significantly lower total protein and lipid contents in the carcass than those reared at 0, 5, and 10 ppt (P < .05). The glucose content was higher while the protein profile was lower in fish reared at 15 ppt than those reared at 0, 5, and 10 ppt (P < .05). The superoxide dismutase, glutathione peroxidase, and catalase were higher while the malondialdehyde level was lower in fish reared at 15 ppt than those reared at 0, 5, and 10 ppt (P < .05). The results indicated that brackish water (5 –10 ppt) is suitable for farming Nile tilapia under RAS conditions.

263 Dietary Supplementation of Tryptophan, Threonine, and Methionine Improves the Growth and Immune Status for Lighter Body Weight Pigs But Not for Heavier Pigs Under a Sanitary Challenge

Abstract Great variability in growth performance and blood metabolites is observed between animals and within the same group. This variation may exist between individuals due to the initial body weight (BW) which may determine different abilities to cope with a sanitary challenge (SC). Besides, supplementing tryptophan (Trp), threonine (Thr), and methionine (Met) above NRC requirements supports the immune system and growth performance costs during a SC. Therefore, this study aimed to investigate the effect of initial BW on changes in body composition, and blood metabolites of growing pigs housed under poor SC and receiving Trp, Thr, and Met at 100 or 120% of NRC recommended levels. Twenty gilts were categorized into two groups according to initial BW: light (22.5 ± 0.8 kg) and heavy (28.5 ± 1.0 kg). Both BW groups were group-housed for a 28-d trial. Pigs were orally inoculated with 2 × 109 CFU of Salmonella typhimurium, and manure from a commercial pig farm was spread on the floor. Two dietary treatments were provided: control (CN) or supplemented (AA+) diet with Trp, Thr, and Met:Lysine 20% above the NRC (2012) requirements. Serum albumin and urea, along with BW were measured on days 0, 14, and 28. Body composition was estimated by dual-energy X-ray densitometry on days 0, and 28 to obtain protein (BP, % of BW) and lipid (BL, % of BW) masses. A linear mixed regression considering repeated measures in time was used to compare the slopes of the BW groups, day, and their interaction within dietary treatments. The BW and BP increased, whereas BL decreased with time (P &amp;lt; 0.10; Table 1). However, light pigs had greater BL than heavy pigs (P &amp;lt; 0.10). Dietary treatment influenced BW differently, and BL changes over time within BW groups (Figure 1). Light pigs fed the CN diet had a faster decrease in BL and a slower increase in BW over time than heavy pigs (P &amp;lt; 0.10), which was not observed in pigs fed AA+ diet. Light pigs fed CN diet had greater serum urea than heavy pigs (P &amp;lt; 0.10), with no differences for pigs fed AA+ diet. No changes in serum albumin were observed between BW within diets. Heavier pigs tend to adapt and cope better under a SC and may not need AA supplementation above the requirement. On the other hand, increasing AA improved ability of lighter pigs to cope with the SC allowing for a greater growth potential under a poor SC.

PSVI-15 Effect of Split Iron Injection to Sucking Pigs on Growth Performance and Hematological Variables in Pre- and Post-Weaning Periods

Abstract The aim of this study was to evaluate the effects of split iron injection to suckling pigs on growth performance and hematological variables in pre- and postweaning periods. A total of 23 piglets (initial body weight: 2.19 ± 0.15 kg) were allotted into 3 treatments within litter based on body weight and sex. Treatments were: 1) Iron100: 100 mg iron at d 0 of experiment (d 3-4 of age) + no additional iron injection - control), 2) Iron100/100: 100 mg iron at d 0 of experiment + 100 mg iron injection at d 9 of experiment (d 14 before weaning), and 3) Iron200: 200 mg iron at d 0 of experiment + no additional iron injection. 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 (initial), 9 (second dose for the Iron100/100 treatment), 16, 23 (weaning), and 36 of experiment. Body weight and average daily gain did not differ among treatments before weaning whereas the Iron100/100 treatment had greater body weight than the Iron100 treatment at d 36 of experiment (P &amp;lt; 0.05; 10.17, 12.55, and 11.45 kg for the Iron100, Iron100/100 and Iron200 treatments, respectively) and the Iron100/100 treatment had greater average daily gain in d 23-36 of experiment than the Iron100 (P&amp;lt; 0.05) and Iron200 (P = 0.08) treatments (0.112, 0.238, and 0.156 kg/d for Iron100, Iron100/100 and Iron200 treatments, respectively). At d 9 of experiment, the Iron200 treatment had greater hematocrit than the Iron100 and Iron100/100 treatments (P &amp;lt; 0.05; 30.35, 29.88, and 33.85% for Iron100, Iron100/100, and Iron200 treatments, respectively) and tended to have greater hemoglobin levels than the Iron100/100 treatment (P = 0.06). At d 16 and 23 (weaning) of experiment, hemoglobin concentrations and hematocrit were greater in the Iron100/100 and Iron200 treatments (P &amp;lt; 0.05) than the Iron100 treatment (9.39, 11.66, and 11.41 g/dL for Iron100, Iron100/100, and Iron200 treatments, respectively for hemoglobin concentrations at d 23 of experiment). At d 36 of experiment, hemoglobin concentrations tended to be greater in the Iron200 treatment than the Iron100 treatment (P = 0.09) and hematocrit were greater in the Iron100/100 (P = 0.10) and Iron200 (P &amp;lt; 0.05) treatments than the Iron100 treatment (29.73, 31.56, and 33.54% for the Iron100, Iron100/100, and Iron200 treatments, respectively) with greater values (P = 0.10) in the Iron200 treatment than the Iron100/100 treatment. In conclusion, the piglets that received low level of iron at birth had decreased growth rate and hematological variable values while split iron injection could increase growth rate after weaning even though it maintained postweaning hematocrit slightly less than high level of iron injection at birth.

138 Effects of Antibiotics and Low Crude Protein Diets on Growth Performance, Carcass Characteristics, and Disease Incidence of Growing Pigs

Abstract This study investigated the effect of antibiotics and low crude protein (CP) diets on growth performance, carcass characteristics, and disease incidence of growing pigs. Barrows (n = 180; 59-d-old; 18.5 ± 2.5 kg BW; AGPIC 800 × TN70) were distributed in a randomized complete block design, in a 2 × 2 factorial arrangement, nine replicates, and five pigs per pen. The factors were CP (18.5% or 13.0%) and antibiotics (none or 100 mg/kg tiamulin + 506 mg/kg oxytetracycline). Medicated diets were fed for 14 days. After that, all pigs were fed their respective CP diets for an additional 14 days (Post-medication period). Diets were formulated according to the NRC, (2012). Growth performance, backfat thickness, loin muscle area (ultrasound; Aloka SSD 500V), and disease incidence (couch and diarrhea) were evaluated. Data were analyzed using the Mixed procedure in SAS 9.4. For the first 14 days, pigs with antibiotics had improved (P &amp;lt; 0.05) BW, ADG, ADFI, and G:F compared with those without antibiotics. Pigs with 18.5% CP had greater (P &amp;lt; 0.05) BW, ADG, and G:F, whereas decreased (P &amp;lt; 0.05) ADFI compared with those with 13.0% CP. There was no interaction (P &amp;gt; 0.05) between CP and antibiotics for growth performance and carcass variables. Reduced (P &amp;lt; 0.05) cough and diarrhea incidence were observed in pigs fed antibiotics diets compared with those without antibiotics. Pigs fed 13.0% CP diets presented with less (P &amp;lt; 0.05) diarrhea incidence only when fed without antibiotics. During post-medication period, there was no carryover effect (P &amp;gt; 0.05) of antibiotics on growth performance, whereas pigs fed the 18.5% CP diets had greater (P &amp;lt; 0.05) BW, ADG, and G:F than those with 13.0% CP. Overall, G:F was improved (P &amp;lt; 0.05) by the use of antibiotics and the 18.5% CP diets improved (P &amp;lt; 0.05) ADG and G:F compared with 13.0% CP. Antibiotics did not have carryover effects (P &amp;gt; 0.05) on cough and diarrhea incidence whereas, pigs with 13.0% CP diets had less (P &amp;lt; 0.05) diarrhea incidence than those with 18.5% CP. Pigs fed 18.5% CP diets had improved (P &amp;lt; 0.05) loin muscle area compared with the 13% CP, whereas treatments did not influence the backfat thickness (P &amp;gt; 0.05). In conclusion, the reduction of dietary CP from 18.5% to 13.0% reduces the growth performance and loin muscle area of growing pigs, although it was effective to reduced diarrhea incidence. Antibiotics improved growth performance and reduced cough and diarrhea incidence. However, overall, only G:F was improved by the use of antibiotics.

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 &amp;lt; 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&amp;lt; 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 &amp;lt; 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 &amp;lt; 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 &amp;lt; 0.05) of experiment. Hematocrit levels only at d 17 of experiment was greater in the Iron14 treatment than the Iron7 treatment (P &amp;lt; 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.

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 &amp;lt; 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 &amp;lt; 0.05; 30.97, 35.57, and 37.07% for the Fe100, Fe200, and FeBW, respectively) and tended to be greater (P &amp;lt; 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.

Multi-enzymatic complex on growth performance, blood parameters, and economic viability in piglets

The aim of the present study was to evaluate the dietary effect of an enzymatic complex on the growth performance variables, blood parameters, and economic viability of piglets. To achieve this, we used 80 piglets (40 castrated males and 40 females) in a 2 × 2 factorial design following a randomized block experimental distribution, with two levels of metabolizable energy (adequate: 3206.09 and low: 3005.45 kcal kg-1) and two enzyme levels (0 and 50 g ton-1). The results showed no significant difference between treatments in the growth performance variables or blood parameters of piglets. The economic viability, economic efficiency index, and cost index were improved when we used a diet with a low energy supplemented with the enzyme complex as compared to other experimental diets. Thus, we concluded that enzyme complex supplementation can maintain growth performance and blood parameters in piglets even when they are fed low energy diets. Moreover, this could reduce production costs.

Dietary citric acid improves phosphorus and calcium availability and intestinal morphology of Nile tilapia Oreochromis niloticus

Citric acid is an organic acid, which has been used as a feed additive because it has a reasonable cost, pleasant taste, and fast assimilation, showing positive effects on the growth and health of some livestock and aquatic species. This study aimed to evaluate the effects of increased levels of citric acid (0, 10, 20, 30, and 40 g/kg) in an isonitrogenous (280.00 g/kg of digestible protein) and isoenergetic diet (12.98 MJ/kg of digestible energy) on growth performance, body composition, apparent digestibility of nutrients and minerals, hematology, pH in stomach and intestine, and intestinal histomorphometry of Nile tilapia juveniles. Fish (n = 200, initial average weight of 14.59 ± 0.81 g) were randomly distributed in 25 experimental tanks (five replicates per treatment) and fed experimental diets over a 40-day period. Increasing levels of citric acid supplementation resulted in a decrease in the pH of the experimental diets (P = 0.021). However, no significant differences in pH levels were observed in the stomach and intestine among the treatments (P > 0.05). Citric acid supplementation did not significantly (P > 0.05) affect the growth performance variables, body composition, or the apparent digestibility coefficients (ADC) of dry matter, crude protein, gross energy, ether extract, and ash of the diets. Fish fed diets with 10 and 30 g/kg citric acid exhibited higher values for total leukocytes (P = 0.043) and total plasma protein (P = 0.019) compared to the control group. Diets supplemented with 20 g/kg citric acid showed a higher ADC value for phosphorus (P = 0.027) and calcium (P = 0.032) compared to the control. Additionally, fish fed with diets containing 20 g/kg citric acid demonstrated higher values for villus height (P = 0.002) and width (P = 0.048), crypt depth (P = 0.035), and villus: crypt ratio (P = 0.014) compared to the control group. In conclusion, the supplementation of 20 g/kg citric acid improved the availability of phosphorus and calcium and positively influenced the intestinal morphology of Nile tilapia juveniles.

Digestible methionine plus cystine requirement in tambaqui (Colossoma macropomum) diets: Growth performance and plasma biochemistry

Most animals require methionine as an indispensable amino acid in their dietary protein, the normal growth of animals being affected by any deficiency or excess of methionine and cystine in the diet. The current study aimed to determine the digestible methionine plus cystine requirement in diets for tambaqui (Colossoma macropomum). A total of 288 tambaqui with an initial body weight of 54.53 ± 0.15 g were used in a dose-response experiment with five levels of digestible methionine plus cystine (0.400; 0.600; 0.800; 1.000; 1.200 %) and four replicates per treatment. The results showed that increasing the dietary digestible methionine plus cystine level influenced all growth performance variables evaluated in the study, except feed intake. Methionine plus cystine intake increased linearly (P < 0.05). Quadratic effects on weight gain, specific growth rate, and feed conversion ratio were observed, with estimated requirements being 0.876 %, 0.883 % and 0.907 % of digestible methionine plus cystine, respectively. The deposition of body protein, body fat, and body ash also showed a quadratic response with requirements estimated at 0.920 %, 1.124 % and 0.879 % of digestible methionine plus cystine, respectively. The methionine plus cystine levels evaluated influenced plasma biochemistry, except glucose. The requirement for digestible methionine plus cystine in the diet for tambaqui was determined as 0.920 % (0.297 g/Mcal of digestible energy), as it allows greater deposition of body protein.

Growth performance, carcass traits, meat quality, and blood variables of small-sized meat ducks with different feed efficiency phenotypes

The study investigated the effects of feed efficiency (residual feed intake, RFI and residual intake and gain, RIG) on the production performance of small-sized meat ducks. Ninety ducks with intermediate and extreme (high and low) RFI values were selected from 1,083 male ducks of similar body weight, and the 3 groups were then redivided according to RIG. For both efficiency measures, the feed conversion ratio (FCR) and average daily feed intake (ADFI) of efficient ducks were significantly lower than those of inefficient ducks (P < 0.05), while the residual body weight gain (RG) was significantly higher in efficient ducks (P < 0.05). Inefficient-RFI animals showed greater skin fat yield (P < 0.05), but no other differences in carcass traits were observed (P > 0.05). RIG had positive effects on the pH1 value of the breast muscle (P < 0.05), but feed efficiency did not affect the other meat quality traits (P > 0.05). With regard to blood biochemical parameters, efficient ducks had significantly lower triglycerides (TG) (P < 0.05). Correlation analysis demonstrated that RFI was positively correlated with average daily feed intake and feed conversion ratio (P < 0.05), while RIG exhibited a strong negative correlation with both (P < 0.05). The average daily body weight gain was positively correlated with RIG (P < 0.05). RIG had a positive effect on the pH1 value of the breast muscle (P < 0.05). Furthermore, triglyceride and high-density lipoprotein cholesterol levels correlated with both efficiency classifications (P < 0.05). Overall, the efficiency measures did not affect the carcass and meat quality of small-sized meat ducks but could identify ducks with lower feed consumption and fast growth.

Insect Larval Meal as A Possible Alternative to Fish Meal in Rainbow Trout (Oncorhynchus mykiss) Diets: Black Soldier Fly (Hermetia illucens), Mealworm (Tenebrio molitor)

This study was conducted to determine the effect on growth performance and intestinal histomorphology of the rainbow trout (Oncorhynchus mykiss) fed diets including black soldier fly (Hermetia illucens) prepupae meal (HI) and mealworm (Tenebrio molitor) larvae meal (TM) used instead of fish meal. Six diets with HI and TM at three inclusion levels (10%, 20% and 30%) and a control diet based on fish meal were prepared. Test diets were encoded as control, HI10, HI20, HI30, TM10, TM20 and TM30. Fish (average initial weight of 34.17±0.88 g) were randomly placed (30 for each) in 500 L fibreglass tanks. Each of the seven diet treatments was tested in triplicated tanks. Fish were fed by hand at a level of 2.5% of body weight three times a day for 90 days. Results demonstrated that the growth performance and intestinal histomorphology were significantly affected by black soldier fly (HI) prepupae meal substitution (p&amp;lt;0.05). HI prepupae meal used instead of the fish meal had a negative effect on the growth performance, but not on the intestinal villi length. In addition, intestinal villi width decreased in fish on diets containing 10% or 20% HI prepupae meal. The growth performance and intestinal histomorphology were significantly affected by diets including TM. The diets containing 20% and 30% TM meal significantly decreased growth performance variables, but intestinal villi length increased. The results suggest that mealworm meal (10%) can be included in diets of rainbow trout at a level of 10% instead of fish meal without adversely affecting growth performance. Future studies should be expanded using a highly defatted TM and HI larvae meals.

The Benefits of Exogenous Xylanase in Wheat–Soy Based Broiler Chicken Diets, Consisting of Different Soluble Non-Starch Polysaccharides Content

Four wheat-based diets with either a low soluble content of non-starch polysaccharides (NSPs, 13 g/kg); low viscosity, LV) or a high content of NSPs (33.5 g/kg; high viscosity, HV), with and without exogenous xylanase (XYL), were fed to male Ross 308 broiler chickens from 7 to 21 days age. The enzyme was supplemented at 100 FXU/kg diet, and its preparation was based on endo-1,4-beta-xylanase produced by Aspergillus oryzae. Each diet was fed to eight pens, with five birds in each pen, following randomisation. Chicks fed XYL had an improved feed efficiency, hepatic coenzyme Q10, caecal butyric acid concentration, nitrogen digestibility (p &lt; 0.05) and increased dietary ME (p &lt; 0.001). Compared to HV, birds fed LV diets had reduced weight of proventriculus, gizzard and the pancreas and higher blood glutathione peroxidase and dietary ME (p &lt; 0.05), but no differences were observed on nutrient digestibility and growth performance variables. This also suggests that birds may tolerate a greater dietary NSPs content; thus, further benefits may be obtained by the application of XYL in low energy wheat-based diets.

Diferentes níveis de fitase e de densidades energéticas em dietas de frangos de corte sobre desempenho, digestibilidade de nutrientes e integridade óssea de 28 a 35 dias de idade

ABSTRACT The study was carried out with the objective of evaluating the effects of using phytase levels at different energy densities in the diet of broilers, from 28 to 35 days of age. The experimental diets contained increasing levels of apparent metabolizable energy corrected for nitrogen balance and different levels of phytase. Growth performance variables, nutrient digestibility, as well as variables related to bone integrity were examined. Diets containing 500 FTU/kg in combination with 3150kcal.kg-1 of AMEn resulted in better growth performance. Supplementation with 500 and 1000 FTU/kg in the diets provide better coefficients of apparent and ileal digestibility of calcium and phosphorus, but negatively influence the deposition of calcium, phosphorus, dry matter, and ash in the tibia, in addition to adversely affecting the breakage and area of these bones in broilers. Bone length and the levels of magnesium and zinc present in the tibias were not influenced by the energy and phytase levels of the diets. There is no interaction between the different energetic densities and the phytase doses in the variables analyzed in the studied period. Increasing the energy density of diets resulted in improved apparent and ileal digestibility for most nutrients.