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Made available in DSpace on 2022-04-28T19:42:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-09-01 Two nitrogen balance (NB) studies were performed to estimate individual responses and the ideal standardized ileal digestible (SID) of valine (Val) and isoleucine (Ile) to lysine (Lys) ratios, as well as to examine the individual variability among pigs of 20 to-30 kg. Eight castrated male pigs with an initial average body weight of 20.80 ± 1.30 kg were used to evaluate SID Val:Lys in experiment 1 (Exp 1), and eight males weighing 21.90 ± 1.66 kg were used to assess SID Ile:Lys in experiment 2 (Exp 2). The experiments lasted 28 days, consisting of 7 days of adaptation and 21 days of collection. The SID Val:Lys and SID Ile:Lys in diets increasing by a total of seven equal increments (SID Val:Lys from 0.56 to 0.74 and SID Ile:Lys from 0.43 to 0.61) were sequential fed every 3 days for each pig. Nitrogen retention (NR) as a function of SID Val:Lys and SID Ile:Lys was estimated per individual and per group using a linear broken-line (LBL) and was also estimated per group using a quadratic broken-line (QBL). In the LBL adjusted for each individual in Exp 1, the highest breakpoint was 0.68 and the lowest was 0.62. In terms of NR, the highest plateau in the LBL was 52.03 g and the lowest was 34.78 g. In the LBL adjusted for each individual in Exp 2, the highest breakpoint was 0.60 and the lowest was 0.52. The highest plateau for NR in the LBL was 56.04 g and the lowest was 36.44 g. In the LBL model including all animals, the optimal ratio in Exp 1 was estimated to be 0.67 (breakpoint), and the NR plateau was 43.25 g. In the QBL model, the optimal ratio estimated was 0.70 (breakpoint) and the NR plateau was 42.75 g. In the LBL model including all animals, the optimal ratio in Exp 2 was estimated to be 0.55 (breakpoint) and the NR plateau was 40.89 g. In the QBL model, the optimal ratio estimated was 0.62 (breakpoint) and the NR plateau was 42.32 g. The individual ideal ratios for pigs of 20 to-30 kg varied from 0.62 to 0.68 for SID Val:Lys and from 0.52 to 0.60 for SID Ile:Lys. The estimated ideal ratios to optimize NR were 0.70 for SID Val:Lys and 0.62 for SID Ile:Lys. São Paulo State University (Unesp) School of Agricultural and Veterinarian Sciences Federal Rural University of Rio de Janeiro, Seropédica São Paulo State University (Unesp) School of Agricultural and Veterinarian Sciences

This study evaluated the responses of individual daily precision (IPF) and conventional 2-phase (CON) feeding systems (FS) in terms of pig growth performance, nutrient balance, serum parameters, and meal patterns of growing pigs reared under thermoneutral (TN: 23 °C) and heat stress (high temperature [HT]: 30 °C) conditions. The animals in each treatment were assigned on the basis of equal BW to the experimental treatments (12 animals per treatment at 41.0 ± 4.87 kg of BW). The experiment lasted 55 d (phase 1 from days 0 to 27 and phase 2 from days 28 to 55). Pigs fed CON received within each phase a constant blend of diets with high and low nutrient density supplying the estimated nutrient requirements of the group, whereas the IPF pigs received daily a personalized blend providing the estimated amount of nutrients according to individual feed intake and body weight information. Body mineral content, and lean and fat masses were assessed through dual-energy X-ray absorptiometry at the beginning and end of each phase. Data were analyzed using a linear mixed-effect model, with fixed effects of the FS, temperature (AT), and the 2-way interaction between FS and AT and random effects of blocks. In relation to CON pigs, IPF pigs reduced (P 0.05) body composition. Nitrogen excretion was 24% lower (P < 0.05) in IPF pigs than in CON pigs; however, both groups had similar N retention efficiency thoroughly the trial. Amount of time feeding, feed intake rate, and feed intake per meal were 15% lower (P < 0.05) in pigs raised under HT than under TN conditions. During the phase 2, only amount of time feeding, feed intake rate, and feed intake per meal were decreased (P < 0.05) in pigs under HT conditions during nocturnal (2000 to 0500 h) and diurnal (0501 to 1959 h) periods. Haptoglobin levels were affected by the AT, showing an increase of 70% and 43% in HT at 28 and 55 d of the experiment, respectively. Pigs raised under HT conditions had 10% lower (P < 0.05) serum albumin concentration at day 55 than those under TN conditions. For serum urea concentrations, IPF pigs had 28% lower (P < 0.01) levels than CON pigs. Even though HT conditions considerably reduced growth performance and activated inflammatory responses in growing pigs, IPF was not able to rescue performance during HT; however, it was equally effective at improving nutrient utilization and maintaining body composition in HT and TN conditions.

Two nitrogen (N) balance studies were conducted to compare the relative bioavailability (RBV) of L-Met with DL-Met as Met sources in young pigs. In each experiment, 42 barrows (PIC; initial BW in Exp. 1: 10.7 kg and Exp. 2: 20.5 kg) were allotted to 7 experimental diets with 6 pigs per treatment. The basal diets (diet 1) were formulated based on corn and soybean meal being deficient in Met, but adequate for the other AA (Exp. 1: 0.24% standardized ileal digestible [SID] Met; 0.53% SID Met + Cys; 1.30% SID Lys; Exp 2: 0.23% SID Met; 0.47% SID Met + Cys; 1.15% SID Lys). Three graded levels of DL-Met and L-Met (0.03, 0.06 and 0.09%) were supplemented to the basal diet on top to create diets 2 to 7 for both studies. In Exp.1, N retention (% of N absorbed) increased linearly (P < 0.05) with supplementation with both Met sources. The slope-ratio regression estimated the RBV of 106% [95% confidence interval (CI): 39 to 173%] for N retention (% of absorbed) on an equi-molar basis. In Exp. 2, N retained (g/d), N retention (% of N intake and % of N absorbed) increased linearly (P < 0.05) by supplementing with both Met sources. There was no effect of Met sources on all N balance parameters in both studies. The slope-ratio estimated the RBV of 89% (95% CI: -28 to 206%) for N retained (g/d), 95% (95% CI: 13 to 177%) for N retention (% of N intake) and 94% (95% CI: 20 to 167%) for N retention (% of N absorbed), respectively on an equi-molar basis. In conclusion, the 95% CI for the RBV of L-Met covers 100%, indicating the RBV of L-Met is not different from that of DL-Met as a Met source for weaned and growing pigs.

Made available in DSpace on 2018-12-11T16:53:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-07-01 The relative bioavailability (RBV) of a dipeptide DL-methionyl-DL-methionine (DL-Met-Met) was compared with DL-methionine (DL-Met) in growing pigs (experiment 1; N-balance study) and in weaned pigs (experiment 2; performance study). In experiment 1, 42 barrows with an initial body weight (BW) of 21.0 ± 1.37 kg were assigned to 7 dietary treatments with 6 replicate/pigs per treatment in a nitrogen (N) balance study to evaluate the RBV of DL-Met-Met to DL-Met. A basal diet (BD) was formulated to be adequate for all amino acids with the exception of Met + Cys which was 68% of the requirement [4.7 g/kg standardized ileal digestible (SID) Met + Cys; 11.5 g/kg SID Lys] for 20–25 kg pigs. Three graded levels of DL-Met (0.3, 0.6 and 0.9 g/kg) and DL-Met-Met (0.306, 0.612 and 0.919 g/kg) were supplemented to the BD to create diets 2–7. In experiment 2, a total of 189 weaned pigs (initial BW of 10.2 ± 0.98 kg) were assigned to 7 dietary treatments with 9 replicates/pens of 3 pigs per treatment. The dietary treatments consisted of a Met-deficient BD (5.3 g/kg SID Met + Cys; 13.0 g/kg SID Lys) and the same 3 graded levels of DL-Met and DL-Met-Met as in Exp. 1. In experiment 1, supplementation with DL-Met or DL-Met-Met linearly decreased (P ≤ 0.01; linear) urinary N excretion and increased (P ≤ 0.02; linear) N retained (g/day), N retention (% of intake and % of absorbed). However, there was no effect of Met sources on all N balance parameters. Based on the slope-ratio regression the RBV for DL-Met-Met compared to DL-Met was estimated 111% [95% confidence interval (CI): 63-158%] for N retained (g/d), 109% (95% CI: 57-160%) for N retention (% of intake) and 98% (95% CI: 43–154%) for N retention (% of absorbed) on an equi-molar basis. In experiment 2, the overall average daily gain (ADG) and gain:feed ratio (G:F) increased linearly (P < 0.01) by supplementation with DL-Met or DL-Met-Met. The average daily feed intake increased by supplementation with DL-Met (P = 0.02) and DL-Met-Met (P = 0.09). For ADG, the RBV for DL-Met-Met was estimated 104% (95% CI: 66-141%) on an equi-molar basis by the slope-ratio. Based on G:F, the RBV for DL-Met-Met was estimated 117% (95% CI: 61–174%) on an equi-molar basis. The results of both experiments indicate that the bioavailability DL-Met-Met is not different and at least equally bioavailable as DL-Met as a Met source for pigs. São Paulo State University (UNESP) School of Agricultural and Veterinarian Sciences Animal Science Department Evonik Nutrition & Care GmbH Evonik Degussa Brasil Ltda São Paulo State University (UNESP) School of Agricultural and Veterinarian Sciences Animal Science Department

This study evaluated the responses of individual daily precision (IPF) and conventional 2-phase (CON) feeding systems (FS) in terms of pig growth performance, nutrient balance, serum parameters, and meal patterns of growing pigs reared under thermoneutral (TN: 23 °C) and heat stress (high temperature [HT]: 30 °C) conditions. The animals in each treatment were assigned on the basis of equal BW to the experimental treatments (12 animals per treatment at 41.0 ± 4.87 kg of BW). The experiment lasted 55 d (phase 1 from days 0 to 27 and phase 2 from days 28 to 55). Pigs fed CON received within each phase a constant blend of diets with high and low nutrient density supplying the estimated nutrient requirements of the group, whereas the IPF pigs received daily a personalized blend providing the estimated amount of nutrients according to individual feed intake and body weight information. Body mineral content, and lean and fat masses were assessed through dual-energy X-ray absorptiometry at the beginning and end of each phase. Data were analyzed using a linear mixed-effect model, with fixed effects of the FS, temperature (AT), and the 2-way interaction between FS and AT and random effects of blocks. In relation to CON pigs, IPF pigs reduced (P < 0.05) Lys (19%), protein (16%), and P (14%) intake without impairing (P > 0.05) body composition. Nitrogen excretion was 24% lower (P < 0.05) in IPF pigs than in CON pigs; however, both groups had similar N retention efficiency thoroughly the trial. Amount of time feeding, feed intake rate, and feed intake per meal were 15% lower (P < 0.05) in pigs raised under HT than under TN conditions. During the phase 2, only amount of time feeding, feed intake rate, and feed intake per meal were decreased (P < 0.05) in pigs under HT conditions during nocturnal (2000 to 0500 h) and diurnal (0501 to 1959 h) periods. Haptoglobin levels were affected by the AT, showing an increase of 70% and 43% in HT at 28 and 55 d of the experiment, respectively. Pigs raised under HT conditions had 10% lower (P < 0.05) serum albumin concentration at day 55 than those under TN conditions. For serum urea concentrations, IPF pigs had 28% lower (P < 0.01) levels than CON pigs. Even though HT conditions considerably reduced growth performance and activated inflammatory responses in growing pigs, IPF was not able to rescue performance during HT; however, it was equally effective at improving nutrient utilization and maintaining body composition in HT and TN conditions.

Feeding pigs with low protein diets is suggested to attenuate the negative effects of heat stress in pigs reared in hot climate areas, without changes on pigs performance. This study aimed to evaluate the nitrogen balance of pigs raised under tropical conditions and fed in conventional group-phase feeding systems (CON) or fed individually with daily tailored diets (IPF) receiving diets formulated with low (LCP) or high (HCP) crude protein. Sixty male castrated pigs (39kg±0.98) were assigned to 4 treatments in a 2×2 factorial arrangement. The experiment lasted 56 days (phase 1: d 0–28, and 2: d 29–56). CON fed pigs received within each phase a constant blend of diets A (high nutrient) and B (low nutrient density) supplying the estimated nutrient requirements of the group, whereas IPF pigs received daily a personalized blend providing the estimated amount of nutrients. Body lean was assessed by a dual-energy X-ray absorptiometry at the beginning and at the end of each phase and converted to body protein. Data were analyzed using the MIXED procedure of SAS including the fixed effects of feeding system, feed formulation, and their interactions. Pigs receiving LCP diets reduced the CP intake in 27% (P < 0.001). However, IPF pigs consumed on average 15% less CP than CON pigs (P < 0.001). Regardless of the reduced CP intake, LCP fed pigs showed a greater N retention than pigs receiving HCP diets during the first phase (P < 0.01). Moreover, pigs fed LCP diets excreted 30% less N to the environment than pigs fed HCP diets (P < 0.001). When LCP diets are complemented with the use of IPF technique, the N excreted can be reduced 18% more than in CON system (P < 0.001). Our results indicate that LCP diets and IPF are feasible to improve the nitrogen utilization of pigs raised under tropical conditions.

This study aimed to compare growing pigs feeding behavior when fed with conventional group-phase feeding systems (CON) or fed individually with daily tailored diets (IND: individual precision feeding) under two ambient temperature conditions (TN: thermoneutral, 23°C; and HT: high temperature, 30°C). Forty-eight barrow pigs 44-kg (±0.98) BW were assigned to treatments in a 2 × 2 factorial arrangement (12 animals per treatment), with one room per thermal condition and two automatic feeders per room. The experiment lasted 55 days (phase 1 from d0-27; phase 2 from d28-55). Diurnal and nocturnal feeder visits and feed intake were recorded automatically. Data were analyzed using the MIXED procedure of SAS with the fixed effects of feeding system, ambient temperature and their interaction. Each pig was considered the experimental unit. Over the experiment, IND pigs reduced (P

Made available in DSpace on 2015-10-22T07:15:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-05-01. Added 1 bitstream(s) on 2015-10-22T09:46:01Z : No. of bitstreams: 1 S0103-90162015000300210.pdf: 146495 bytes, checksum: 329b55b4c8320d4c2ef2d3d3ba1d721a (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Broilers are traditionally managed with feeding programs that often consist of three or four phases. In this study we investigated whether a multiphase feeding program (14 phases) of broilers based on the optimal mix of two feeds could replace a traditional four phase system while maintaining broiler performance. To evaluate this prposed program we measured variables of performance, carcass yield, and nitrogen excretion. In addition, we determined if the multiphase feeding program (14 phases) would be equally effective regardless of bird gender. A total of 480 day-old Cobb chicks were used, with an average weight of 44.74 +/- 0.16 g (females) and 44.71 +/- 0.11 g (males). The birds were distributed in a completely randomized 2 x 2 factorial design. Each treatment consisted of six replicates with 20 animals per experimental unit. Results were analyzed separately in two periods (1-21 and 22-42 days) as determined by slaughter date, as well as for the entire growth period (1-42 days). The multiphase program led to improvements in final body weight and average daily weight gain, in addition to an increase in breast yield. Sao Paulo State Univ, FCAV Anim Sci Dept, BR-14884900 Jaboticabal, SP, Brazil Sao Paulo State Univ, FCAV Anim Sci Dept, BR-14884900 Jaboticabal, SP, Brazil FAPESP: 2012/03781-0

Made available in DSpace on 2018-12-11T16:59:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-01-01 The objective of this meta-analysis was to evaluate the response of growing-finishing pigs to different dietary methionine sources and to determine the ideal methionine:lysine ratio for nursery to finishing pigs. Data were obtained from peer-reviewed journals. Information were extracted from the material and methods and results sections of pre-selected articles. Forty one articles were included in the first database. Graphical and correlation analyses, multivariate exploratory analysis of factors, variance-covariance analysis, and non-linear models were applied to estimate nutritional requirements. Eighty-three percent of the articles in the database were not used for the determination of the methionine:lysine ratio because the diets did not meet the pigs' lysine requirements. Methionine sources were compared using 21 articles of the first database, and performance differences were not found (P