Ileal Digestible Lysine Research Articles

135 Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance of PIC 337 × Camborough Commercial Pigs that were Sired by High Index Boars

Abstract Our objective was to determine the effects of increasing dietary standardized ileal digestible lysine levels on the growth performance of PIC 337 × Camborough commercial pigs that were sired by high-index boars. A total of 2,200 barrows and gilts (PIC 337 × Camborough) were used in six experiments covering body weight ranges of 11-25 kg (Exp.1), 26-46 kg (Exp.2), 45-66 kg (Exp.3), 63-85 kg (Exp.4), 86-110 kg (Exp.5), and 108-134 kg (Exp.6). Pigs were placed in two rooms with 45 pens in Room 1 and 43 pens in Room 2, and there were 25 pigs/pen (12 or 13 gilts and 13 or 12 barrows) for both rooms. Room 1 was used in Exp. 1, 3, and 5; Room 2 was used in Exp. 2, 4, and 6. At the beginning of each trial, on-test pens were blocked by body weight and randomly allotted to one of five treatments (90, 100, 105, 110, or 120% of PIC SID Lys recommendations for Exp.1 to Exp. 5; whereas 80, 90, 100, 110, or 120% of PIC SID Lys recommendations for Exp. 6) in a randomized complete block design. Off-test pens were fed a common wash-out diet between trials, and common diets were formulated to meet PIC nutrient requirements according to the specific weight range. Data were analyzed using generalized linear mixed model with pen as the experimental unit in R Studio (Version 3.5.2, R Core Team; Vienna, Austria). Dietary SID Lys levels were included as fixed effects, and weight block was included as random effects in the model. All data are reported as least square means and considered statistically significant at P < 0.05 and marginally significant at P < 0.10. Increasing SID Lys improved average daily gain (ADG; linear, P = 0.003) and gain-to-feed ratio (G:F; quadratic, P = 0.007) in Exp.1; improved ADG (quadratic, P = 0.045) in Exp.4; improved ADG (quadratic, P = 0.009) and G:F (quadratic, P = 0.002) in Exp.5; and improved ADG (linear, P = 0.037) and G:F (linear, P = 0.030) in Exp.6 (Table 1). However, there was no evidence for difference among treatments on growth performance in Exp.2 and 3. With increasing dietary SID Lys levels, gram of SID Lys per kilogram of bodyweight gain increased in a quadratic manner in Exp.1 (P = 0.025) and 5 (P = 0.002); and increased in a linear manner in Exp.2, 3, 4, and 6 (P < 0.001). In conclusion, increasing dietary SID Lys levels improved the growth performance of PIC 337 × Camborough commercial pigs sired by high-index boars when the bodyweight was below 25 kg or beyond 63 kg.

220 Impact of Bump Feeding During Late Gestation on Reproductive Performance of Over-Conditioned Sows

Abstract Our objective was to evaluate the effect of bump-feeding during late gestation on reproductive performance of multiparous over-conditioned sows. A total of 220 PIC Camborough sows were assigned to one of three feeding levels in a completely randomized design. Caliper was individually collected at d 90 of gestation from a larger group of sows to assess body condition, and only sows from parity 1+ and considered over-conditioned by the sow caliper were selected for the study. Sows were equally balanced by parity (P1 and P2 as young, and P3+ as mature) when allocated to treatments. All sows were fed a common gestation diet containing 3.20 Mcal of metabolizable energy (ME) per kg and 0.56% standardized ileal digestible lysine, but feed drop-boxes were adjusted to different feeding levels according to treatment. Treatments consisted of 5.09 Mcal of ME/d (1.59 kg/d; CONTROL), 6.54 Mcal of ME/d (2.04 kg/d; 0.45kg-BUMP), or 8.00 Mcal of ME/d (2.49 kg/d; 0.90kg-BUMP); and fed to sows from d 90 of gestation until they were moved to the farrowing room. Sows were housed in crates during gestation. Sow body weight (BW) and caliper measurements were collected at pre-farrowing and weaning, and their difference was calculated. Additionally, post-farrowing 48h BW was predicted using the following equation: 48h post-farrow BW = -20.81 + (0.98 × pre-farrow BW). Total born, born alive (BA), stillborn (SB), and mummified were collected for each sow at farrowing. Individual piglet BW were recorded at birth, at cross-foster, and at weaning. Data were analyzed using a generalized linear model considering sow as the experimental unit. Models included treatment, parity group, and their interaction as fixed effects. Covariates were included if they were statistically significant and improved model fit. There was no treatment by parity group interaction for any response criteria. There was no evidence for differences between treatments for caliper at d 90 of gestation, caliper pre-farrow, caliper at weaning, or caliper change between d 90 to pre-farrow and pre-farrow to weaning (P >0.10; Table 1). Sows that received 0.90 kg-BUMP were marginally heavier at farrow than CONTROL sows (P < 0.10), with those receiving 0.45 kg-BUMP intermediate. CONTROL sows lost less BW during lactation compared with 0.45kg-BUMP sows (P < 0.05), with 0.90 kg-BUMP sows intermediate. Sows receiving 0.45kg-BUMP from d90 of gestation to farrowing had greater percentage BA piglets and decreased percentage SB compared with sows receiving 0.90 kg-BUMP (P < 0.05), with CONTROL sows intermediate. There was no evidence (P >0.10) for treatment differences for piglet birth weight, litter and piglet BW gain, or percentage weaned piglets. In summary, increasing the feeding level for over-conditioned sows during late gestation did not impact sow reproductive or litter performances.

144 Effect of Protein Source on Piglet Performance and Dietary Protein Digestibility in Regular Nursery and Escherichia Coli Challenged Conditions

Abstract Compared with conventional soybean meal (SBM), processed soy protein has been demonstrated to have greater nutrient digestibility, leading to better animal growth performance and gut health. The aim of the present study was to test hypothesis that Provisoy, a SBM product produced via hydrothermal mechanical treatment could improve weaning piglet growth performance via greater crude protein (CP) digestibility compared with SBM, and this benefit would be greater in pigs under Escherichia coli (ETEC) challenged conditions. A total of 268 weaned pigs [initial body weight (BW) = 6.82 ± 0.85 kg] were allotted to a split plot design and pigs were housed in either a regular nursery condition (5 pigs/pen, 10-11 pens/treatment) or an ETEC challenged condition (3 pigs/pen, 12 pens/treatment, 1 pig per pen was orally gavaged with 10 mL O149K91K88 on d 5 post-weaning). All pigs were fed one of the following diets: SBM, Provisoy or HP300. A standard wheat-barley-SBM based nursery diet was used and test soy products were added to replace SBM in the treatment diets. All diets were formulated to be isocaloric and had similar standardized ileal digestible lysine level in a three-phase (38 days) nursery program. One pig per pen was euthanized for ileal digesta and fecal samples were collected on post-weaning day 13 and 14. Data were analyzed by general linear model in R. In summary, there was no interaction between challenge condition and dietary protein source on intake and gain throughout all three phases. A significant interaction in G:F between d 0-7 post-weaning (P < 0.05) was observed. As expected, pigs performed better in regular conditions compared with challenged conditions (P < 0.05). Dietary protein source significantly affected ADG (P < 0.05) and BW (P < 0.01) on post-weaning d 7 regardless of challenge condition, with pigs fed Provisoy exhibiting increased ADG and d 7 BW versus the control but not different than HP300. Similar improvements in growth performance were observed during d 7-12 post-weaning. However, the effect of protein source on piglet growth was no longer evident during the last phase of nursery. There was no interaction observed between challenge condition and protein source on CP apparent ileal digestibility (AID) or apparent total tract digestibility (ATTD). Dietary protein source affected CP ATTD (P < 0.01), with Provisoy treatment having the greatest value compared with other treatments. Challenge conditions tended to decrease CP AID (P = 0.109). In conclusion, dietary inclusion of Provisoy could improve piglet growth performance during the early nursery phase regardless of challenge condition and this benefit was likely partially due to better CP digestibility.

129 Effects of Standardized Ileal Digestible Lysine on Growth Performance of 12- to 136-kg PIC Line 800-Sired Pigs

Abstract The objective of this study was to evaluate growth performance and economic return of PIC 800 × Camborough pigs fed increasing SID Lys from approximately 12- to 136-kg. Pens of pigs were blocked by body weight (BW) and randomly assigned to 1 of 5 dietary treatments in a randomized complete block design with 26 pigs per pen and 16 pens per treatment. Pens were provided 1 of 5 dietary treatments with increasing SID Lys at 85, 93, 100, 107, and 115% of current (2021) PIC recommendations within 6 dietary phases as follows: phase 1 (1.09, 1.19, 1.28, 1.36, and 1.47%), phase 2 (0.97, 1.06, 1.14, 1.22, and 1.32%), phase 3 (0.87, 0.95, 1.02, 1.09, and 1.17%), phase 4 (0.75, 0.82, 0.88, 0.94, and 1.01%), phase 5 (0.66, 0.72, 0.77, 0.82, and 0.89%), and phase 6 (0.59, 0.64, 0.69, 0.74, and 0.79%). Two corn-soybean meal-based diets containing low and high Lys were blended to achieve target SID Lys levels for each treatment diet within phase. Overall (d 0 to 143), increasing SID Lys improved (linear, P ≤ 0.007) ADG and G:F, but did not impact ADFI (P > 0.10; Table). A tendency (linear, P = 0.067) for heavier hot carcass weights (HCW) was observed in pigs fed increasing SID Lys. However, there was no evidence for differences (P > 0.10) in carcass yield, backfat depth, loin depth, or carcass lean percentage across treatments. The linear (LM) model served as the best fit for both growth and economic parameters. The LM model predicted maximum ADG and G:F at levels greater than 115% of PIC’s current recommendations. However, for income over feed cost (IOFC), the LM model predicted maximum profitability at or below 85% of the current Lys recommendations of PIC. In conclusion, the optimal SID Lys level for PIC 800 × Camborough pigs from 12- to 136- kg differed upon response criteria, with growth performance maximized at levels at or above 115% of the recommendation for SID Lys by PIC; however, maximal economic returns were observed at or below 85% of PIC’s current SID Lys recommendations.

216 Effect of Dietary Standardized Ileal Digestible Lysine Level on Growth Performance of 12.4 to 31.3 kg Pigs Sired by PIC 800 Boars

Abstract A total of 1,156 PIC 800-sired pigs (12.4 kg BW) were used in a 27-day experiment to estimate the SID lysine requirement of pigs ranging from 12.4 to 31.3 kg BW. Forty-eight pens of mixed sex pigs were used. Pens were blocked by location within the barn, with barrow and gilt numbers in pens kept consistent within block. Pens were allotted to one of five dietary treatments in a randomized design with 9 to 10 replicate pens (10 pens for treatments 1, 3, 5 and 9 pens for treatments 2, 4) per treatment. Dietary SID lysine concentrations evaluated were 1.12, 1.19, 1.26, 1.33, and 1.40%. Diets were corn-soybean meal-based and formulated to equal NE concentrations across treatment. Data were analyzed using a general linear model. Orthogonal contrasts with coefficients for equally spaced treatments were used to analyze for linear and quadratic effects. For significant quadratic effects, breakpoint analysis was conducted (two slope regression or quadratic broken line analysis) using nonlinear regression analysis to estimate for SID lysine requirement. A linear (P < 0.05) response was observed for BW to increase as SID lysine level in the diet increased. Increasing SID lysine increased average daily gain (ADG) quadratically (P = 0.05) with a plateau observed above 1.357% SID Lys. Additionally, increased SID lysine yielded a quadratic effect on G:F (P < 0.05) with a plateau above 1.327% SID lysine. There was a quadratic response (P < 0.05) observed for cost of gain (COG), with no benefit to COG when feeding above 1.201% SID lysine. However, there was a linear response (P < 0.05) observed for return over feed cost (ROFC) as SID lysine increased due to increased BW. There was no effect of SID lysine level fed on feed intake or mortality and morbidity. These data indicate that the estimated SID lysine requirement for PIC 800-sired pigs ranging from 12.4 to 31.3 kg to be 1.327 and 1.357 for optimal feed efficiency and ADG, respectively.

131 Effect of Dietary Standardized Ileal Digestible Lysine Concentration Curve on Growth Performance and Carcass Characteristics of Finishing Pigs of DNA Genetics

Abstract A total of 1,125 pigs (31.4 kg BW) of DNA genetics were used in a 109-d experiment to evaluate the effect of SID Lys feeding curve of pigs from 31.4 to 133.3 kg BW. Forty-five pens of mixed sex pigs were used. Pens were blocked by location within the barn with barrow and gilt numbers in pens kept consistent within block. Pens were allotted to one of five dietary treatments in a randomized complete block design with 9 replicate pens per treatment. Dietary SID lysine concentrations were evaluated on a curve (corresponding to 90, 95, 100, 105, and 110% of the DNA Genetics SID lysine recommendations) using a 6-phase feeding program throughout the experimental period. The 100% curve concentrations used were 1.16% for phase 1 (31.4 – 47.5 kg), 1.02% for phase 2 (47.5 – 64.4 kg), 0.92% for phase 3 (64.4 – 81.8 kg), 0.79% for phase 4 (81.8 – 98.9 kg), 0.72% for phase 5 (98.9 – 117.1 kg), and 0.65% for phase 6 (117.1 – 133.3 kg). Diets were corn-soybean meal-DDGS-based and formulated for equal NE concentrations across treatment within diet phase. Data were analyzed using a general linear model. Orthogonal contrasts with coefficients for equally spaced treatments were used to analyze for linear and quadratic effects. A linear (P < 0.05) increase was observed for BW, average daily gain, and G:F as SID lysine level in the diet increased. There was a linear increase observed (P < 0.05) for lysine intake (g/d and g per lb. gain) as SID lysine level of the diet increased. While no difference (P > 0.10) was observed for NE intake, caloric efficiency improved linearly (P < 0.05) as lysine level in the diet increased. Furthermore, return over feed cost improved linearly (P < 0.05) as dietary SID lysine level increased. There was no effect of SID lysine level fed on mortality and morbidity. A linear response (P < 0.05) for hot carcass weight and loin depth was observed as SID lysine level increased. Additionally, a quadratic response was observed (P < 0.05) for fat depth and percent lean as SID lysine level increased. These data indicate the SID lysine level that optimized growth and carcass measurements for DNA pigs ranging from 31.4 to 133.3 kg to be above the 105% curve, corresponding to 1.22, 1.071, 0.966, 0.83, 0.756, and 0.683 for diet phases 1 through 6, respectively.

207 Effects of Crude Protein and Non-Essential Amino Acids Supplementation on Growth Performance and Gut Health of Nursery Pigs

Abstract This study investigated the effect of crude protein (CP) and non-essential amino acids (NEAA) supplementation on growth performance and gut health of nursery pigs. Weaned pigs (n = 90; 22 days old; 7.5 ± 0.7 kg BW; AGPIC 415 × Camborough) barrows and gilts, were distributed in a randomized complete block design (BW as block) to three dietary treatments fed for 14 days: 1) 24% CP, 2) 18% CP, and 3) 18% CP + NEAA, including 5 g/kg L-arginine and 10 g/kg L-glutamate + L-glutamine (AminoGut, Ajinomoto, São Paulo, Brazil). There were 10 replicates per treatment and three pigs per pen. A corn-soybean meal-based diet was formulated to have 3,400 kcal/kg of metabolizable energy and 1.45 g/kg of standardized ileal digestible lysine. Crystalline amino acids, L-Lys, L-Thr, DL-Met, L-Trp, L-Val, L-Ile, L-His, and L-Leu were used (if necessary) to satisfy the ideal amino acid profile according to the Brazilian Tables for Poultry and Swine (Rostagno et al., 2017). On day 14, pigs were weighed and then euthanized to collect duodenum, jejunum, and ileum tissue. Growth performance, diarrhea incidence, intestinal morphology, goblet cells, and Peyer’s patches were evaluated. Data were analyzed using the Mixed procedure in SAS 9.4 and means were compared by Tukey’s test. Pigs fed 24% CP diet had improved (P < 0.05) G:F compared with 18% CP and 18% CP + NEAA (Table 1). There was no effect (P > 0.05) of dietary treatments on ADFI, ADG, BW, and diarrhea incidence. In the duodenum, pigs fed 18% CP + NEAA diets had greater (P < 0.05) villus height compared with the 24% CP and 18% CP (427 to 381 and 383 µm). Moreover, goblet cells proportion in pigs fed 24% CP and 18% CP + NEAA diets were greater (P < 0.05) than that of 18% CP (53.2 and 53.4 to 45.3%). In the jejunum, pigs fed 18% CP + NEAA diet had reduced (P < 0.05) crypt depth than those fed 24% CP (161 and 141 µm), whereas pigs fed 18% CP presented intermediate results (144 µm). In the ileum, pigs fed the 24% CP diets presented a greater (P < 0.05) number of Peyer’s patches compared with 18% CP and 18% CP + NEAA (48 to 38 and 41 units). In conclusion, nursery pigs fed 24% CP diets presented improved G:F compared with those fed 18% CP or 18% CP + NEAA. However, pigs fed the 18% + NEAA diets presented better gut health compared with 24% CP or 18% CP.

223 Impact of Bump Feeding in Late Gestation on Reproductive Performance and Body Weight and Body Condition at Pre- and Post-Farrowing and at Weaning in Hyper Prolific Gilts

Abstract The study aimed to quantify the effect of increasing the feeding level during late gestation on reproductive performance, body weight (BW) and body condition (BC) at pre- and post-farrowing and at weaning in gilts. A total of 815 PIC Camborough X54 gilts were individually weighed at day 90 of gestation and assigned to two feeding levels in a randomized complete block design. Gilts received either 2.3 kg/d [4.95 Mcal/d of net energy (NE) and 11.5 g/d of standard ileal digestible lysine (SID Lys); CONTROL] or 3.1 kg/d (6.67 Mcal/d of NE and 15.5 g/d of SID Lys; BUMP) from 90 d until farrowing. Gilts were housed in group pens during gestation and feed was provided using a feed box setting. Feed contained 2.15 Mcal/kg of NE and 5 g/kg of SID Lys. Caliper information was individually collected at day 90 of gestation to assess BC. Caliper and BW measurements were collected pre-farrowing and at weaning and their difference was calculated. Additionally, post-farrowing 48 h BW was predicted using the following equation: Gilt 48h post-farrow BW = -20.81 + (0.98 × pre-farrow BW). Total born (TB), born alive (BA), stillborn (SB), and mummified (MM) were collected for each gilt at farrowing, and their percentage per litter was calculated and used for analysis. Data were analyzed using a general linear model considering gilt as the experimental unit. The model included treatment as fixed effect and gilt as random effect. Caliper or BW at 90 days of gestation were considered as covariable for BW and BC analysis, respectively. Alpha for determination of significance was 0.05 and trend were identified at 0.10. BUMP gilts were 7.5 and 7.4 kg heavier than CONTROL gilts at pre- and post-farrowing, respectively (P < 0.001; Table 1). The BW at weaning did not differ between treatments (P = 0.32); however, BUMP gilts lost 6.3 kg BW more than CONTROL gilts (P < 0.001; Table 1) during the lactation period. Regarding BC, caliper at pre-farrow was 0.3 units greater for BUMP gilts compared with CONTROL gilts (P < 0.001; Table 1). No differences were observed in caliper loss during the lactation period and at weaning between treatments (P > 0.05; Table 1). The BUMP gilts tended to have 0.5 more TB compared with CONTROL gilts (P = 0.054; Table 1). Nevertheless, TB is related to the early gestation period and embryo survivability. No differences were observed in BA, SB and MM between treatments (P > 0.05; Table 1). In summary, increasing the feeding level by 0.9 kg/d in late gestation resulted in increased gilt weight and caliper at pre-farrow, and greater weight loss during the lactation period. Although reproductive performance traits were not altered by treatments, these will be followed in subsequent parities.

Standardized ileal digestible lysine requirement of pregnant sows under commercial conditions.

The present experiment aimed to determine standardized ileal digestible (SID) lysine (Lys) requirements for pregnant sows individually housed under commercial farm conditions. Two hundred multiparous sows (parity = 5.1±2.0) on day 42 of gestation were randomly allocated to five dietary treatments with a balanced parity. Experimental diets were formulated to contain 0.22%, 0.32%, 0.42%, 0.52%, and 0.62% of SID Lys for the mid-gestation period (days 42 to 76) and 0.36%, 0.46%, 0.56%, 0.66%, and 0.76% of SID Lys for the late gestation period (days 77 to 103). All indispensable amino acids except Lys were provided at 110% of their requirement estimates. Daily feed allowance per sow was determined based on the back-fat thickness and body condition score at the second pregnancy check and on day 90 of gestation. Three different statistical models were used to estimate the SID Lys requirement. Total born piglets alive per litter increased linearly and quadratically (p<0.001) as dietary SID Lys increased. For total born piglets alive per litter, the SID Lys requirement estimates ranged from 9.69 to 12.4 g/d for the mid-gestation period (1.19 to 1.52 g/Mcal metabolizable energy; 0.39% to 0.49%) and 14.6 to 17.4 g/d for the late gestation period (1.62 to 1.93 g/Mcal metabolizable energy; 0.52% to 0.62%). The mean values of the SID Lys requirement for the mid-gestation period and the late gestation period are 11.1 and 16.1 g/d (1.36 and 1.79 g/Mcal metabolizable energy; 0.44% and 0.58%), respectively, for maximal total born piglets alive per litter.

Effects of dietary standardized ileal digestible lysine to net energy ratio and wheat level on growth performance, meat quality, intestinal microbiota and body metabolism of finishing pigs

Lowing lysine (Lys): energy ratio based on corn-soybean diets could increase intramuscular fat (IMF) content, the effectiveness of it in enhancing IMF content when corn is partially substituted by wheat is unclear. This study aimed to determine the effects of dietary wheat levels and standardized ileal digestible (SID) Lys: net energy (NE) ratio on growth performance and meat quality, alteration in gut microbiota and body metabolism, as well as its correlation with meat quality are revealed via combined microbiome and metabolomic methods. A total of 72 pigs were randomly divided into four groups and fed with high SID Lys:NE ratio (HR) diets containing 25% wheat (W25HR), low SID Lys:NE ratio (LR) diets containing 25% wheat (W25LR), HR diets containing 55% wheat (W55HR) or LR diets containing 55% wheat (W55LR). Increasing dietary wheat level impaired feed utilization during 65–90 kg phase (P < 0.05) and enhanced meat color values (P < 0.05) of longissimus dorsi (LD) in finishing pigs. Enhancing dietary wheat level decreased relative abundance of Lactobacillus and Coprococcus (P < 0.05), and inhibited microbial carbohydrate metabolism capacity (P < 0.05) in colon of finishing pigs. Changes in microbial composition and carbohydrate metabolism capacity caused by wheat level led to alteration in meat color. LR diets improved feed utilization (P < 0.05), affected amino acid and lipid metabolism, and increased IMF content in LD (P < 0.05). Reducing SID Lys:NE ratio changed the concentrations of PA, delta-tocopherol, L-arginine, AzA, BA, and L-carnitine at the 25% wheat level and ARA, SDA, Glu, fructose-6-phosphate, and isorhamnetin at the 55% wheat level in the serum (P < 0.05, VIP > 1), which could serve as key biomarkers for predicting meat quality. LR diets upregulated mRNA expression levels of CCAAT/enhancer binding protein (C/EBP) α (P < 0.05), C/EBPβ (P < 0.01), sterol regulatory element-binding transcription factor 1c, fatty acid synthase (FAS) (P < 0.05), while downregulated mRNA abundance of adipose triglyceride lipase (ATGL) (P < 0.05) in liver at the 25% wheat level. The mRNA expression levels of C/EBPβ (P < 0.01), FAS, acetyl-coA carboxylase and fatty acid binding protein 1 (P < 0.05) were higher in the W55LR than W55HR groups, whereas mRNA abundance of ATGL was lower (P < 0.05). These results indicated that lowering SID Lys:NE ratio promoted lipogenesis, inhibited lipolysis and improved IMF deposition in LD via altering serum metabolism in different manner at two wheat level. LR diets containing 25% wheat was recommended to enhance the growth performance of finishing pigs, while concurrently achieving higher IMF content and improved meat color in the LD.

Effect of Increasing the Methionine Level and Reducing the Threonine Level in the Diet of Fast-Growing Rabbits.

The main aim of this work was to evaluate a novel combination of the first limiting amino acids (lysine, methionine, and threonine) in fast-growing rabbits (combination MHL, shown to minimise levels of plasmatic urea nitrogen in previous research, medium level of lysine, high level of methionine, and low level of threonine) and compare it with current recommendations (combination MMM, medium level of all amino acids). A total of 165 weaned rabbits (28 d old) from a paternal line selected for growth rate were used in the growth trial. The effect of the diet on apparent fecal digestibility, as well as the apparent and true ileal digestibility, were studied. Nutrient retention was also determined. Although no differences in digestibility between diets were observed, animals fed with Diet MHL improved the global average daily gain (+2.3 g/d; p = 0.0482) and feed conversion ratio (-0.10; p = 0.0229). Animals fed with Diet MMM reduced the protein-to-energy ratio retained (p = 0.0086). In conclusion, Diet MHL promoted an improvement in growth traits in a paternal line. Consequently, we propose its levels of 6.4, 5.4, and 5.0 g/kg DM of true ileal digestible lysine, methionine, and threonine, respectively.

Standardized ileal digestible lysine requirements based on growth performance and histochemical characteristics of male broilers from 10 to 21d of age.

The growth performance and histochemical characteristics of breast muscle fibers were used to estimate the standardized ileal digestible (SID) Lys requirements for 10- to 21-d-old male broilers. Three hundred and sixty 10-d-old Ross 308 broilers (290±16.6g) were allocated to 6 diets in a randomized complete block design with 6 replicate cages per treatment and 10 birds per cage. The 6 experimental diets were formulated to contain equally spaced increasing levels of SID Lys from 0.86% to 1.36%. The data were analyzed using the MIXED procedure of SAS. The Lys requirements were estimated by the NLIN procedure of SAS. An increase in dietary SID Lys from 0.86% to 1.36% resulted in a quadratic increase (P<0.05) in body weight gain (BWG), gain to feed ratio (G:F), breast weight, muscle cross-sectional area (MCSA), and fiber area. The SID Lys requirements based on the one-slope broken-line, quadratic line, the first intercept between the plateau of the one-slope broken-line and quadratic-line models and 95% of the upper asymptote of the quadratic-line model were estimated to be 1.01%, 1.19%, 1.08%, and 1.13% for BWG, 1.06%, 1.22%, 1.11%, and 1.16% for G:F, 1.10%, 1.29%, 1.19%, and 1.22% for breast weight, 1.06%, 1.22%, 1.12%, and 1.16% for MCSA, and 1.14%, 1.22%, 1.16%, and 1.16% for breast muscle fiber area, respectively. It was concluded that the SID Lys requirements for broilers at the age of 10 to 21d depended on the response variables used for estimation, and that histochemical characteristics of breast muscle fibers could be good indicators for estimating SID Lys requirements.

Modulating the Growth Curve in Broiler Chicken through Varying Balanced Protein Regimen (All Step-up, Designed to Get Compensatory Responses)

Background: Compensatory growth is a well-established characteristic even in broiler chicken having very short grow-out cycle. Feeding manipulations that take advantages of compensatory growth after a period of nutrient restriction might be beneficial to poultry industry. Methods: In total, 1400 one-day-old straight run broiler chicks (Hubbard) were allocated to 8 experimental treatments, replicated 7 times with 25 chicks in each, in a completely randomized design. The 3 isocaloric corn soybean meal experimental diets; a high BP (HBP) with 1.2% standardized ileal digestible lysine (SID Lys), a medium BP (MBP) with 1.1% SID Lys and a low BP (LBP) 1.0% SID Lys, were offered in starter, grower and finisher phases, as HML (conventional) and LHH, MHH, LMM, MMH, LLM, LLH and LMH as all steps-up. Result: Greater (P less than 0.05) BW and BWG were observed in HML groups during all phases. The MMH group had greater FI (P less than 0.05) during grower and finisher phases. The HML group had better FCR (P less than 0.05) during starter and grower phases. The LMM group had heavier (P less than 0.05) abdominal fat pad, whereas, MHH and HML groups had greater (P less than 0.05) dressed carcass, breast meat, drumstick and thigh yield. The MHH and HML groups, similarly, had higher (P less than 0.05) spleen, thymus, bursa weights, greater antibody titers against NDV and IBDV and total protein concentration. The LLH group had greater (P less than 0.05) blood glucose, urea and total cholesterol concentrations. It is, therefore, recommended that HBP (1.2% SID Lys) should be gradually step down to LBP (1.10% SID Lys) for efficient and sustainable production of broiler chicken.

Prediction of the daily nutrient requirements of gestating sows based on sensor data and machine-learning algorithms.

Precision feeding is a strategy for supplying an amount and composition of feed as close that are as possible to each animal's nutrient requirements, with the aim of reducing feed costs and environmental losses. Usually, the nutrient requirements of gestating sows are provided by a nutrition model that requires input data such as sow and herd characteristics, but also an estimation of future farrowing performances. New sensors and automatons, such as automatic feeders and drinkers, have been developed on pig farms over the last decade, and have produced large amounts of data. This study evaluated machine-learning methods for predicting the daily nutrient requirements of gestating sows, based only on sensor data, according to various configurations of digital farms. The data of 73 gestating sows was recorded using sensors such as electronic feeders and drinker stations, connected weight scales, accelerometers, and cameras. Nine machine-learning algorithms were trained on various dataset scenarios according to different digital farm configurations (one or two sensors), in order to predict the daily metabolizable energy and standardized ileal digestible lysine requirements for each sow. The prediction results were compared to those predicted by the InraPorc model, a mechanistic model for the precision feeding of gestating sows. The scenario predictions were also evaluated with or without the housing conditions and sow characteristics at artificial insemination usually integrated into the InraPorc model. Adding housing and sow characteristics to sensor data improved the mean average percentage error by 5.58% for lysine and by 2.22% for energy. The higher correlation coefficient values for lysine (0.99) and for energy (0.95) were obtained for scenarios involving an automatic feeder system (daily duration and number of visits with or without consumption) only. The scenarios including an automatic feeder combined with another sensor gave good performance results. For the scenarios using sow and housing characteristics and automatic feeder only, the root mean square error was lower with Gradient Tree Boosting (0.91 MJ/d for energy and 0.08g/d for lysine) compared with those obtained using linear regression (2.75 MJ/d and 1.07g/d). The results of this study show that the daily nutrient requirements of gestating sows can be predicted accurately using data provided by sensors and machine-learning methods. It paves the way to simpler solutions for precision feeding.

Evaluation of Phase Feeding and Complete Diet Blending at Different Standardized Ileal Digestible Lysine Levels on Growing-Finishing Pigs’ Growth Performance, Carcass Characteristics, and Diet Economics

Evaluation of Phase Feeding and Complete Diet Blending at Different Standardized Ileal Digestible Lysine Levels on Growing-Finishing Pigs’ Growth Performance, Carcass Characteristics, and Diet Economics

Optimal dietary standardized ileal digestible lysine level for pigs during the grower, early and late finisher periods

BackgroundLysine (Lys) is the first limiting amino acid for pigs fed corn-soybean meal diets. Three experiments were conducted to estimate the optimal standardized ileal digestible (SID) Lys requirement for growing (Exp. 1), early finishing (Exp. 2), and late finishing (Exp. 3) pigs under commercial conditions.Results and conclusionsIn Exp. 1, a total of 650 growing pigs (32.21 ± 0.33 kg bodyweight), were allocated to 5 dietary treatments supplemented with 0.75, 0.85, 0.94, 1.03, and 1.13% SID Lys. Each treatment had 5 replicate pens with 26 pigs per pen. The lowest feed to gain ratio (F:G) was obtained by pigs fed the 1.03% Lys diet and F:G showed both a linear and a quadratic response with increasing Lys (P < 0.05). Based on broken-line and quadratic analysis models, dietary SID Lys levels for the minimum F:G were 0.94%. In Exp. 2, 650 finishing pigs (57.24 ± 2.00 kg bodyweight) were allotted to 5 dietary treatments providing SID Lys of 0.63, 0.71, 0.79, 0.87, and 0.95%. Each treatment had 5 replicates, 26 pigs per replication. The highest final bodyweight was achieved by 0.79% Lys while the highest average daily gain (ADG) and average daily feed intake (ADFI) was achieved by pigs consuming the 0.87% Lys diet (P < 0.05). Additionally, the lowest F:G was obtained by pigs fed the 0.79 and 0.87% Lys diet (P < 0.05). Based on broken-line and quadratic analysis models, the optimum Lys was 0.81 and 0.82% for ADG and F:G, respectively. In Exp. 3, 600 late finishing pigs (92.22 ± 2.41 kg bodyweight), were divided into 5 treatments providing Lys levels of 0.53, 0.60, 0.66, 0.73, and 0.79%. Each treatment had 5 replicates, 24 pigs per replication. Results showed that final bodyweight, ADG, ADFI, and F:G was not affected by increasing dietary Lys level, suggesting that the lowest SID Lys (0.53%) was sufficient for this group of pigs. Taken together, the SID Lys requirement for pigs from 30 to 60 kg, 60 to 90 kg, 90 to 120 kg was 0.94%, 0.81 to 0.82, and 0.53%, respectively, depending on the response criteria with performance maximized.

Effects of dietary lysine levels on growth performance, nutrient digestibility, serum metabolites, and carcase and meat quality of Yacha pigs

The objective was to evaluate the effect of different standardised ileal digestible lysine (SID-Lys) levels on performance, nutrient digestibility, serum metabolites, and carcase and meat traits of Yacha pigs. A total of 50 pigs were blocked by body weight and randomly assigned to five dietary treatments with six replicate pens (2 pigs/pen) per treatment using a randomised complete block design. Five diets in mash form were formulated to contain SID-Lys at 0.57%, 0.62%, 0.67%, 0.72%, 0.77% of diet in phase 1 (15 ∼ 30 kg), at 0.40%, 0.48%, 0.56%, 0.64%, 0.72% of diet in phase 2 (30 ∼ 50 kg), and at 0.30%, 0.39%, 0.48%, 0.57%, 0.66% of diet in phase 3 (50 ∼ 90 kg), respectively. The results showed that the average daily gain and gain to feed ratio increased with increasing dietary Lys levels in phases 1 and 2 (p ≤ 0.05). Increasing dietary Lys levels increased linearly (p ≤ 0.05) apparent total-tract digestibility of dry matter, gross energy, crude protein, and phosphorus in Phase 3 and also increased (p ≤ 0.05) concentration of serum glucose and tended to increase (p < 0.10) serum total protein in Phase 2. Compared with the Lys deficiently treatment, the adequate Lys treatment had increased carcase weight, lean meat percentage, and shear force and decreased cooking loss (p ≤ 0.05). Moreover, the optimal dietary SID-Lys levels preliminarily determined for 15 ∼ 30 kg, 30 ∼ 50 kg, and 50 ∼ 90 kg Yacha pigs were 0.760%, 0.628%, and 0.553% of the diet, respectively. HIGHLIGHTS Dietary appropriate SID-Lys levels can improve performance and feed utilisation in Yacha pigs. Dietary appropriate SID-Lys levels contributed to enhancing carcase lean meat yield of Yacha pigs.

254 Effects of Increasing Daily Dietary Standardized Ileal Digestible Lysine Intake of Gilts and Sows During day 35-to-112 of Gestation on Reproductive Performance

Abstract Our objective was to determine the effects of increasing daily dietary standardized ileal digestible (SID) lysine (Lys) intake during d35-to-112 of gestation on sow and litter performance. A total of 583 gilts and sows (PIC Camborough) were used. Females were group-housed after d35 of gestation and individually fed with electronic sow feeders (ESF). At d35 of gestation, females were randomly allotted to 1 of 4 treatments that were balanced for body weight (BW) and caliper scores (CS) within parity categories. Treatments consisted of increasing daily dietary SID Lys intake (11.1, 13.5, 16.1, and 18.5 g/d). Both gilts and sows received 1.85 kg/d of a gestation diet containing 2.38 Mcal of NE/kg. Treatments were achieved by different blends of low (0.60% SID Lys) and high (1.00% SID Lys) Lys diets via ESF. Sow was the experimental unit and data were analyzed using generalized linear mixed models with the lmer and glmer functions of R. Body weight and CS at d112 of gestation increased (linear, P&amp;lt; 0.05) with increasing daily dietary SID Lys intake. There was no evidence for treatment difference on d112 backfat depth (BD), or changes of BW, CS, and BD during lactation. There was no evidence for treatment difference on total born, percentage born alive and stillbirth, but there was a marginal reduction (linear, P=0.086) on mummified fetuses. Increasing daily dietary SID Lys intake during d35-to-112 of gestation did not affect piglet birth weight, percentage of piglets born with less than 900g, pre-weaning mortality, or piglet average daily gain. In summary, increasing daily dietary SID Lys intake during d35-to-112 of gestation increased female BW and CS, without changing BD, indicating that more lean tissue had been deposited. However, there was no evidence for treatment differences on reproductive performance.

274 Effects of Feeding Levels in Early Gestation on PIC Camborough Sows and Litter Performance

Abstract Our objective was to determine the effects of increasing feeding levels for PIC Camborough sows during early gestation on sow and litter performance. A total of 636 sows (PIC Camborough) were randomly assigned at weaning to 1 of 4 treatments that were balanced for weight and caliper scores within parity categories. Treatments consisted of feeding sows with daily feed allowances to meet 85, 115, 145, or 175% of the NRC (2012) maintenance metabolizable energy (MEm) requirement calculated as MEm, kcal/d = 100 × (body weight, kg)0.75. A common corn-soybean meal-distillers dried grains with solubles-based diet with 3,092 kcal of ME/kg and 0.64% standardized ileal digestible lysine was used. Treatments were applied from d 6 to 35 of gestation, after which sows were moved to gestation pens and fed according to body condition through an electronic sow feeder until moved to the farrowing room. Sow was the experimental unit and data were analyzed using generalized linear mixed models with the lmer and glmer functions of R. On average, females were ideal condition at weaning across treatment as determined by the caliper scores. Average feed allowances were 1.6, 2.1, 2.6, and 3.2 kg/day for the 85, 115, 145, and 175% treatments, respectively. Increasing feed allowances reduced (linear, P&amp;lt; 0.05) body weight loss (-13.8, -10.3, -4.7 and -0.5 kg, respectively) and increased caliper score gain (-0.43, -0.03, 0.64, 0.76 units, respectively) from weaning to d 35 of gestation. There was no evidence for treatment effects on farrowing rate, total born, stillborn rate, average litter weight, piglet throughput, or subsequent reproductive performance. In summary, increasing feed allowances to meet 85 to 175% of the MEm requirements during early gestation on Camborough sows resulted in a reduction in body weight loss and an improvement in caliper gain until d 35 of gestation without evidence of impact in reproductive performance.

Influence of the energy concentration and the standardized ileal digestible lysine content of the diet on performance and egg quality of brown-egg laying hens from 18 to 41 weeks of age

The influence of the energy and the standardized ileal digestible lysine (DLys) content of the diet on egg production and egg quality, was studied in brown-egg laying hens from 18 to 41 wk of age. The experimental design was completely randomized with 10 treatments organized as a 2 × 5 factorial with 2 energy concentrations (2,750 and 2,800 kcal AMEn/kg) and 5 levels of DLys (values varied from 0.66 to 0.78% and 0.67 to 0.79%, for the low and high energy diets, respectively). Each treatment was replicated 10 times (10 hens per replicate). The data were analyzed using the MIXED procedure of SAS with energy concentration and DLys content of the diets as main effects. In addition, the effects of the DLys on the variables studied were partitioned into its lineal and quadratic components. From 18 to 21 wk of age (pre-peak phase), diet composition had limited effects on egg production. From 22 to 41 wk of age (peak phase), however, an increase of 50 kcal AMEn/kg diet increased egg weight (P < 0.05) and tended to improve energy intake (P = 0.083) and feed conversion ratio (P = 0.074). An increase in DLys improved linearly (P < 0.001) egg production, egg weight, egg mass, feed conversion, and energy conversion ratio, and tended to increase BW gain (P = 0.074). Diet composition did not any affect egg quality trait except shell strength that increased linearly (P < 0.05) with increases in the DLys. Cumulatively (18–41 wk of age), egg weight increased (P < 0.05) as the energy and the DLys content of the diet increased. In summary, an increase in energy and DLys content of the diet had limited effects on egg production during the prepeak phase but improved egg production, feed conversion ratio, and BW gain during the peak phase. The data indicate that hens require at least 839 mg DLys/d to maximize egg production in the peak production phase.