Gain Feed Research Articles

206 Development and Validation of an Indigestible Protein Index to Investigate the Effects of Protein Content in Weaned Pigs: A Multivariate Approach

Abstract Increased proteolytic fermentation may lead to negative effects on gastrointestinal health and function, which ultimately impact on performance. The objective was to develop and validate, by investigating performance and gut structure outcomes, an index of indigestible protein content (IDP) in weaned pigs. Ninety-four studies reporting growth performance [average daily gain (ADG), average daily feed intake (ADFI), gain: feed (GF), initial (IBW) and final body weight (FBW)] and duodenal histomorphometries [villus height (VH), crypt depth([CD), and villus height: crypt depth ratio (VCR)] variables of pigs fed different protein content (CP) and sources in the diet were included. Diets were recalculated using a common database to generate the IDP from each study. Studies were grouped by similarity in performance in two clusters (C1 and C2) by hierarchical clustering on principal components (HCPC). The effects of cluster were investigated. Quadratic response plateau (QRP) models were fitted to assess the interrelationships between ADG, ADFI, GF, VH, CD, and VCR with the dietary CP or calculated IDP content within cluster. Pigs from C2 had greater IBW (6.3 vs. 8.8 ± 0.2kg), FBW (10.2 vs. 17.2 ± 0.7kg), ADG (0.2 vs. 0.4 ± 0.0kg/d), and ADFI (0.3 vs. 0.6 ± 0.1kg/d) compared with C1 (P < 0.05). There was no effect of cluster (P > 0.05) on VH (405.5 vs. 405.5 ± 15.8μm), CD (232.5 vs. 220.7 ± 10.1μm), or VCR (1.9 vs. 2.0 ± 0.3μm). Pigs from C1 achieved break point (BP) and plateau (Pl) for VH (BP = 24.25%, Pl = 96.32μm; P < 0.05) when fed increasing CP content and for ADG (BP = 2.32%, Pl = 0.28kg/d; P < 0.05) and GF (BP = 2.18%, Pl = 0.83kg/kg; P < 0.05) when fed increasing calculated IDP content. Pigs from C2 fed increasing content of calculated IDP achieved BP and Pl for ADG (BP = 3.04%, Pl = 0.54kg/d; P < 0.05). Our findings suggest that calculated IDP might be a reliable index to investigate the effects of proteolytic fermentation on pig performance, particularly in the immediate post-weaning phase.

Effects of Aspergillus oryzae prebiotic on animal performance, nutrients digestibility, and feeding behavior of backgrounding beef heifers fed with either a sorghum silage- or a byproducts-based diet.

Eighty-four Angus crossbred heifers (13 ± 1 mo of age, 329.5 ± 61.92 kg of body weight [BW]) were used in a generalized randomized block design with a 2 × 2 factorial arrangement of treatments. The factors evaluated were: 1) diet type (whole plant sorghum silage [SS] vs. byproducts-based [BP]), and 2) feed additive: Aspergillus oryzae prebiotic (AOP; 2 g/d) vs. Negative control (CTL; 0 g/d), resulting in four treatments: sorghum silage-control (SC), sorghum silage-AOP (SA), byproducts-control (BC), and byproducts-AOP (BA). Heifers were stratified by body weight (BW), randomly assigned to treatments (21 heifers per treatment) and housed in 12 pens equipped with two GrowSafe feed bunks each to measure individual dry matter intake (DMI). After a 14-d adaptation, BW was measured every 14 d for 56 d. Chewing activity was monitored through collar-mounted HR-Tags (heat-related tags). Following the performance period, apparent total tract digestibility was measured in 40 heifers, using indigestible neutral detergent fiber as a marker. Heifers fed with the BP diets had greater DMI (2.92% vs. 2.59% of BW, P < 0.01) and average daily gain (ADG; 1.16 vs. 0.68 kg, P ≤ 0.01) than heifers fed with SS diets. Compared with BP-fed animals, heifers consuming the SS diets had 23 more visits/d to the feed bunks (P ≤ 0.01), consumed 53% less dry matter on each visit (P ≤ 0.01), and spent 39% more min chewing/d and 63% more min chewing/kg of DMI (P ≤ 0.01). However, chewing measured in min/kg of neutral detergent fiber intake was not affected by treatment (average 111.3 min/kg of NDF intake). Feeding AOP improved gain:feed (GF) by 15% in BP-fed heifers (0.120 vs. 0.104 kg/kg; P < 0.05). Inclusion of AOP increased organic matter digestibility (OMD) in SS diets (55.88% vs. 49.83%; P < 0.01), whereas it decreased OMD in BP diets (61.67% vs. 65.77%; P < 0.05). In conclusion, ADG and GF of BP-fed heifers was greater than SS-fed heifers, and GF was greater with AOP supplementation in BP-fed heifers. Improvement in GF in BP-fed heifers was likely not related to differences in nutrient digestibility as AOP inclusion did not enhance digestibility in the BP diet. Additionally, the effects of the AOP inclusion appear to be diet-dependent, where the 15% improvement in GF by AOP occurred in heifers fed with the more fermentable diet. Therefore, further research should explore the mechanisms responsible for the observed improvements in growth performance when feeding AOP to BP-fed heifers.

210 A Longer Adaptation Period to a Functional Amino Acid-supplemented Diet Improves Growth Performance and Attenuates Acute-phase Response in Salmonella Typhimurium-challenged Pigs

Abstract Functional amino acid supplementation during disease challenge enhances growth performance and immune status. The present study investigated the effect of duration of adaptation period to a functional amino acid (FAA)-supplemented diet on growth performance and immune status during a subsequent Salmonella challenge in pigs. Thirty-two mixed-sex weanling pigs (8 pigs/treatment; 11.6 ± 0.34 kg initial body weight) received either a basal diet without FAA supplementation throughout the experimental period (FAA-) or a diet containing a supplemented FAA profile (Thr, Met, and Trp at 120% of requirements) fed for either 0 (FAA+0), 1 (FAA+1) or 2 (FAA+2) wk pre- and 1 wk post-inoculation with Salmonella Typhimurium (ST). Pigs were orally inoculated with saline containing ST after the 2 wk pre-inoculation period and monitored for 1 wk post-inoculation. Pigs had ad libitum access to diets throughout the experiment. Performance parameters [average daily gain (ADG), feed intake, and gain:feed (GF)] were measured in the pre- and post-inoculation periods. Blood samples were collected on d 0, 4, and 7 post-inoculation for serum haptoglobin and albumin analysis. There was no effect of diet on pre-inoculation performance (P &amp;gt; 0.05). Post-inoculation, FAA+2 pigs had the highest ADG (0.46 kg/d) and GF (0.63 kg/kg), FAA- the lowest (0.21 kg/d; 0.29 kg/kg), with FAA+0 (0.33 kg/d; 0.46 kg/kg) and FAA+1 (0.40 kg/d; 0.53 kg/kg) being intermediate (ADG, P &amp;lt; 0.05, SEM=0.059; GF, P &amp;lt; 0.05, SEM=0.099). Overall, albumin was higher in FAA+2 (35.25 g/L) and FAA+1 (34.63 g/L) pigs compared to FAA+0 (30.38 g/L) and FAA- (29.67 g/L) pigs (P &amp;lt; 0.05, SEM=0.717). Furthermore, FAA+2 pigs had the lowest overall haptoglobin (0.90 g/L), FAA- the highest (1.54 g/L), with FAA+0 (1.32 g/L) and FAA+1 (1.06 g/L) being intermediate (P &amp;lt; 0.05, SEM=0.111). In conclusion, a longer adaptation period to FAA supplementation improved performance and attenuated the immune response of pigs when exposed to an enteric disease challenge.

Effect of long-term feeding of graded levels of deoxynivalenol on performance, nutrient utilization, and organ health of grower-finisher pigs (35 to 120 kg).

The objective of this study was to evaluate the effect of long-term feeding of graded levels of deoxynivalenol (DON) on performance, nutrient utilization, and organ health of grower-finisher pigs. A total of 240 mixed-sex grower-finisher pigs (35.9 ± 1.1 kg initial body weight, BW) were randomly assigned to 1 of 4 dietary treatments (6 pigs/pen; 10 pens/treatment) for 77 d. Diets consisted of a control diet without DON (CONT) and diets containing 1, 3, or 5 ppm DON (DON1, DON3, or DON5). Nitrogen-balance was determined in 1 pig/pen during weeks 6 and 12 of the study. Growth performance measures were taken weekly for average daily feed intake (ADFI), average daily gain (ADG), and gain:feed (GF) until day 77. Blood samples were collected on days 0, 14, 42, 56, and 84 from 1 pig/pen for analysis of indicators of liver and kidney function. On day 7, ADG and ADFI for pigs fed DON3 and DON5 diets were lower (P < 0.05) compared with DON1- and CONT-fed pigs. Overall, ADG and ADFI (days 0 to 77) were lower in DON3- and DON5-fed pigs compared with CONT and DON1 pigs (P < 0.05), with no difference in GF (P > 0.05). Final BW was reduced in DON3- and DON5-fed pigs (P < 0.05) compared with CONT and DON1, which were not different (P > 0.05). No significant (P > 0.05) treatment effects were observed on carcass characteristics. In the grower-phase, protein deposition (PD) was reduced in DON3 and DON5 pigs compared with CONT and DON1 pigs (P < 0.05). In the finisher phase, PD was not affected by dietary treatment (P > 0.05). There was no effect of dietary treatment on the majority of selected serum chemistry (P > 0.05). In summary, pigs exposed to diets containing > 1 ppm DON had reduced growth performance with little or no effect on nitrogen utilization, organ health, or carcass characteristics, suggesting that the negative effects of DON may be largely due to depressed feed intake.

PSXVI-23 Effects on nursery pig growth performance and economics of protease inclusion in feeds with and without matrix contribution.

Feed ingredient prices and markets competitiveness prompt animal nutritionists to modulate nutrients density of diets in order to control feed cost. By improving raw material digestibility, protease enzyme is an interesting tool to reduce costs and secure animal performance. This trial aimed to demonstrate usefulness of protease enzyme in piglets feeds by using it either on top or according to its matrix of valorization. A 42d pen study was conducted using 360 pigs (PIC) with an initial body weight (BW) of 6.15 kg equally distributed in 36 pens with 12 replications fed one of the following three treatments: CTRL) Control diet with ME of 3502/3386/3367 kcal/kg, Crude protein (CP) of 22.9/21.9/20.7 % for phases I (d0-7), II (d7-21), III (d21-42) respectively; OT) CTRL diet + 125 g/t Jefo Protease (Jefo, Canada) supplemented “On Top”; MT) CTRL diet reformulated to incorporate 125 g/t Jefo Protease according to its matrix of valorization. Data were subjected to statistical analyses of variance as a randomized complete block design. Differences among treatment means were determined with level of significance at P<0.05. Overall, pigs fed with protease on top (OT diets) showed significant (P<0.05) improvement on feed/gain (FG) with 1.273 versus 1.301 for CTRL. Pigs fed MT diets achieved similar growth performance to pigs fed CTRL diets but with cheaper feeds resulting in higher income over feed cost by comparison to pigs fed with CTRL diets ($42.87 vs $42.73 USD). In this trial, protease use with its matrix in a commercial pelleted diet accordingly reformulated in CP, AA and energy demonstrated potential to maintain BW and FG of pigs up to the level of classic diet and to allow economic savings on incomes over feed costs.

Efficacy of adsorbents (bentonite and diatomaceous earth) and turmeric (Curcuma longa) in alleviating the toxic effects of aflatoxin in chicks

A study was conducted to determine the efficacy of bentonite clay (BC), diatomaceous earth (DE) and turmeric powder (TUM) in alleviating the toxic effects of aflatoxin B1 (AFB1).A total of 250 Ross-308 d-old male broiler chicks were assigned to 10 dietary treatments (5 replicates of 5 chicks) from hatch to d 21. Dietary treatments were: basal diet; basal diet plus AFB1 (2 mg) or BC (0.75%), or DE (0.75%), or TUM (200 mg/kg curcuminoids) and different combinations of AFB1, BC, DE and TUM.Feed intake (FI), body weight gain (BWG) and feed gain (FG) of the birds fed on BC or DE separately were not different from control birds. Birds fed on TUM only had similar FI and FG but lower BWG than control chicks.Aflatoxin B1 reduced FI, BWG and serum concentrations of glucose, albumin, total protein calcium, but increased FG and relative liver and kidney weights. Chicks fed on the combination of AFB1 and BC had similar FI and FG to control chicks. Chicks fed on the combination of DE and AFB1 had lower FI (23.1%) and BWG (28.6%) compared with control chicks.Chicks fed on the combination of TUM and AFB1 also had decreased FI (26.2 %) and BWG (31%) compared with control chicks. Chicks fed on the combination of AFB1, BC and TUM consumed significantly higher amounts of feed compared with chicks fed on only AF, but gained less when compared with control diet chicks.Chicks fed on the combination of AFB1, DE and TUM diet had poorer growth performance than those fed on AFB1 alone. None of the combination diets reduced the severity of liver lesions.

Phosphorus availability of rock phosphates as compared with feed-grade phosphates for swine

One hundred ninety two swine were used in a trial to assess the relative bioavailability of phosphorus (RBP) in six phosphate sources. Phosphates were three feed grade phosphates (FP), two made in Brasil, and one USA made, and three rock phosphate samples (RP) originated from two mines sites in Brasil, and one mine site in Israel. Levels of calcium, phosphorus and fluorine in RP were 29, 12 and 1.7% (RP source 1), 33, 14 and 1.4% (RP source 2), and 30, 14 and 3.6% (RP source 3), respectively. Pigs were fed a corn-soybean meal basal diet (18% CP, 0.95% Lys, 0.75% Ca, 0.37% P) or the basal diet with 0.15% P from a standard purified grade calcium phosphate (SP), or with 0.15% P from experimental FP or RP. Each diet was fed to six pen replicates of four pigs per pen for 35 days (14.4 to 39.9 kg). Weight gain (WG), feed/gain (FG), plasma P (PP), bone ash (BA), and breaking strength of metacarpals and metatarsals (BS-MM) and femurs (BS-F) were improved by phosphorus addition. However, performance and bone parameters were depressed by RP, as compared to FP dietary supplementation. WG, BA, BS-MM and BS-F were regressed to P added, and slope-ratios were calculated to assess RBP in the FP and RP sources. The average bioavailability of P in the FP and RP sources, relative to SP, were 89 and 49% (WG), 112 and 49% (BA), 78 and 28% (BS-MM), and 101 and 52% (BS-F), respectively. Low animal performance and bone strength related to toxicity should be expected if rock phosphates are used to feed pigs.

The interactive effects of Eimeria acervulina infection and phytase for broiler chicks

An experiment was conducted to determine the interactive effects of Eimeria acervulina infection and phytase in male broiler chicks. Chicks were standardized from 0 to 4 d posthatching, and the assay period was 5 to 15 d. Treatments were replicated with 6 pens of 5 chicks each. The initial and final BW were 67 and 363 g. A corn-soybean meal diet formulated to provide 1.26% total Lys and 3,200 kcal of ME/kg was used, and it was adequate in all other nutrients except Ca and nonphytate P (NPP) when appropriate. The treatments were in a 2 × 2 × 2 factorial arrangement: adequate Ca and NPP (1.0% Ca and 0.45% NPP) or inadequate Ca and NPP (0.80% Ca and 0.25% NPP), 0 or 600 phytase units/kg of diet, and uninfected or infected with 400,000 E. acervulina oocysts on d 0, 3, and 6 of the experiment. Daily gain, average daily feed intake, and gain:feed (GF) were reduced (P < 0.01) by the coccidial infection and the reduction in Ca and NPP. Phytase addition increased (P < 0.02) average daily gain and average daily feed intake, regardless of the Ca and NPP contents of the diet or the presence of coccidiosis. The GF was increased by phytase but only in uninfected chicks (phytase × coccidiosis, P < 0.02). Toe and tibia ash percentages were decreased (P < 0.01) in chicks fed diets deficient in Ca and NPP, but tibia ash was decreased more by Ca and NPP in healthy chicks than in infected chicks (coccidiosis × Ca and NPP, P < 0.02). Phytase increased (P < 0.02) toe and tibia ash but only in diets deficient in Ca and NPP (phytase × Ca and NPP, P < 0.01). Phytase increased toe ash percentage of healthy chicks fed diets deficient in Ca and NPP, but it had less of an effect in infected chicks fed diets deficient in Ca and NPP (coccidiosis × Ca and NPP × phytase, P < 0.08). Also, phytase was less effective in increasing tibia ash percentage in coccidiosis-infected chicks than in uninfected chicks (phytase × coccidiosis, P < 0.02). These data indicate that phytase is effective in the presence of a coccidial infection, but based on GF and tibia ash percentage, it may not be as effective as in uninfected chicks. Also, phytase increased average daily gain and average daily feed intake in uninfected chicks fed diets formulated to be adequate (or in excess) in all nutrients for male broiler chicks.

Desempenho de alevinos de tilapia do Nilo submetidos a diferentes niveis de inclusao do farelo de algodao

With the objective of evaluating the Nile tilapia fingerlings performance submitted to different levels of cottonseed meal (CM) inclusion (0,00; 20,00; 40,00; 60,00 and 80,00%) in rations with 30,00% of digestible protein and 3000 kcal/kg of digestible energy, the experiment was carried out in the Laboratorio de Aquicultura/UEM, 250 Nile tilapia fingerlings, were used, sexually reverted, divided in 25 tanks with 150 L, in a completely randomized design with five treatments and five replications. The evaluated variables were diary weight gain (DWG), feed gain (FG), protein efficiency rate (PE), survival (S), hepatic-somatic index (HSI), condition factor (CF), dry matter (DM), protein in the carcass percentage (PC) and fat in the carcass percentage (FP). The medium values of temperature, dissolved oxygen, electrical conductivity and pH during the experimental period, were 26,93 ± 0,29oC; 5,47 ± 0,86 mg/L; 245,80 ± 54,29 µS/cm and 7,78 ± 0,19, respectively. The WG and PE presented linear decrease when the CM was included in the ration, the FG and HSI presented linear increase. The DM, PC and WG presented quadratic effect with point maxim to 45,25, 47,84 and 45,15, respectively. The S and CF didn’t present significative differences (P>0,05). Concluded that the cottonseed meal influences in a negative way the Nile tilapia fingerlings performance. .

Effect of mannan oligosaccharides on growth performance of weanling pigs.

Four experiments were conducted to evaluate the effects of mannan oligosaccharides (provided by Bio-Mos [BM], a product containing a minimum of 28% glucomannoprotein from S. cerevisiae) on growth performance of nursery pigs. Treatments were replicated with five to six pens of four to five pigs each. Initial BW ranged from 4.7 to 5.4 kg, and pigs were weaned at 16 to 20 d of age. Experiments 1, 2, and 4 consisted of Phase 1 (7 to 8 d), Phase 2 (12 to 14 d), and Phase 3 (7 to 8 d) periods, but Exp. 3 consisted only of Phase 1 (7 d) and 2 (14 d) periods. The diets for Phase 1, 2, and 3 contained 1.6, 1.5, and 1.1% Lys, respectively. The treatments in Exp. 1 were 0, 0.20, and 0.30% BM, which did not affect growth performance. The treatments in Exp. 2 were two levels of excess Zn (0 and 3,000 ppm) and three levels of BM (0, 0.20, and 0.30%) in a 2 x 3 factorial. Excess Zn increased (P < 0.08) ADG and ADFI in Phase 2 and 3 and overall. The 0.20% BM addition increased ADG (Phase 3 and overall) and ADFI (Phase 2 and overall) in the absence of excess Zn but did not affect or decreased these response variables in the presence of excess Zn (Zn x BM quadratic, P < 0.08). Experiment 3 was similar to Exp. 2, but the 0.30% BM addition was not used. Excess Zn decreased (P < 0.09) ADG in Phase 1 but increased (P < 0.09) ADG and ADFI in Phase 2. The BM decreased (P < 0.03) overall ADFI but increased Phase 2 and overall ADG and gain:feed (GF) in the absence of excess Zn but not in the presence of excess Zn (Zn x BM, P < 0.07). The BM decreased ADFI during Phase 2, but the decrease was greater in pigs fed excess Zn (Zn x BM, P < 0.07). Experiment 4 evaluated the interactive effects of the antibiotic (oxytetracycline and neomycin) and BM and of Zn and BM. Antibiotic (no excess Zn) increased (P < 0.01) ADG and ADFI in Phases 2 and 3 and overall. The BM addition decreased ADG and GF in Phase 2 when the antibiotic was not in the diet but increased ADG when the antibiotic was in the diet (antibiotic x BM, P < 0.05). Excess Zn increased (P < 0.07) ADG and ADFI during Phases 2 and 3 and overall. In Phase 2, the 0.20% BM decreased GF when excess Zn was not added to the diet but increased GF when Zn was included (Zn x BM, P < 0.03). Mannan oligosaccharides improved pig performance in some instances during Phase 2 when fed in combination with an antibiotic and no excess dietary Zn, but it had no effect or negative effects in the presence of excess Zn or in the absence of an antibiotic.

The tryptophan requirement of nursery pigs1,2

Five experiments were conducted to determine the true digestible Trp (dTrp) requirement of nursery pigs. Treatments were replicated with four or five pens of five or six pigs each. Pigs were weaned at 21 (Exp. 1, 2, and 5) or 19 d (Exp. 3 and 4), and fed common diets for various times and then experimental diets for 8 (Exp. 1), 13 (Exp. 2 and 3), or 14 d (Exp. 4 and 5). Experiment 1 (160 pigs, initial and final BW of 8.4 and 11.4 kg) evaluated six protein sources low in Trp relative to a positive control diet to identify the protein source to be used in subsequent experiments. The results indicated that a diet with Canadian field peas (CFP) supplemented with Trp resulted in ADG, ADFI, and gain:feed (GF) equal to (P > 0.10) the positive control diet. In Exp. 2, 75 pigs (initial and final BW of 13.2 and 19.2 kg) were fed 1) Trp-deficient diet (0.13% dTrp) with CFP, 2) Diet 1 with added Trp (0.23% dTrp), or 3) positive control diet (0.22% dTrp). Daily gain, ADFI, and GF were decreased (P < 0.01) in pigs fed Diet 1 compared with pigs fed Diets 2 and 3, but ADG, ADFI, and GF were equal (P > 0.10) in pigs fed Diets 2 and 3. Experiments 3 (180 pigs, initial and final BW of 5.2 and 7.3 kg), 4 (120 pigs, initial and final BW of 6.3 and 10.2 kg), and 5 (144 pigs, initial and final BW of 10.3 and 15.7 kg) were conducted to estimate the dTrp requirement of nursery pigs with diets using CFP as a primary protein source. The diets used in Exp. 3, 4, and 5 contained 1.35, 1.19, or 1.01% dLys, respectively, and other amino acids were provided at 105% the ratio relative to Lys. Response variables were ADG, ADFI, GF, and plasma urea N concentrations, and data were analyzed using the broken-line model. The levels of dTrp in the diets for Exp. 3 (Phase I, 5.2 to 7.3 kg) were 0.14, 0.17, 0.20, 0.23, 0.26, and 0.29%. The average dTrp requirement was estimated to be 0.21% (0.24% total Trp). The levels of dTrp in the diets for Exp. 4 (Phase II, 6.3 to 10.2 kg) were 0.13, 0.16, 0.19, 0.22, 0.25, and 0.28%. The average dTrp requirement was estimated to be 0.20% (0.23% total Trp). The levels of dTrp in the diets for Exp. 5 (Phase III, 10.3 to 15.7 kg) were 0.130, 0.155, 0.180, 0.205, 0.230, and 0.255%. The average dTrp requirement was estimated to be 0.18% (0.22% total Trp). These results indicate that the true dTrp requirement is 0.21, 0.20, and 0.18% for Phase I (5.2 to 7.3 kg), II (6.3 to 10.2 kg), and III (10.3 to 15.7 kg) nursery pigs, respectively.

The tryptophan requirement of nursery pigs

Five experiments were conducted to determine the true digestible Trp (dTrp) requirement of nursery pigs. Treatments were replicated with four or five pens of five or six pigs each. Pigs were weaned at 21 (Exp. 1, 2, and 5) or 19 d (Exp. 3 and 4), and fed common diets for various times and then experimental diets for 8 (Exp. 1), 13 (Exp. 2 and 3), or 14 d (Exp. 4 and 5). Experiment 1 (160 pigs, initial and final BW of 8.4 and 11.4 kg) evaluated six protein sources low in Trp relative to a positive control diet to identify the protein source to be used in subsequent experiments. The results indicated that a diet with Canadian field peas (CFP) supplemented with Trp resulted in ADG, ADFI, and gain:feed (GF) equal to (P > 0.10) the positive control diet. In Exp. 2, 75 pigs (initial and final BW of 13.2 and 19.2 kg) were fed 1) Trp-deficient diet (0.13% dTrp) with CFP, 2) Diet 1 with added Trp (0.23% dTrp), or 3) positive control diet (0.22% dTrp). Daily gain, ADFI, and GF were decreased (P < 0.01) in pigs fed Diet 1 compared with pigs fed Diets 2 and 3, but ADG, ADFI, and GF were equal (P > 0.10) in pigs fed Diets 2 and 3. Experiments 3 (180 pigs, initial and final BW of 5.2 and 7.3 kg), 4 (120 pigs, initial and final BW of 6.3 and 10.2 kg), and 5 (144 pigs, initial and final BW of 10.3 and 15.7 kg) were conducted to estimate the dTrp requirement of nursery pigs with diets using CFP as a primary protein source. The diets used in Exp. 3, 4, and 5 contained 1.35, 1.19, or 1.01% dLys, respectively, and other amino acids were provided at 105% the ratio relative to Lys. Response variables were ADG, ADFI, GF, and plasma urea N concentrations, and data were analyzed using the broken-line model. The levels of dTrp in the diets for Exp. 3 (Phase I, 5.2 to 7.3 kg) were 0.14, 0.17, 0.20, 0.23, 0.26, and 0.29%. The average dTrp requirement was estimated to be 0.21% (0.24% total Trp). The levels of dTrp in the diets for Exp. 4 (Phase II, 6.3 to 10.2 kg) were 0.13, 0.16, 0.19, 0.22, 0.25, and 0.28%. The average dTrp requirement was estimated to be 0.20% (0.23% total Trp). The levels of dTrp in the diets for Exp. 5 (Phase III, 10.3 to 15.7 kg) were 0.130, 0.155, 0.180, 0.205, 0.230, and 0.255%. The average dTrp requirement was estimated to be 0.18% (0.22% total Trp). These results indicate that the true dTrp requirement is 0.21, 0.20, and 0.18% for Phase I (5.2 to 7.3 kg), II (6.3 to 10.2 kg), and III (10.3 to 15.7 kg) nursery pigs, respectively.

Substituição parcial do farelo de soja por proteína texturizada de soja na dieta de leitões desmamados

Foram desenvolvidos dois experimentos para avaliação da proteína texturizada de soja (PTS), em substituição parcial ao farelo de soja (FS) na dieta pré-inicial para leitões desmamados aos 21 dias de idade. Em cada um dos experimentos, foram comparados quatro níveis (0, 25, 50 e 75% e 0, 20, 40 e 60%, respectivamente) de substituição do FS pela PTS. No experimento um, a substituição do FS pela PTS proporcionou redução linear da conversão alimentar (CA) no período de fornecimento das dietas e diminuição da incidência de diarréia e da altura média da mucosa intestinal (AMM), com o aumento dos níveis de PTS na dieta. No experimento dois, houve efeito cúbico sobre o ganho de peso diário (GPD) e o peso dos leitões ao final da creche (PM35), com a substituição parcial do FS pela PTS. Não foi possível estimar o melhor nível de substituição do FS por PTS. Foi concluído que a substituição parcial do FS pela PTS na dieta de leitões desmamados aos 21 dias de idade melhorou o desempenho dos leitões na fase inicial após o desmame, mas este efeito nem sempre se prolonga até o final da fase de creche. A substituição do FS pela PTS acarretou redução na ocorrência e na duração da diarréia após o desmame e diminuição das alterações na morfologia da mucosa intestinal.

Performance, Body Temperature and Egg Quality of Laying Hens Fed Vitamins D and C Under Three Environmental Temperatures

Three experiments were conducted in a climatic chamber to determine the effects of vitamins D3 and C supplementation on performance, body temperature, and egg quality under thermoneutral temperature (24.8º to 27.0º C), a cyclic heat stress (26.2º C for 16 h and 32.1º C for 8 h) and a constant heat stress (30.0º to 32.0º C) for three weeks in each temperature. One hundred forty-four White Leghorn hens aged 31 weeks were used in a completely randomized design with a factorial arrangement of 3 x 3: vitamin D3 (2,500, 3,000, and 3,500 IU/kg) and vitamin C (0, 200, and 400 ppm), with a total of nine treatments with four replicates of four hens each. Parameters measured included feed intake (FI), feed:gain (FG), egg production (EP), egg weight (EW), egg mass (EM), rectal (RT) and dorsal temperatures (DT), percentages of albumen (AP) and yolk (YP), Haugh units (HU), yolk index (YI), shell percent (SP), shell thickness (ST) and egg specific gravity (ESG). Vitamin D3 influenced the parameters SP, ST, ESG and DT; vitamin C influenced YI, SP and ESG. There was no influence of environmental temperature only on HU. It was concluded that higher levels of vitamin D3 and 200 or 400 ppm of vitamin C can be improve eggshell quality and that heat stress impaired the main characteristics evaluated.

Nível de proteína bruta para bezerros de corte desmamados aos 66 dias de idade

O objetivo deste trabalho foi avaliar o consumo médio diário de matéria seca (CMS), CMS por 100 kg de peso vivo (CMSP), CMS por unidade de peso metabólico (CMSM), a conversão alimentar (CA) e o ganho de peso médio diário (GMD) de bezerros de corte, alimentados com diferentes níveis de proteína bruta (PB) na dieta. Foram utilizados 47 bezerros inteiros, da raça Braford, desmamados aos 66 dias de idade com peso médio de 76,4 kg. Os animais foram alimentados à vontade com silagem de aveia e concentrado (50/50), com níveis de 13, 15, 17 e 19% de PB na dieta total. O período de adaptação ao alimento e manejo foi de 21 dias. Os animais foram pesados com jejum de sólidos de 14 horas, a intervalos regulares de 21 dias durante o período experimental de 84 dias. Verificou-se, por meio da análise de regressão linear e múltipla, que não ocorreram efeitos significativos relacionando o CMS, CMSP, CMSM, CA e GMD e o nível de PB na dieta. Observou-se que CMS, CMSP e CMSM aumentaram linearmente com o avanço do período experimental, demonstrando o aumento da capacidade de ingestão com o aumento do peso vivo. Os valores de GMD obtidos foram de 644; 701; 693 e 730 g/dia para os níveis de 13; 15; 17 e 19% de PB na dieta, respectivamente. Os ganhos de peso foram superiores àqueles normalmente atingidos ao pé da vaca em condições de campo nativo ou desmamados precocemente e mantidos em pastagem cultivada.

The lysine requirement and ratio of total sulfur amino acids to lysine for chicks fed adequate or inadequate lysine

Experiments (Exp.) were conducted with Cornish Rock males (4 to 14 or 15 d of age) to determine the Lys requirement (Exp. 1) and the optimum ratio of TSAA:Lys for chicks fed adequate or inadequate Lys (Exp. 2). In Exp. 1, 180 chicks were allotted on the basis of BW to six treatments with six replications of five chicks each in a completely randomized design (CRD). Average initial and final BW were 73.5 and 415.5 g. The Lys levels fed were: 0.8, 0.9, 1.0, 1.1, 1.2, and 1.3% digestible Lys. In Exp. 2, 240 chicks were allotted on the basis of BW to 12 treatments with four replications of five chicks each in a CRD. Average initial and final BW were 68.5 and 336.3 g. Chicks were fed either 0.82 or 1.0% digestible Lys and within each Lys level, a ratio of TSAA:Lys of: 0.55, 0.63, 0.72, 0.80, 0.88, and 0.96, resulting in a 2 x 6 factorial arrangement of treatments. At the end of each trial, all chicks were weighed and pen feed consumption was measured. In Exp. 1, average daily gain (ADG) and gain:feed (GF) increased (linear, P < 0.01; quadratic, P < 0.02) as dietary Lys increased. A cubic (P < 0.04) effect of Lys for average daily feed intake (ADFI) was observed. One-slope, broken-line regression models estimated Lys requirements of 1.0, 0.9, and 1.1% for ADG, ADFI, and GF, respectively. In Exp. 2, chicks fed 1.0% Lys had higher (P < 0.01) ADG, ADFI, and GF than chicks fed 0.82% Lys. Daily gain, ADFI, and GF increased (linear, P < 0.01; quadratic, P < 0.01) as TSAA:Lys increased. For ADG, ADFI, and GF, one-slope, broken-line regression models estimated required ratios of TSAA:Lys of 0.66, 0.71, and 0.63 for chicks fed 1.0% Lys and 0.66, 0.67, and 0.63 for chicks fed 0.82% Lys. There were no differences (P > 0.05) in the estimated ratios of TSAA:Lys required to maximize ADG, ADFI, and GF for chicks fed 0.82 and 1.0% Lys. Thus, similar ratios of an indispensable amino acid to Lys can be obtained when chicks are fed at or slightly below their Lys requirement.

The role of feed consumption and feed efficiency in copper-stimulated growth.

Two experiments were conducted to study the role of feed intake and feed efficiency in Cu-stimulated growth of weanling pigs. In Exp. 1, 42 pigs were randomly assigned into three treatments: 1) control: ad libitum access to a corn-soybean meal-dried whey basal diet; 2) ad libitum/Cu: ad libitum access to the basal diet supplemented with 215 ppm of Cu; or 3) pair-fed/Cu: pair-fed the Cu-supplemented diet to the level of the control. Over the 14-d experiment, the ad libitum/Cu pigs had greater (P < .05) ADG and ADFI than the control pigs. The pair-fed/Cu group had an intermediate ADG. Gain:feed (GF) was not significantly affected by treatments but tended to be improved in the pair-fed/Cu pigs. Feeding copper increased (P < .05) the concentration of Cu in the serum, liver, and brain. Also, feeding Cu increased (P < .05) serum mitogenic activity and growth hormone mRNA concentrations for both feeding methods. In Exp. 2, a 2 x 2 x 2 factorial arrangement of treatments with two levels of Cu (15 vs 200 ppm), two levels of feeding (ad libitum vs restricted [85% of the ad libitum]), and two sources of Cu (Cu sulfate vs Cu lysine) was used in a 24-d experiment involving 96 pigs. Feeding copper increased (P < .05) ADG and GF. The magnitude of the Cu-stimulated growth was reduced by restricted feeding (Cu level x feeding level interaction; P < .05). The ADFI was greater (P < .05) for the pigs fed high dietary Cu only during d 1 to 6. Pigs fed Cu lysine had greater ADG and ADFI than those fed Cu sulfate (P < .05); the benefit in ADG from Cu lysine was reduced by restricted feeding (Cu source x feeding level interaction, P < .05). High dietary Cu stimulated (P < .05) serum mitogenic activity; the stimulation was greater for Cu lysine than for Cu sulfate. Feeding Cu numerically increased GH mRNA concentration. Restricted feeding reduced overall serum mitogenic activity (P < .05), but the response to high dietary Cu and Cu lysine was still evident. In summary, Cu-stimulated growth was largely dependent on a simultaneous increase in feed intake, but there were some improvements in GF. The influence of Cu on serum mitogenic activity was independent of feed intake or growth in both experiments, which indicates a direct action of Cu on the growth regulatory system.

Relationships of Certain Performance Traits to Sale Price of Centrally Tested Boars

Data from 1578 boars evaluated at a central test station were used to analyze relationships of average daily gain (ADG), feed/gain (FG), backfat thickness (BF), longissimus muscle area (LMA), and days to 104kg (DAYS) with sale prices of boars sold at a test station auction. Breeds included Duroc, Hampshire, Spotted, and Yorkshire. Least squares mean sale price, adjusted for sale date, ranged from $432.70 ± 5.82 for Duroc to $399.29 ± 10.55 for Spotted. Pooled across breeds, residual correlation coefficients of sale price with performance traits were .40, -.26, -.22, -.11 and .06 for ADG, DAYS, FG, BF, and LMA, respectively. Within-breed regression analyses were conducted to estimate the change in sale price per unit change in performance. The change in sale price per .045kg increase in ADG was significant for all breeds, ranging from $32.68 for Yorkshire to $20.31 for Spotted. The linear effect of DAYS on sale price was significant only for Duroc and Spotted. Linear effects of FG and BF were at or near significant levels (P<.07) for all breeds except Spotted. The linear effect of LMA on sale price was significant only for Hampshire and Yorkshire. The effect of breeder of the boar was also an important source of variation for boar sale price. Results indicate that limited consideration of the performance traits evaluated in this study was used to determine boar price, and that ADG was the most important individual trait of those evaluated.

POTENTIAL OF TRITICALE AS A FEED FOR FINISHING HEIFERS

Commercial heifers (n = 120) were randomly assigned to 12 pens (10 heifers/pen) and fed one of four grain diets in combination with barley silage and vitamin premix. Treatments were 100% barley control, 100% triticale, 50% triticale 50% barley, 25% triticale 75% barley. Treatment differences were not significant (P &gt; 0.05) for body weight (BW), average daily gain (ADG), feed intake (FI) and feed:gain (FG).ADG, FI and FG for the 100% triticale treatment were 1.24 kg d−1, 7.88 kg d−1 and 6.29 kg kg−1 respectively, while in the control they were 1.23 kg d−1, 8.03 kg d and 6.39 kg kg−1. Key words: Triticale, heifers, body weight, feed:gain

Nutritive Value of Whole Soybeans Fermented with Aspergillus oryzae or Rhizopus oligosporus as Evaluated by Neonatal Pigs

Two experiments were conducted to evaluate the nutritive effects of heated whole soybeans fermented with the mold Aspergillus oryzae (AOS) or Rhizopus oligosporus (ROS) in diets fed to neonatal pigs from 1 to 22 d of age. In experiment 1, either soybean meal or heated whole soybeans fermented with ROS replaced 75% of the dried skim milk protein. The average daily gain (ADG) and gain-feed (G-F) ratio of pigs fed the diet containing 100% milk protein were greater than those of pigs fed the diets containing either soybean meal or ROS. In experiment 2, heated nonfermented whole soybeans (HUS) or heated whole soybeans fermented with either AOS or ROS replaced 50% of the milk protein in isonitrogenous and isoenergetic diets. Proximate and amino acid analyses of HUS and the fermented soybean products, AOS and ROS were similar. Pigs fed a diet containing either HUS or AOS had greater (P less than 0.05) mean ADG and G-F ratios than pigs fed the diet containing ROS. Apparent biological value, apparent net protein utilization and digestible and metabolizable energy utilization were similar for all dietary treatments. In conclusion, the protein and energy values of whole soybeans were not improved by fermentation with ROS or AOS compared to nonfermented heated whole soybeans, soybean meal or dried skim milk in diets fed to neonatal pigs.