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1.
Walsh MC Sholly DM Hinson RB Trapp SA Sutton AL Radcliffe JS Smith JW Richert BT 《Journal of animal science》2007,85(2):459-467
Weanling pigs with mean initial BW of 6.04 kg (Exp.1) and 5.65 kg (Exp. 2) and mean age at weaning of 18.2 d (Exp. 1) and 17.7 d (Exp. 2) were used in two 5-wk experiments (Exp. 1, n = 180; Exp. 2, n = 300) to evaluate the effects of an organic acid blend (Acid LAC, Kemin Americas Inc., Des Moines, IA) and an inorganic/organic acid blend (Kem-Gest, Kemin Americas Inc.) on weanling pig growth performance and microbial shedding. In Exp. 1, the 5 dietary treatments were 1) negative control, 2) diet 1 + 55 ppm carbadox, 3) diet 1 + 0.4% Acid LAC, 4) diet 1 + 0.2% Kem-Gest, 5) diet 1 + 0.4% Acid LAC and 0.2% Kem-Gest. In Exp. 2, the 6 dietary treatments were diets 1 through 4 corresponding to Exp. 1, plus 5) sequence 1: 0.4% Acid LAC for 7 d followed by 0.2% Kem-Gest for 28 d, and 6) sequence 2: 0.2% Kem-Gest for 7 d followed by 0.4% Acid LAC for 28 d. Pigs were housed at 6 (Exp. 1) or 10 (Exp. 2) pigs/pen. Treatments were fed throughout the experiment in 3 phases: d 0 to 7, d 7 to 21, and d 21 to 35. In Exp. 1, there were no differences (P > 0.05) in ADG, ADFI, or G:F among the dietary treatments at any time during the study. In Exp. 2, throughout the study, pigs fed carbadox (diet 2) and sequence 1 (diet 5) diets had the greatest ADG (d 0 to 35; 262, 294, 257, 257, 292, and 261 g/d, diets 1 through 6, respectively; P < 0.05), greater ADFI than all other acid treatments (P < 0.05), and tended to have greater ADFI than diet 1 (P < 0.10). Fecal pH, Escherichia coli concentrations, and Salmonella presence were determined at d 6, 20, and 34 for Exp. 1, and on d 32 for Exp. 2. For both experiments, there was no effect of treatment on the presence of fecal Salmonella (P > 0.10) at any sampling time. In Exp. 1, fecal E. coli concentrations for pigs fed the carbadox (P < 0.05) diet were greater than for pigs fed the combination diet with 0.4% Acid LAC and 0.2% Kem-Gest on d 34, and the pigs fed the negative control diet tended (P < 0.10) to have greater fecal E. coli concentrations than those fed the combination diet on d 34. In Exp. 2, fecal pH of pigs fed sequence 1 tended to be greater than fecal pH of pigs fed diet 1, diet 4, or sequence 2 (P < 0.10), but there was no dietary effect on fecal E. coli. In Exp. 1, growth performance of pigs fed the Acid LAC and Kem-Gest diets was similar to each other and to that of the carbadox-fed pigs. Adding the combination of 0.4% Acid LAC and 0.2% Kem-Gest to nursery pig diets reduced ADFI and pig growth rate. In Exp. 2, pigs fed the acid sequence of Acid LAC-Kem-Gest had similar growth performance to pigs fed carbadox, and this novel dietary acid sequence may have merit as a replacement for antibiotics in the nursery phase. 相似文献
2.
Effect of feeding organic and inorganic sources of additional zinc on growth performance and zinc balance in nursery pigs 总被引:16,自引:0,他引:16
Three experiments were conducted to evaluate the effect of feeding pharmacological concentrations of zinc (Zn), from organic and inorganic sources, on growth performance, plasma and tissue Zn accumulation, and Zn excretion of nursery pigs. Blood from all pigs was collected for plasma Zn determination on d 14 in Exp. 1, d 7 and 28 in Exp. 2, and d 15 in Exp. 3. In Exp. 1, 2, and 3, 90, 100, and 15 crossbred (GenetiPorc USA, LLC, Morris, MN) pigs were weaned at 24+/-0.5, 18, and 17 d of age (6.45, 5.47, and 5.3 kg avg initial BW), respectively, and allotted to dietary treatment based on initial weight, sex, and litter. A Phase 1 nursery diet was fed as crumbles from d 0 to 14 in Exp. 1, 2, and 3, and a Phase 2 nursery diet was fed as pellets from d 15 to 28 in Exp. 1 and 2. The Phase 1 and Phase 2 basal diets were supplemented with 100 ppm Zn as ZnSO4. Both dietary phases contained the same five dietary treatments: 150 ppm additional Zn as zinc oxide (ZnO), 500 ppm added Zn as ZnO, 500 ppm added Zn as a Zn-amino acid complex (Availa-Zn 100), 500 ppm added Zn as a Zn-polysaccharide complex (SQM-Zn), and 3,000 ppm added Zn as ZnO. Overall in Exp. 1, pigs fed 500 ppm added Zn as SQM-Zn or 3,000 ppm added Zn as ZnO had greater ADG (P < 0.05) than pigs fed 150 ppm, 500 ppm added Zn as ZnO, or 500 ppm added Zn as Availa-Zn 100 (0.44 and 0.46 kg/d vs 0.35, 0.38, and 0.33 kg/d respectively). Overall in Exp. 2, pigs fed 3,000 ppm added Zn as ZnO had greater (P < 0.05) ADG and ADFI than pigs fed any other dietary treatment. On d 14 of Exp. 1 and d 28 of Exp. 2, pigs fed 3,000 ppm added Zn as ZnO had higher (P < 0.05) plasma Zn concentrations than pigs on any other treatment. In Exp. 3, fecal, urinary, and liver Zn concentrations were greatest (P < 0.05) in pigs fed 3,000 ppm added Zn as ZnO. On d 10 to 15 of Exp. 3, pigs fed 3,000 ppm added Zn as ZnO had the most negative Zn balance (P < 0.05) compared with pigs fed the other four dietary Zn treatments. In conclusion, feeding 3,000 ppm added Zn as ZnO improves nursery pig performance; however, under certain nursery conditions the use of 500 ppm added Zn as SQM-Zn may also enhance performance. The major factor affecting nutrient excretion appears to be dietary concentration, independent of source. 相似文献
3.
Effect of phosphorylated mannans and pharmacological additions of zinc oxide on growth and immunocompetence of weanling pigs 总被引:6,自引:0,他引:6
Davis ME Brown DC Maxwell CV Johnson ZB Kegley EB Dvorak RA 《Journal of animal science》2004,82(2):581-587
Three experiments were conducted to evaluate the efficacy of phosphorylated mannans (MAN) and pharmacological levels of ZnO on performance and immunity when added to nursery pig diets. Pigs (216 in each experiment), averaging 19 d of age and 6.2, 4.6, and 5.6 kg of BW in Exp. 1, 2, and 3, respectively, were blocked by BW in each experiment, and penned in groups of six. A lymphocyte blastogenesis assay was performed in each experiment to measure in vitro lymphocyte proliferation response. In Exp. 1, diets were arranged as a 2 x 2 factorial with two levels of Zn (200 and 2,500 ppm) and two levels of MAN (0 and 0.3% from d 0 to 10, and 0 and 0.2% from d 10 to 38). Zinc oxide increased (P < 0.05) ADG, ADFI, and G:F from d 0 to 10, and ADG and ADFI from d 10 to 24. In Exp. 2, diets were arranged as a 2 x 3 factorial with two levels of Zn (200 and 2,500 ppm) and three levels of MAN (0, 0.2, and 0.3%). Pigs fed 2,500 ppm Zn from d 0 to 10 had greater (P < 0.05) ADG, ADFI, and G:F than pigs fed 200 ppm Zn. From d 10 to 24, ADG was similar when pigs were fed 200 ppm Zn, regardless of MAN supplementation; however, ADG increased (P < 0.05) when 0.2% MAN was added to dietscontaining 2,500 ppm Zn (MAN x Zn interaction, P < 0.05). In Exp. 3, diets were arranged as a 2 x 3 factorial with two levels of MAN (0 and 0.3%) and three levels of Zn (200, 500, and 2,500 ppm). Zinc was maintained at 200 ppm from d 21 to 35, so only two dietary treatments (0 and 0.3% MAN) were fed during this period. Average daily gain was greater (P < 0.05) from d 7 to 21 when pigs were fed 2,500 ppm Zn compared with pigs fed 200 or 500 ppm Zn. The addition of MAN improved (P < 0.05) G:F from d 7 to 21 and d 0 to 35. Lymphocyte proliferation of unstimulated cells and phytohemagglutinin-stimulated cells was decreased (P < 0.05) in cells isolated from pigs fed MAN compared with cells isolated from pigs fed diets without MAN. Lymphocyte proliferation of pokeweed mitogen-stimulated cells isolated from pigs fed MAN was less (P < 0.05) than for pigs fed diets devoid of MAN when diets contained 200 ppm Zn; however, MAN had no effect on lymphocyte proliferation when the diet contained 500 or 2,500 ppm Zn (MAN x Zn interaction, P < 0.05). Although the magnitude of response to MAN was not equivalent to that of pharmacological concentrations of Zn, MAN mayimprove growth response when pharmacological Zn levels are restricted. 相似文献
4.
Carlson MS Boren CA Wu C Huntington CE Bollinger DW Veum TL 《Journal of animal science》2004,82(5):1359-1366
Three experiments were conducted to evaluate the effects of feeding dietary concentrations of organic Zn as a Zn-polysaccharide (Quali Tech Inc., Chaska, MN) or as a Zn-proteinate (Alltech Inc., Nicholasville, KY) on growth performance, plasma concentrations, and excretion in nursery pigs compared with pigs fed 2,000 ppm inorganic Zn as ZnO. Experiments 1 and 2 were growth experiments, and Exp. 3 was a balance experiment, and they used 306, 98, and 20 crossbred pigs, respectively. Initially, pigs averaged 17 d of age and 5.2 kg BW in Exp. 1 and 2, and 31 d of age and 11.2 kg BW in Exp. 3. The basal diets for Exp. 1, 2, and 3 contained 165 ppm supplemental Zn as ZnSO4 (as-fed basis), which was supplied from the premix. In Exp. 1, the Phase 1 (d 1 to 14) basal diet was supplemented with 0, 125, 250, 375, or 500 ppm Zn as Zn-polysaccharide (as-fed basis) or 2,000 ppm Zn as ZnO (as-fed basis). All pigs were then fed the same Phase 2 (d 15 to 28) and Phase 3 (d 29 to 42) diets. In Exp. 2, both the Phase 1 and 2 basal diets were supplemented with 0, 50, 100, 200, 400, or 800 ppm Zn as Zn-proteinate (as-fed basis) or 2,000 ppm Zn as ZnO (as-fed basis). For the 28-d Exp. 3, the Phase 2 basal diet was supplemented with 0, 200, or 400 ppm Zn as Zn-proteinate, or 2,000 ppm Zn as ZnO (as-fed basis). All diets were fed in meal form. In Exp. 1, 2, and 3, pigs were bled on d 14, 28, or 27, respectively, to determine plasma Zn and Cu concentrations. For all three experiments, there were no overall treatment differences in ADG, ADFI, or G:F (P = 0.15, 0.22, and 0.45, respectively). However, during wk 1 of Exp. 1, pigs fed 2,000 ppm Zn as ZnO had greater (P < or = 0.05) ADG and G:F than pigs fed the basal diet. In all experiments, pigs fed a diet containing 2,000 ppm Zn as ZnO had higher plasma Zn concentrations (P < 0.10) than pigs fed the basal diet. In Exp. 1 and 3, pigs fed 2,000 ppm Zn as ZnO had higher fecal Zn concentrations (P < 0.01) than pigs fed the other dietary Zn treatments. In conclusion, organic Zn either as a polysaccharide or a proteinate had no effect on growth performance at lower inclusion rates; however, feeding lower concentrations of organic Zn greatly decreased the amount of Zn excreted. 相似文献
5.
In each of two experiments, 924 pigs (4.99 kg BW; 16 to 18 d of age) were assigned to 1 of 42 pens based on BW and gender. Pens were allotted randomly to dietary copper (Cu) treatments that consisted of control (10 ppm Cu as cupric sulfate, CuSO4 x 5H2O) and supplemental dietary Cu concentrations of 15, 31, 62, or 125 ppm as cupric citrate (CuCit), or 62 (Exp. 2 only), 125 (Exp. 1 only), or 250 ppm as CuSO4. Live animal performance was determined at the end of the 45-d nursery phase in each experiment. On d 40 of Exp. 2, blood and fecal samples were collected from two randomly selected pigs per pen for evaluation of plasma and fecal Cu concentrations and fecal odor characteristics. In Exp. 1, ADG, ADFI, and G:F were increased (P < 0.05), relative to controls, when pigs were fed diets containing 250 ppm Cu as CuSO4. Pigs fed diets containing 125 ppm Cu as CuCit had increased (P < 0.05) ADG compared with pigs fed diets supplemented with 15 or 62 ppm Cu as CuCit. The ADG, ADFI, and G:F did not differ among pigs fed diets containing 125 and 250 ppm Cu as CuSO4 or 125 ppm Cu as CuCit. In Exp. 2, pigs fed diets containing 250 ppm Cu as CuSO4 had improved (P < 0.05) ADG, ADFI, and G:F compared with controls. In addition, ADG, ADFI, and G:F were similar when pigs were fed diets containing either 250 ppm Cu as CuSO4 or 125 ppm Cu as CuCit. Pigs fed diets containing 62 ppm Cu as CuSO4 or CuCit had similar ADG, ADFI, and G:F. Plasma Cu concentrations were not affected by dietary Cu source or concentration, but fecal Cu concentrations were increased (P < 0.05) as the dietary concentration of Cu increased. Pigs consuming diets supplemented with 125 ppm Cu as CuCit had fecal Cu concentrations that were lower (P < 0.05) than pigs consuming diets supplemented with 250 ppm Cu as CuSO4. Fecal Cu did not differ in pigs receiving diets supplemented with 62 ppm Cu as CuSO4 or CuCit. Odor characteristics of feces were not affected by Cu supplementation or source. These data indicate that 125 and 250 ppm Cu gave similar responses in growth, and that CuCit and CuSO4 were equally effective at stimulating growth and improving G:F in weanling pigs. Fecal Cu excretion was decreased when 125 ppm Cu as CuCit was fed compared with 250 ppm Cu as CuSO4. Therefore, 125 ppm of dietary Cu, regardless of source, may provide an effective environmental alternative to 250 ppm Cu as CuSO4 in weanling pigs. 相似文献
6.
Davis ME Maxwell CV Brown DC de Rodas BZ Johnson ZB Kegley EB Hellwig DH Dvorak RA 《Journal of animal science》2002,80(11):2887-2894
Two experiments were conducted to determine the efficacy of mannan oligosaccharides (MOS) fed at two levels of Cu on growth and feed efficiency of weanling and growing-finishing pigs, as well as the effect on the immunocompetence of weanling pigs. In Exp. 1, 216 barrows (6 kg of BW and 18 d of age) were penned in groups of six (9 pens/treatment). Dietary treatments were arranged as a 2 x 2 factorial consisting of two levels of Cu (basal level or 175 ppm supplemental Cu) with and without MOS (0.2%). Diets were fed from d 0 to 38 after weaning. Blood samples were obtained to determine lymphocyte proliferation in vitro. From d 0 to 10, ADG, ADFI, and gain:feed (G:F) increased when MOS was added to diets containing the basal level of Cu, but decreased when MOS was added to diets containing 175 ppm supplemental Cu (interaction, P < 0.01, P < 0.10, and P < 0.05, respectively). Pigs fed diets containing 175 ppm Cu from d 10 to 24 and d 24 to 38 had greater (P < 0.05) ADG and ADFI than those fed the basal level of Cu regardless of MOS addition. Pigs fed diets containing MOS from d 24 to 38 had greater ADG (P < 0.05) and G:F (P < 0.10) than those fed diets devoid of MOS. Lymphocyte proliferation was not altered by dietary treatment. In Exp. 2, 144 pigs were divided into six pigs/pen (six pens/treatment). Dietary treatments were fed throughout the starter (20 to 32 kg BW), grower (32 to 68 kg BW), and finisher (68 to 106 kg BW) phases. Diets consisted of two levels of Cu (basal level or basal diet + 175 ppm in starter and grower diets and 125 ppm in finisher diets) with and without MOS (0.2% in starter, 0.1% in grower, and 0.05% in finisher). Pigs fed supplemental Cu had greater (P < 0.05) ADG and G:F during the starter and grower phases compared to pigs fed the basal level of Cu. During the finisher phase, ADG increased when pigs were fed MOS in diets containing the basal level of Cu, but decreased when MOS was added to diets supplemented with 125 ppm Cu (interaction, P < 0.05). Results from this study indicate the response of weanling pigs fed MOS in phase 1 varied with level of dietary Cu. However, in phase 2 and phase 3, diets containing either MOS or 175 ppm Cu resulted in improved performance. Pharmacological Cu addition improved gain and efficiency during the starter and grower phases in growing-finishing pigs, while ADG response to the addition of MOS during the finisher phase seems to be dependent upon the level of Cu supplementation. 相似文献
7.
Benefits of feeding pharmacological concentrations of zinc (Zn) provided by Zn oxide (ZnO) to 21-d conventionally weaned pigs in the nursery have been documented; however, several management questions remain. We conducted two experiments to evaluate the effect on growth from feeding 3,000 ppm Zn as ZnO during different weeks of the nursery period. In Exp. 1 (n = 138, 11.5 d of age, 3.8 kg BW) and Exp. 2 (n = 246, 24.5 d of age, 7.2 kg BW), pigs were fed either basal diets containing 100 ppm supplemental Zn (adequate) or the same diet with an additional 3,000 ppm Zn (high) supplied as ZnO. Pigs were fed four or two dietary phases in Exp. 1 and 2, respectively, that changed in dietary ingredients and nutrient content (lysine and crude protein) to meet the changing physiological needs of the pigs for the 28-d nursery period. Dietary Zn treatments were 1) adequate Zn fed wk 1 to 4, 2) high Zn fed wk 1, 3) high Zn fed wk 2, 4) high Zn fed wk 1 and 2, 5) high Zn fed wk 2 and 3, and 6) high Zn fed wk 1 to 4. In Exp. 1 and 2, pigs fed high Zn for wk 1 and 2 or the entire 28-d nursery period had the greatest (P < .05) ADG. During any week, pigs fed high Zn had greater concentrations of hepatic metallothionein and Zn in plasma, liver, and kidney than those pigs fed adequate Zn (P < .05). In summary, both early- and traditionally weaned pigs need to be fed pharmacological concentrations of Zn provided as ZnO for a minimum of 2 wk immediately after weaning to enhance growth. 相似文献
8.
Rincker MJ Carter SD Real DE Nelssen JL Tokach MD Goodband RD Dritz SS Senne BW Fent RW Pettey LA Owen KQ 《Journal of animal science》2003,81(9):2259-2269
Four experiments were conducted to evaluate the effects of supplementing graded levels (0 to 100 ppm) of L-carnitine to the diet of weanling pigs on growth performance during a 34- to 38-d experimental period. A fifth experiment was conducted to determine the effects of addition of L-carnitine to diets with or without added soybean oil (SBO) on growth performance. In Exp. 1, 128 pigs (initial BW = 5.5 kg) were allotted to four dietary treatments (six pens per treatment of four to six pigs per pen). Dietary treatments were a control diet containing no added L-carnitine and the control diet with 25, 50, or 100 ppm of added L-carnitine. In Exp. 2, 3, and 4, pigs (4.8 to 5.6 kg of BW) were allotted to five dietary treatments consisting of either a control diet containing no added L-carnitine or the control diet with 25, 50, 75, or 100 ppm of added L-carnitine. All diets in Exp. 1 to 4 contained added soybean oil (4 to 6%). There were seven pens per treatment (four to five pigs per pen) in Exp. 2, whereas Exp. 3 and 4 had five and six pens/treatment (eight pigs per pen), respectively. In general, dietary carnitine additions had only minor effects on growth performance during Phases 1 and 3; however, dietary L-carnitine increased (linear [Exp. 1], quadratic [Exp. 2 to 4], P < 0.03) ADG and gain:feed (G:F) during Phase 2. The improvements in growth performance during Phase 2 were of great enough magnitude that carnitine addition tended to increase ADG (linear, P < 0.10) and improve G:F (quadratic, P < 0.02) for the entire 38-d period. In Exp. 5, 216 weanling pigs (5.8 kg of BW) were allotted (12 pens/treatment of four to five pigs per pen) to four dietary treatments. The four dietary treatments were arranged in a 2 x 2 factorial with main effects of added SBO (0 or 5%) and added L-carnitine (0 or 50 ppm). Pigs fed SBO tended (P < 0.07) to grow more slowly and consumed less feed compared with those not fed SBO, but G:F was improved (P < 0.02). The addition of L-carnitine did not affect (P > 0.10) ADG or ADFI; however, it improved (P < 0.03) G:F. Also, the increase in G:F associated with L-carnitine tended to be more pronounced for pigs fed SBO than those not fed SBO (carnitine x SBO, P < 0.10). These results suggest that the addition of 50 to 100 ppm of added L-carnitine to the diet improved growth performance of weanling pigs. In addition, supplemental L-carnitine tended to be more effective when SBO was provided in the diet. 相似文献
9.
Four experiments were conducted to determine the effects of adding a beta-mannanase preparation (Hemicell, ChemGen, Gaithersburg, MD) to corn-soybean meal-based diets on growth performance and nutrient digestibility of weanling and growing-finishing pigs. In Exp. 1, 156 weanling pigs (20 d, 6.27 kg BW) were allotted to four dietary treatments in a randomized complete block design. Treatments were a factorial arrangement of diet complexity (complex vs simple) and addition of 3-mannanase preparation (0 vs 0.05%). Pigs were fed in three dietary phases (Phase 1, d 0 to 14; Phase 2, d 14 to 28; and Phase 3, d 28 to 42). Pigs fed complex diets gained faster and were more efficient (P < 0.05) during Phase 1 compared with pigs fed simple diets. Overall, gain:feed ratio (G:F) tended to be improved (P < 0.10) for pigs fed complex diets and it was improved (P < 0.01) for those fed diets with beta-mannanase. In Exp. 2, 117 pigs (44 d, 13.62 kg BW) were allotted randomly to three dietary treatments. Dietary treatments were 1) a corn-soybean meal-based control, 2) the control diet with soybean oil added to increase metabolizable energy (ME) by 100 kcal/kg, and 3) the control diet with 0.05% beta-mannanase preparation. Beta-mannanase or soybean oil improved (P < 0.05) G:F compared with pigs fed the control diet. In Exp. 3, 60 pigs (22.5 kg BW) were allotted randomly to the three dietary treatments used in Exp. 2. Dietary treatments were fed in three phases (23 to 53 kg, 53 to 82 kg, and 82 to 109 kg with 0.95, 0.80, and 0.65% lysine, respectively). Overall, the addition of soybean oil tended to improve G:F (P < 0.10) compared with that of pigs fed the control diet, and G:F was similar (P > 0.54) for pigs fed diets with soybean oil or beta-mannanase. Also, addition of beta-mannanase increased ADG (P < 0.05) compared with that of pigs fed the control or soybean oil diets. There were no differences (P > or = 0.10) in longissimus muscle area or backfat; however, on a fat-free basis, pigs fed the diet with beta-mannanase had greater (P < 0.05) lean gain than pigs fed the control or soybean oil diets. In Exp. 4, 12 barrows (93 kg BW) were allotted randomly to one of the three dietary treatments used in Exp. 3. Addition of 3-mannanase had no effect (P > 0.10) on energy, nitrogen, phosphorus, or dry matter digestibility. These results suggest that beta-mannanase may improve growth performance in weanling and growing-finishing pigs but has minimal effects on nutrient digestibility. 相似文献
10.
Three experiments were conducted to investigate the effects of beta-glucan supplementation on pig performance and immune function. In Exp. 1, 100 weaned pigs (8.65 +/- 0.42 kg of BW and 28 +/- 2 d of age) were used in a 35-d experiment to determine the effects of graded levels of beta-glucan. Pigs were randomly allotted to 1 of 5 treatments containing beta-glucan supplemented at 0, 25, 50, 100, or 200 ppm. Each treatment was replicated using 5 pens containing 4 pigs per pen. The ADG of pigs between d 14 to 28 and d 0 to 28 responded to dietary beta-glucan in a quadratic fashion (P < 0.05), whereas beta-glucan had no effect on ADFI and G:F in any period. In Exp. 2, 80 crossbred pigs (8.23 +/- 0.56 kg of BW and 28 +/- 2 d of age) were used in a 35-d experiment. Pigs were allotted to 1 of 2 dietary treatments (0 or 50 ppm of beta-glucan in the diet) using 10 pens with 4 pigs per pen. Pigs treated with beta-glucan had greater ADG in the 14- to 28-d (P = 0.05) and 0-to 28-d (P = 0.035) periods. The ADFI of pigs receiving beta-glucan was increased (P < 0.05) in the periods from 0 to 14, 0 to 28, and 28 to 35 d. The lymphocyte proliferation index in response to phytohemagglutinin (P = 0.051) and concanavalin A (P = 0.052) tended to decrease on d 14 in pigs supplemented with beta-glucan compared with pigs without supplementation. In Exp. 3, 24 barrows (8.89 +/- 0.20 kg of BW and 28 d of age) were used to investigate the immunological and somatotropic responses of pigs challenged with lipopolysaccharide (LPS). Experimental treatments were arranged in a 2 x 2 factorial, with the main effects of LPS challenge (saline vs. LPS) and dietary addition of beta-glucan (0 vs. 50 ppm). Pigs were raised individually in metabolic cages. Pigs were fed 0 or 50 ppm of beta-glucan for 28 d and then challenged with LPS (25 microg/kg of BW) or saline. After LPS injection, blood was obtained at 0, 1.5, 3, 4.5, 6, and 7.5 h to determine cytokine production and the somatotropic response. Dietary beta-glucan increased plasma interleukin-6 at 1.5, 3, and 4.5 h and tumor necrosis factor-alpha at 3 and 4.5 h and increased plasma interleukin-10 from 3 to 7.5 h after LPS challenge. The beta-glucan treatments had no effect on growth hormone. In conclusion, beta-glucan can selectively influence performance and partially offer benefits on somatotropic axis and immune function in weaned piglets challenged with LPS. 相似文献
11.
Tran H Moreno R Hinkle EE Bundy JW Walter J Burkey TE Miller PS 《Journal of animal science》2012,90(3):790-801
Two experiments were conducted to evaluate effects of corn distillers dried grains with solubles (DDGS) on growth performance and health status of weanling pigs. Experiment 1 evaluated effects of increasing concentrations of DDGS on growth performance and health of weanling pigs. Dietary treatments included 1) control (CTL), 2) 0% DDGS (0% DDGS in phase 2 and 30% DDGS in phase 3), 3) 5% DDGS (5% DDGS in phase 2 and 30% DDGS in phase 3), and 4) 30% DDGS (phases 2 and 3). Overall, pigs fed 30% DDGS during phases 2 and 3 had decreased (22.1 vs. 25.1 and 24.0 kg; P = 0.003) BW compared with CTL pigs and pigs that only received DDGS during phase 3. In addition, pigs fed 5 or 30% DDGS in phase 2 had decreased (422.7 or 390.0 vs. 468.2 g; P = 0.003) ADG compared with CTL pigs. However, pigs fed 0% DDGS during phase 2 had similar BW, ADG, and ADFI compared with CTL pigs. Experiment 2 was conducted to evaluate effects of DDGS, lactose, and their interaction on growth performance and health of weanling pigs. Dietary treatments included 1) CTL, 2) lactose (20%), 3) DDGS (15%), and 4) lactose + DDGS. Diets of interest were fed during phase 1 (d 0 to 14), and a common diet was fed during phase 2 (d 14 to 28). Pigs receiving DDGS in phase 1 had greater ADG (576.2 vs. 534.6 g; P = 0.01) and ADFI (814.9 vs. 751.6 g; P = 0.01) during phase 2 compared with non-DDGS-fed pigs. Pigs receiving lactose during phase 1 had greater ADG (214.7 vs. 177.2 g; P = 0.01) and G:F (741.0 vs. 660.3 g/kg; P = 0.01) and tended to have greater ADFI (289.3 vs. 267.6 g; P = 0.07) during phase 1 but decreased (537.7 vs. 573.1 g; P = 0.09) ADG during phase 2. Serum immunoglobulin analyses and fecal microbial profiling were conducted in both experiments as indicators of health status. No effects of dietary treatment were observed for serum immunoglobulin in either experiment. Fecal microbial profiling resulted in statistically significant effects of dietary treatment with respect to microbial similarity and diversity indices (Exp. 1) and lactic acid-producing bacteria (Exp. 2), where main effects of both lactose and DDGS were observed with respect to putative Lactobacillus reuteri (P < 0.05). Results from Exp. 1 indicate that decreased concentrations of DDGS early in the nursery phase may negatively affect growth performance; however, growth performance may be maintained when inclusion of high concentrations (30%) of DDGS is delayed until the late nursery period. Results from Exp. 2 indicate that lactose may be incorporated in nursery diets containing DDGS to help maintain growth performance, and DDGS and lactose may affect fecal microbial profiles. 相似文献
12.
Evaluation of methods to reduce bacteria concentrations in spray-dried animal plasma and its effects on nursery pig performance 总被引:1,自引:0,他引:1
DeRouchey JM Tokach MD Nelssen JL Goodband RD Dritz SS Woodworth JC James BW Webster MJ Hastad CW 《Journal of animal science》2004,82(1):250-261
Four experiments with 1,040 weanling pigs (17 +/- 2 d of age at weaning) were conducted to evaluate the effects of spray-dried animal plasma source, drying technique, and methods of bacterial reduction on nursery pig performance. In Exp. 1, 180 barrows and gilts (initial BW 5.9 +/- 1.8 kg) were used to compare effects of animal plasma, animal plasma source, drying technique (spray-dried or freeze-dried), and plasma irradiation in nursery pig diets. From d 0 to 10, pigs fed diets containing irradiated spray-dried animal plasma had increased ADG and ADFI (P < 0.05) compared with pigs fed diets containing nonirradiated spray-dried animal plasma. Pigs fed irradiated animal plasma Sources 1 and 2 were similar in ADG and ADFI, but pigs fed animal plasma Source 1 had greater ADG (P < 0.05) than pigs fed animal plasma Source 2 and pigs not fed plasma. Pigs fed freeze-dried animal plasma had growth performance similar (P > 0.36) to pigs fed spray-dried animal plasma. Overall (d 0 to 24), pigs fed irradiated spray-dried animal plasma were heavier (P < 0.05) than pigs fed no animal plasma, whereas pigs fed nonirradiated spray-dried plasma were intermediate. In Exp. 2, 325 barrows and gilts (initial BW 5.8 +/- 1.7 kg) were used to compare the effects of irradiation or formaldehyde treatment of animal plasma and formaldehyde treatment of the whole diet. Pigs fed diets containing irradiated animal plasma had greater ADG (P < 0.05) than pigs fed nonirradiated plasma. Pigs fed formaldehyde-treated plasma had greater ADG and ADFI (P < 0.05) than pigs fed diets with either nonirradiated plasma or whole diet treated with formaldehyde. In Exp. 3 (360 barrows and gilts; initial BW 6.3 +/- 2.7 kg) and Exp. 4 (175 barrows and gilts; initial BW 6.1 +/- 1.7 kg), the irradiation of feed (high bacteria) and food-grade (low bacteria) animal plasma in nursery pig diets was examined. Pigs fed irradiated feed-grade plasma Product 2 had increased ADG (P < 0.05) compared with pigs fed nonirradiated plasma Product 2 and pigs fed the control diet without plasma. In Exp. 3 and 4, pigs fed irradiated food-grade plasma had growth performance similar to pigs fed nonirradiated food-grade plasma (P > 0.12). These studies indicate that bacterial reduction of feed-grade, but not food-grade animal plasma, improves nursery pig performance. 相似文献
13.
Apple JK Roberts WJ Maxwell CV Boger CB Fakler TM Friesen KG Johnson ZB 《Journal of animal science》2004,82(11):3267-3276
Three hundred sixteen crossbred pigs were used in two experiments to determine the effect of supplemental manganese source and dietary inclusion level during the growing-finishing period on performance and pork carcass characteristics. All pigs were blocked by weight, and treatments were assigned randomly to pens within blocks. In Exp. 1, a total of 20 pens (five pigs/pen) was randomly assigned to one of five dietary treatments consisting of control grower and finisher diets, or control diets supplemented with either 350 or 700 ppm (as-fed basis) Mn either from MnSO4 or a Mn AA complex (MnAA). In Exp. 2, a total of 36 pens (six pigs per pen) was assigned randomly to one of six dietary treatments formulated with 0, 20, 40, 80, 160, or 320 ppm (as-fed basis) Mn from MnAA. Pigs were slaughtered when the lightest block averaged 120.0 kg (Exp. 1) or at a mean BW of 106.8 kg (Exp. 2). Neither ADG nor ADFI was affected (P > 0.21) by Mn source or high inclusion level (Exp. 1); however, across the entire feeding trial, pigs consuming 320 ppm Mn from MnAA were more (P < 0.04) efficient than pigs fed diets formulated with 20 to 160 ppm Mn from MnAA (Exp. 2). Color scores did not differ (P > 0.79) at the low inclusion (20 to 320 ppm Mn) levels used in Exp. 2; however, in Exp. 1, the LM from pigs fed Mn tended to receive higher (P = 0.10) American color scores than that of pigs fed the control diet, and Japanese color scores were higher for the LM from pigs fed diets containing 350 ppm Mn from MnAA than 350 Mn from ppm MnSO4 or 700 ppm Mn from MnAA (source x inclusion level; P = 0.04; Exp. 2). Chops of pigs fed 350 ppm Mn from MnAA were darker than the LM of pigs fed 350 ppm Mn from MnSO4, and 700 ppm Mn from MnAA diets (source x inclusion level; P = 0.03; Exp. 1), but L* values were not (P = 0.76) affected by lower MnAA inclusion levels (Exp. 2). Even though the LM tended to became redder as dietary MnAA inclusion level increased from 20 to 320 ppm Mn (linear effect; P < 0.10), a* values were not (P = 0.71) altered by including 350 or 700 ppm Mn (Exp. 1). Chops of pigs fed MnAA had lower cooking losses (P = 0.01) and shear force values (P = 0.07) after 2 d of aging than did chops from pigs fed diets formulated with MnSO4. Results from these experiments indicate that feeding 320 to 350 ppm Mn from MnAA during the growing-finishing period may enhance pork quality without adversely affecting pig performance or carcass composition. 相似文献
14.
Two experiments were conducted to evaluate the efficacy of beta-glucan on growth performance, nutrient digestibility, and immunity in weanling pigs. In Exp. 1, 210 weanling pigs (6.38 +/- 0.92 kg of BW) were fed dietary beta-glucan (0, 0.01, 0.02, 0.03, or 0.04%) for 5 wk. In Exp. 2, 168 pigs (6.18 +/- 1.31 kg of BW) were fed no beta-glucan or antibiotics (T1), 0.02% beta-glucan (T2), only antibiotics (T3), or 0.02% beta-glucan with antibiotics (T4) for 8 wk. In Exp. 2, the antibiotics fed were apramycin and carbadox in phase I (0 to 2 wk) and carbadox and chlortetracycline in phase II (3 to 8 wk). During Exp. 2, the performance study was conducted for 5 wk, and the immune response was tested until 8 wk. In Exp. 1, there was a trend for a linear increase (P = 0.068) in ADG as the dietary beta-glucan concentration increased in the diet. The digestibilities of DM, GE, CP, ether extract, Ca, and P increased linearly (P < 0.05) in the beta-glucan-supplemented pigs. In Exp. 2, the overall ADG was greater (P < 0.05) in treatment T4 compared with the control group (T1). Also, except for P, this group showed greater (P < 0.05) nutrient digestibilities than the control group. In Exp. 2, at d 15, 24, and 46 antibody titers were measured by ELISA against Pasteurella multocida type A and D after vaccination with atrophic rhinitis, and they differed significantly (P < 0.05) with no particular trend. Flow cytometry was used to determine porcine lymphocyte subpopulations at 4 and 8 wk of Exp. 2. There was an increase in CD4 cells (P < 0.05) and a trend for an increase in CD8 cells (P < 0.10) at 8 wk in pigs fed the T2 diet compared with the other groups. Overall, increasing the dietary concentrations of beta-glucan did not improve ADG without antibiotic, and in weanling pigs antibiotics seem to be more effective in improving nutrient digestibilities and growth performance than beta-glucan. 相似文献
15.
This study was conducted to evaluate the effects of dietary energy density and weaning environment on pig performance. Treatment diets were formulated to vary in DE concentration by changing the relative proportions of low (barley) and high (wheat, oat groats, and canola oil) energy ingredients. In Exp. 1, 84 pigs in each of 3 replications, providing a total of 252 pigs, were weaned at 17 x 2 d of age and randomly assigned to either an on-site or an off-site nursery and to 1 of 3 dietary DE concentrations (3.35, 3.50, or 3.65 Mcal/kg). Each site consisted of a nursery containing 6 pens; 3 pens housed 7 barrows and 3 housed 7 gilts. All pigs received nontreatment diets in phase I (17 to 19 d of age) and phase II (20 to 25 d of age), respectively. Dietary treatments were fed from 25 to 56 d of age. Off-site pigs were heavier at 56 d of age (23.4 vs. 21.3 kg; P < 0.05) and had greater ADFI (0.77 vs. 0.69 kg/d; P < 0.01) than on-site pigs. There was a linear decrease in ADG (P < 0.01) and ADFI (P < 0.001) with increasing DE concentration. Efficiency of gain improved (P < 0.01) with increasing DE concentration. There was no interaction between weaning site and diet DE concentration, indicating that on-site and off-site pigs responded similarly to changes in diet DE concentration. In Exp. 2, nutrient digestibility of the treatment diets used in Exp. 1 was determined using 36 pigs with either ad libitum or feed intake restricted to 5.5% of BW. Energy and N digestibility increased (P < 0.001) with increasing DE concentration. Nitrogen retention and daily DE intake increased with DE concentration in pigs fed the restricted amount of feed (P < 0.05). These results indicate that weaning off-site improves pig weight gain. The weanling pig was able to compensate for reduced dietary DE concentration through increased feed intake. Growth limitation in the weanling pig may not be overcome simply by increasing dietary DE concentration. 相似文献
16.
Effects of dietary humic substances on pig growth performance, carcass characteristics, and ammonia emission 总被引:1,自引:0,他引:1
Five experiments were conducted to test the effects of various dietary humic substances (HS; HS1, 2, 3, and 4, each with different fulvic and humic acid contents) on pig growth, carcass characteristics, and ammonia emission from manure. In Exp. 1, 120 pigs were allotted to 3 dietary treatments without HS (control) or with HS1 at 0.5 and 1.0% (8 pens/treatment and 5 pigs/pen) and fed diets, based on a 5-phase feeding program, from weaning (d 21.3 +/- 0.3 of age) to 60 kg of BW. In Exp. 2 and 3, 384 pigs (192 for each experiment) were allotted to 3 dietary treatments without HS, with HS1, or with HS2 (0.5%) for Exp. 2 and without HS, or with HS3 or HS4 (0.5%) for Exp. 3 (8 pens/treatment and 8 pigs/pen in each experiment). Pigs were fed diets, based on a 6-phase feeding program, from weaning (25.4 +/-0.2 and 23.6 +/-0.3 d of age for Exp. 2 and 3, respectively) to 110 kg of BW. In Exp. 4, 96 pigs were weaned at 22.1 +/-0.2 d of age and allotted to 2 treatments without or with HS1 at 0.5% (6 pens/treatment and 8 pigs/pen), and in Exp. 5 96 pigs were weaned at 20.9 +/-0.3 d of age and allotted to 3 treatments without HS, or with HS3 or HS4 (0.5%; 4 pens/treatment and 8 pigs/pen). Pigs were fed the diets for at least 2 wk before they were moved to an environmental chamber to measure aerial ammonia and hydrogen sulfide for 48 h at 5-min intervals. In Exp. 1, pigs fed diets with HS1 at 0.5% had greater (P < 0.05) ADG during phase 3 and greater (P < 0.05) G:F during phases 3 and 5 than control pigs. In Exp. 2, pigs fed diets with HS1 or HS2 at 0.5% had greater (P < 0.05) ADG and G:F than control pigs during the entire feeding period, whereas in Exp. 3 HS3 or HS4 did not improve pig growth performance. Ammonia emission from manure was reduced by 18 or 16% when pigs were fed diets with HS1 (P = 0.067) or HS4 (P = 0.054), respectively. The results of this study indicate that the effects of dietary HS are variable but may improve growth performance of pigs and reduce ammonia emission from manure. Further research is needed to clarify these effects and the mechanisms by which HS may cause them. 相似文献
17.
Two 28-d experiments were conducted to evaluate the efficacy of low dietary concentrations of Cu as Cu-proteinate compared with 250 ppm Cu as CuSO4 with growth performance, plasma Cu concentrations, and Cu balance of weanling swine as the criteria. In the production study (Exp. 1), 240 crossbred pigs that averaged 19.8 d of age and 6.31 kg BW initially were group-fed (two or three pigs per pen) the basal diets (Phase 1: d 0 to 14 and Phase 2: d 14 to 28) supplemented with 0 (control), 25, 50, 100, or 200 ppm Cu as Cu-proteinate, or 250 ppm Cu as CuSO4 (as-fed basis). The basal diets contained 16.5 ppm Cu supplied as CuSO4 before supplementation with Cu-proteinate or 250 ppm Cu as CuSO4. There were quadratic responses (P < or = 0.05) in ADFI and ADG for wk 1, Phases 1 and 2, and overall because ADFI was higher for pigs fed 25 or 50 ppm Cu as Cu-proteinate, and ADG increased with increasing Cu-proteinate up to 50 ppm Cu. The Cu-proteinate treatment groups combined had a higher (P < or = 0.05) Phase 2 and overall ADFI and ADG than the CuSO4 group. In the mineral balance study (Exp. 2), 20 crossbred barrows that averaged 35 d of age and 11.2 kg/BW initially were placed in individual metabolism pens with total urine and fecal grab sample collections on d 22 to 26. Treatments were the basal Phase 2 diet supplemented with 0, 50, or 100 ppm Cu as Cu-proteinate, or 250 ppm Cu as CuSO4 (as-fed basis). Treatments did not differ in growth performance criteria. There were linear increases (P < 0.001) in Cu absorption, retention, and excretion (milligrams per day) with increasing Cu-proteinate. Pigs fed 100 ppm Cu as Cu-proteinate absorbed and retained more Cu and excreted less Cu (mg/d, P < or = 0.003) than pigs fed 250 ppm Cu as CuSO4. Plasma Cu concentrations increased linearly (P = 0.06) with increasing Cu-proteinate. In conclusion, weanling pig growth performance was increased by 50 or 100 ppm Cu as Cu-proteinate in our production Exp. 1, but not in our balance Exp. 2, compared with 250 ppm Cu as CuSO4. However, 50 or 100 ppm Cu as Cu-proteinate increased Cu absorption and retention, and decreased Cu excretion 77 and 61%, respectively, compared with 250 ppm Cu as CuSO4. 相似文献
18.
Utilization of spray-dried blood cells and crystalline isoleucine in nursery pig diets 总被引:1,自引:0,他引:1
Kerr BJ Kiddt MT Cuaron JA Bryant KL Parr TM Maxwell CV Weaver E 《Journal of animal science》2004,82(8):2397-2404
Three experiments were conducted to evaluate spray-dried blood cells (SDBC) and crystalline isoleucine in nursery pigs. In Exp. 1, 120 pigs were used to evaluate 0, 2, 4, and 6% SDBC (as-fed basis) in a sorghum-based diet. There were six replicates of each treatment and five pigs per pen, with treatments imposed at an initial BW of 9.3 kg and continued for 16 d. Increasing SDBC from 0 to 4% had no effect on ADG, ADFI, and G:F. Pigs fed the 6% SDBC diet had decreased ADG (P < 0.01) and G:F (P = 0.06) compared with pigs fed diets containing 0, 2, or 4% SDBC. In Exp. 2, 936 pigs were used to test diets containing 2.5 or 5% SDBC (as-fed basis) vs. two control diets. There were six replicates of each treatment at industry (20 pigs per pen) and university (six pigs per pen) locations. Treatments were imposed at an initial BW of 5.9 and 8.1 kg at the industry and the university locations, respectively, and continued for 16 d. Little effect on pig performance was noted by supplementing 2.5% SDBC, with or without crystalline Ile, in nursery diets. Pigs fed the 5% SDBC diet without crystalline Ile had decreased ADG (P < 0.01), ADFI (P < or = 0.10), and G:F (P < 0.05) compared with pigs fed the control diets. Supplementation of Ile restored ADG, ADFI, and G:F to levels that were not different from that of pigs fed the control diets. In Exp. 3, 1,050 pigs were used to test diets containing 5, 7.5, or 9% SDBC (as-fed basis) vs. a control diet. There were six replicates of each treatment at the industry (20 pigs per pen) location and five replicates at the university (six pigs per pen) locations. Treatments were imposed at an initial BW of 6.3 and 7.0 kg at the industry and university locations, respectively, and continued for 16 d. Supplementation of 5% SDBC without crystalline Ile decreased ADG and G:F (P < 0.01) compared with pigs fed the control diet, but addition of Ile increased ADG (P < 0.01) to a level not different from that of pigs fed the control diet. The decreased ADG, ADFI, and G:F noted in pigs fed the 7.5% SDBC diet was improved by addition of Ile (P < 0.01), such that ADG and ADFI did not differ from those of pigs fed the control diet. Pigs fed diets containing 9.5% SDBC exhibited decreased ADG, ADFI, and G:F (P < 0.01), all of which were improved by Ile addition (P < 0.01); however, ADG (P < 0.05) and G:F (P = 0.09) remained lower than for pigs fed the control diet. These data indicate that SDBC can be supplemented at relatively high levels to nursery diets, provided that Ile requirements are met. 相似文献
19.
Groesbeck CN Goodband RD Tokach MD Dritz SS Nelssen JL DeRouchey JM 《Journal of animal science》2007,85(10):2492-2497
Two experiments evaluated effects of added pantothenic acid on performance of growing-finishing pigs. In Exp. 1, 156 pigs (PIC, initial BW = 25.7 kg) were used in a 3 x 2 x 2 factorial to evaluate the effects of added pantothenic acid (PA; 0, 22.5, or 45 ppm), ractopamine.HCl (RAC; 0 or 10 mg/kg), and sex on growth performance and carcass traits. Pigs were fed increasing PA from 25.7 to 123.6 kg (d 0 to 98) and RAC for the last 28 d before slaughter. Increasing the amount of added PA had no effect (P > 0.40) on ADG, ADFI, or G:F from d 0 to 70. A PA x sex interaction (P < 0.03) was observed for ADG and G:F from d 71 to 98. Increasing the amount of added PA increased ADG and G:F in gilts, but not in barrows. Increasing the amount of added PA had no effect (P > 0.38) on carcass traits. Added RAC increased (P < 0.01) ADG and G:F for d 71 to 98 and d 0 to 98 and increased (P < 0.01) LM area and percentage lean. In Exp. 2, 1,080 pigs (PIC, initial BW = 40.4 kg, final BW = 123.6 kg) were used to determine the effects of increasing PA on growth performance and carcass characteristics of growing-finishing pigs reared in a commercial finishing facility. Pigs were fed 0, 22.5, 45.0, or 90 mg/kg of added PA. Increasing the amount of added PA had no effect (P > 0.45) on ADG, ADFI, or G:F, and no differences were observed (P > 0.07) for carcass traits. In summary, adding dietary PA to diets during the growing-finishing phase did not provide any advantages in growth performance or carcass composition of growing-finishing pigs. Furthermore, it appears that the pantothenic acid in corn and soybean meal may be sufficient to meet the requirements of 25- to 120-kg pigs. 相似文献
20.
DeRouchey JM Tokach MD Nelssen JL Goodband RD Dritz SS Woodworth JC Webster MJ James BW 《Journal of animal science》2003,81(4):1013-1022
A total of 720 nursery pigs in three experiments were used to evaluate the effects of blood meal with different pH (a result of predrying storage time) and irradiation of spray-dried blood meal in nursery pig diets. In Exp. 1, 240 barrows and gilts (17 +/- 2 d of age at weaning) were used to determine the effects of blood meal pH (7.4 to 5.9) in diets fed from d 10 to 31 postweaning (7.0 to 16.3 kg of BW). Different lots of dried blood meal were sampled to provide a range in pH. Overall (d 0 to 21), pigs fed diets containing blood meal had greater ADG (P < 0.05) and ADFI (P < 0.05) than pigs fed diets without blood meal. Ammonia concentrations in blood meal rose as pH decreased. However, blood meal pH did not influence (P > 0.16) ADG, ADFI, or gain:feed (G:F). In Exp. 2, 180 barrows (17 +/- 2 d of age at weaning) were used to determine the effects of post drying pH (7.6 to 5.9) and irradiation (gamma ray, 9.5 kGy) of blood meal on growth performance of nursery pigs from d 5 to 19 postweaning (6.8 to 10.1 kg of BW). One lot of whole blood was isolated with 25% of the total lot dried on d 0, 3, 8, and 12 after collection to create a range in pH. Overall, pigs fed blood meal had improved G:F (P < 0.01) compared to pigs fed the control diet. Similar to Exp. 1, the ammonia concentration of blood meal increased with decreasing pH. Blood meal pH did not influence ADG, ADFI, or G:F (P > 0.21), but pigs fed irradiated blood meal (pH 5.9) had greater ADG and G:F (P < 0.05) than pigs fed nonirradiated blood meal (pH 5.9). In Exp. 3, 300 barrows (17 +/- 6 d of age at weaning) were used to determine the effects of blood meal irradiation source (gamma ray vs. electron beam) and dosage (2.5 to 20.0 kGy) on growth performance of nursery pigs from d 4 to 18 postweaning (8.7 to 13.2 kg of BW). Overall, the mean of all pigs fed blood meal did not differ in ADG, ADFI, or G:F (P > 0.26) compared to pigs fed the control diet without blood meal. Pigs fed irradiated blood meal had a tendency (P < 0.10) for increased G:F compared with pigs fed nonirradiated blood meal. No differences in growth performance were detected between pigs fed blood meal irradiated by either gamma ray or electron beam sources (P > 0.26) or dosage levels (P > 0.11). These studies suggest that pH alone as an indicator of blood meal quality is not effective and irradiation of blood meal improved growth performance in nursery pigs. 相似文献