Safety of Improved Milbond-TX When Fed to Laying Hens at Higher-Than-Recommended Levels

A corn-soybean meal diet was supplemented with 0, 1, or 2% Improved Milbond-TX (IMTX, a hydrated sodium calcium aluminosilicate) for Hy-Line W-36 laying hens selected for good or poor eggshell quality. Supplementing the diet with IMTX had no detrimental effects on egg weight, eggshell weight, albumen quality, feed consumption, or feed conversion during 5 consecutive 28-d periods. Increase in BW over the 5-mo experimental period was not influenced by the addition of IMTX. Results from this study show that an accidental oversupplementation of a laying hen diet with up to 8 times the recommended level of IMTX of the manufacturer, which may occur due to a feed mill mixing error, should not result in adverse performance of laying hens nor should it affect the concentration of moisture in the excreta.     

Rice mill feed as a replacement for broiler litter in diets for growing beef cattle

The efficacy of replacing broiler litter with rice mill feed was evaluated in four experiments. In Exp. 1, 40 predominantly Angus steers (initial BW = 277+/-18.2 kg) were fed four dietary treatments for 112 d (five steers per pen; two pens per diet). Dietary treatments (DM basis) were as follows: 1) 47% broiler litter:53% corn; 2) 60% rice mill feed:40% corn; 3) 50% rice mill feed:50% corn; and 4) 40% rice mill feed:60% corn. All diets, along with bermudagrass hay, were fed free choice. Daily gains were faster (P < 0.10) for the 50:50 and 40:60 diets (1.26 and 1.30 kg/d, respectively) than for the broiler litter diet (0.89 kg/d). Daily DMI was less (P < 0.10) by steers consuming rice mill feed-based diets than by those consuming broiler litter-based diets. In Exp. 2, 16 Angus x Charolais steers (initial BW = 277+/-22.7 kg) were fed the same four diets used in Exp. 1 while housed in individual metabolism stalls for determination of nutrient digestibility. Daily DMI was not different (P > 0.10) among diets. Nutrient digestibilities did not differ among diets (P > 0.10). In Exp. 3, 40 Continental cross steers (initial BW = 257+/-21.3 kg) were fed one of four dietary treatments for 112 d (five steers per pen; two pens per diet). On a DM basis, diets were as follows: 1) 47% broiler litter:53% soyhulls; 2) 70% rice mill feed:30% soyhulls; 3) 60% rice mill feed:40% soyhulls; and 4) 50% rice mill feed:50% soyhulls. All diets, along with bermudagrass hay, were fed free choice. Daily gains were less (P < 0.05) for the broiler litter diet than for the 60:40 and 50:50 diets (1.05, 1.16, and 1.28 kg/d, respectively), and steers fed the broiler litter diet consumed less DM than did steers fed the varying rice mill feed-based diets (P < 0.10). In Exp. 4, 16 Angus x Charolais steers (initial BW = 292+/-21.1 kg) were fed the same four diets as in Exp. 3 while housed in individual metabolism stalls for determination of nutrient digestibility. Daily DMI was less (P < 0.01) for the broiler litter diet (5.0 kg/d) than for the 70:30, 60:40, and 50:50 diets (7.8, 7.9, and 7.9 kg/ d, respectively). Digestibilities for DM, OM, and ADF did not differ (P > 0.10) among treatments; however, CP digestibility was greatest (P < 0.10) for the 60:40 diet, and NDF digestibility was least (P < 0.10) for the 70:30 diet. Rice mill feed can be used to replace broiler litter to formulate low-cost diets for stocker calves. Soyhulls and corn can be blended with rice mill feed to produce acceptable backgrounding diets for growing beef calves.     

Supplementation of diets containing pea meal with exogenous enzymes: effects on weight gain,feed conversion,nutrient digestibility and gross morphology of the gastrointestinal tract of growing broiler chicks

1. The potential for the nutritional improvement of pea-based diets by supplementation with a cocktail of exogenous carbohydrases was investigated using growing broiler chicks. 2. Pea meals (grown in the UK) were included in wheat-based diets at 300 g/kg as a partial replacement for an approximately isonitrogenous mixture of wheat and soybean meal. A wheat/soybean meal diet served as a control and each diet was supplemented with a cocktail of alpha-amylase, pectinase and cellulase. The diets were fed to 1-d-old broiler chicks for a period of 21 d. Weight gain and feed conversion were monitored weekly and excreta were collected during the final week in order to determine nutrient digestibility coefficients and metabolisable energy. On d 21, the gastrointestinal (GI) tract was excised and gross morphology measured. 3. Inclusion of pea meal reduced weight gain, feed conversion, nutrient digestibility and also increased the relative sizes of the distal sections of the GI tract. 4. Enzyme addition partially ameliorated the detrimental effects of pea meal inclusion although similar improvements were also noted for birds fed on the control diet. 5. It is concluded that the nutritive value of pea-meal-based diets can be improved by the addition of carbohydrases, and that some pea cultivars show considerable potential as vegetable protein sources for broiler chicks.     

Sulfur concentration in diets containing corn, soybean meal, and distillers dried grains with solubles does not affect feed preference or growth performance of weanling or growing-finishing pigs

Four experiments were conducted to investigate the effects of distillers dried grains with solubles (DDGS) and dietary S on feed preference and performance of pigs. In a 10-d feed preference experiment (Exp. 1), 48 barrows (20.1 ± 2.2 kg of BW) were randomly allotted to 3 treatment groups, with 8 replicate pens per treatment and 2 pigs per pen. A control diet based on corn and soybean meal, a DDGS diet containing 20% DDGS, and a DDGS-sulfur (DDGS-S) diet were prepared. The DDGS-S diet was similar to the DDGS diet with the exception that 0.74% CaSO(4) was added to the diet. Two diets were provided in separate feeders in each pen: 1) the control diet and the DDGS diet, 2) the control diet and the DDGS-S diet, or 3) the DDGS diet and the DDGS-S diet. Preference for the DDGS diet and the DDGS-S diet vs. the control diet was 35.2 and 32.6%, respectively (P < 0.05), but there was no difference between the DDGS diet and the DDGS-S diet. In Exp. 2, a total of 90 barrows (10.3 ± 1.4 kg of BW) were allotted to 3 treatments, with 10 replicate pens and 3 pigs per pen, and were fed the diets used in Exp. 1 for 28 d, but only 1 diet was provided per pen. Pigs fed the control diet gained more BW (497 vs. 423 and 416 g/d; P < 0.05) and had greater G:F (0.540 vs. 0.471 and 0.455; P < 0.05) than pigs fed the DDGS or the DDGS-S diet, but no differences between the DDGS and the DDGS-S diets were observed. In a 10-d feed preference experiment (Exp. 3), 30 barrows (49.6 ± 2.3 kg of BW) were allotted to 3 treatment groups, with 10 replicates per group. The experimental procedures were the same as in Exp. 1, except that 30% DDGS was included in the DDGS and DDGS-S diets and 1.10% CaSO(4) was added to the DDGS-S diet. Feed preference for the DDGS and the DDGS-S diets, compared with the control diet, was 29.8 and 32.9%, respectively (P < 0.01), but there was no difference between the DDGS and the DDGS-S diets. In Exp. 4, a total of 120 barrows (34.2 ± 2.3 kg of BW) were fed grower diets for 42 d and finisher diets for 42 d. Diets were formulated as in Exp. 3. Pigs on the control diets gained more BW (1,021 vs. 912 and 907 g/d; P < 0.05) and had greater G:F (0.335 vs. 0.316 and 0.307; P < 0.05) than pigs fed the DDGS or DDGS-S diet, respectively, but no differences between pigs fed the DDGS and the DDGS-S diets were observed. In conclusion, dietary S concentration does not negatively affect feed preference, feed intake, or growth performance of weanling or growing-finishing pigs fed diets based on corn, soybean meal, and DDGS.     

Soybean hulls as a primary ingredient in forage-free diets for limit-fed growing cattle

In Exp. 1, 300 heifers (260 kg initial BW) were used to compare growth performance of cattle fed forage-free diets containing predominantly soybean hulls with that of cattle receiving roughage- and corn-based diets and to determine whether cattle fed soybean hull-based diets would respond to supplementation with methionine hydroxy analogue (MHA), lipid-coated betaine, or concentrated separator by-product (CSB; a source of betaine). Treatments included 1) a roughage-based diet fed at 2.75% of BW, 2) a corn-based diet fed at 1.5% of BW, 3) a corn-based diet fed at 2.25% of BW, 4) a soybean hull-based diet fed at 1.5% of BW (SH1.5), 5) a soybean hull-based diet fed at 2.25% of BW (SH2.25), 6) SH1.5 top-dressed with 11.4 g/d Alimet (10 g/d MHA), 7) SH2.25 top-dressed with 11.4 g/d Alimet, 8) SH2.25 top-dressed with 7 g/d of a lipid-coated betaine product (4.2 g/d betaine), and 9) SH2.25 top-dressed with 250 g/d CSB (15.5 g/d betaine). Supplemental MHA, betaine, and CSB did not change DMI, ADG, or gain:feed ratio for cattle fed soybean hulls. Heifers fed soybean hull-based diets gained 29% slower (P < 0.05) and had 27% lower gain:feed ratios than heifers fed the corn-based diets. Cattle fed soybean hull-based diets had gains that were lower (P < 0.05) than those of cattle fed the roughage-based diets, but gain:feed ratios were similar because cattle were fed less of the soybean hull-based diets. Roughage-fed cattle had similar gains but 25% lower (P < 0.05) gain:feed ratios than cattle fed the corn-based diets. In Exp. 2, degradation by ruminal microbes of betaine in anhydrous betaine, betaine-HCl, feed-grade betaine, lipid-coated betaine, and CSB was evaluated in vitro using ruminal inocula collected from steers fed a high-grain or high-roughage diet. The roughage diet led to less betaine disappearance than the grain diet. More betaine was degraded from CSB than from other sources, perhaps because sugars provided by CSB stimulated fermentation, but no large differences occurred among the other four sources. Betaine from all sources was extensively degraded, although some betaine may escape ruminal degradation.     

Effects of diet complexity and dietary lactose levels during three starter phases on postweaning pig performance

Four experiments involving 1,005 crossbred pigs weaned at 19 +/- 2 d of age evaluated the effect of diet complexity and lactose level on starter pig performances. Experiment 1 was a randomized complete block (RCB) conducted in nine replicates with 135 pigs. A complex diet using several protein sources, a semicomplex diet with fewer protein sources, and a simple diet of corn and soybean meal comprised the three treatment groups. All diets contained 25% lactose (as-fed basis) with lysine (total) constant from d 0 to 14 (1.55%) and d 14 to 28 (1.45%), respectively. Gain, feed intake, and feed efficiency (P < 0.05) improved as diet complexity increased during both periods. In Exp. 2, 240 pigs in eight replicates in a RCB design were fed complex diets, but dietary lactose (total; as-fed basis) levels ranged from 10 to 35% in 5% increments from 0 to 14 d after weaning. From 14 to 30 d, a common 17% lactose diet was fed to evaluate the effects of early lactose level on subsequent responses. Gains (P < 0.05) increased for the 0- to 7- and 0- to 14-d periods as lactose increased to 30%. Similar gains resulted for all treatment groups from 14 to 30 d after weaning, with no evidence of compensatory responses to early lactose levels. In Exp. 3, 330 pigs were fed complex diets. From 0 to 7 d after weaning, the diets contained 25% lactose (as-fed basis), and from 7 to 21 d postweaning, the lactose levels ranged from 7 to 31% in 5% increments. Gain (P < 0.01) and feed efficiency (P < 0.05) increased from 7 to 21 d to the 17% lactose level. In Exp. 4, 300 pigs were fed 25 and 17% (as-fed basis) lactose diets from 0 to 7 and 7 to 21 d postweaning, respectively. From 21 to 35 d postweaning, lactose levels of 0 to 20% in 5% increments were added to a corn-soybean meal diet. The experiment was conducted as a RCB design in 12 replicates. Gain (P < 0.05) and feed intake (P < 0.05) increased to 10 to 15% lactose. When the data from Exp. 4 were partitioned into lighter (15.0 kg) and heavier (17.7 kg) pig weight replicates, only the lighter replicates had significant improvements in gain, feed intake, and feed efficiency (P < 0.05) in response to dietary lactose. These results demonstrated that starter pigs performed better when fed complex diets, that dietary lactose levels of 25 to 30% (to 7 kg BW) during the initial week postweaning, 15 to 20% lactose during d 7 to 21 (to 12.5 kg BW), and 10 to 15% lactose during d 21 to 35 postweaning (to 25 kg BW) resulted in maximum performance.     

Nutritional evaluation of high-digestible sorghum for pigs and broiler chicks

Two experiments were conducted to evaluate the nutritional quality of 2 varieties of Purdue high-digestible sorghum (PHD1 and PHD2) and a normal sorghum, compared with corn, in diets of pigs and broiler chicks. In Exp. 1, 12 pigs (average BW, 55 kg) fitted with ileal T-cannula were fed 4 diets containing 946 g of corn or sorghum (PHD1, PHD2, and normal) per kg in a 2-period crossover design (i.e., each pig received 2 diets over a 2-wk period with 6 pigs per dietary treatment) to determine apparent ileal or total tract digestibility of nutrients and energy. There was no difference in the ileal or total tract digestibility of DM, energy, P, Ca, or N among dietary treatments. In Exp. 2, a total of 192 broiler chicks were grouped by weight into 8 blocks of 4 cages each with 6 chicks per cage, and cages were assigned randomly to 1 of the 4 dietary treatments within each block. Chicks were fed corn-soybean meal (SBM) or sorghum-SBM diets for 21 d to determine apparent total tract retention and then switched to diets containing 935 g of the corresponding corn or 1 of the 3 sorghum varieties per kg for 7 d to determine apparent ileal digestibility and total tract retention. Apparent ileal digestibilities of DM and P, as well as energy, were not different in chicks fed diets containing 935 g of corn or 1 of the 3 sorghum varieties per kg. However, apparent total tract retention of DM, energy, and N in chicks fed corn was greater (P < 0.05) than those fed 1 of the 3 sorghum varieties. Although the apparent ME content of corn was greater than PHD1 and normal sorghum (P < 0.01), it was not different from PHD2 sorghum. There was no difference in apparent total tract retention of DM between chicks fed the corn-SBM and PHD-SBM diets, but it was greater (P < 0.05) in chicks fed the corn-SBM diet than those fed the normal sorghum-SBM diet. Apparent total tract retention of N in chicks fed the PHD1-SBM diet was lower (P < 0.05) than in those fed the corn-SBM diet but greater (P < 0.05) than in chicks fed the normal sorghum-SBM meal diet. No difference in the apparent ME content between the corn-SBM and PHD2-SBM diets was observed, but it was greater (P < 0.05) for the corn-SBM diet than the PHD1- or normal sorghum-SBM diet. Weight gain, feed intake, and feed efficiency were not different in chicks fed the corn-SBM or sorghum-SBM diets. Sorghum could serve as a substitute for corn in cereal grain-SBM diets for pigs and broiler chicks.     

Effects of dietary arginine supplementation during gestation and lactation on the performance of lactating primiparous sows and nursing piglets

A 2 x 2 factorial arrangement of treatments in a randomized block design was used to determine the effects of dietary Arg supplementation during gestation and lactation on the lactation performance of 38 first-parity sows. At 30 d of gestation, pregnant gilts were allotted based on BW to 1 of 2 diets supplemented with 1% L-Arg.HCl or 1.7% L-Ala (isonitrogenous control). After farrowing, sows were further allotted based on BW within previous gestation treatment groups to 1 of 2 lactation diets supplemented with 1% L-Arg.HCl or 1.7% L-Ala (isonitrogenous control). All gestation diets contained 3.1 Mcal/kg and 12.2% CP (as is) and were fed 2 kg/d in 2 equally sized meals, whereas all lactation diets contained 3.2 Mcal/kg and 18.6% CP (as is) and were fed ad libitum. Litter size was standardized to 10 piglets by cross-fostering within 24 h postfarrowing. On a weekly basis, BW and backfat (BF) thickness of sows, as well as piglet BW were measured, and blood and milk samples were obtained from the sows. Number of days from weaning to estrus and ADFI were also recorded. There were no differences in BW, BF thickness, ADFI, or days until return to estrus among treatment groups. There was no effect of the gestation diet or a gestation x lactation diet interaction on any parameter measured. On d 7 of lactation, plasma concentrations of Arg and insulin in sows, as well as concentrations of most AA in milk, were greater (P < 0.05) in response to Arg supplementation during lactation compared with the control. Weight gain of piglets from sows fed the Arg-supplemented diet during lactation was greater between d 0 and 7 (P < 0.01) and between d 0 and 21 (P < 0.05) of lactation compared with piglets from sows fed the control diet. Collectively, results from this study indicate the potential beneficial effects of dietary Arg supplementation in improving the lactation performance of first-parity sows.     

Evaluation of Illinois Bundleflower (Desmanthus illinoensis) for Broiler Chicks

Illinois bundleflower (IBF; Desmanthus illinoensis) is a warm-season perennial legume native to the central plains of the United States and has potential as both a forage and grain crop. The objective of this research was to evaluate the potential of IBF seeds as a feed ingredient in broiler starter diets. One-day-old broiler chicks were fed 1 of 4 isocaloric and isonitrogenous experimental diets containing 0, 5, 10, or 15% IBF seed. Illinois Bundleflower seed is a high-protein (31.5% CP) feed ingredient with a Lys:Met similar to that of soybean meal. The TME content of IBF seed depends on the form in which it is fed. When fed ground, the TME_n content was determined to be 1,974 kcal/kg. When fed whole, with supplemental grit, the TME_n content was 1,067 kcal/kg. Inclusion of IBF seed in broiler starter diets had adverse affects on both feed consumption and BW gain, even at a 5% inclusion level. Further studies are required to determine whether IBF seed could be included in diets for older broiler chicks or laying hens.     

Effects of high fat diets or prednisolone treatment on femoral head separation in chickens

1. The effects of high fat diets and prednisolone treatment were studied to understand the etiology of femoral head separation (FHS) in fast growing broiler chickens. Dietary effects on production parameters such as growth, feed conversion ratio (FCR) and blood chemistry were also measured.

2. Three groups of chickens, consisting of 30 birds each, in two replicate pens, were fed isonitrogenous diets containing 40 (control), 60, or 80?g poultry fat supplements per kg feed. The birds were fed a starter diet containing the fat supplements for the first three weeks, then switched to a grower diet containing the same supplements for the rest of the experimental period. Two groups of birds were also raised with the control diets, but were administered either cholesterol or prednisolone intramuscularly at 30 and 32 days of age to evaluate their effects on FHS incidences.

3. The chickens were euthanised and necropsied at 37?d of age. The presence of femoral head weakness was determined by applying mild pressure on the pelvic joint to cause the growth plate to become detached from its articular cartilage in affected cases.

4. High fat diets did not change FHS incidences, but increased 28?d body weights (BW) and FCR. At 37?d of age the BW differences were not significant but the FCR (gain: feed ratio) remained higher in high fat fed groups. Prednisolone treatment, by contrast, resulted in decreased BW, decreased feed efficiency, increased FHS index, and elevated blood lipid levels.

5. The results suggest that high dietary fats do not affect FHS incidence in broilers. Prednisolone treatment causes hyperlipidaemia and increases FHS index, and may therefore provide a suitable experimental model of FHS pathogenesis in growing chickens.     

A regional evaluation of the effect of fiber type in gestation diets on sow reproductive performance

A cooperative regional research study using 194 sows, from which data were collected from 381 litters, was conducted at 3 research stations to determine the effects of added psyllium (a concentrated fiber source) or soybean hulls to gestation diets on reproductive performance of sows and preweaning performance of their pigs. Primiparous and multiparous sows were allotted to the 3 treatments of control (corn and soybean meal-based), 0.30% psyllium, or 20% soybean hulls. Sows fed the control and 0.30% psyllium diets were provided 1.82 kg/d, and sows fed the 20% soybean hulls diet were provided 2.0 kg/d to equalize ME, Lys, Ca, P, and vitamin and trace mineral intake. Treatments 1 to 3 had 130, 130, and 121 litters per treatment from 64, 64, and 63 sows, respectively. Gestating sows fed psyllium had a greater (P < 0.01 to 0.10) d 110 gestation, farrowing, weaning, and 17 d postpartum BW and gestation ADG compared with sows fed soybean hulls. Sows fed psyllium also had a greater (P < 0.10 and 0.08) d 110 gestation BW and gestation ADG than the control sows. Sows fed soybean hulls had a reduced (P < 0.06) farrowing BW compared with the control sows. Sows fed psyllium weaned lighter (P < 0.09) pigs than sows fed the control diet. Litter size was not affected (P > 0.10) by diet. Sows fed psyllium had a reduced (P < 0.03) feed intake compared with sows fed soybean hulls for d 5 to 7 postpartum, and sows fed the control diet were intermediate. Fecal scores (1 to 5 with 1 = dry and 5 = watery) were greater (P < 0.001) and DM content was less (P < 0.001 to 0.01) in the feces of sows fed soybean hulls compared with sows fed psyllium or the control diet on d 112 of gestation and d 4 postpartum. Fecal scores were greater (P < 0.10) and fecal DM content was less (P < 0.02) in sows fed psyllium compared with sows fed the control diet only on d 4 postpartum. In summary, sows fed soybean hulls during gestation had reduced BW compared with sows fed the control diets. In contrast, sows fed psyllium had an increased BW.     

Impact of dietary chitosan oligosaccharide and its effects on coccidia challenge in broiler chickens

ABSTRACT

1. Two experiments were conducted, the first to determine the optimum inclusion of chitosan oligosaccharide (COS) in broiler diets to support growth performance, digestive functions, intestinal morphology, and immune organs. The second experiment evaluated the immune-protective properties of COS on broiler chickens during coccidia challenge (CC).

2. Experiment 1 investigated the effect of graded dietary concentration of COS in the diets of broiler chickens using eight cage replicates for each of the six diets. A corn-soybean meal-based diet was used as the basal diet and supplemented with 0.0, 0.5, 1.0, 1.5, 2.0, or 2.5 g of COS/kg feed to form the six treatments.

3. The diet supplemented with 1.0 g COS/kg of feed provided the optimal inclusion level for broiler chickens regarding body weight (BW) gain, jejunal villus height, villus height to crypt depth ratio, and ileal energy digestibility at d 22 of age.

4. Experiment 2 investigated the immune-protective properties of COS in broiler chickens during CC. A total of 224 male broiler chicks were randomly assigned to eight replicate cages in a 2 × 2 factorial arrangement of treatments with two COS concentrations (0 or 1 g of COS/kg of diet), with or without CC.

5. On d 18 of age, birds in the CC group received twice the recommended coccidia vaccine dose of 30 doses/kg BW.

6. Coccidia challenge reduced (P < 0.05) and dietary COS increased (P < 0.05) BW gain, and feed intake. Dietary COS mitigated (P < 0.05) the CC-induced effects on gain:feed. Dietary COS supplementation attenuated the CC-induced effects (P < 0.05) on the expression of occludin genes.

7. In conclusion, dietary COS improved performance, and the immune-related beneficial impact of COS supplementation was associated with reduced expression of pro-inflammatory cytokine genes.     

酶制剂提升大麦营养价值后对肉鸡生产性能的影响

通过对大麦代谢能、蛋白质和氨基酸的营养价值提升后进行饲料配方设计,研究饲喂大麦基础日粮加酶、不加酶以及玉米基础日粮的肉鸡生产性能。结果表明：大麦基础日粮加酶能促进7～21日龄雏鸡的生长、提高增重和饲料利用率,且生产性能等同于同水平玉米基础日粮组;而对21～42日龄生长鸡的作用效果不明显,但饲料回收率高于玉米基础日粮组。因此饲料厂家在根据市场行情选择饲料原料方面更具有灵活性。     

Impact of dietary energy level and ractopamine on growth performance, carcass characteristics, and meat quality of finishing pigs

A total of 54 finishing barrows (initial BW = 99.8 ± 5.1 kg; PIC C22 × 337) reared in individual pens were allotted to 1 of 6 dietary treatments in a 2 × 3 factorial arrangement of treatments with 2 levels of ractopamine (0 and 7.4 mg/kg) and 3 levels of dietary energy (high, 3,537; medium, 3,369; and low, 3,317 kcal of ME/kg) to determine the effects of dietary ractopamine and various energy levels on growth performance, carcass characteristics, and meat quality of finishing pigs. High-energy diets were corn-soybean-meal-based with 4% added fat; medium-energy diets were corn-soybean meal based with 0.5% added fat; and low-energy diets were corn-soybean meal based with 0.5% added fat and 15% wheat middlings. Diets within each ractopamine level were formulated to contain the same standardized ileal digestible Lys:ME (0 mg/kg, 1.82; and 7.4 mg/kg, 2.65 g/Mcal of ME). Individual pig BW and feed disappearance were recorded at the beginning and conclusion (d 21) of the study. On d 21, pigs were slaughtered for determination of carcass characteristics and meat quality. No ractopamine × energy level interactions (P > 0.10) were observed for any response criteria. Final BW (125.2 vs. 121.1 kg), ADG (1.2 vs. 1.0 kg/d), and G:F (0.31 vs. 0.40) were improved (P < 0.001) with feeding of ractopamine diets. Feeding of the low-energy diet reduced (P = 0.001) final BW and ADG compared with the high- and medium-energy diets. Gain:feed was reduced (P = 0.005) when the medium-energy diets were fed compared with the high-energy diets. Additionally, G:F was reduced (P = 0.002) when the low-energy diets were compared with the high- and medium-energy diets. Feeding ractopamine diets increased (P < 0.05) HCW (93.6 vs. 89.9 kg) and LM area (51.2 vs. 44.2 cm(2)). The LM pH decline was reduced (P ≤ 0.05) by feeding ractopamine diets. The feeding of low-energy diets reduced (P = 0.001) HCW when compared with the high- and medium-energy diets and reduced (P = 0.024) 10th-rib backfat when compared with the high- and medium-energy diet. These data indicate that feeding ractopamine diets improved growth performance and carcass characteristics, while having little or no detrimental effect on meat quality. Reductions in energy content of the diet by adding 15% wheat middlings resulted in impaired ADG, G:F, and 10th-rib backfat. There were no ractopamine × energy level interactions in this trial, which indicates that the improvements resulting from feeding ractopamine were present regardless of the dietary energy levels.     

Use of pet food-grade poultry by-product meal as an alternate protein source in weanling pig diets

Three experiments were conducted to evaluate pet food-grade poultry by-product meal (PBM) as a replacement protein source for fish meal (FM), blood meal (BM), and spray-dried plasma protein (SDPP) in weanling pig diets. In the first study, 200 crossbred pigs (initial BW = 6.5 kg) were weaned (21 d) and randomly allotted to one of four dietary treatments, which included a control and three test diets where PBM was substituted for FM, blood products, or both. Experimental diets were fed during Phase I (d 0 to 5 postweaning) and Phase II (d 5 to 19), and a common Phase III diet was fed from d 19 to 26. Overall (d 0 to 26), there was no difference in performance of pigs fed PBM in place of the other ingredients. However, during Phase I, BW (P < 0.05), ADG (P < 0.02), and intake (P < 0.001) in pigs fed diets containing SDPP were greater than those fed diets with PBM. In Exp. 2, the performance of pigs (n = 100, initial BW = 6.5 kg) fed diets containing 20% PBM (as-fed basis, replacing SDPP, BM, FM, and a portion of the soybean meal) in all phases of the nursery diet was compared with a group fed conventional diets without PBM. There were no differences in overall performance (d 0 to 26); however, ADG (P < 0.10) and feed intake were higher (P < 0.01) for pigs fed the conventional diet than for pigs fed the 20% PBM diet during Phase I (d 0 to 5). Experiment 3 was a slope-ratio assay to determine the ability of PBM to replace SDPP. A total of 320 pigs (initial BW = 7.32 kg) was weaned (21 d) and allotted to five treatment groups in three trials in a blocked design with product (SDPP or PBM) as the first factor, and lysine level (1.08, 1.28, 1.49%; as-fed basis) as the second factor. Growth rate increased with increasing lysine (P < 0.05), regardless of the source. These results indicate that PBM can be used in nursery diets in place of blood meal and fish meal without affecting performance. Furthermore, although feeding PBM in Phase I diets was not equivalent to SDPP during the first week, there was no overall difference in performance at the end of the nursery phase.     

Replacement of soybean meal with levels of inclusion of soya waste in the diet of growing goats

An experiment was conducted to investigate the effect of replacing soybean meal with soya waste at different levels on intake, digestibility and growth in goats. Eighteen male goat kids with initial body weight (BW) of 13.0 kg were distributed equally to three dietary groups. They were fed Napier grass (Pennisetum purpureum) and concentrate mixture, and each goat was assigned to an individual pen. Soybean meal in the concentrate mixture was replaced with soya waste at 0% (T1), 50% (T2) and 100% (T3) levels in respective dietary groups. These diets were isocaloric and isonitrogenous. Results showed that animals fed T3 diet exhibited higher Napier grass intake than those fed T1 or T2 diet. There was no influence on total intakes of dry matter (DM), organic matter (OM), crude protein (CP), metabolic BW, per cent BW and metabolisable energy by the dietary groups. However, there was an increasing trend on intake and digestibility of neutral detergent fibre (NDF) with increasing levels of soya waste in the diets. Animals fed T3 diet showed higher intake and digestibility of NDF than those fed T1 diet. There was no influence of the dietary groups on digestibilities of DM, OM and CP. Similarly, there was no effect of them on the final BW, total BW gain, daily BW gain, feed conversion ratio and feed cost. Soya waste can replace 100% soybean meal in diets for growing goats, because no change was observed in nutrient intake, digestibility and growth performance; inclusion of soya waste enhanced the intake and digestibility of NDF.

     

Effect of low doses of Aspergillus niger phytase on growth performance, bone strength, and nutrient absorption and excretion by growing and finishing swine fed corn-soybean meal diets deficient in available phosphorus and calcium

Two experiments were conducted to evaluate the efficacy of low doses of Aspergillus niger (AN) phytase for growing and finishing pigs fed corn-soybean meal (SBM) diets with narrow Ca:P ratios that were about 0.9 g/kg deficient in available P and Ca. Experiment 1 utilized 120 pigs with an early finisher period from 51.5 +/- 0.2 to 89.7 +/- 0.9 kg of BW and a late finisher period that ended at 122.5 +/- 2.0 kg of BW. During each period, treatments were the low-P diets with 0, 150, 300, or 450 units (U) of AN phytase added/kg of diet, and a positive control (PC) diet. There were linear increases (P < or = 0.001) in bone strength and ash weight, the absorption of P (g/d and %) and Ca (%), and overall ADG (P = 0.01) with increasing concentration of AN phytase. Pigs fed the diets with 150, 300, or 450 U of AN phytase/kg did not differ from pigs fed the PC diet in growth performance overall, and pigs fed the diets with 300 or 450 U of AN phytase did not differ in P and Ca absorption (g/d) or bone ash weight from pigs fed the PC diet. However, only pigs fed the diet with 450 U of AN phytase/kg had bone strength similar to that of pigs fed the PC diet. Experiment 2 utilized 120 pigs in a grower phase from 25.3 +/- 0.1 to 57.8 +/- 0.8 kg of BW and a finisher phase that ended at 107.6 +/- 1.0 kg of BW. Treatments were the low-P diet with AN phytase added at 300, 500, or 700 U/kg of grower diet, and 150, 250, or 350 U/kg of finisher diet, respectively, resulting in treatments AN300/150, AN500/250, and AN700/350. Growth performance and the absorption (g/d) of P and Ca for the grower and finisher phases were not different for pigs fed the diets containing AN phytase and pigs fed the PC diets. However, pigs fed the PC diets excreted more fecal P (g/d, P < or = 0.01) during the grower and more P and Ca (g/d, P < 0.001) during the finisher phases than the pigs fed the diets with phytase. There were linear increases (P < or = 0.05) in bone strength and bone ash weight with increasing concentration of AN phytase. However, pigs fed the PC diets had a greater bone strength and bone ash weight than pigs fed diets AN300/150, AN500/250 (P < or = 0.02), or AN700/350 (P < or = 0.08). There were no treatment responses for N or DM digestibility in either experiment. Phytase supplementation reduced fecal P excretion from 16 to 38% and fecal Ca excretion from 21 to 42% in these experiments. In conclusion, 450 U of AN phytase/kg was effective in replacing 0.9 g of the inorganic P/kg of corn-SBM diet for finishing swine based on bone strength, whereas 300 or 150 U of AN phytase/kg of diet maintained growth performance of grower or finisher pigs, respectively.     

Effects of forage and protein source on feedlot performance and carcass traits of Holstein and crossbred beef steers.

Fifty-eight Holstein and 58 crossbred beef steers were individually fed one of four isonitrogenous diets to evaluate the effects of forage source (corn silage and alfalfa haylage) and protein source (soybean meal and fish meal) on feedlot performance. Phase 1 diets (up to 354 kg of BW) were 40% forage and 60% concentrates and were fed for 70 to 136 d (depending on diet and breed group). Phase 2 diets (354 kg of BW until slaughter) were 20% forage and 80% concentrates and were fed for 127 to 150 d (depending on diet and breed group). Slaughter end points were .6 cm of 12th rib fat for Holsteins and 1.0 cm of rib fat for crossbreds using real-time ultrasonic estimates. The steers were fed for a maximum of 330 d each year. Forage source was a significant component of variation for most growth, efficiency, and carcass traits. Holstein and crossbred steers fed alfalfa haylage had significantly lower average daily gain, feed efficiency, dressing percentage, and empty body fat and required more days on feed to reach slaughter end points, but had higher total feed energy intake available for production. Steers fed corn silage diets had significantly greater energetic efficiency (P less than .05) than those fed alfalfa haylage, due to increased use of ME to produce fat in the carcass. Protein type did not influence gain, feed or energetic efficiency, energy intake, or most carcass traits. A significant protein system x forage source interaction among the four diets was detected for crossbred steers fed corn silage and fish meal, for which there was significantly greater feed conversion with lower energy intake above maintenance, possibly due to better fiber digestion and(or) amino acid flow to the lower tract. Alfalfa haylage plus soybean meal diets decreased (P less than .05) the percentage of Holsteins grading USDA Choice or higher. These results indicate that corn silage, because of greater energy concentration, was a more desirable forage in feedlot diets composed of less than or equal to 40% forage and that protein type (soybean meal and fish meal) in growing diets is not an important factor in feedlot performance or carcass traits of Holstein or crossbred steers that are fed these diets.     

Effects of supplemental biotin during gestation and lactation on reproductive performance of sows: a cooperative study

A cooperative experiment to evaluate biotin addition to sow diets was conducted at three research stations using 303 litters. Primiparous and multiparous sows (overall average parity 2.8) were fed a 14% CP corn-soybean meal diet (140 micrograms/kg biotin), with or without supplemental biotin (330 micrograms added biotin per kg feed), throughout gestation and lactation. As many sows as possible were fed their respective diets through three successive parities. During gestation, sows were given from 1.82 to 2.27 kg of feed per day, depending on environmental conditions; during lactation sows had ad libitum access to feed. Supplemental biotin had no effect (P greater than .35) on sow weights at breeding, at d 109 of gestation, at farrowing or at weaning. No differences were found in litter size at birth (P greater than .18), but at d 21 of lactation, sows fed the diet containing supplemental biotin had larger litters than sows fed the unsupplemented diet (9.4 vs 8.7 pigs, respectively; P = .01). Pig weights at birth and d 21 of lactation were not affected (P greater than .20) by dietary treatment. Biotin supplementation did not affect (P greater than .28) the length of the interval from weaning to estrus. No evidence was found that feet cracks or bruises were reduced by biotin supplementation. The results indicate that biotin supplementation of a corn-soybean meal diet during gestation and lactation increased the number of pigs at d 21 of lactation, but it did not decrease the incidence of foot lesions.     

Effects of exogenous enzymes in corn-based and Canadian pearl millet-based diets with reduced soybean meal on growth performance, intestinal nutrient digestibility, villus development, and selected microbial populations in broiler chickens

An experiment was conducted to compare a commercial corn-soybean meal diet with a pearl millet diet containing less soybean meal (-27%), alone or in combination with exogenous enzymes, on growth performance, jejunal villus development, ileal CP, and AA digestibility, and cecal microbial populations in broilers. One hundred sixty 1-d-old male Ross 508 broilers (5/cage) were randomly allocated to one of the following dietary treatments: 1) a standard corn-soybean meal control diet (CTL); 2) a pearl millet-soybean meal diet (PM); 3) CTL + exogenous enzymes (CE); and 4) PM + exogenous enzymes (PE) with 8 replicate cages/treatment. The PM and PE diets contained less soybean meal because of greater CP and AA contents of pearl millet. All diets were isonitrogenous and isocaloric. Body weight and feed intake were recorded weekly over 35 d. At d 21 and 35, 8 broilers per treatment were euthanized for sample collection and analyses. Gain-to-feed was greater (P < 0.01) for pearl millet- than corn-based diets. Apparent ileal digestibility (AID) of CP and most AA was similar between corn-based and pearl millet-based diets, and enzyme supplementation improved AID of CP (P < 0.01) and most AA at both d 21 and 35. However, for AID of some AA at d 21, the response to enzyme supplementation was less pronounced in broilers fed pearl millet-based diets than those fed corn-based diets (grain × enzyme, P ≤ 0.05). The villus was longer (P < 0.01) in broilers fed PM and PE than CTL and CE at d 35. Similarly, at d 35, lactobacilli loads were greater (P < 0.01) in broilers fed PM and PE than CTL and CE. It is concluded that, in comparison with corn, broiler diets formulated with pearl millet require less soybean meal and can be used to improve growth performance traits, intestinal lactobacilli populations, and villus development, whereas enzyme supplementation increases AID of CP and AA.