Growth performance, carcass characteristics, nutrient digestibility and fecal odorous compounds in growing-finishing pigs fed diets containing hydrolyzed feather meal

This study was designed to determine the effects of hydrolyzed feather meal inclusion on growth performance, carcass characteristics, nutrient digestibility and fecal odorous compounds in modern lean growth genotype pigs. Two hundred forty pigs (BW = 23.2 +/- 1.3 kg) were allotted based on BW and sex to a 2 x 6 factorial arrangement of treatments (four pens per treatment; five pigs per pen) in a randomized complete block design. Factors consisted of 1) sex (barrows or gilts) and 2) dietary treatment (0, 2, 4, 6, 8, or 10% hydrolyzed feather meal). Diets were formulated to contain 1.00, 0.90, 0.75, or 0.60% apparent ileal digestible lysine for phases 1 to 4, respectively, with other amino acids provided at an ideal ratio. Available P and ME were kept constant within each phase. No significant interactions between feather meal inclusion and sex were observed for growth performance (P > 0.15). Body weight gain was reduced (P < 0.05) for pigs fed 10% feather meal compared to pigs fed 0, 4, or 8% feather meal. Feed intake of pigs fed 10% feather meal was reduced (P < 0.05) compared to pigs fed 0 or 4% feather meal. Ultrasound backfat measurements tended (P = 0.12) to increase with increasing levels of feather meal. Daily lean gain was less (P < 0.05) in pigs fed 10% feather meal than in pigs fed either 0, 2, 4, or 8% feather meal. Digestibility of N measured on wk 9 decreased quadratically (P < 0.001) with increasing levels of feather meal. Phosphorus digestibility increased in a linear fashion (P < 0.02), however, the improvement in P digestibility with increasing levels of feather meal was more pronounced in barrows compared to gilts (interaction, P < 0.05). Fecal samples obtained from pigs fed 0, 4, or 8% feather meal were analyzed for odorous compounds. Concentrations of butanoic, pentanoic, and 3-methylbutanoic acid were greater (P < 0.05) and concentrations of 3-methylphenol, 4-methylphenol, indole, and decane were less (P < 0.05) in feces from pigs fed feather meal. These results suggest that feather meal can be included in diets for growing-finishing pigs at a rate of 8%. Excretion of N in feces increased but P excretion decreased with increasing levels of feather meal. Odorous compounds in feces can be affected by the inclusion of hydrolyzed feather meal, but the exact impact of these changes on odor perception remains to be elucidated.     

Effects of supplementation of high-dosing Trichoderma reesei phytase in the corn-wheat-soybean meal-based diets on growth performance,nutrient digestibility,carcass traits,faecal gas emission,and meat quality in growing-finishing pigs

We conduct this study to investigate the effects of corn-wheat-soybean meal (SBM)-based diet supplemented with high-dosing Trichoderma reesei phytase on the growth performance, nutrient digestibility, carcass traits, faecal gas emission and meat quality in growing-finishing pigs (29.71–110.58 kg live weight; 70-day-old to 166-day-old). A total of 56 crossbred pigs [(Landrace × Yorkshire) × Duroc] were used in 96-day experiment with a completely randomized block design. The growing period was from day 0 to 42, and the finishing period was from day 43 to 96. Pigs were randomly allocated to one of two treatments with seven replicate pens and four pigs (two barrows and two gilts) per pen and fed corn-wheat-SBM-based nutrient adequate basal diet or the basal diet supplemented with 1500 FTU/kg diet Trichoderma reesei phytase. One phytase unit (FTU) was defined as the amount of enzyme that catalyses the release of one micromole phosphate from phytate per minute at 37°C and pH 5.5. Dietary supplement with Trichoderma reesei phytase had increased body weight on day 96 and average daily gain in days 0–96. Moreover, high apparent total tract digestibility (ATTD) of phosphorus (P) was observed in pigs fed with Trichoderma reesei phytase. However, the carcass traits, faecal gas emission and meat quality of pigs were unaffected by Trichoderma reesei phytase supplementation. In conclusion, supplementation of high-dosing Trichoderma reesei phytase (1500 FTU/kg diet) in the corn-wheat-SBM-based nutrient adequate basal diet increased body weight and the ATTD of P, while no adverse effects were observed on the production characteristics.     

非淀粉多糖酶对生长育肥猪生长性能、胴体性状和肉品质的影响

本研究主要通过生长育肥猪的饲养试验,观察日粮中添加非淀粉多糖酶(Non-Starch Polysaccharide Enzyme,NSP酶)对生长育肥猪生长性能、胴体性状和肉品质的影响。试验选择体质量约为40kg的杜长大三元杂交猪48头,公母各半。本试验随机分为2个处理,每个处理3个重复,每个重复8头猪,对照组饲喂基础日粮,NSP酶组饲喂基础日粮+0.6%NSP酶。结果表明:(1)生长性能方面,NSP酶组的平均日增重和平均日采食量均显著高于对照组(P<0.05),分别提高了9.8%和4.7%;NSP酶组的料重比显著低于对照组(P<0.05),降低了5.0%;(2)在胴体性状和背最长肌化学组成方面,NSP酶组眼肌面积比对照组显著提高(P<0.05),提高了9.8%;与对照组相比,滴水损失和剪切力2个指标分别降低了2.0%和14.6%,但在统计学上未达到显著水平(P>0.05)。结果显示,基础饲粮中添加NSP酶能有效提高生长育肥猪生长性能,并在一定程度上改善肉品质。     

小肽复合剂对育肥猪的生长性能及胴体和肉质性状的影响效应研究

试验旨在研究小肽复合剂对育肥猪生长性能、胴体性状及肉质性状的影响效果。将72头同批次健康的65日龄的(长×大)二元杂交商品猪随机分为试验组和对照组,每组设3个重复,每重复12头猪。试验组在正常饲粮中添加0.2%的小肽复合剂,对照组为正常饲粮。试验结果发现:育肥阶段饲喂0.2%的小肽复合剂能够显著提高育肥猪生长性能和改善肉质性状。表现为提高育肥猪的日增重(P<0.05),增加育肥猪的采食量,提高饲料转化效率,提高育肥猪群的成活率,降低生病率和腹泻率。肉质性状方面,显著降低滴水损失(P<0.05),增加了肌肉的保水力,生长性能和肉质性状的改善显著地提高了育肥猪的综合经济效益。     

Effects of supplementation of beta-glucans on growth performance, nutrient digestibility, and immunity in weanling pigs

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.     

Virginiamycin improves phosphorus digestibility and utilization by growing-finishing pigs fed a phosphorus-deficient, corn-soybean meal diet

Evaluations of the nutritional effect of antibiotics have largely centered on effects related to the digestibility and utilization of protein and energy. The current study evaluated the potential effect of virginiamycin (VIR) on P digestibility in swine. A total of 70 barrows (mean initial BW = 51 to 64 kg) were used in 4 nutrient-balance experiments. A basal, corn-soybean meal diet that was not supplemented with any inorganic source of P was used in each experiment. In Exp. 1, two diets were tested: basal vs. basal plus 11 mg/kg of VIR. In Exp. 2, four diets were used with a 2 x 2 factorial arrangement of 0 and 11 mg/kg of VIR and 0 and 750 phytase (PHY) units/kg of diet (PU/kg). Experiments 3 and 4 were the same as Exp. 2, except PHY was reduced to 300 PU/kg. For all experiments, VIR improved P digestibility (32.71 to 37.72%, P < 0.001) and Ca digestibility (54.99 to 58.30%, P = 0.002). The addition of PHY improved both P and Ca digestibility (P < 0.001); 750 PU/kg increased P digestibility 27.3% (from 34.6 to 61.9%, P < 0.001), whereas 300 PU increased it 13.8% (from 33.4 to 47.2%, P < 0.001). In an experiment conducted to evaluate the long-term effects of VIR on gut microbial profile, pigs (24 gilts and 8 barrows; mean BW = 29.1 +/- 0.50 kg) were fed a simple corn-soybean meal diet for 16 wk with a 2 x 2 factorial arrangement of VIR (0 and 11 mg/kg) addition and 0.15% dicalcium phosphate deletion. The long-term feeding of VIR in both the control diet and the diet with a marginally reduced P level resulted in a change in ileal microbial profile. A positive numerical increment in the number of phytate-utilizing bacteria was observed in both the normal and P-deleted diets (log unit increments of 12.4 and 17.2% over the respective controls, P = 0.13) when VIR was added. The addition of VIR also tended to affect lactobacilli populations (main effect, P = 0.11; interaction, P = 0.02); VIR decreased lactobacilli in the normal-P diet but did not affect this bacterial population in the P-deleted diet. In conclusion, the antibiotic VIR improves both Ca and P digestibility in pigs. The increase in digestibility is not as great as that provided by PHY, but because the potential mechanism of action (altered microbial populations) differs from that of PHY (direct addition of an enzyme), there can be a degree of additivity in P digestibility improvement when both products are used.     

Effects of single or carbohydrases cocktail in low-nutrient-density diets on growth performance, nutrient digestibility, blood characteristics, and carcass traits in growing–finishing pigs

This study was conducted to evaluate the effects of single or carbohydrases cocktail in low-nutrient-density diets on growth performance, nutrient digestibility, blood characteristics, and carcass traits of growing–finishing pigs. A total of 96 pigs with an average initial BW of 47.50 ± 1.25 kg were used in this 8-week growth trial. Pigs were randomly allocated to 1 of the 4 treatments according to its BW and sex (4 pigs/pen, 6 replicate pens/treatment). The diets included: 1) control (CON) corn–soybean meal diet (DE, 3400 kcal/kg; CP, 17%), 2) low-nutrient-density (LC) diet with 6% DDGS and 5% tapioca (DE, 3280 kcal/kg; CP, 15%), 3) LC + 0.05% β-mannanase (LCS), and 4) LC + 0.05% enzyme mixture (LCM). The LC treatment had a lower ADG, and G/F compared to the other treatments in 0–4 weeks and the overall period of the feeding trial (P < 0.05). The ADFI were decreased in LC, LCS, and LCM groups related to CON (P < 0.05). The LCS treatment had higher DM digestibility than pigs in both the LC and LCM groups (P < 0.05) on 4 weeks while LCM improved N and energy digestibility compared to LC treatment. Blood urea nitrogen and creatinine values were not affected by the experimental treatments. After the feeding period, pigs (2 per pen) which reached marketing BW were collected meat samples from slaughter house. Backfat thickness was decreased in LC, LCS and LCM groups (P < 0.05). No numerical differences were observed in meat color, pH value and water holding capacity among four treatments. In conclusion, the results of this study indicate that single or carbohydrases cocktail in low-density diets can partially improve ADG, G/F, nutrient digestibility, and meat quality in finishing pigs, which can counteract the negative effects caused by the decreased nutrient concentration.     

Dried skim milk as a replacement for soybean meal in growing-finishing diets: effects on growth performance, apparent total-tract nitrogen digestibility, urinary and fecal nitrogen excretion, and carcass traits in pigs

Two trials were conducted to determine the replacement nutritive value of dried skim milk for growing-finishing pigs. In a three-phase feeding trial, 180 growing composite barrows (40.8 +/- 2.9 kg BW) were allotted to three dietary treatments. Each phase lasted 28 d. Treatment 1 comprised a basal corn-soybean meal diet supplemented with crystalline AA to contain true ileal digestible concentrations (as-fed basis) of 0.83, 0.66, and 0.52% Lys; 0.53, 0.45, and 0.40% Thr; and 0.51, 0.45, and 0.42% sulfur amino acids (SAA; Met + Cys) in Phases 1, 2, and 3, respectively. Treatments 2 and 3 were the basal diets with 5 and 10% (as-fed basis) dried skim milk added. The three diets at each phase were formulated to have the same quantities of DE, true ileal digestible Lys, Thr, Trp, SAA, Ca, and available P. Pigs were housed 10 per pen (six pens/treatment), allowed ad libitum access to feed, and slaughtered at 121.6 +/- 9.3 kg BW. No differences were detected between pigs fed the basal diet and the dried skim milk diets or between pigs fed the 5 and 10% dried skim milk diets, respectively, in 84-d ADG (P = 0.84 or P = 0.71), ADFI (P = 0.54 or P = 0.91), and G:F (P = 0.80 or P = 0.97), in hot carcass weight (P = 0.66 or P = 0.74), 45-min postmortem LM pH (P = 0.90 or P = 0.53), 10th-rib backfat thickness (P = 0.24 or P = 0.77), LM area (P = 0.13 or P = 0.63), weights of belly (P = 0.43 or P = 0.70), trimmed wholesale cuts (P = 0.18 to 0.85 or P = 0.06 to 0.53), and ham components (P = 0.25 to 0.98 or P = 0.32 to 0.63). In the N balance trial, four littermate pairs of finishing gilts (82.9 +/- 2.0 kg BW) were assigned within pair to the basal or the 10% dried skim milk (as-fed basis) finishing diet. Daily feed allowance was 2.6x maintenance DE requirement and was given in two equal meals. Total fecal collection from eight meals and a 96-h urine collection began on d 14 when gilts weighed 92.1 +/- 2.2 kg BW. No differences were found between dietary treatments in gilt's daily N intake (P = 0.33) and the daily output of urinary urea (P = 0.88), urinary N (P = 0.97), fecal N (P = 0.69), and total manure (P = 0.62), as well as apparent total-tract N digestibility (P = 0.84) and N retention (P = 0.84). It is concluded that growing-finishing pigs fed diets containing 10% dried skim milk would have growth performance, carcass traits, and N digestibility and use similar to those fed typical corn-soybean meal diets.     

Effects of chromium propionate on growth, carcass traits, and pork quality of growing-finishing pigs

An experiment was conducted to determine the effect of dietary Cr propionate (CrProp) on growth, carcass traits, and pork quality of crossbred finishing gilts. Dietary treatments were 0 or 200 ppb Cr (as CrProp; as-fed basis), and each treatment was replicated four times with five gilts per replicate pen. Gilts were fed diets containing 0.82% lysine from 73 to 80 kg BW and 0.64% lysine from 80 to 115 kg BW. At the end of the trial, carcass and pork quality data were collected from four gilts per replicate. Average daily gain, ADFI, and G:F were not affected (P = 0.76 to 0.96) by CrProp. Before delivery at the abattoir, shrink loss was determined after an 18-h fast (fasting shrink) and after hauling (shipping shrink) pigs for 2.66 h (209.2 km). Fasting, shipping, and overall shrink were not affected (P = 0.14 to 0.39) by CrProp. Carcass length was increased (P = 0.03) in pigs fed CrProp. Loin muscle area, 10th-rib backfat thickness, average backfat thickness, dressing percent, muscle score, fat-free lean, and percent lean were not affected (P = 0.18 to 0.95) by CrProp. Twenty-four-hour loin pH was increased (P = 0.10) in pigs fed CrProp, but 45-min loin and ham pH and 24-h ham pH were not affected (P = 0.39 to 0.83) by CrProp. Subjective (color, marbling, firmness, and wetness) and objective (Commission Internationale de l'Eclairage L*, a*, b*) assessments of the loin muscle (at the 10th-rib interface) were not affected (P = 0.62 to 0.99) by CrProp. Forty-eight-hour drip (P = 0.10) and 21-d purge loss (P = 0.01) were decreased in pigs fed CrProp, but cook and total loss (drip + cook loss) and shear force were not affected (P = 0.35 to 0.53) by CrProp. Plasma cortisol, glucose, and lactate concentrations were not affected (P = 0.28 to 0.97) by CrProp after transportation or during exsanguination. These data indicate that CrProp may improve some aspects of pork quality (loin pH, drip and purge loss) but not growth performance or carcass traits.     

不同能量和营养浓度饲粮添加益生素对生长肥育猪生长性能、养分消化率、肉品质和血液指标的影响

<正>本研究旨在测定添加益生素(枯草芽孢杆菌孢子和丁酸梭菌孢子混合物)以及不同能量和营养浓度对生长肥育猪生长性能、养分消化率和肉品质的影响。选择96头初始体重为(47.50±1.14)kg的生     

Effect of carbohydrate source on growth performance, carcass traits, and meat quality of growing-finishing pigs

Two experiments were conducted to determine the effect of substituting a more available dietary carbohydrate (CHO) for portions of corn or fat in the diet on growth performance, carcass traits, meat quality, and serum or plasma metabolites in growing-finishing pigs. A three-phase feeding program was used with corn-soybean meal diets formulated to provide 105% of the Lys requirement for barrows or gilts gaining 325 g of lean daily in Exp. 1 or gilts gaining 350 g of lean daily in Exp. 2. Diets were isoenergetic within experiments. All other nutrients met or exceeded suggested requirements. In Exp. 1, pigs were allotted to three dietary treatments (0, 7.5, or 15.0% sucrose), with three replications of barrows and three replications of gilts, and with three or four pigs per replicate pen; average initial and final BW were 25.2 and 106.7 kg. In Exp. 2, gilts were allotted to two dietary treatments (waxy [high amylopectin] or nonwaxy [75% amylopectin and 25% amylose] corn as the grain source), with five replications of four gilts per replicate pen; average initial and final BW were 37.7 and 100.0 kg. In Exp. 1, ADG and gain:feed ratio increased linearly (P < 0.02) as dietary sucrose increased. Minolta color scores, a* and b*, and drip loss (P < 0.06) also increased linearly with added sucrose. In Exp. 2, ADG, carcass weight and length, and the Minolta a* value were greater for pigs fed waxy corn (P < 0.08) than for those fed nonwaxy corn. Feed intake, longissimus muscle area, 10th-rib and average backfat thickness, dressing percentage, fat-free lean, percentage of lean and muscling, lean gain per day, total fat, percentage fat, lean:fat ratio, serum or plasma metabolites (Exp. 1: serum urea N; Exp. 2: serum urea N, and plasma nonesterified fatty acids, triacylglycerols, total and high-density lipoprotein cholesterol, insulin, and total protein), pH of the longissimus muscle, and subjective muscle scores (color, firmness-wetness, and marbling) were not affected by diet in either experiment. In summary, increasing availability of dietary CHO in growing-finishing pig diets improved growth performance, but it did not affect carcass traits.     

Effects of dietary soy isoflavones on growth, carcass traits, and meat quality in growing-finishing pigs

Two experiments were conducted to determine the effect of soy isoflavones on growth, meat quality, and carcass traits of growing-finishing pigs. In Exp. 1, 36 barrows (initial and final BW, 26 and 113 kg, respectively) were used and each treatment was replicated four times with three pigs each. The dietary treatments were 1) corn-soybean meal (C-SBM), 2) corn-soy protein concentrate (low isoflavones, C-SPC), or 3) C-SPC + isoflavones (isoflavone levels equal to those in C-SBM). Daily gain and ADFI were increased (P < 0.10) in pigs fed the C-SPC relative to pigs fed the C-SPC + isoflavone diet in the late finishing period; otherwise, growth performance was not affected (P > 0.10) by diet. Longissimus muscle area, 10th-rib fat depth, percentage muscling (National Pork Producers Council), 24-h pH and temperature, color, firmness-wetness, marbling, drip loss, and CIE L*, a*, and b* color values were not affected (P > 0.10) by diet. Dressing percentage, carcass length, weight and percentage of fat-free lean in ham and carcass, lean gain per day, lean:fat, and ham weight were increased (P < 0.10), and ham fat and percentage fat in ham and carcass were decreased (P < 0.10) in pigs fed the C-SPC + isoflavone diet compared with pigs fed the C-SPC diet. Pigs fed the C-SPC + isoflavone diet had similar (P > 0.10) carcass traits as pigs fed the C-SBM diet, except carcass length, percentage ham lean and thaw loss were greater (P < 0.10), and total ham fat was less (P < 0.10) in pigs fed the C-SPC + isoflavone diet. In Exp. 2, 60 gilts (initial and final BW, 31 and 116 kg, respectively) were used, and each treatment was replicated five times with four pigs per replicate. The treatments were 1) C-SBM, 2) C-SBM + isoflavone levels two times those in C-SBM, and 3) C-SBM + isoflavone levels five times those in C-SBM. Daily feed intake was linearly decreased (P < 0.10) in the growing phase and increased (P < 0.10) in the late finishing phases as isoflavone levels increased; otherwise, growth performance was not affected (P > 0.10) by diet. Diet did not affect (P > 0.10) carcass traits; however, CIE a* and b* color scores and drip loss were decreased (P < 0.06) as isoflavone levels increased. Soy isoflavones decreased fat and increased lean in barrows when fed within the dietary concentrations found in typical C-SBM diets but not when fed to gilts at concentrations above those present in C-SBM diets.     

生长肥育猪性别对甲基吡啶铬使用效果的影响

选择 48头平均体重为 30.7kg± 3.1kg的三元杂交健康生长猪，按单因子随机区组设计分为两个处理，分别饲喂未加甲基吡啶铬的日粮和添加 0.05％甲基吡啶铬的日粮。试验结果显示：同对照组青年母猪相比，试验组青年母猪的平均日增重（ ADG）（ P=0.27）、饲料转化效率（ FCR）（ P=0.08）和瘦肉率（ P=0.20）得到不同程度的提高和改善；同对照组阉公猪相比，试验组肥育阉公猪的 ADG和 FCR受到显著（ P=0.04）抑制，瘦肉率表现出降低的趋势（ P=0.27）。结论：性别是影响生长肥育猪对甲基吡啶铬使用效果的一个重要因素。     

不同添加水平的紫花苜蓿草粉对育肥猪生长性能、养分表观消化率的影响

为探讨饲料中添加不同水平的紫花苜蓿草粉对育肥猪生长性能、养分表观消化率的影响,采用单因素设计试验,选择体重相近的健康三元杂交育肥猪120头,随机分成4组,每个组3个重复,每个重复10头。1组饲喂基础日粮为对照组,2、3、4组分别在基础日粮中添加2.0%、4.0%、8.0%紫花苜蓿草粉,预试验10 d,试验期60 d。试验期间测定育肥猪生长性能、养分表观消化率。结果表明:(1)试验2、3、4组猪只的平均日采食量均高于1组(P > 0.05),试验2、3组平均日增重较1组分别提高9.84%、12.05%(P < 0.05),料重比分别降低4.33%、6.50%(P < 0.05);(2)试验2、3、4组干物质、粗灰分表观消化率均高于1组(P > 0.05),试验2、3组总能较1组分别提高5.46%、5.85%(P < 0.05),试验2、3组粗蛋白质、粗脂肪的表观消化率较1组分别提高7.24%、9.11%、6.50%、7.20%(P < 0.05)。综上,紫花苜蓿草粉可以提高育肥猪的生长性能和养分表观消化率,并以4.0%添加较为适宜。     

吡啶羧酸铬对生长肥育猪生产性能、胴体性状及血清生化指标的影响

本试验选用 40头体重约 2 8kg的杜× (大×长 )三元杂交猪 ,随机分为 4组 ,分别饲喂添加0、2 0 0、 40 0、 60 0 μg/kg铬 (吡啶羧酸铬 )的玉米—豆粕型饲粮 (生长、肥育期粗蛋白水平分别为1 7 0 %、 1 5 0 % ) ,直至体重约 95kg左右结束。结果表明 ,铬水平对生长期 (约 2 8～ 60kg)日增重、采食量、料重比无显著影响 ,也不影响血清钙、镁、钾、钠、氯、尿素氮浓度。虽然肥育阶段 (约 60～ 95kg) 40 0 μg/kg铬组的日增重和 60 0 μg/kg铬组的日增重、饲料转化效率有降低趋势 ,但各组间日增重、料重比、采食量差异不显著。铬不影响肥育猪血清镁、钾、钠、尿素氮浓度 ,但对氯、钙浓度有影响 (P <0 0 5 )。纵观全期来看 ,铬不影响生长肥育猪全期的生产性能 (P >0 0 5 )。虽然 60 0 μg/kg铬组有增加瘦肉率、降低脂肪率的趋势 ,但肥育猪各组间胴体性状无显著差别。以上结果提示 ,在本试验条件下 ,添加 2 0 0～ 60 0 μg/kg铬 (吡啶羧酸铬 )对生长肥育猪生产性能和胴体性状无显著影响。     

Effects of exogenous emulsifiers and fat sources on nutrient digestibility, serum lipids, and growth performance in weanling pigs.

Three experiments were conducted to determine whether emulsifiers improve utilization of fat from diets for early-weaned pigs. In Exp. 1, 96 weanling pigs (17 d old) were used in metabolism cages, with main effects of fat source (soybean oil, tallow, lard, and coconut oil) and emulsifier treatment (no emulsifier, lecithin, and lysolecithin as 10% of the added fat). Soybean oil and coconut oil were more digestible than tallow and lard (P < .001). Tallow was more digestible when lecithin and lysolecithin were added (P < .007), and pigs fed lecithin had lower serum triglycerides and cholesterol than pigs fed lysolecithin (P < .03). In Exp. 2, 270 weanling pigs (21 d old) were used in a growth assay. Treatments were 1) control diet; 2) Diet 1 with soybean oil; 3) Diet 1 with tallow; 4, 5, and 6) Diet 3 with lecithin replacing 5, 10, and 30% of the tallow, respectively; and 7, 8, and 9) Diet 3 with lysolecithin replacing 5, 10, and 30% of the tallow, respectively. At d 14 of the experiment, digestibility of tallow was improved more by lecithin than lysolecithin (P < .008). For the total experiment (d 0 to 35), the control pigs had poorer gain:feed ratio than did the pigs fed the fat sources (P < .002). In Exp. 3, 420 weanling pigs (21 d old) were used. Treatments were 1) control diet with soybean oil; 2) Diet 1 with tallow; and 3, 4, and 5) Diet 2 with 10% of the added fat as soybean oil, lecithin, or monoglyceride, respectively. Adding soybean oil, lecithin, and monoglyceride to tallow increased digestibility of total fat (P < .07). From d 0 to 14, pigs fed soybean oil gained weight faster than pigs fed the other treatments (P < .06), and pigs fed tallow without emulsifiers had the lowest ADG. Considering all experiments, addition of emulsifiers increased digestibility of nutrients but had minimal effect on growth performance.     

Effects of increasing L-lysine HCl in corn- or sorghum-soybean meal-based diets on growth performance and carcass characteristics of growing-finishing pigs

We conducted three experiments to determine the effects of increasing L-lysine HCl in growing-finishing pig diets. Experiments 1 and 2, conducted at the Kansas State University research center, each used 360 growing-finishing pigs with initial BW of 56 and 63 kg, respectively. Dietary treatments were sorghum- (Exp. 1) or corn- (Exp. 2) soybean meal-based and consisted of a control (no L-lysine HCl) or 0.15, 0.225, and 0.30% L-lysine HCl replacing lysine provided by soybean meal. Experiment 3 was conducted in a commercial research facility using a total of 1,200 gilts with an initial BW of 29 kg. Pigs were allotted to one of eight dietary treatments fed in four phases. These consisted of a positive control diet with no added L-lysine HCl and the control diet with 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30% L-lysine HCl replacing the lysine provided by soybean meal. The eighth dietary treatment was a negative control diet with no added L-lysine HCl and formulated to contain 0.10% less total lysine than the other treatments to ensure that dietary lysine was not above required levels. In Exp. 1, increasing L-lysine HCl decreased (linear, P < 0.01) ADG, feed efficiency (G:F), and percentage lean and increased (linear, P < 0.01) backfat depth. In Exp. 2, increasing L-lysine HCl decreased (quadratic, P < 0.03) ADG, G:F, and ADFI, but carcass characteristics were not affected. In Exp. 3, increasing L-lysine HCl decreased ADG (linear, P < 0.01) and G:F (quadratic P < 0.03). In all three experiments, the greatest negative responses were observed when more than 0.15% L-lysine HCl was added to the diet. Therefore, unless other synthetic amino acids are added to the diet, no more than 0.15% L-lysine HCl should replace lysine from soybean meal in a corn- or sorghum-soybean meal-based diet to avoid deficiencies of other amino acids. Based on the content of diets containing 0.15% Lysine-HCl, it appears the requirements for methionine plus cystine expressed as ratios relative to lysine are not greater than 50% during the early growing-finishing period (30 to 45 kg) and 62% during the late finishing period (90 to 120 kg) on a true digestible basis. For similar periods, the ratio requirements for threonine are not greater than 59% and 64% on a true digestible basis.     

Effects of pantothenic acid on growth performance and carcass characteristics of growing-finishing pigs fed diets with or without ractopamine hydrochloride

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.     

Effect of different protein sources on growth and carcass traits in growing-finishing pigs

Crossbred gilts (n = 180) and barrows (n = 180) from the Louisiana State University (LSU) Agricultural Center and the University of Illinois (UI) were used to compare the effect of soybean meal in swine diets, relative to other protein sources, on growth performance and carcass traits of growing-finishing pigs. Four replications with five pigs each at each location were allotted to nine dietary treatments: soybean meal control (SBM), crystalline AA (corn-AA), extruded soybeans (ESB), canola meal (CAN), peanut meal (PNT), sunflower meal (SFLR), ground peas, meat and bone meal (MBM), and poultry by-product meal (PLTY). The diets were formulated to meet or exceed NRC nutrient requirements and to have equal Lys:ME according to dietary phase and sex. Corn was the grain source in all diets and the protein sources were the sole source of supplemental protein in all diets except when AA were added to meet the requirement. Pigs (three per pen at each location) were killed at an average final BW of 114 kg in the LSU or UI Meat Science Laboratories. Pigs fed SBM had greater (P < 0.05) ADG than pigs fed the corn-AA, CAN, SFLR, MBM, or PLTY and greater (P < 0.05) ADFI relative to pigs fed the corn-AA, ESB, MBM, or PLTY. Gain:feed was decreased (P < 0.05) in pigs fed corn-AA or SFLR but increased (P < 0.05) in pigs fed ESB compared with pigs fed the SBM diet. Loin muscle area was decreased (P < 0.05) in pigs fed the corn-AA or MBM diets compared with pigs fed the SBM diet. Tenth-rib backfat thickness was greater (P < 0.10) in pigs fed corn-AA, peas, or MBM than in those fed SBM. The NPPC percentage acceptable quality lean and kilograms of lean were decreased (P < 0.10) in pigs fed corn-AA, peas, or MBM compared with those fed SBM. Results from this experiment suggest that pigs fed SBM have equal or better growth performance and carcass traits than pigs fed other protein sources.     

DDGS对生长育成猪的生产性能及胴体品质的影响

本试验旨在研究DDGS对生长育成猪的生产性能和胴体品质的影响。432头体重为29.8±0.2kg的育成猪被随机分成1-9个日粮组,分别为对照组（D0）,D15-0wk,D15-3wk,D15-6wk,D15-9wk,D30-0wk,D30-3wk,D30-6wk和D30-9wk,其中D0、D15和D30分别代表DDGS在猪日粮中的百分含量;0wk、3wk、6wk和9wk代表在屠宰0、3、6和9周前分别取消DDGS在猪日粮的添加时间。结果显示,当生长育成猪日粮中的DDGS含量为15%或30%时,不管屠宰前是否取消DDGS的添加,除了D30-0wk处理组的猪的ADG比对照组（D0）稍降外（0.87：0.92kg/d;P〈0.05）,其他处理组猪的ADG、ADFI和G：F均没有显著差异（P=0.76）。DDGS的不同含量或屠宰前取消DDGS的添加时间（0周、3周、6周和9周）对猪胴体质量、背最长肌（LM）猪肉品质、背脂和腹脂颜色评分分数没有显著影响（背脂,P=0.47;腹脂,P=0.17）。相对对照组,D30-0wk组的腹部猪肉嫩度稍低（P=0.04）,其他处理组猪的腹部猪肉嫩度与对照组的差别均不大（P=0.26）。当增加猪日粮中的DDGS含量时,腹脂的亚油酸含量（C18：2;P〈0.001）和碘值（IV;P〈0.001）有所增加。当猪日粮中含有15%DDGS时,在屠宰前的0～9周取消DDGS添加可以线性的降低猪腹脂的C18：2含量和腹脂碘值（屠宰前的第0-、3-、6-和9周的腹脂C18：2含量分别为：14.6%、13.3%、12.6%、10.9%;P=0.001;碘值分别为：67.3、64.4、64.1和62.7）;而当猪的日粮中含有30%DDGS时,在屠宰前0～9周取消DDGS的添加也可以线性的降低猪腹脂的C18：2含量和腹脂碘值（屠宰前的第0-、3-、6-和9周的腹脂C18：2含量分别为：17.3%、16.1%、14.2%和12.4%;P〈0.001;碘值分别为：71.2、68.2、64.5和62.7）。总体来看,当在生长育肥猪中添加高达30%DDGS对猪的生产性能有极小影响,且在屠宰前的3周取消在猪日粮中的DDGS的添加可以降低猪腹脂的C18：2含量和碘值。