复合寡糖对肉鸡生产性能和免疫器官指数的影响

1组为对照组饲喂基础日粮,2～4组在基础日粮基础上分别添加250、500和750 mg/kg的复合寡糖,研究其对内鸡生产性能和免疫器官指数的影响.结果表明:复合寡糖对肉鸡前期生产性能有极显著的促进作用,后期趋于平缓;但对内鸡的免疫器官指数影响不明显.     

牛至油对东北白鹅生长性能和屠宰性能的影响

研究了东北白鹅日粮中添加牛至油对东北白鹅生长性能和屠宰性能的影响.对照组饲喂基础日粮,试验组在基础日粮中分别添加50、100和150 mg/kg的牛至油预混剂,测定28 d和70 d的生长性能指标及70 d的屠宰性能指标.结果表明:添加不同水平的牛至油制剂均可提高平均日增重(前期提高0.86%～5.78%,整个生长期2.92%～8.93%),降低料重比,改善屠宰性能.前期150 mg/kg增重效果显著,整个生长期100 mg/kg效果最佳;添加牛至油对腹脂率的降低效果较为明显.     

牛至油对东北白鹅免疫器官指数及部分血清生化指标的影响

研究了东北白鹅日粮中添加牛至油预混剂对其生长性能、屠宰性能和免疫器官指数及部分血清生化指标的影响。168只公母混合鹅雏按试验要求分为4组,对照组饲喂基础日粮,试验各组在基础日粮中分别添加50、100和150 mg/kg的牛至油预混剂。结果表明：在东北白鹅日粮中添加100 mg/kg及150 mg/kg质量分数10%牛至油预混剂可提高免疫器官指数,提高血清中的免疫球蛋白IgG、IgM、总蛋白含量及补体C₃、C₄水平,降低乳酸脱氢酶活性,增强机体的免疫性能,提高抗应激能力。     

不同粒度低聚木糖对断奶仔猪生产性能、血清生化、抗氧化和粪便微生物的影响

试验主要比较不同粒度低聚木糖对断奶仔猪生产性能、血清生化指标、抗氧化性能及粪便微生物的影响。选取72头35日龄窝别、体重相近(10±0.5kg)的三元(杜×长×大)杂交断奶仔猪,随机分为3组,分别饲喂基础日粮(对照组),以及在基础日粮中添加100g/t常规低聚木糖(常规组)和添加100g/t超微低聚木糖(超微组)。结果表明:与对照组相比,添加低聚木糖对断奶仔猪生产性能、血清生化指标无显著影响;但与常规组相比,超微组平均日采食量和平均日增重分别提高了7.71%、7.35%(P0.05);添加低聚木糖可以提高血清抗氧化性能和调节粪便微生物菌群,其中常规组显著提高血清总抗氧化活力,显著降低粪便中大肠杆菌数量。     

氨基乙酰丙酸和柠檬酸对肉鸡生长性能、免疫器官指数和血液指标的影响

研究日粮中添加氨基乙酰丙酸(ALA)和柠檬酸(CA)对爱拔益加(AA~+)肉鸡生长性能、免疫器官指数、血常规、血液生化指标及血清抗体滴度的影响。试验选用1日龄健康AA~+肉鸡720只,随机分为3组,每组6个重复,每个重复40只鸡,分别饲喂基础日粮、添加10 g/t ALA和15 kg/t CA的试验日粮,试验期28 d。结果表明,ALA一定程度上提高了日采食量和日增重,ALA和CA有降低料重比的趋势,但差异均不显著(P0.05);ALA和CA有提高全血中血红蛋白浓度的趋势(P0.05);ALA和CA对免疫器官指数、血清免疫球蛋白、铁含量及肝脏铁没有显著影响(P0.05);ALA对27日龄新城疫抗体效价有提高的趋势(P0.05)。因此,肉鸡日粮中添加ALA和CA可一定程度改善肉鸡生产性能和血液携氧能力。     

亚麻籽和茶多酚对肉鸭生长性能、屠宰性能、血液抗氧化能力和肌肉不饱和脂肪酸含量的影响

研究以亚麻籽为n-3 PUFA来源的肉鸭饲粮中添加茶多酚(TP),对其生长性能、屠宰性能、抗氧化能力和肌肉不饱和脂肪酸含量的影响。选用240只1日龄樱桃谷肉鸭,随机分为4组,其中对照组饲喂基础饲粮,实验组一、二、三分别饲喂含3%亚麻籽、3%亚麻籽+100 mg/kg TP、3%亚麻籽+200 mg/kg TP的实验饲粮。实验期为40d。结果表明:实验组一的平均日采食量(ADFI)和料重比(F/G)显著高于对照组(P 0.05);实验组二、三的ADFI和F/G与对照组差异不显著(P 0. 05)。屠宰率、半净膛率和全净膛率各组间均差异不显著(P 0. 05)。实验组三血浆的总抗氧化能力(T-AOC)、总超氧化物歧化酶(T-SOD)活力显著高于对照组(P 0. 01),丙二醛(MDA)含量显著低于对照组(P 0. 01)。各实验组腿肌中n-3 PUFA的含量均显著高于对照组(P 0. 05)。因此,饲粮中添加3%亚麻籽会显著增加樱桃谷肉鸭的料重比,以及肌肉中n-3PUFA的含量,但对屠宰性能无显著影响。在肉鸭饲粮中添加3%亚麻籽用于生产富含n-3 PUFA肉产品时加入200 mg/kg TP对肉鸭生长性能及机体抗氧化效果最佳。     

不同类型日粮添加酶制剂对蛋品质和蛋鸭生产性能的影响

选用500羽50周龄金定蛋鸭,研究不同类型日粮添加酶制剂对蛋鸭生产性能和蛋品质的影响.试验随机分成2组,分别设为对照组(玉米-豆粕型+植酸酶500 FTU/kg)和试验组(小麦-豆粕型+植酸酶500 FTU/kg+木聚糖酶),每组5个重复,每个重复50羽.研究结果表明,试验组与对照组相比,平均产蛋率提高6.6%(P>0.05),平均蛋重提高1.6%(P>0.05),料蛋比降低12.4%(P>0.05);蛋品质方面,试验组和对照组在蛋壳重、蛋形指数、蛋壳色泽、蛋壳强度、蛋白高度、哈氏单位均差异不显著(P>0.05);蛋黄重与蛋黄色泽均差异极显著(P<0.01).结论:用小麦替代日粮中的全部玉米并添加植酸酶和木聚糖酶饲喂蛋鸭,可以提高蛋鸭生产性能,增加经济效益.     

日粮高剂量添加葡萄糖氧化酶对肉杂鸡生长和屠宰性能的影响

试验旨在研究日粮高剂量添加葡萄糖氧化酶对笼养肉杂鸡生长和屠宰性能的影响。将864只1日龄肉杂鸡随机分为2个组(对照组和试验组,试验组在对照组基础上添加200 g/t 2 000 IU耐温葡萄糖氧化酶),每组8个重复,每个重复54只鸡。进行为期49 d的试验。研究结果表明：在日粮中添加200 g/t葡萄糖氧化酶能显著改善肉鸡的耗料增重比(P<0.05),但对日均采食量和日均增重无显著改善(P>0.05),对肉鸡屠宰性能无显著影响(P>0.05)。综上所述,笼养肉杂鸡日粮中高剂量添加葡萄糖氧化酶对于提升肉鸡肠道健康水平,改善耗料增重比有一定作用。     

饲粮添加胆碱对鹅免疫性能和肝脏组织学的影响

研究饲粮中添加不同水平胆碱对鹅免疫性能和肝脏组织学的影响。选用1日龄青农灰鹅180只,随机分为6个处理,每处理3重复,每重复10只。在玉米-豆粕型饲粮中分别添加0、600、1 200、1 800、2400和3 000 mg/kg的胆碱。试验期15周。结果表明:1)饲粮中添加胆碱能显著提高4、15周龄鹅免疫器官指数(P0.05或P0.01),但对血清禽流感抗体效价无显著影响(P0.05)。2)饲粮未添加胆碱组鹅肝脏细胞肿大,胞浆内有较多大小不等的脂肪空泡,将细胞核挤压到一侧,添加1 200~3 000 mg/kg胆碱均可有效改善肝脏内脂肪的沉积现象。综合衡量各项指标,在饲粮中添加胆碱是可行的,胆碱添加水平均1 200 mg/kg为宜。     

饲粮中添加米糠和抗氧化剂对肥育猪生产性能和肉品质的影响

研究饲粮中添加米糠和不同抗氧化剂对肥育猪生长性能和肉品质的影响;对其分别饲喂4种不同的饲粮:Ⅰ组"玉米-豆粕型"饲粮、Ⅱ组"含15%米糠饲粮"、Ⅲ组"在Ⅱ组饲粮基础上+200 mg/kgVE"和Ⅳ组"在Ⅱ组饲粮基础上+200 mg/kg普生源"。试验猪80 kg时屠宰。结果表明:平均日增重Ⅱ组极显著低于Ⅰ、Ⅳ组,Ⅲ组显著低于Ⅳ组。料肉比Ⅱ组极显著高于Ⅲ、Ⅳ组,显著高于Ⅰ组。肌肉嫩度Ⅰ、Ⅲ组极显著高于Ⅱ组,极显著低于Ⅳ组,肌肉脂肪含量Ⅱ组显著高于Ⅲ、Ⅳ组。     

Effects of dietary sources of vegetable oils on performance of high-yielding lactating cows and conjugated linoleic acids in milk

This study was conducted to examine the effects of dietary supplementation with vegetable oils on performance of high-yielding lactating cows and conjugated linoleic acid (CLA) content in milk fat. Twelve lactating Holstein cows in early lactation (30 to 45 d postpartum) were used in a triple 4 × 4 Latin square design. In each period, the cows in each group were fed the same basal diet and received one of the following treatments: 1) control (without oil), 2) 500 g of cottonseed oil, 3) 500 g of soybean oil, and 4) 500 g of corn oil. Each experimental period lasted for 3 wk, with the first 2 wk used for adaptation to the diet. Supplementation with vegetable oils tended to increase milk yield, with the highest milk yield in the cottonseed oil group (35.0 kg/d), compared with the control (34.4 kg/d). Milk fat percentage was decreased, but there were few effects on percentage and yield of milk protein as well as milk fat yield. The cows fed added soybean oil produced milk with the highest content of trans-11 C_18:1 (23.8 mg/g of fat), which was twice that of the control (12.6 mg/g of fat). Content of cis-9, trans-11 CLA in milk fat increased from 3.5 mg/g in the control to 6.0, 7.1, and 10.3 mg/g for the cows fed oils from cottonseed, corn, and soybean, respectively. A significant linear relationship existed between trans-11 C_18:1 and cis-9, trans-11 CLA. Supplementation with oils doubled the content of total fatty acids in blood plasma, with little difference between different vegetable oil sources. Octadecenoic acid content was significantly higher in blood plasma of animals fed added oils from cottonseed and soybean than those fed with corn oil and control. The plasma trans-11 C_18:1 content was significantly higher in the oil-added animals than in control. Supplementation of vegetable oils tended to improve milk production of lactating cows, and the CLA content in milk fat was significantly increased. Soybean oil seemed to be the optimal source to increase CLA production.     

酵母硒和枣粉对鸡肉成熟过程中肉品质及氧化特性的影响

研究酵母硒和枣粉对肉鸡生长性能、肉品质和抗氧化性能的变化.选取240只1日龄白羽肉鸡,随机分为4组,每组3个重复,每个重复20只.分别为CK组(基础日粮)、J组(基础日粮+8％枣粉替换8％玉米,质量分数)、0.3S组(基础日粮+0.3 mg/kg酵母硒)和0.3S+J组(基础日粮+0.3 mg/kg酵母硒+8％枣粉替换...     

Supplementation of Energy-restricted Diets with Coconut Oil Improves Nitrogen Balance Without Elevation of Blood Cholesterol Levels

ABSTRACT: Thirty-six growing male rats were fed 1 of 6 diets for 4 wk: (1) semipurified basal diet (B) with 10% corn oil, 21.6% fat calories (FC), 14 g B diet/day; (2) B + 1 g of coconut oil (32% FC); (3) B + 1 g olive oil; (4) B + 1 g corn oil; (5) B + 2.25 g starch (18.7% FC); and (6) B + 2 g coconut oil (40% FC). Weight gain and nitrogen balance were higher (p < 0.;05) for supplemented diet groups. Serum cholesterol and triglyceride levels were not different (p > 0.05). It may be suggested that under restricted energy intake conditions (67% to 75% of the requirements) a high-fat diet (32% to 40% fat calories), including a diet rich in highly saturated coconut oil, can serve as a source of energy and contribute to improved nitrogen balance, without elevating blood cholesterol levels.     

Effect of different fat supplements on performance of dairy calves during cold season

The objective of this experiment was to evaluate the effects of starter supplementation with fat sources differing in their fatty acid (FA) profile on performance of dairy calves during cold season. Sixty Holstein calves (3 d of age; 39.7 ± 3.8 kg of body weight) were randomly assigned to 1 of 5 starter diets supplemented with (1) no fat or oil source (control), (2) 3% palm fat (PLF), (3) 3% soybean oil (SBO), (4) 3% tallow (TAL), and (5) a 3.2% mixture (MIX) of PLF, SBO, and fish oil. The fat supplements were substituted for corn in the basal starter diet. Both the control and fat-supplemented diets contained similar amounts of dietary crude protein (19.4%), but the latter had a slightly higher quantity of calculated metabolizable energy (3.17 vs. 3.07 Mcal/kg) than did the former. Calves were reared outdoor in individual pens during the cold of winter with a mean ambient temperature of 5.0°C during the study period. Whole milk was offered twice daily from d 3 to 45 and once from d 46 to 49. The animals were weaned on d 50 and monitored in their individual pens until d 70. Supplementation with SBO and MIX increased both the dietary concentration and ratio of essential FA (n-6 and n-3), whereas supplementation with TAL and PLF made no change in the essential FA profile. Starter intake and average daily gain were not affected by PLF and TAL supplements, but were reduced as a result of feeding MIX. Feeding supplemental SBO did not affect starter intake, but tended to improve average daily gain and final body weight. Fat sources had no effects on body skeletal measurements, fecal score, digestibility, ruminal pH, ammonia, and total volatile FA concentrations; however, feeding MIX increased rumen molar proportion of propionate. No differences were observed in blood metabolites across the treatments during the preweaning period. Plasma concentrations of triacylglycerol and cholesterol increased when fat sources were supplemented and glucose concentration increased when SBO was supplemented during the postweaning period. Overall, addition of 3% PLF or TAL to the diet of young calves failed to improve growth performance. Although addition of SBO and MIX increased the dietary essential FA concentration, calf performance was only improved when SBO was supplemented.     

Effects of Rumen-Mate on lactational performance of Holsteins fed a high grain diet

Three Latin-square trials were conducted to determine the effects of supplementing Rumen-Mate, a commercial buffer containing KCl, NaCl, and Mg and Na carbonates, on lactation performance of Holsteins. Cows were fed a basal ration of 40% corn silage and 60% concentrate in Trials 1 and 2, and 40% corn silage, 55% concentrate, and 5% alfalfa hay in Trial 3 (DM basis). In Trial 1, treatments were: basal diet, or basal diet supplemented with either 1% NaHCO3, or 1, 3, or 4.4% Rumen-Mate. Increasing dietary Rumen-Mate resulted in a linear increase in milk fat production and concentration with no difference between 1% Rumen-Mate and 1% bicarbonate. There was a significant linear decrease in milk protein concentration, but not production, with increasing concentrations of Rumen-Mate. In Trial 2 treatments were: basal diet, or basal diet supplemented with either .8% NaHCO3, 2.6% Rumen-Mate, .5% MgO, .8% NaHCO3 plus .5% MgO, or 1.8% Rumen-Mate plus .8% NaHCO3. Organic matter and CP intakes and milk protein yield and concentration were decreased by Rumen-Mate with a nonsignificant increase in milk fat concentration. Data from Trials 1 and 2 were combined with data from Trial 3, which compared basal diet, 1% bicarbonate, and 3% Rumen-Mate. The combined data showed a larger increase over basal diet in milk fat yield and concentration for 2.6 to 3% Rumen-Mate vs. .8 to 1% bicarbonate. Rumen-Mate did not decrease DM intake or protein yield relative to basal diet but did decrease protein yield 34 g/d compared with that of bicarbonate.     

Addition of glycerol to lactating cow diets stimulates dry matter intake and milk protein yield to a greater extent than addition of corn grain

The objective of this study was to determine if the addition of glycerol to the diet of dairy cows would stimulate milk protein yield in the same manner as the addition of corn grain. Twelve multiparous lactating dairy cows at 81 ± 5 d in milk were subjected to 3 dietary treatments in a replicated 3 × 3 Latin square design for 28-d periods. The diets were a 70% forage diet considered the basal diet, the basal diet with 19% ground and high-moisture corn replacing forages, and the basal diet with 15% refined glycerol and 4% added protein supplements to be isocaloric and isonitrogenous with the corn diet. Cows were milked twice a day and samples were collected on the last 7 d of each period for compositional analysis. Within each period, blood samples were collected on d 26 and 27, and mammary tissue was collected by biopsy on d 28 for Western blot analysis. Dry matter intake increased from 23.7 kg/d on the basal diet to 25.8 kg/d on the corn diet and 27.2 kg/d on the glycerol diet. Dry matter intake tended to be higher with glycerol than corn. Milk production increased from 39.2 kg/d on the basal diet to 43.8 kg/d on the corn diet and 44.2 kg/d on the glycerol diet. However, milk yield did not differ between corn and glycerol diets. Milk lactose yields were higher on the corn and glycerol diets than the basal diet. Milk fat yield significantly decreased on the glycerol diet compared with the basal diet and tended to decrease in comparison with the corn diet. Mean milk fat globule size was reduced by glycerol feeding. Milk protein yield increased 197 g/d with addition of corn to the basal diet and 263 g/d with addition of glycerol, and the glycerol effect was larger than the corn effect. The dietary treatments had no effects on plasma glucose concentration, but plasma acetate levels decreased 27% on the glycerol diet. Amino acid concentrations were not affected by dietary treatments, except for branched-chain amino acids, which decreased 22% on the glycerol diet compared with the corn diet. The decreases in plasma acetate and branched-chain amino acid concentrations with glycerol and the larger effects of glycerol than corn on milk protein and fat yields suggest that glycerol is more glucogenic for cows than corn grain.     

The effects of sources of supplemental fat on performance,egg quality,and fatty acid composition of egg yolk in laying hens

BACKGROUND: The objective of this study was to determine the effects of sources of supplemental fat on laying performance, egg quality, and fatty acid composition of egg yolk. RESULTS: Two hundreds Isa Brown layers were assigned randomly to be fed ad libitum a standard commercial layer feed (BD), basal diet plus 2% tallow (T), basal diet plus a mixture of 1% tallow and 1% flaxseed oil (MTFO), basal diet plus 2% sunflower oil (SO), or basal diet plus 2% flaxseed oil (FO), which were offered for 8 weeks. Each diet was given to five groups, each containing 10 hens. The feed efficiency and egg production were 2.78 and 53.51% for BD; 2.30 and 63.47% for T; 2.45 and 60.14% for MTFO; 2.29 and 64.30% for SO, and 2.62 and 61.18% for FO groups, respectively. Dietary fat supplementation affected the laying performance but had no significant effects on egg quality parameters. The fatty acid composition of egg yolk lipids were significantly affected by dietary fatty acid composition. The supplemental tallow increased palmitic fatty acid. The proportions of linoleic and arachidonic fatty acids in egg yolks for layers fed the SO diet were higher than in the BD group and those on diets containing other fats. Concentrations of oleic and omega‐3 fatty acids were the highest in layers fed the FO diet during the laying period. CONCLUSION: The results indicated that dietary animal and plant fats changed the fatty acid composition of egg yolk. Copyright © 2008 Society of Chemical Industry     

Milk production and composition from cows fed high oil or conventional corn at two forage concentrations

Twelve multiparous Holstein cows (63 +/- 24 d in milk) were used in a replicated 4 x 4 Latin square with 28-d periods to evaluate conventional and high oil corn grains when fed at two different forage-to-concentrate ratios. Dietary treatments consisted of conventional or high oil corn supplementing a diet with a 25:25:50 mixture of corn silage: alfalfa: concentrate mix, or a high forage diet with a 30:30:40 mixture of corn silage: alfalfa: concentrate mix. Dry matter intake (28.1, 28.7, 26.9, and 26.2 kg/d for normal diets with conventional and high oil corn, and high forage diets with conventional and high oil corn, respectively) and milk yields (36.8, 37.2, 35.5, and 35.2 kg/d) were similar for conventional and high oil corn diets and were lower with the high forage diet, regardless of corn source. Milk fat concentrations were greater when cows were fed diets containing 60% forage (4.03 vs. 3.88%, for the 60 and 50% forages, respectively), but milk protein concentrations were not affected by forage content. Corn source did not affect milk fat or protein concentrations. Long-chain fatty acid concentrations, unsaturated fatty acid concentrations, and total 18:1 fatty acid concentrations were greater when cows were fed high oil corn but were unaffected by forage content of the diet. Concentrations of transvaccenic acid (0.58, 0.81, 0.62, and 0.69 g/100 g of fatty acids) and cis-9, trans-11 conjugated linoleic acid (0.28, 0.39, 0.32, and 0.33 g/100 g of fatty acids) were greater when cows were fed high oil compared with conventional corn when fed 50% forage but were similar for both corn sources at 60% forage. Total n-3 fatty acids were not affected by corn source or forage content. High forage diets decreased milk production and increased milk fat concentration. Feeding high oil corn increased concentrations of long-chain, unsaturated, transvaccenic, and conjugated linoleic fatty acids in milk; however, production of transvaccenic and conjugated linoleic acids were attenuated by high forage diet.     

Production performance,nutrient digestibility,and milk fatty acid profile of lactating dairy cows fed corn silage- or sorghum silage-based diets with and without xylanase supplementation

The objective of this study was to evaluate the effects of supplementing xylanase on production performance, nutrient digestibility, and milk fatty acid profile in high-producing dairy cows consuming corn silage- or sorghum silage-based diets. Conventional corn (80,000 seeds/ha) and brown midrib forage sorghum (250,000 seeds/ha) were planted, harvested [34 and 32% of dry matter (DM), respectively], and ensiled for more than 10 mo. Four primiparous and 20 multiparous Holstein cows were randomly assigned to 1 of 4 diets in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments and 19-d periods. Treatment diets consisted of (1) corn silage-based diet without xylanase, (2) corn silage-based diet with xylanase, (3) sorghum silage-based diet without xylanase, and (4) sorghum silage-based diet with xylanase. The xylanase product was supplemented at a rate of 1.5 g of product/kg of total DM. Corn silage had higher concentrations of starch (31.2 vs. 29.2%), slightly higher concentrations of crude protein (7.1 vs. 6.8%) and fat (3.7 vs. 3.2%), and lower concentrations of neutral detergent fiber (36.4 vs. 49.0%) and lignin (2.1 vs. 5.7%) than sorghum silage. Xylanase supplementation did not affect DM intake, milk yield, milk fat percentage and yield, milk protein percentage and yield, lactose percentage and yield, and 3.5% fat-corrected milk yield. Cows consuming corn silage-based diets consumed 13% more DM (28.8 vs. 25.5 kg/d) and produced 5% more milk (51.6 vs. 48.9 kg/d) than cows consuming sorghum silage-based diets. Milk from cows consuming sorghum silage-based diets had 16% greater fat concentrations (3.84 and 3.30%) than milk from cows consuming corn silage-based diets. This resulted in 8% greater fat yields (1.81 vs. 1.68 kg/d). Silage type did not affect milk protein and lactose concentrations. Xylanase supplementation did not affect nutrient digestibility. Cows consuming corn silage-based diets showed greater DM (77.3 vs. 73.5%), crude protein (78.0 vs. 72.4), and starch (99.2 vs. 96.5%) digestibilities than cows consuming sorghum silage-based diets. In conclusion, xylanase supplementation did not improve production performance when high-producing dairy cows were fed corn silage- or sorghum silage-based diets. In addition, production performance can be sustained by feeding sorghum silage in replacement of corn silage.     

Exchanging physically effective neutral detergent fiber does not affect chewing activity and performance of late-lactation dairy cows fed corn and sugarcane silages

The objective of this study was to determine whether replacing the physically effective neutral detergent fiber (peNDF) of corn silage with sugarcane silage peNDF would affect performance in dairy cows. Twenty-four late-lactation Holstein cows were assigned to eight 3 × 3 Latin squares with 21-d periods. The dietary treatments were (1) 25% peNDF of corn silage, (2) 25% peNDF of sugarcane silage, and (3) 12.5% peNDF of corn silage + 12.5% peNDF of sugarcane silage. The physical effectiveness factors (pef) were assumed to be 1 for corn silage and 1.2 for sugarcane silage, as measured previously by bioassay. Thus, peNDF was calculated as neutral detergent fiber (NDF) × pef. The concentrate ingredients were finely ground corn, soybean meal, pelleted citrus pulp, and mineral-vitamin premix. Dry matter intake (22.5 ± 0.63 kg/d), 3.5% fat-corrected milk yield (28.8 ± 1.13 kg/d), milk composition (fat, protein, lactose, urea, casein, free fatty acids, and somatic cell count), and blood metabolites (glucose, insulin, and nonesterified fatty acids) were unaffected by the treatments. The time spent eating, ruminating, or chewing was also similar among the diets, as was particle-sorting behavior. By contrast, chewing per kilogram of forage NDF intake was higher for the sugarcane silage (137 min/kg) than the corn silage diet (116 min/kg), indicating the greater physical effectiveness of sugarcane fiber. Based on chewing behavior (min/d), the estimated pef of sugarcane silage NDF were 1.28 in the corn silage plus sugarcane silage diet and 1.29 in the sugarcane silage diet. Formulating dairy rations of equal peNDF content allows similar performance if corn and sugarcane silages are exchanged.