Effect of long-term feeding of graded levels of deoxynivalenol (DON) on growth performance,nutrient utilization,and organ health in finishing pigs and DON content in biological samples

The prevalence of deoxynivalenol (DON) is a concern for swine producers, and although there has been extensive research into the effects of DON in pigs, focus has been in young pigs and/or in short-term studies. The objective of the study was to determine the effect of long-term exposure to DON-contaminated diets in finisher pigs. A total of 200 pigs (76.6 ± 3.9 kg initial weight) were group housed (five pigs per pen; n = 10 pens/treatment) in a 6-wk trial. Pigs were fed a wheat-barley-soybean meal-based control (CONT) diet with no DON or the basal diet in which clean wheat was replaced by DON-contaminated wheat and wheat screenings to provide DON content of 1, 3, or 5 ppm (DON1, DON3, and DON5, respectively). Individual BW and pen feed intake were recorded weekly to calculate average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F). Blood was collected on days 0, 14, and 43 and analyzed for indicators of liver and kidney health. Nitrogen (N)-balance was conducted immediately following the growth performance period to determine the effect of DON on nutrient utilization. Blood and urine samples collected during N balance were analyzed for DON content. Feeding DON reduced (P < 0.05) ADFI and ADG from days 0 to 28 compared with CONT, after which there was no effect of diet on ADFI and ADG. The G:F was lower (P < 0.05) in DON5 fed pigs compared with all treatments during days 0 to 7; however, no treatment effects on G:F was observed from days 8 to 42. Nitrogen retention was lower (P < 0.05) in DON3 and DON5 compared with DON1-fed pigs. Nitrogen retention efficiency was higher (P < 0.05) in DON1 compared with DON3 and DON5 and protein deposition for DON1 pigs was higher (P < 0.05) than all treatments. There were no treatment effects on indicators of liver and kidney health. As dietary DON intake increased, concentration of DON in blood and urine increased. Overall, although there was an initial decrease in ADG and ADFI in pigs receiving diets containing >1 ppm DON, pig performance recovered after a period of time, whereas nutrient utilization continued to be affected after recovery of performance. Moreover, the lack of DON on G:F indicates that the negative effects of DON on growth performance are largely due to reduced feed intake. Overall, although pigs maybe capable of adapting to intake of DON-contaminated diets, their final body weight will be reduced when fed diets containing >1 ppm DON.     

The effect of feeding system at weaning on performance,health and feeding behaviour of pigs of different sizes

Abstract

Pigs weaned at 31 to 34 days of age (n=280) were mixed into groups of 10 and fed from either feeders (2 feeding places per pen) or troughs (10 feeding places per pen). Analyses on performance, diarrhoea scores and feeding behaviour were made separately on small-, medium- and large-sized pigs, defined as their relative size in the group. During the second week after weaning, feed conversion ratio (FCR) was lower for pigs fed from feeders. Trough feeding resulted in lower total diarrhoea scores for small (p=0.002) and large (p=0.04), and higher scores for medium pigs (p=0.03). Small pigs had lower scores on individual days around the peak on day 6. All three size categories of pigs spent a numerically higher amount of time feeding when fed from a trough. Feeding bouts were longer in pigs fed from a trough (p=0.0002 – 0.05).     

Effect of feeding higher concentrations of limiting amino acids on performance,slaughter variables and nitrogen retention in broiler chicken fed graded levels of toasted guar (Cyamopsis tetragonoloba) meal

ABSTRACT

1. An experiment was conducted to study the effect of supplementing higher concentrations (100% vs. 110%) of critical amino acids (CAA) on performance (body weight gain – BWG, feed efficiency – FE), slaughter variables and nitrogen retention in broiler chicken (1–6 weeks of age) fed graded levels of toasted guar meal (TGM) as a protein source in diets.

2. The TGM was included at five graded concentrations (0, 50, 100, 150 and 200 g/kg) in iso-caloric and iso-protein diets with either the recommended concentration (100%) of CAA (lysine, total sulphur amino acids, threonine, tryptophan and valine) or at 10% higher (110%) concentration. A metabolism trial of 3-day duration was conducted during 6th week of age to study nitrogen retention.

3. The TGM levels and CAA concentration at 21 or 42 d of age did not influence BWG, FI and FE. BWG was not affected with inclusion of TGM up to 100 g/kg in starter and overall production (1–42 d of age) phases. The FE improved with TGM supplementation during starter phase, while at the end of experiment (42 d), FE was depressed by inclusion of TGM in dose dependant manner. All performance variables improved with increase in concentration of CAA from 100% to 110%.

4. Breast meat weight improved and abdominal fat weight reduced with higher levels of CAA in diet. Retention of nitrogen reduced with increase in level of TGM in broiler diet. Increasing concentrations of CAA in diet improved nitrogen retention.

5. It was concluded that TGM could be incorporated up to 100 g/kg with 100% CAA and up to 150 g/kg with 110% CAA without affecting performance. Increasing CAA concentration (110%) in diets significantly improved BWG and FE (21 and 42 d), breast meat weight and nitrogen retention in broiler chicken.     

饲料油菜FTMR的羔羊强度育肥效果研究

为研究饲料油菜发酵全混合日粮(FTMR)的羔羊强度育肥效果,本试验选取2.5月龄的湖羊40只,随机分为2组,每组20只,公母各半。试验组饲喂以油菜为主原料配制的FTMR日粮,对照组饲喂以青贮玉米为主原料配制的TMR日粮。预试期15d后称初试体重,正式期90d,每15d称重,记录采食量,计算平均日增重。结果表明:湖羊母羊采食量、体重和日增重在两种日粮间无显著差异(P>0.05);而试验组公羊采食量显著高于对照组(P<0.05),75d后体重和日增重都显著高于对照组(P<0.05)。根据日增重、采食量、饲料成本、活羊价格计算育肥收益,油菜FTMR日粮育肥湖羊公羊和母羊的收益都高于对照组。因此,饲料油菜FTMR日粮用于羔羊强度育肥效果较好。     

Effect of feeding different sources of selenium on growth performance and antioxidant status of broilers

ABSTRACT

1. This study was conducted to determine the effect of different sources of selenium (Se) on breast and liver tissue deposition, apparent metabolisable energy (AME), growth performance and antioxidant status of broilers, measured as Se content in liver and breast tissues and glutathione peroxidase (GSH-Px) in blood, when used in 0–35 d broiler chicken diets.

2. A total of 200 male Ross 308 broilers were used in the feeding trial, which comprised two dietary phases, a starter from 0 to 21 d and finisher from 21 to 35 d of age. Four treatments with 10 replications each were used. A control diet (C) was formulated that was sufficient in protein and energy (230 and 215 g/kg of crude protein and 12.67 and 13.11 MJ/kg of metabolisable energy, respectively), for both phases, but contained background Se only from the feed ingredients. Diet 2 (IS) was supplemented with 10.35 g/t inorganic, elemental source of Se. Diet 3 (SY) was supplemented with 136.36 g/t selenised yeast, an organic source derived from Saccharomyces cerevisiae. Diet 4 (SS) was supplemented with 0.666 g/t sodium selenite, an inorganic source.

3. Birds fed the SY diet consumed less and weighed less than those fed IS or C (P < 0.05; 0–35 d of age), but there was no difference compared to birds fed SS diets. There were no differences in FCR or dietary AME between broilers fed different Se sources. All diets containing supplementary Se increased concentrations in the liver and breast muscle, and for GSH-Px levels in blood compared to birds fed the C diet (P < 0.001). Birds fed SY diets had greater Se levels in liver and breast tissues compared to birds fed any of the other diets (P < 0.001).

4. Diets supplemented with Se had variable effects on broiler growth performances and antioxidant status. Feeding Se from a yeast source has higher transfer into breast tissues. Feeding different sources and levels of Se to birds in a more challenging situation to induce oxidative stress may bring more conclusive results.     

锌、硒、钴水平及复合饲料添加剂对肉牛增重的影响

制备含锌、硒、钴高水平 (10 0、0 .4、0 .4 PPM)和低水平 (30、0 .2、0 .1PPM)两种复合饲料添加剂 ,并以某商品饲料添加剂为对照。选用 2 8头体重 2 75～ 30 0 kg的夏洛来×南阳牛 F1,在饲喂氨化麦秸、日补混合精料 1.75kg条件下进行饲养试验。结果表明 ,在该饲料类型下牛的日增重处于0 .5～ 0 .7kg;锌、硒、钴高水平组、低水平组和商品饲料添加剂组的平均日增重分别为 0 .6 6 8、0 .4 94和 0 .56 4 kg,三组的精料增重比分别为 2 .6 2 :1、3.54:1和 3.0 2 5:1     

甲壳素水解蛋白对肉仔鸡生长和氮存留率的影响

研究甲壳素水解蛋白对肉仔鸡生长发育和氮存留率的影响,选取初生AA雏鸡360只,采用单因子重复试验设计,甲壳素水解蛋白添加水平分别为0,1％,2％,3％。结果表明添加2％~3％的甲壳素水解蛋白,可显著提高(P<0.05)肉仔鸡的日均增重,添加1％~2％的甲壳素水解蛋白,可显著改善(P<0.05)肉仔鸡的料重比及显著提高(P<0.05)肉仔鸡的氨存留率。     

酵母培养物降低黄曲霉毒素和呕吐毒素对猪生长性能、器官健康和免疫状态影响的研究

文章旨在评估酵母培养物对饲喂毒素污染日粮断奶猪生长性能、器官健康和免疫状态的影响。试验选择体重为(8.75±0.38)kg,28 d断奶的三元杂交猪500头,随机分为5组,每组5个重复(20头/重复),试验共开展42 d。对照组为未加毒素污染原料,处理1组含150μg/kg黄曲霉B1毒素+1100μg/kg呕吐毒素,处理2组在处理1组中添加2 mg/kg蒙脱石,处理3组在处理1组中添加1.0 mg/kg蒙脱石和0.5 mg/kg酵母培养物复合物,处理4组在处理1组中添加0.5 mg/kg蒙脱石和0.5 mg/kg酵母培养物复合物。结果显示:日粮污染降低了仔猪日增重,通过增加单核细胞和免疫球蛋白来改变免疫系统。霉菌毒素可引起肝、胆管增生和核肿大等组织损伤。毒素污染日粮添加2 mg/kg蒙脱石或1.0 mg/kg蒙脱石和0.5 mg/kg酵母培养物复合物降低了霉菌毒素对免疫系统和肝脏的影响,改善了仔猪生长性能。结论:日粮添加2 mg/kg蒙脱石或1.0 mg/kg蒙脱石和0.5 mg/kg酵母培养物复合物对饲喂毒素污染日粮猪的健康和生长性能具有改善作用。     

不同精料添加量及披碱草青贮料对藏羊的育肥效果

将20只藏系羯羊(1岁)分为Ⅰ、Ⅱ、Ⅲ、Ⅳ 4个处理组,Ⅰ、Ⅲ、Ⅳ组分别用150、300、450 g/(d·只) 3种精料添加水平,自由采食干披碱草,Ⅱ组添加青贮料,以研究不同精料添加量和青贮料对藏羊生产性能的影响。试验结果表明,4组藏羊全期平均日增重分别为(41.00±5.48)、(63.00±8.37)、(68.00±9.75)、（69.00±9.2） g,Ⅳ组极显著高于Ⅰ组（P＜0.01）;Ⅱ、Ⅲ组显著高于Ⅰ组（P＜0.05）;Ⅱ、Ⅲ、Ⅳ组间差异不显著(P＞0.05)。在本试验日粮条件下,每天每只饲喂300 g（Ⅲ组）精料时的饲料转化率最高,青贮料比Ⅲ组更为经济。     

不同施肥处理的杂交狼尾草打浆后饲喂育肥猪效果研究

试验设计4个处理3个重复,开展不同施肥处理的杂交狼尾草打浆后饲喂育肥猪效果研究。4个处理为：处理Ⅰ（CK）只饲喂肥育猪的基础日粮,处理Ⅱ为基础日粮＋浇灌沼液的牧草浆0.25kg/头.d,处理Ⅲ为基础日粮＋浇灌沼液的牧草浆0.5kg/头.d,处理Ⅳ为基础日粮＋浇灌沼液并加施尿素的牧草浆0.5kg/头.d。结果表明,处理Ⅱ、Ⅲ、Ⅳ平均日增重分别比处理Ⅰ提高了22.4g,40.4g和48.4g,料肉比分别比处理Ⅰ降低了4.62%、3.96%和7.26%,每头猪效益分别比处理Ⅰ提高了26.0元、34.3元和44.6元,猪肉氨基酸含量也比处理Ⅰ有不同程度的提高,尤其以添加增施尿素的牧草浆后,肥育猪的日增重、料肉比和经济效益都最好。     

Effect of Immunization against Somatostatin (SS) in Cattle: A Review of Performance,Carcass Composition and Possible Mode of Action

Abstract

A review of the effects of immunization against somatostatin in cattle is given. In most experiments (8 out of 9; no information in 2), significant antibody formation was reported in immunized animals but antibody formation may vary between individuals. Only a few have reported data on antibody affinity, but available data indicate that the antibodies formed may act to neutralize SS rather than function as binding proteins. Meta-analysis on weighted group averages showed that anti-SS animals consumed 4.2 ± 1.4% more feed (P = 0.03), had a 11.4 ± 2.3% higher daily gain (P < 0.001) and had a 4.7 ± 2.1% lower feed conversion ratio (P = 0.06), indicating improved feed efficiency. Increased fat deposition has been observed following immunization against SS, but more studies are needed in order to quantify the changes. Immunization does not seem to affect dressing percentage or carcass conformation score. The mode of action of immunization against SS seems to be associated with IGF-I and not GH, but more studies are needed to clarify fully the mechanisms by which immunization modifies performance in cattle.     

Effect of feeding forest foliages, rice straw and concentrate-based total mixed ration on nutrient utilization and growth in mithun (Bos frontalis)

The study aimed to evaluate the effect of feeding Borrena hirticulata (BH), Ficus hirta (FH), rice straw (RS) and concentrate-based total mixed ration (TMR) on nutrient utilization, rumen fermentation and growth in mithun. Growing male mithun calves were randomly allotted to 2 feeding groups (6 in each), TMR₁ and TMR₂. The TMRs consisted of RS 300 g kg^− 1, concentrate 400 g kg^− 1 and BH 300 g kg^− 1 (TMR₁) or FH 300 g kg^− 1 (TMR₂) on a dry matter (DM) basis. Both TMRs were fed ad libitum to the animals for 121 d and a digestibility study was conducted during the last 7 d of the experiment. To assess rumen fermentation, rumen fluid was collected at 2 h interval for 24 h. Apparent digestibility of DM, crude protein (CP) and crude fibre (CF) did not differ significantly between the TMRs. Nevertheless, apparent digestibility of ether extract was found to be significantly (P < 0.01) greater in TMR₂ (0.59) compared to TMR₁ (0.54). Body weight gain (BWG; g d^− 1), DM intake (kg d^− 1), CP intake (g d^− 1) and feed efficiency (kg feed kg^− 1 gain) were found to be significantly (P < 0.05) greater in TMR₁ (548, 5.14, 713 and 9.28) compared to TMR₂ (496, 4.91, 703 and 10.03). An insignificant positive association (r = 0.35) between DM intake and BWG, but a significant (P < 0.01) positive association (r = 0.74) between CP intake and BWG were evident. Rumen pH (5.71 to 7.18) and ammonia-nitrogen (8.0 to 25.0 mg/dl) did not differ significantly between the TMRs, but differed significantly (P < 0.01) at different h post-feeding. In contrast, rumen total volatile fatty acid (42 to 105 mM) and total nitrogen (40.4 to 90.3 mg/dl) differed significantly (P < 0.05) between the TMRs and at different h post-feeding. The study revealed that BH, FH, RS and concentrate-based TMRs may be fed to mithun for satisfactory growth.     

Effects of grass forage species and long‐term period of low quality forage diet feeding on growth performance,nutrient utilization and microbial nitrogen yield in growing wether lambs

Six growing lambs were used to evaluate the feeding value of two forage‐based diets in a long‐term feeding period by measuring body weight (BW) gain, digestibility, nitrogen (N) retention and microbial N (MBN) yield. The animals were fed imported low‐quality timothy hay (TH) with concentrate diet (THD) or imported low‐quality Italian ryegrass straw (IR) with concentrate diet (IRD) for 9 months. The forages were offered at 2% BW, and concentrate was fed at 40% of forage intake. The BW gain averaged 82.6 and 66.2 g/day for THD and IRD, respectively, without showing significant difference. Average forage intake (% BW) was significantly greater for IR than for TH, although it was not affected by feeding periods. The digestibility did not differ between diets or periods. The numerically greater (P = 0.06) ratio of retained N to absorbed N for IRD than that for THD was prominent. Neither diet nor period had significant effect on MBN supply and efficiency of MBN synthesis. The results suggest that the IR‐based diet can be also used for long‐term periods of feeding to growing ruminant animals as a grass hay‐based diet without any detrimental effects on nutrient utilization and growth performance.     

Effect of feeding Acacia nilotica pods to sheep on nutrient digestibility,nitrogen balance,ruminal protozoa and rumen enzymes activity

This study was conducted to evaluate the effect of supplying two levels of Acacia nilotica (A. nilotica) pods to rations of sheep on nutrient digestibility, nitrogen balance and rumen liquor parameters (pH, total protozoa count, protein concentration and enzymes activity). Twelve mature rams (50 ± 1.25 kg B.W.) were distributed into three groups, each with four rams. Animals in group one were considered as a control which fed a basal diet, consisting of concentrate mixture and Egyptian clover. The second group and the third one received the same basal diet with supplying the concentrate mixture by 1.5% and 3.0% of A. nilotica pods meal respectively. The experiment lasted for 3 weeks. It was found that supplementation of A. nilotica pods to the concentrate mixture at a rate of 1.5% and 3.0% significantly improved the total feed intake compared to the control. The digestibility of dry matter and crude fibre was significantly reduced with A. nilotica supplements, whereas the digestibility of crude protein was significantly improved. All of nitrogen intake and N‐retained were significantly increased in rams fed on concentrates with 1.5% and 3.0% A.  nilotica pods when compared to the control. The pH of ruminal fluid was not affected by the dietary treatments. Nevertheless, the total rumen protozoa count was significantly decreased in A. nilotica pods supplemented groups. Also, the rumen protein concentration and the ruminal enzymes activity, especially α‐amylase, cellulase and protease, were lower in A. nilotica pods supplemented treatments. In conclusions, inclusion of low levels of A. nilotica pods (1.5% and 3.0%) in the concentrates can be used as a natural protein protectant in ruminants by forming tannin protein complexes in the rumen to maximize the amino acids available in the lower digestive tract. Also, these levels can increase the protein digestibility as well as the N‐retained in the body .     

Effect of Mediterranean saltbush (Atriplex halimus) ensilaging with two developed enzyme cocktails on feed intake,nutrient digestibility and ruminal fermentation in sheep

The aim of this study was to assess the effects of feeding Atriplex halimus (AH) silage treated with two developed enzyme cocktails to sheep on feed intake, nutrient digestibility and ruminal fermentation. The AH silage was treated without or with 2 L of ZAD1^® or ZAD2^®/1000 kg with 5% molasses and ensiled for 30 days. Barley grain (300 g/head/day) was fed as an energy supplement once daily at 10.00 hours and AH silage with or without enzyme treatment was offered ad libitum to animals twice daily at 09.00 and 16.00 hours. Sheep were fed on four experimental forage diets comprised of AH silage and barley (D1), AH silage treated with ZAD1^® and barley (D2), AH silage treated with ZAD2^® and barley (D3) and AH silage treated with a combination of ZAD1^® and ZAD2^® (1:1) and barley (D4). Ensiling AH with enzymes reduced its contents of neutral detergent fiber and acid detergent fiber. The dry matter intake of AH of D2, D3 and D4 decreased (P < 0.001) as compared to D1. However, enzyme‐treated diets had greater total digestible nutrients intake (P < 0.001) as compared to D1. The nutrients digestibility for D2, D3 and D4 were higher than those for D1 (P < 0.001), and were higher for D3 as compared to both D2 and D4. Sheep fed on D3 had highest (P < 0.001) ruminal total volatile fatty acids concentration, ammonia nitrogen concentration and microbial protein yield. It could be concluded that AH silage treated with ZAD1^® or ZAD2^® improved digestibility and rumen fermentation in sheep.     

日粮纤维素水平及饲养环境对断奶猪生长性能、养分消化及肠道健康的影响

文章旨在评估日粮添加不同水平的纤维素及不同饲养环境对断奶仔猪生长性能、营养物质表观消化率及小肠绒毛形态的影响.试验将1296头24?d断奶、平均体重无显著差异的仔猪随机分为4组,每组324头,每组6个重复(54头/重复).将T1和T2组断奶仔猪饲养在环境条件良好的圈舍中,在断奶后前2周分别饲喂纤维素水平为0％和2％的日...     

Effect of graded levels of dietary corn steep liquor on growth performance,nutrient digestibility,haematology and histopathology of broilers

This experiment was conducted to assess nutritional potential of corn steep liquor (CSL) as an alternative protein source in broiler's diet. A total of 280‐day‐old unsexed broiler chicks were randomly distributed into four experimental groups in a simple randomised experimental design (each group had seven replicates; 10 birds per each). Four iso‐nitrogenous and iso‐caloric broiler starter and finisher diets (C, LCSL, MCSL and HCSL) were formulated containing 0%, 5%, 10% and 15% CSL respectively. Results revealed that chicks fed MCSL diet had significantly (p ≤ .05) the heaviest Body weight, highest Body weight gain and the lowest feed conversion ratio followed by those fed HCSL diet. In the starter period, LCSL and MCSL diets resulted in better (p ≤ .05) dry matter (DM) (89.57%) and crude protein (67.67%) digestibilities respectively. In the finisher period, DM, crude fibre and fat digestibilities were not affected by CSL inclusion levels; while crude protein digestibility was significantly (p ≤ .05) high in the groups fed LCSL and HCSL diets. The CSL inclusion had no effect on blood haematology except serum uric acid, which tended to increase with increasing CSL levels. No microscopic changes were exhibited on liver, heart, kidneys and intestine of birds across all dietary treatments. However, crops in birds fed HCSL diet showed moderate to severe hypertrophy and hyperplasia of the mucosal lining. The study showed that CSL could be added up to 15% in broiler's diet without any adverse effect on bird's performance.     

The effects of protein sources supplemented with urea-treated potato pulp (PP) silage and feeding levels of the PP silage-based concentrate on feed intake, digestibility and ruminal fermentation in beef steers

Six Japanese Black (Wagyu) steers (average initial weight 467 ± 45 kg) fitted with a ruminal cannula were used in a split‐plot design experiment comprising a 3 × 3 Latin square design (whole‐plot) and a randomized block design (subplot). The whole‐plot treatments were three different feeding levels of urea‐treated potato pulp (PP) silage‐based concentrate: 1.00%, 1.75% and 2.50% of body weight (BW) (on a dry matter (DM) basis). The subplot treatments consisted of the concentrate formulated to contain either soybean meal (SBM) as a rapidly rumen‐degraded protein source or corn gluten meal (CGM) as a slowly degraded protein source. Dry matter intake tended to be lower (P = 0.071) for CGM (8.9 kg/day) than for SBM (9.4 kg/day). Protein sources had no significant effect on digestibility and in situ degradation. Ruminal ammonia nitrogen (NH₃‐N) was lower (P = 0.033) for CGM (7.5 mg/dL) than for SBM (9.5 mg/dL). Protein sources did not affect ruminal pH and the total volatile fatty acids (VFA) concentrations. The molar proportions of ruminal acetate and valerate were higher (P = 0.032) for CGM than for SBM. The maximum daily intake of the PP silage‐based concentrate expressed as a percentage of BW was approximately 1.4% of BW. Dry matter intake was higher (P = 0.046) for steers fed at 1.0% of BW of the PP silage‐based concentrate than for steers fed at 1.75% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate had no effect on DM and nutrients digestibility, except for crude protein (CP) digestibility. CP digestibility tended to be lower (P = 0.071) for steers fed at 1.75% of BW of the PP silage‐based concentrate than for steers fed at 1.0% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate also did not affect the in situ degradation parameter of hay and PP silage. The feeding levels of the PP silage‐based concentrate did not affect ruminal pH, NH₃‐N and total VFA concentrations. The molar proportion of acetate was highest for steers fed at 1.0% of BW of the concentrate. In conclusion, in the urea‐treated PP silage‐based concentrate, CGM seems to be more effective than SBM for stabilizing the ruminal NH₃‐N concentration and to be advantageous for fiber digestion in the rumen. The feeding levels of the PP silage‐based concentrate did not change the amount of VFA production in the rumen and the DM digestibility.     

不同代谢葡萄糖水平饲粮对8～10月龄后备奶牛生长发育、营养物质消化率和血清生化指标的影响

本试验旨在研究不同代谢葡萄糖水平饲粮对8～ 10月龄荷斯坦后备奶牛生长发育、营养物质消化率和血清生化指标的影响.试验选用24头月龄、体重接近的健康荷斯坦后备奶牛,随机分为4组,每组6头牛,分别饲喂代谢葡萄糖水平为86.43(A组)、99.93(B组)、113.59(C组)和126.42∥kg(D组)的4种试验饲粮,试验期60 d.在试验期开始当天、第30天、第60天测定生长发育指标和血清生化指标;在试验期第21 ～ 25天、第51～55天,采用酸不溶灰分(AIA)法进行消化试验,测定营养物质消化率.结果表明:1)随着饲粮代谢葡萄糖水平的提高,后备奶牛平均日增重呈先升高后趋于稳定的趋势,A、B、C、D组平均日增重分别为0.49、0.71、0.87、0.87 kg/d,A组显著低于B组(P＜0.05),极显著低于C和D组(P＜0.01).同一时间点各组后备奶牛体高、体斜长、胸围、腹围和管围接近.2)第30天和第60天,A组血清尿素氮含量均显著高于C组(P＜0.05),第30天,B组血清胰岛素含量极显著低于C组(P＜0.01).3)饲粮代谢葡萄糖水平对后备奶牛营养物质消化率无显著影响(P＞0.05).综合得出,饲粮代谢葡萄糖水平为113.59g/kg时能满足8～10月龄荷斯坦后备奶牛0.8～ 1.0 kg/d日增重的需要.