Effect of fibrolytic enzyme inclusion in high concentrate fattening diets on nutrient digestibility and growth performance of Awassi lambs

The objective of this study was to study the effect of fibrolytic enzyme (FE) inclusion on nutrient digestibility and growth performance of Awassi lamb fed on a high concentrate diet. Thirty weaned Awassi lambs (initial body weight = 20.4 ± 3.0 kg) were fed a high concentrate diet (with or without the addition of FE (15 lambs/treatment)) for 60 d in a completely randomized design. The diet contained 17, 7, 58.5, 15, and 2.5% wheat straw, wheat bran, barley grain, soybean meal and minerals, respectively. Lambs were fed ad libitum twice daily at 08:00 and 15:00 h. Dry matter, OM, CP, and NDF intakes were all similar (P > 0.05) for lambs fed diet with or without the FE and averaged 1078, 941, 171, and 432 g/d, respectively. Metabolizable energy intake was also not affected (P > 0.05) by the enzyme supplementation and averaged 2.87 Mcal/d. Dry matter, OM, CP, and NDF digestibilities were all unaffected (P > 0.05) by the enzyme inclusion and averaged 64.8, 67, 65.7 and 60.4%. Final body weight, average daily gain, and feed to gain ratio were all unaffected (P > 0.05) by the FE inclusion and averaged 34.9 kg, 222 g/d, and 5.4, respectively. In summary, FE treatment of high concentrate diet for lambs had no effect on nutrient intake or any of the growth performance parameters. Therefore, supplementing such diets with FE for fatting Awassi lambs is not recommended.     

Graded methionine dietary inclusions influence growth performance and apparent ileal amino acid digestibility coefficients and disappearance rates in broiler chickens

Graded quantities of 1.38,2.76 and 4.14 g/kg L-methionine were included in a control diet formulated to contain 3.07 g/kg digestible methionine.Each of the 4 dietary treatments was offered to 6 replicate cages(initially 8 birds per cage)from 1 to 21 d postehatch.The parameters assessed included growth performance,nutrient utilisation(apparent metabolisable energy[AME],AME:GE ratios,N retention,Ncorrected apparent metabolisable energy[AMEn]),apparent digestibility coefficients and disappearance rates of amino acids in the distal ileum.They also included free amino concentrations in systemic plasma(brachial vein)at 20 d postehatch and in hepatic tissue at 14 and 21 d postehatch.Graded L-methionine inclusions quadratically influenced weight gain(r=0.688;P=0.001)and FCR(r=0.780;P<0.001).It may be deduced from the quadratic regressions that 3.43 g/kg L-methionine supported maximum weight gain of 1,036 g/kg and 3.50 g/kg L-methionine minimum FCR of 1.193,from 1 to 21 d postehatch.The control diet contained specified levels of 3.07 g/kg digestible methionine and 13.0 g/kg digestible lysine.Thus,an inclusion of 3.465 g/kg L-methionine corresponded to a total of 6.535 g/kg methionine or a methionine-to-lysine ratio of 50.3,which is higher than standard recommendations.The implications of this and other outcomes of the present study are reported and discussed.     

Evaluation of tagasaste (Chamaecytisus palmensis) forage as a substitute for concentrate in diets of sheep

A feeding trial was carried out for 90 days to asses the supplementing effect of tagasaste forage as a substitute for a concentrate supplement (wheat bran–noug seed cake (Gizotia abyssinica) mixture in 3:1 proportion) using 24 Menz male sheep (initial weight of 18.3 ± 1.6 kg). The sheep were fed on natural pasture hay as basal diet. The treatments were iso-nitrogenous supplements of 100% concentrate offered at 200 g DM/sheep/day (T1), 67% concentrate + 33% tagasaste (T2), 33% concentrate + 67% tagasaste (T3) and 100% tagasaste (T4). Digestibility tests of treatment diets were done for 10 days following the feeding trial using the same experimental animals. At the end of the experiment, carcass parameters were also evaluated. In situ degradability of feeds was determined using three rumen fistulated crossbred steers. Tagasaste forage contains more CP (215 g/kg), ADF (221 g/kg), ADL (69 g/kg); and less NDF (351 g/kg) compared to the concentrate. The concentrate had a high immediately soluble fraction (a), and a low insoluble but potential degradable matter (b), while tagasaste had a low a and higher b values and the overall potential degradability was 755, 702, and 586 g/kg, for tagasaste, concentrate and natural pasture hay respectively. Tagasaste forage had also shown higher rates of degradation (c) compared to the concentrate which might increase the total effective degradability. In the feeding trial the supplements made 26.8, 27.0, 28.3 and 29% of the total dry matter (DM) intake for T1, T2, T3, and T4, respectively. Increasing the inclusion of tagasaste forage significantly (P < 0.01) decreased the daily total DM intake of the basal diet and total metabolizable energy (ME), and increased the CP intake. The average weight gain of sheep did not show significant difference (P > 0.05), but had a decreasing trend, with 44.4, 41.4, 38.9 and 38.1 g/sheep for T1, T2, T3, and T4, respectively. The in vivo digestibility of DM and nutrients generally followed the order of T1 > T2 > T3 > T4. The dressing percentage of the carcass was 40.4% and all other parameters measured did not show significant variation due to treatment diets (P > 0.05). However, weight of liver, kidney and spleen was higher for sheep fed with higher tagasaste forage diet. The result of this study revealed that tagasaste can substitute wheat bran–noug seed cake concentrate mixture as a protein supplement. Options to increase the low ME and minimize the effect of the anti nutritional factors will improve nutrient digestibility in tagasaste forage and will enhance the overall efficiency of feed utilization.     

饲养系统和日粮对羔羊屠宰性能和肌肉矿物质含量的影响

文章旨在探讨不同饲养系统和日粮对羔羊生长、屠宰性能及肌肉矿物质含量的影响。试验将平均体重为（13.97±0.55）kg的120只羔羊随机分为3组，每组4个重复，每个重复10只。T1组在室内饲喂基础浓缩料，每天补充100 g稻草，T2组在室内饲喂基础浓缩料，每天补充100 g稻草和锌硒复合矿物质（0.2 mg/d硒，50 mg/d锌），T3组在室外放牧，除了采食苜蓿草外，每天额外补充100 g稻草和100 g燕麦。试验时间为9周。结果：T1和T2组羔羊的末重、日增重、半胴体重、下肢深度、下肢重量、眼肌面积、颈、胸肌、肾重量均显著高于T3组（P＜0.05），但骨盆骨重量显著低于T3组（P＜0.05）。各处理组羔羊的可食用部分和骨盆肌肉重量无显著差异（P＞0.05）。T2组63 d羔羊血液硒含量较T1和T3组分别显著提高了19.83%和25.0%（P＜0.05），血液锌含量较T1和T3组分别显著提高了31.71%和45.91%（P＜0.05）。T3组羔羊肌肉钙含量较T1和T2组分别显著提高了8.79%和5.37%（P＜0.05）。T2羔羊肌肉硒和锌含量较T1和T3组分别显著提高了41.18%、65.52%和38.19%、46.15%（P＜0.05），T2和T3组羔羊肌肉钾含量较T1组分别显著提高了3.27%和4.28%（P＜0.05）。结论：在本试验条件下，放牧羔羊胴体的脂肪含量低于室内饲养的羔羊，室外放牧可以提高肌肉钙和钾含量，但肌肉硒含量降低。 [关键词]饲养系统|羔羊|屠宰性能|矿物质     

The effects of plastic slatted floor or straw bedding on performance, liver weight and liver copper concentrations in intensively reared lambs

One hundred and eight Texel sired lambs were weaned at 37 days old and allocated three days later to one of two treatments, using two pens per treatment, in order to evaluate lamb hepatic copper (Cu) values. In Treatment 1 (T1) the lambs were confined to pens having recycled plastic slatted flooring, while in Treatment 2 (T2) the lambs were confined to pens having straw bedded floors, with fresh straw added on alternate days. The lambs had ad libitum access to a coarse lamb concentrate. The crude protein (g/kg DM), crude fibre (g/kg DM), total zinc (mg/kg) and background levels of copper (Cu) (mg/kg) and molybdenum (Mo) (mg/kg) of the diet were 17.2, 10.9, 152, 9.7 and 0.92, respectively. The lambs were slaughtered when they reached about 39 kg live weight. Following slaughter, the liver was removed and weighed and the caudal lobe frozen for subsequent Cu analysis. The livers of lambs on the plastic floor treatment had higher liver weights (843 vs. 804 g, S.E.M. 11.0; P < 0.05) and higher hepatic copper (396 vs. 315 mg/kg DM, S.E.M. 18.2; P < 0.05) than those from lambs that were bedded with straw. The Cu accumulation per kg of liver DM per week was estimated to be 8.4 and 13.7 mg for lambs on the straw bedding and plastic slated treatments, respectively. It is concluded that when lambs are housed on plastic slatted flooring, relative to straw bedding, there is a higher accumulation of hepatic copper levels likely to result in a greater risk of Cu toxicity when lambs are reared on all concentrate diets.     

生长抑素基因工程苗和半胱胺对放牧羔羊增重效果的影响

选择 4～ 5月龄体重相近的杂种羔羊 90只 ,随机分成对照、添加半胱胺 (CS87)和生长抑素 (SS)苗免疫共 3组 ,每组公母各半。CS87按每千克体重 80mg每周添加 1次 ,持续 6周 ;SS苗按 1mL/只一次性免疫 ,9周结束。结果显示 ,添加CS87组 0～ 2 1d增重提高 1 6 46 % (P <0 0 5) ,2 1～ 42d增重提高 1 5 95 % (P <0 0 5) ;SS苗免疫组在 2 1～ 42d提高 5 86 % (P >0 0 5) ,42～ 63d提高 1 7 5 % (P <0 0 5) ,母羊效果优于公羊。     

Diet selection by growing lambs offered whole barley and a protein supplement, free choice: Effects on performance and digestion

Feeding whole barley and a protein supplement at choice to early weaned lambs (15 kg initial weight) was studied in four experiments. In a first experiment whole barley and a pelleted soybean meal-based supplement (348 g crude protein (CP)/kg dry matter (DM)) were given either at choice (CH) or mixed in a 75 / 25 ratio (M) and compared to a pelleted compound feed containing the same ingredients and supplemented with barley straw (C). The effect of allowing free access to straw in the CH treatment (CHS) was tested in a second experiment. Rumen fermentation was also studied in six lambs per treatment slaughtered after the growing period, and digestibility and allantoin excretion were determined in other four lambs per treatment. In Experiments 3 and 4 supplements containing 253–264 (L), 341–329 (M) and 424–427 (H) g CP/kg DM were offered at choice with whole barley to lambs penned individually (Experiment 3) or in a group (Experiment 4) and diet selection and lamb performance were recorded.

The protein supplement was selected in proportions of 0.28 and 0.34 (S.E. 0.021) of concentrate intake with treatments M and CH (Experiment 1) and 0.45 and 0.52 (S.E. 0.033) with treatments CH and CHS (Experiment 2). The concentration of rumen ammonia increased (P < 0.05) to 28 and 56 (S.E. 8.6) mg/l compared to 12 mg/l in treatment C. Rumen pH also increased (P < 0.001) from 4.95 to 5.48 and 5.60 (S.E. 0.080) with treatments CH and CHS while the concentration of volatile fatty acids and the acetate to propionate ratio tended to decrease (P < 0.1). Organic matter digestibility and allantoin excretion were higher with whole barley feeding (0.82 vs. 0.75 (S.E. 0.18) and 13.1 vs. 7.7 (S.E. 1.06) mmol/d) but decreased with straw supplementation (0.78 and 10.2 mmol/d). Daily weight gain of male lambs (but not of females) tended (P = 0.08) to be higher with whole barley than with the compound feed due to higher concentrate intake (P < 0.05), which was also depressed by straw supplementation of whole barley reducing the rate of gain (P = 0.06). Incidence of hyperparakeratosis and ulceration of rumen wall was high with all treatments (0.80 and 0.36) but papillary clogging was less frequent (P < 0.01) with whole barley (0.16) than with the compound feed (0.70) and tended (P = 0.01) to be reduced by straw supplementation. In Experiments 3 and 4 the proportion of protein supplements selected ranked in reverse order to their CP content, resulting in diets of similar CP concentration (180–200 g/kg DM). It is concluded that choice feeding of whole barley may be a practical alternative that offers some advantages over conventional compound feeding of growing lambs.     

磷酸脲添加量对羔羊生长性能、屠宰性能和肉品质的影响

本试验旨在研究磷酸脲添加量对羔羊生长性能、屠宰性能和肉品质的影响,并对磷酸脲在肉羊生产中的安全使用剂量进行评价。试验选用80只杜寒杂交F1代平均体重(25.86±1.06)kg的公羔羊,随机分为5组,每组8个重复,每个重复2只,在精粗比为1∶1的饲粮中分别以0(对照)、0.5%、1%、2%、4%的磷酸脲替代部分豆粕类饲料。预试期为12 d,正试期为60 d。结果表明:1%组的羔羊在各时期平均日增重、宰前活重、胴体重、屠宰率均达到最高值;4%组的羔羊在各时期平均日增重、宰前活重、胴体重均极显著低于其他各组(P0.01);与对照组相比,磷酸脲添加量对肉色红度值、p H、滴水损失无显著影响(P0.05);2%组的黄度值显著高于其他各组(P0.05);在剪切力方面,1%组(5.16 kg/cm2)显著高于0.5%组(4.47 kg/cm2)、4%组(3.69 kg/cm2)和对照组(4.21 kg/cm2)(P0.05)。结果提示:磷酸脲可以作为氮磷添加剂用于肉羊饲粮中。羔羊饲粮中的磷酸脲添加量为1%时,羔羊达到最佳生长性能和屠宰性能;当磷酸脲替代比例达到4%时,极显著降低羔羊的平均日增重、胴体重,增加肌肉的亮度值;当磷酸脲替代比例为2%时,为有效安全水平,对羔羊生长性能、屠宰性能和肉品质除肌肉黄度值外无显著影响。因此,饲粮中磷酸脲适宜添加量为1%。     

Growth performance and meat characteristics of hair lambs grazing stargrass pasture without supplementation or supplemented with concentrate containing different levels of crude protein

Abstract

Forty crossbreed hair lambs (19.1 kg body weight; 8 months of age) grazing on a Cynodon plestoctachyus pasture without supplementation or supplemented with 300 g of concentrate containing different levels of crude protein (CP) were randomly assigned to treatments defined as follows: control (without supplementation); CP130 (concentrate 130 g CP/kg), CP150 (concentrate 150 g/kg), CP170 (concentrate 170 g/kg), and CP190 (concentrate 190 g CP/kg). Lambs fed supplements had higher final body weight (BW), total gain, average daily gain (ADG), total dry matter intake (DMI), total tract digestion, and carcass dressing than lambs in control treatment. Final BW, total gain, ADG, total DMI, feed conversion, and total tract digestion were improved linearly as protein level in concentrate increased. Meat of lambs fed supplements was lighter, redder, and less yellow than meat of lambs in control treatment. It is concluded that supplementation improved ADG, feed conversion, carcass dressing, and meat color.     

半胱胺对藏绵羊断奶羔羊增重及饲料转化效率的影响

试验研究了半胱胺(Cs)对藏绵羊断奶羔羊增重、饲料转化效率的影响。将40只(公母各半)80日龄左右且体重平均为(16.00±0.31)kg的藏绵羊断奶羔羊随机分为2组(试验组和对照组),在日粮精料中添加300 mg/(kg·BW)的Cs,隔日添加1次,试验期42 d。分别于开始用药后的第0、7、14、21、28、35天称重,并记录各组所采食的精料量。试验结果表明,试验组精料中添加Cs使藏绵羊断奶羔羊35 d增重提高43.25%(P0.01),开始用药后的前7 d差异不显著,但8~35 d最为明显,以后随时间延长促生长效果逐渐减弱;精料/增重比下降43.33%。     

Improvement of growth and nitrogen utilization in sheep using sugar beet pulp treated with Trichoderma reesei or urea

Twenty-five intact Barki lambs with mean body weight of 24.81 ± 0.16?kg were used to investigate the effect of including in the diet sugar beet pulp (SBP) treated biologically with Trichoderma reesei or chemically with urea 4 % on nutrients digestibility, growth performance, nitrogen (N) utilization, and hematological and biochemical parameters. Two experiments were conducted. In the growth experiment, five lambs were randomly assigned to one of five dietary treatments. Lambs were offered isonitrogenous and isoenergetic concentrate feed mixture containing on dry matter basis 0 % SBP (D0), 50 % SBP (D1), 50 % SBP treated with 4 % urea (D2), 50 % SBP treated with T. reesei (D3), and 25 % SPB treated with 4 % urea plus 25 % SPB treated with T. reesei (D4). In the metabolism experiment, five rams were used in a 5?×?5 Latin square design and housed in metabolism crates for 21?days. The present study showed that inclusion of SBP at the level of 50 % (D1) negatively affected diet digestibility coefficients of crude protein, crude fiber, and ether extract, in addition to average daily gain, feed conversion, and N utilization. However, treatment of SBP with urea (D2), T. reesei (D3), or the combination (D4) of both had improved (P?相似文献   

Effects of soybean raffinose on growth performance,digestibility,humoral immunity and intestinal morphology of growing pigs

There are appreciable does of raffinose in soybean, but the impacts of raffinose on pigs are poorly investigated. We used 2 experiments to investigate the influence of soybean raffinose on growth performance, digestibility, humoral immunity and intestinal morphology of growing pigs. In Exp. 1, a total of 30 crossbred (Duroc × Landrace × Yorkshire) barrows (21.93 ± 0.43 kg) were randomly divided into 3 groups, and were fed with the control diet, the control diets supplemented with 0.2% and 0.5% raffinose, respectively, for 21 d. Results showed that the addition of 0.2% or 0.5% raffinose reduced (P < 0.05) average daily feed intake (ADFI), average daily gain (ADG) and nutrient digestibility, and dietary 0.5% raffinose increased the ratio of feed to gain (P < 0.05). For serum indexes, dietary 0.5% raffinose decreased growth hormone and increased glucagon-like peptide-2, immunoglobulin G, tumor necrosis factor-α (TNF-α) and interleukin-6 concentration (P < 0.05). In Exp. 2, a total of 24 crossbred barrows (38.41 ± 0.45 kg) were randomly divided into 3 groups, and were fed with the control diet (ad libitum), the raffinose diet (0.5% raffinose, ad libitum), and the control diet in the same amount as the raffinose group (feed-pair group) for 14 d, respectively. Compared with the control diet, dietary 0.5% raffinose decreased ADFI (P < 0.05). Intriguingly, the raffinose group had lower ADG than the feed-pair group, lower nutrient digestibility, lower amylase activity in duodenum, lower amylase, lipase and trypsin activities in jejunum and higher TNF-α concentration in serum compared with the other 2 groups, and a higher ratio of villus height to crypt depth compared with the control group (P < 0.05). These results showed that soybean raffinose could reduce feed voluntary intake and body gain while improving intestinal morphology without a significant negative influence on immunity. Taken together, dietary raffinose could decrease growth performance by reducing both feed intake and nutrient digestibility while inducing humoral immune response of growing pigs.     

Glutamic acid supplementation recovers the reduced performance of weanling pigs fed reduced crude protein diets

This study was conducted to evaluate the supplementation of glutamic acid(Glu)to reduced protein diets on the performance of weanling pigs.One hundred and eighty crossbred weanling pigs([Yorkshire
Landrace]
Duroc,21 d old)having similar body weight(BW)of 6.45 kg were randomly allotted to 1 of 6 dietary treatments(5 pigs per pen[2 barrows and 3 gilts];6 pens per treatment)based on BW and sex during a 6-week trial.Dietary treatments consisted of positive control(PC)diet formulated to have 226.9,205.6,and 188.8 g crude protein(CP)during phases 1,2,and 3,respectively,and negative control(NC)diets with 20 g CP reduction from PC diets and addition of Glu with increasing levels,resulting in the calculated Lys-to-Glu ratios of 1:2.25,1:2.30.1:2.35,1:2.40,and 1:2.45,designated as NC,NC1,NC2,NC3,and NC4,respectively.The BW of pigs receiving PC diet was higher(P<0.05)than those receiving NC diet at d 7,21 and 42.A higher(P<0.05)average daily gain(ADG)from d 1 to 7,8 to 21,22 to 42 and during the overall experiment period was observed in pigs fed PC than NC diet.Pigs fed NC diets including the graded level of Glu linearly increased(P<0.05)BW at d 42,ADG and gain-to-feed ratio(G:F)during the overall experimental period.In addition,trends in linear increase in BW(P=0.056)at d 7 and ADG from d 1 to 7 and d 22 to 42(linear effect,P=0.081,P=0.058 respectively)were observed.A tendency in the linear increment of NH3(P=0.082)at d 21 and linear reduction in methyl mercaptans(P=0.054)emission at d 42 was observed in pigs fed NC diets supplemented with graded level of Glu.In conclusion,supplementing the reduced protein diet with Glu enhanced the growth performance in weanling pigs suggesting that supplementation of Glu can compensate the reduction of 2%CP in the basal diets.     

补饲精料对乌珠穆沁羊生产性能、屠宰性能和肉品质的影响

试验旨在研究草颗粒和草颗粒补饲精料对乌珠穆沁羊生产性能、屠宰性能和肉品质的影响。选取20只6月龄体重为(28.83±0.19) kg乌珠穆沁羊,采用随机区组设计,随机分为2组,每组10只。设计2种日粮饲喂乌珠穆沁羊,分别为草颗粒(对照组)和草颗粒补饲精料(试验组)。结果表明:补饲精料未能显著影响羊的日增重(P>0.05),日增重分别为56.33和60.00 g。对照组和试验组的3项屠宰性能指标(宰前活重、胴体重、屠宰率)、6项化学成分指标(粗蛋白、粗脂肪、有机物、干物质、钙、磷)、6项肉品质指标(pH1、pH24、大理石纹、亮度、熟肉率、剪切力)、16项脂肪酸指标和15项氨基酸指标差异均不显著(P>0.05)。试验组羊4项屠宰性能指标(净肉重、净肉率、眼肌面积、GR值)、4项肉品质指标(红度、黄度、胆固醇、失水率)、6项脂肪酸指标(十三碳酸、肉豆蔻酸、珍珠酸、γ-亚麻酸、α-亚麻酸、花生酸)和3项氨基酸指标(异亮氨酸、酪氨酸、精氨酸)均显著高于对照组(P<0.05)。对照组7项主要脂肪酸(丁酸、月桂酸、肉豆蔻烯酸、十五碳酸、十五碳烯酸、棕榈酸、棕榈油酸、硬脂酸、油酸、n-6/n-3)、苏氨酸和谷氨酸显著高于试验组(P<0.05)。饲喂草颗粒补饲精料对乌珠穆沁羊生长性能影响不大;天然草地草颗粒饲喂能满足家畜营养需求,在促进乌珠穆沁羊生产性能、屠宰性能和肉品质方面具有重大潜力。     

Dietary soluble non-starch polysaccharide level and xylanase supplementation influence performance,egg quality and nutrient utilization in laying hens fed wheat-based diets

The aim of this study was to evaluate the effects of dietary soluble non-starch polysaccharide (sNSP) content and xylanase supplementation on production performance, egg quality parameters, and nutrient digestibility in Hy-line Brown layers from 25 to 32 wk of age. A total of 144 Hy-line Brown laying hens (25 wk of age) were randomly allocated to 1 of 4 wheat-based dietary treatments in a 2 × 2 factorial experimental design, with 36 replicates of individual hens per treatment. The diets were formulated to contain either a high or low sNSP level (at 13.3 or 10.8 g/kg) and were supplemented with either 0 or 12,000 BXU/kg exogenous xylanase. Birds were fed these treatment diets for an 8-wk period, and hen production performance, including daily egg production, average egg weight, daily egg mass, feed conversion ratio and proportion of dirty and abnormal eggs were measured at bird age 25 to 28 wk and 29 to 32 wk. An interaction between sNSP content of the diet and xylanase supplementation was observed on daily egg production from 25 to 28 wk of age (P = 0.018); birds fed the high sNSP diet without xylanase had lower egg production than those fed any other treatment. An interaction between the 2 dietary factors was also observed on hen weight gain at 29 to 32 wk of age (P = 0.014), with birds fed the low sNSP diet with 12,000 BXU/kg xylanase presenting greater weight gain compared to those fed the high sNSP diet with 12,000 BXU/kg xylanase. Feed intake at 29 to 32 wk of age was reduced by xylanase supplementation (P = 0.047). Xylanase supplementation also increased yolk colour score at both 28 and 32 wk of age, and decreased yolk weight at 32 wk of age (P = 0.014, 0.037 and 0.013, respectively). Birds fed the low sNSP diet presented lower protein digestibility (P = 0.024) than those fed the high sNSP diet. Additionally, birds fed high sNSP presented higher shell reflectivity at both 28 and 32 wk of age (P = 0.05 and 0.036, respectively). The influence of duration of feeding the treatment diets on egg quality was also determined. It was observed that egg weight, yolk weight and yolk colour score consistently increased over time, regardless of experimental treatment effects. In contrast, Haugh Unit and albumen height significantly decreased throughout the study period in all treatments, although this was less pronounced in hens fed the treatment with high sNSP and no supplemental xylanase. A reduction in shell breaking strength over time was observed only in hens fed the treatments without xylanase addition, and shell thickness was improved over time only in birds fed the low sNSP diet with xylanase. The impacts of the dietary treatments were largely inconsistent in this study, so a solid conclusion cannot be drawn. However, these findings do indicate that dietary NSP level influences layer production performance, and thus should be considered when formulating laying hen diets. It also proved that further research is warranted into how to optimize the benefits of xylanase application in laying hens.     

Characteristics of lambs fed concentrates or grazed on ryegrass to traditional or heavy slaughter weights. II. Wholesale cuts and tissue accretion

Targhee x Hampshire lambs (average BW 24 +/- 1 kg) were used to determine the effect of finishing on concentrate or by grazing ryegrass forage on slaughter weights of 52 kg (N) or 77 kg (H) on tissue accretion and lamb wholesale cutout. When fed to similar slaughter weights, the wholesale cuts of concentrate-fed lambs were heavier (P < 0.05) than the same cuts from forage-fed lambs; however, when expressed as a percentage of side weight, carcasses of forage-fed lambs had a higher (P < 0.001) percentage of leg than concentrate-fed lambs. Increasing slaughter weight from 52 to 77 kg resulted in a 1-kg increase in loin weight for lambs finished on concentrate and a 0.60-kg increase for lambs finished on forage (diet x slaughter weight, P < 0.03); however, the increased loin weight for lambs finished on concentrate was due largely to increased fat deposition. For lambs slaughtered at 77 kg, those finished on forage had more lean mass in the leg, loin, rack, and shoulder than those finished on concentrate, but lean mass in these cuts did not differ between diets for lambs slaughtered at 52 kg (diet x slaughter weight, P < 0.01). At the normal slaughter weight (52 kg), concentrate-fed lambs had 50% more dissectible fat than forage-fed lambs, whereas at the heavy slaughter weight, a 79% greater amount of dissectible fat was observed for concentrate- vs. forage-fed lambs (diet x slaughter weight, P < 0.001). Lean and fat accretion rates were higher (P < 0.001) for concentrate-fed lambs than for forage-fed lambs. The lean-to-fat ratio of forage-fed lambs was higher (P < 0.001) than that of concentrate-fed lambs; however, forage finishing decreased accretion rates of all tissues compared with concentrate feeding, and these differences between forage and concentrate feeding were magnified at heavier slaughter weights.     

Potential of blended organic acids to improve performance and health of broilers infected with necrotic enteritis

Organic acids (OA) and their blends have been shown to positively affect performance and health of broilers. However, the data in the literature are not consistent. This study examined the potential of blended short-chain fatty acids (SCFA) with medium-chain fatty acids (MCFA) as alternatives to antibiotic growth promoters (AGP) on performance, health and welfare of broilers infected with necrotic enteritis (NE). The additives used were: A) a blend of SCFA, MCFA, and a phenolic compound (SMP); B) a blend of free and buffered SCFA with MCFA (SMF); C) a blend of free and buffered SCFA with a high concentration of MCFA (SHM). A total of 1,404 Ross 308 one-day-old male parental chicks were randomly distributed into 78-floor pens with 13 replicates of 18 birds each. Six treatments were the following: T1, unchallenged control (UCC); T2, challenged control (CHC); T3, challenged group plus zinc bacitracin (BAC); T4, challenged group plus additive SMP; T5, challenged group plus additive SMF; T6, challenged group plus additive SHM. Challenged birds were gavaged with Eimeria spp. on d 9 and Clostridium perfringens EHE-NE18 on d 14. Post NE challenge and cumulatively, BWG, FCR, and nutrient digestibility of birds were compromised (P < 0.05) by NE challenge indicating a successful induction of sub-clinical NE. Additive SHM had higher BWG compared to CHC and BAC groups (P = 0.001; d 10 to 24) but not different from SMP and SMF groups (P > 0.05). All the 3 additive groups had lower FCR compared to CHC (P = 0.001; d 0 to 35), and exhibited similar jejunal lesions (d 16) compared to BAC and apparent ileal protein digestibility (d 21) compared to UCC and BAC groups (P > 0.05). Birds in additive SHM group had a higher concentration of serum IgA compared to all groups (P = 0.001) except additive SMF (P > 0.05; d 21). All the additive groups had lower footpad dermatitis and hock burns compared to CHC (P < 0.05). The findings suggest the potential of blended OA as alternatives to BAC to protect broilers from NE indicated by improved FCR, immunity, digestibility, and bird welfare.     

Partial or total replacement of commercial concentrate with on-farm-grown mulberry forage: effects on lamb growth and feeding costs

Replacing commercial concentrate with mulberry foliage was evaluated in a feeding trial lasting 126 days. Forty-eight weaned male Pelibuey lambs (20.6?±?0.80 kg of BW) were randomly allocated to four groups: (1) supplementing the basal diet with mulberry at 1% (DM basis; M-1), (2) mulberry at 0.75% plus 0.1 kg concentrate fresh matter basis (M-0.75), (3) mulberry at 0.50% plus 0.2 kg concentrate (M-0.50) and (4) basal diet plus 0.3 kg concentrate (control; M-0). During the first 90 days, the basal diet was Pennisetum purpureum forage which was substituted by a mixture of guinea grass and sugarcane from 90 days. Average daily gain (ADG, g/day), dry matter intake (DMI) and feed conversion rate (FCR; DMI/ADG) were determined. The ADG was affected (P?<?0.01) by the diet, with the lowest obtained in M-1 lambs (71?±?6.4 g/day), whereas no differences among the other groups were observed (94?±?6.4 g DM/lamb). The DMI was higher (P?<?0.01) in M-0 (937 g DM/lamb) which concomitantly affected differences in FCR (11.9, 9.9, 10.5 and 9.7 kg DMI/kg BW gain for M-1, M-0.75, M-0.50 and M-0 lambs, respectively). Final BW at slaughtering and hot or cold carcass yields were coherent with growth rate findings. Biological yield (cold carcass weight/empty BW) was higher (P?<?0.01) in M-0.75. Without compromising animal productivity, replacing imported concentrate with mulberry reduced the feeding cost. Optimum results were obtained with M-75 diet. Further studies must be conducted for optimizing energy/protein ratios with different ingredients while increasing DMI and lamb growth rates in this tropical genotype.     

饲粮精料水平和蛋氨酸铬添加剂量对舍饲滩羊生长性能、屠宰性能、肉品质和脂肪沉积的影响

本试验旨在探究饲粮精料水平和蛋氨酸铬(Cr-Met)添加剂量对舍饲滩羊生长性能、屠宰性能、肉品质和脂肪沉积的影响.采用2×3双因素试验设计,2个因素分别为饲粮精料水平和Cr-Met添加剂量,其中饲粮精料水平分别设为35％(低精料饲粮,饲粮精粗比为35:65)和55％(高精料饲粮,饲粮精粗比为55:45),Cr-Met添...