Effect of relative humidity at either acute or chronic moderate temperature on growth performance and droppings' corticosterone metabolites of broilers

The present study aimed to investigate the effect of relative humidity(RH) at either acute or chronic moderate ambient temperature(Ta) on growth performance and droppings' corticosterone metabolites of broilers.Two experiments were conducted: effect of RH(35,60 or 85%) on average daily feed intake(ADFI) and droppings' corticosterone metabolites at acute(1 d: 20–26 or 31–20°C,26 or 31°C for 6 h d–1 at 10:00–16:00) moderate Ta(experiment 1) and effect of RH(35,60 or 85%) on growth performance and droppings' corticosterone metabolites at chronic(step-wisely increasing temperature by 3°C every 3 d from 20 to 32°C within 15 d: 20–23–26–29–32°C) moderate Ta(experiment 2).Droppings were collected at the 2,4,6,8,and 22 h after Ta-RH controlled in experiment 1 and at the 2,4,6,and 22 h after Ta controlled to 32°C in experiment 2.The results showed that: 1) In experiment 1,85% RH increased(P0.05) the droppings' corticosterone metabolites at the 2,6,8,and 22 h and 35% RH increased(P0.05) it at the 2 and 22 h compared to the 60% RH.Moreover,85% RH further increased(P0.05) it compared to the 35% RH,however,no difference(P0.05) was found in ADFI among the three RH groups at acute moderate 26°C; 35 and 85% RH increased(P0.05) droppings' corticosterone metabolites at the 2,6,8 and 22 h and decreased(P0.05) ADFI compared to the 60% RH,moreover,85% RH further increased(P0.05) droppings' corticosterone metabolites and further decreased(P0.05) ADFI compared to the 35% RH at acute moderate 31°C; and the average of droppings' corticosterone metabolites in the whole period had a negative correlation(P0.02) with the ADFI.2) In experiment 2,85% RH increased(P0.01) droppings' corticosterone metabolites only at the 2 h and decreased(P0.02) ADFI and average daily gain(ADG) compared to the 60% RH,no difference(P0.05) in droppings' corticosterone metabolites was found between the 35 and 60% RH,however,35% RH decreased(P0.01) ADG compared to the 60% RH,and the average of droppings' corticosterone metabolites in the whole period also had a negative correlation(P0.02) with ADFI and ADG.In conclusion,droppings' corticosterone metabolites could be used as a RH stress index and low and high RH,especially high RH,reduced growth performance possibly through inducing RH stress at moderate temperature.     

The toxicological effect of dietary excess of saccharicterpenin,the extract of camellia seed meal,in piglets

Recently, saccharicterpenin extracted from Camellia oleifera seed meal has become a widely used feed supplement in animal husbandry. In order to assess its safety, this study was designed to investigate the toxicity and histopathological effects of saccharicterpenin on piglets. One hundred-fifty weaned pigs((Yorkshire×Landrace)×Duroc), 75 males and 75 females with body weight(BW) of(7.35±0.29) kg, were randomly allotted to groups receiving diets supplemented with 0, 500, 1 000, 2 500 or 5 000 mg kg~(–1) saccharicterpenin for 70 d. The diet with 500 mg kg~(–1) saccharicterpenin supplementation improved liver glutathione peroxidase(GSH-Px) activity, and the diet with 1 000 mg kg~(–1) saccharicterpenin supplementation improved liver glutathione S-transferase(GSH-S) activity in piglets on d 70(P0.05). At 2 500 mg kg~(–1), saccharicterpenin in the diets reduced average daily feed intake(ADFI) and average daily gain(ADG) of piglets from d 1 to 35, damaged the cardiac tissue and liver on d 35, and decreased white blood cell counts(WBC), activities of catalase(CAT) and GSH-Px, and concentrations of glucose(GLU) and urea nitrogen(BUN) in the blood of piglets on d 70(P0.05). In addition, diets with 5 000 mg kg~(–1) saccharicterpenin supplementation reduced ADFI, ADG and increased diarrhea rates of piglets from d 36 to 70, and decreased hemoglobin(HGB) concentration and activity of CAT in the blood of piglets on d 70(P0.05). Moreover, at a rate of 5 000 mg kg~(–1), saccharicterpenin supplementation increased pancreas index on d 35 and hepatic index on d 70, and damaged cardiac tissue, liver and spleen during the whole experimental period(P0.05). These results suggested that dietary 500 mg kg~(–1) saccharicterpenin supplementation had beneficial effects on piglets, but excessive supplementation(2 500 or 5 000 mg kg~(–1)) of saccharicterpenin in the diets could lead to growth retardation, hematological abnormalities and organ injuries.     

不同氨气浓度对肉鸡生长性能及肉质性状的影响

【目的】氨气是鸡舍中产生的有害气体之一,探讨不同氨气浓度对肉鸡生长性能及肉质性状的影响。【方法】试验在动物营养学国家重点实验室昌平基地的呼吸舱中进行。选择21日龄健康、体重相近(743.6±8.2) g的AA肉公鸡320只,随机分于4个呼吸舱中饲养,一个舱为一个处理,每个处理设4个组内重复,每个重复20只鸡。对照组氨气浓度控制在（3±3）µL·L^-1,3个试验组氨气浓度分别控制在（25±3）、（50±3）、（75±3）µL·L^-1。网上平养,自由采食和饮水。42日龄时试验结束,试验期间记录肉鸡的日采食量和健康状况,分别于肉鸡32日龄和42日龄时按重复称重,计算肉鸡的日增重及饲料转化率,并从每个重复中随机选取3只肉鸡屠宰取样,测定其屠宰性能和肉质性状。【结果】1)在22-32日龄期间,肉鸡的平均日增重和平均日采食量随着氨气浓度的升高呈线性降低(P＜0.05);当氨气浓度达到50、75µL·L^-1时,肉鸡的平均日增重和平均日采食量显著低于对照组(P＜0.05);氨气浓度对耗料增重比的影响未达显著水平(P＞0.05);在此期间,各处理肉鸡的屠宰率、全净膛率、半净膛率等没有表现出显著差异(P＞0.05)。2)在33-42日龄期间,肉鸡的平均日采食量也随着氨气的浓度升高呈线性降低(P＜0.05);与对照组相比,3个试验组肉鸡的平均日采食量都显著降低(P＜0.05);氨气浓度对肉鸡平均日增重和耗料增重比的影响未达显著水平(P＞0.05)。3)在整个试验期内（22-42日龄）,肉鸡的平均日增重和平均日采食量随着氨气的浓度升高呈线性降低(P＜0.05);与对照组相比,3个试验组肉鸡的平均日采食量和平均日增重都显著降低(P＜0.05),而耗料增重比显著提高(P＜0.05);随着氨气浓度升高,肉鸡腹脂率有升高的趋势,其中75µL·L^-1氨气处理的肉鸡腹脂率显著高于对照组肉鸡的腹脂率(P＜0.05)。在整个试验期内,氨气浓度对肉鸡胸肌pH(24 h后)、肉色的影响都未达显著水平(P＞0.05),但对胸肌的滴水损失产生了明显的影响,与对照组相比,3个试验组肉鸡胸肌的滴水损失都显著升高(P＜0.05)。【结论】鸡舍内氨气浓度达到25µL·L^-1时即会影响肉鸡的生长性能及肉质性状,且随着氨气浓度的增加,这种影响加剧,暴露在高浓度氨气中的肉鸡,其腹脂率、胸肌滴水损失率增加。建议鸡舍内氨气浓度应控制在25µL·L^-1以内。     

不同能量和粗蛋白水平日粮对石岐杂鸡生产性能、屠宰性能及养分表观代谢率的影响

为研究不同蛋白和能量水平日粮对石岐杂鸡生产性能、屠宰性能及养分表观代谢率的影响,选取21日龄体质量相近、健康的石岐杂鸡120只,随机分为4组(每组3个重复,每个重复10只)进行试验饲喂玉米-豆粕型基础日粮,Ⅰ组、Ⅱ组、Ⅲ组和Ⅳ组能量和蛋白水平分别为12.09MJ/kg和18.07％、13.09MJ/kg和18.01％、...     

大豆异黄酮和抗生素对文昌鸡生长性能、肉品质和血浆抗氧化指标的影响

【目的】对比大豆异黄酮和抗生素对文昌鸡生长性能、肉品质及血浆抗氧化指标的影响,为大豆异黄酮在文昌鸡生产中的实际应用提供参考。【方法】选用1日龄文昌鸡母雏540只。试验分3组,包括空白对照组、抗生素组和大豆异黄酮组,每组4个重复,每个重复45羽。分小鸡、中鸡和大鸡3个阶段进行试验。【结果】生长性能结果显示,1~30日龄小鸡各组之间的平均日增质量、平均日采食量和料重比均无显著差异(P0.05);31~80日龄阶段,大豆异黄酮组的平均日增质量显著高于对照组(P0.05);81~120日龄阶段,大豆异黄酮组的平均日采食量显著高于对照组(P0.05)。肉品质结果显示,各组的肉色L*、a*、b*和pH差异均不显著(P0.05);与对照组相比,大豆异黄酮组的熟肉率显著提高(P0.05)。血浆抗氧化指标结果显示,31~80日龄阶段,大豆异黄酮组的总抗氧化能力(Total antioxidant capacity,T-AOC)活性显著高于抗生素组(P0.05);81~120日龄阶段,大豆异黄酮组的肌酸激酶(Creatine kinase,CK)活性显著低于抗生素组,谷胱甘肽(Glutathione,GSH)含量显著高于抗生素组,抗生素组和大豆异黄酮组的T-AOC活性显著高于对照组(P0.05)。【结论】中鸡阶段饲粮中添加20 mg·kg~(–1)大豆异黄酮可以提高鸡日增质量和抗氧化水平;大鸡阶段饲粮中添加15 mg·kg~(–1)大豆异黄酮能够提高鸡采食量、熟肉率和抗氧化水平。     

酵母蛋白替代鱼粉对肉仔鸡饲喂效果的研究

将224只1日龄AA肉仔鸡混合雏,随机分为2组(每组8个重复,每个重复14只鸡),分别施予2个饲粮处理,以此研究用酵母蛋白替代鱼粉对肉鸡饲喂效果的影响.结果表明:1-7d试验组ADG显著低于对照组(P0.05),日采食量显著高于对照组(P0.05),FCR极显著高于对照组(P0.01);14-21d试验组ADFI显著低于对照组(P0.05),FCR显著低于对照组(P0.05),但全期2组3个指标间的差异均不显著(P0.05),成活率组间差异亦不显著(P0.05);组间免疫器官(胸腺指数、法氏囊指数、脾脏指数)的发育差异不显著(P0.05);组间十二指肠、空肠、回肠相对长度、厚度、十二指肠黏膜绒毛高度、隐窝深度、及绒毛高度/隐窝深度之比(V/C)的差异亦不显著(P0.05).因此,在相等营养水平肉仔鸡生长期饲粮中,用酵母提取蛋白等量替代鱼粉能获得相近的生产性能,免疫器官及肠道发育方面也基本一致.     

小刺猴头菌发酵浸膏多糖对肉鸡脂肪沉积的影响

为研究小刺猴头菌发酵浸膏多糖(Polysaccharides from the fermentation extract of Hericium caputmedusae,HFP)对肉鸡血清脂类指标、腹脂沉积、盲肠短链脂肪酸以及肝脏、肌肉、粪便中脂肪含量的影响,选用1日龄AA肉鸡240只,随机分为4个处理,每处理3个重复,每重复20只,分别饲喂含HFP为0、0.1%、0.3%和0.5%的日粮,试验期为42d。结果表明:1)日粮中添加HFP可显著降低14、28和42日龄肉鸡血液甘油三酯(TG)含量(P0.05),0.3%和0.5%水平的HFP添加组可显著降低肉鸡肝脏TG含量(P0.05);2)0.3%和0.5%水平的HFP添加组肉鸡的腹脂率显著低于对照组(P0.05);3)日粮中添加HFP对肉鸡体重、腿肌脂肪含量、胸肌脂肪含量、粪便脂肪含量无显著影响(P0.05);4)添加HFP可显著增加肉鸡盲肠丙酸含量(P0.05),显著降低盲肠乙酸和丙酸的比例(P0.05);5)变量间相关性分析表明,14日龄时,肉鸡盲肠丙酸含量与腹脂率显著负相关(r=-0.992),乙酸和丙酸的比例与腹脂率显著正相关(r=0.989);28日龄时,盲肠丙酸含量与血液TG含量显著负相关(r=-0.985),乙酸和丙酸的比例与血液TG含量显著正相关(r=0.996);42日龄时,乙酸和丙酸的比例分别与血液TG含量、腹脂率显著正相关(r=0.951,0.979)。以上结果提示,在肉鸡日粮中添加HFP可以显著降低血液TG含量,降低腹脂沉积,可能是通过调节肉鸡盲肠短链脂肪酸的含量和比例而促进机体脂类代谢。     

Effect of dioscorea opposite waste on growth performance,blood parameters,rumen fermentation and rumen bacterial community in weaned lambs

This study investigated the effects of dioscorea opposite waste(DOW) on the growth performance, blood parameters, rumen fermentation and rumen microbiota of weaned lambs. Sixty healthy weaned Small-Tailed Han lambs(male,(22.68±2.56) kg initially) were used as the experimental animals. Four levels of concentrate: 0(control, CON), 10%(DOW1), 15%(DOW2) and 20%(DOW3), were replaced with DOW in the basal diet as experimental treatments. The results showed that lambs fed the DOW2 diet had a higher(P&l...     

Effect of dietary calcium or phosphorus deficiency on bone development and related calcium or phosphorus metabolic utilization parameters of broilers from 22 to 42 days of age

This experiment was conducted to investigate the effect of dietary calcium (Ca) or phosphorus (P) deficiency on bone development and related Ca or P metabolic utilization parameters of broilers from 22 to 42 days of age based on our previous study, which indicated that dietary Ca or P deficiency impaired the bone development by regulating related Ca or P metabolic utilization parameters of broilers from 1 to 21 days of age. A total of 504 one-day-old Arbor Acres male broilers were randomly assigned to 1 of 4 treatments with 7 replicates in a completely randomized design, and fed the normal control and Ca- or P-deficient diets from 1 to 21 days of age. At 22 days of age, the broilers were further fed the normal control diet (0.90% Ca+0.35% non-phytate P (NPP)), the P-deficient diet (0.90% Ca+0.18% NPP), the Ca-deficient diet (0.30% Ca+0.35% NPP) or the Ca and P-deficient diet (0.30% Ca+0.18% NPP), respectively. The results showed that dietary Ca or P deficiency decreased (P<0.05) tibia bone mineral density (BMD), bone breaking strength (BBS), ash content, tibia ash Ca content and serum P content on days 28 and 42, but increased (P<0.05) tibia alkaline phosphatase (ALP) activity of broilers on day 42 compared with the control group. Furthermore, the broilers fed the P-deficient diet had the lowest (P<0.05) tibia BMD, BBS, ash content, serum P content and the highest (P<0.05) serum Ca content on day 28 compared with those fed the Ca-deficient or Ca and P-deficient diets. The results from the present study indicated that the bone development and related Ca or P metabolic utilization parameters of broilers were the most sensitive to dietary P deficiency, followed by dietary Ca deficiency or Ca and P-deficiency; dietary Ca or P deficiency impaired the bone development possibly by regulating serum Ca and P contents as well as tibia Ca content and ALP activity of broilers from 22 to 42 days of age.     

N-甲基-D,L-天冬氨酸对肉鸡生长性能的影响

研究了不同添加量的N-甲基-D,L-天冬氨酸(NMA)日粮对AA肉鸡早期生长性能的影响,结果表明,补充适宜的NMA有利于提高肉仔鸡日采食量和日增重,同时降低料重比。     

树舌发酵浸膏多糖对肉鸡肠黏膜组织结构及肠道免疫细胞的影响

为研究肉鸡日粮中添加树舌发酵浸膏多糖(Polysaccharides from the fermentation concentrate of Ganoderma applanatum(Pers.ex Gray.),GAP)对肉鸡肠黏膜结构及上皮内淋巴细胞和杯状细胞数量的影响,选用1日龄健康AA肉鸡225只,随机分成5个处理组,每组3次重复,每次重复15只。5个处理组分别为空白对照组(基础日粮)、抗生素阳性对照组(基础日粮+5mg/kg黄霉素)和3个GAP组(基础日粮中分别添加0.05%、0.10%和0.20%GAP),试验期42d。结果表明:1)与对照组相比,日粮中添加0.10%和0.20%的GAP可显著增加肉鸡肠绒毛高度(P0.05),降低隐窝深度(P0.05),提高肠绒毛高度和隐窝深度的比值(V/C)(P0.05);2)与对照组相比,日粮中添加0.10%和0.20%GAP显著升高小肠各段的上皮内淋巴细胞和杯状细胞数量(P0.05);3)小肠各段上皮内淋巴细胞和杯状细胞数量随年龄增长而逐渐增多;4)同一日龄各试验组的上皮内淋巴细胞数量从十二指肠到回肠递减,而杯状细胞则呈递增趋势。以上结果提示:在肉鸡日粮中添加GAP可显著改善肉鸡小肠黏膜结构,维持肠道黏膜的正常屏障结构,促进肉鸡健康生长。其中以0.10%GAP添加量效果最好。     

Effects of rearing system(floor vs. cage) and sex on performance,meat quality and enteric microorganism of yellow feather broilers

This study investigated the effects of floor and cage rearing systems on performance, meat quality, and enteric microorganisms of male and female yellow feather broilers. Two hundred Xueshan chickens(42 days old; 100 of each sex) were divided into four groups, according to sex and rearing system(stainless-steel cage or litter floor). Male and cage-reared broilers exhibited better(P0.001) performance and higher(P≤0.001) eviscerated percentage than female and floor-reared broilers. The interaction between rearing system and sex had an effect(P0.05) on the percentage of breast and thigh muscles. Female floor-reared broilers presented the highest(P0.02) percentage of breast and thigh muscles among all the groups. In both sexes, the abdominal fat content in cage-reared broilers was higher(P0.01) than that in floor-reared broilers. Female cage-reared broilers exhibited better(P0.05) meat quality of breast muscle than other groups. An analysis of welfare observations indicated that the feather quality of floor-reared broilers was better(P0.01) than that of cage-reared broilers, whereas the gait scores were not significantly affected(P0.05) by rearing system. The enteric microbiota assessment by 16 S rRNA amplicon-based sequencing showed that Firmicutes, Proteobacteria, and Bacteroidetes were the most prevalent phyla in both rearing systems, and that the cecum was relatively stable in terms of microbiome composition. Floor-reared broilers exhibited a richer diversity of bacteria in the intestinal tract than cage-reared broilers, while alpha diversity was not significantly different(P0.05) among the groups. The ratio of Bacteroidetes to Firmicutes and the abundance of Helicobacter and Romboutsia could potentially affect the production of broilers. These findings indicate that cage rearing improved the production of male Xueshan broilers, which may be due to the difference in enteric microbiota between cage and floor rearing systems.     

角鲨烯对1~21日龄白羽肉鸡生长性能、抗氧化能力 和免疫功能的影响

为了研究SQ对1～21日龄白羽肉鸡生长性能、抗氧化能力和免疫功能的影响,选取体重为（38.38±0.25） g的 1日龄雄性AA⁺白羽肉鸡360只,将雏鸡随机分为3组,每组6个重复,每个重复20只,分别饲喂基础日粮,基础日粮+175 mg·kg^-1角鲨烯（squalene,SQ）和基础日粮+350 mg·kg^-1 SQ,试验期为21 d。结果表明：（1）饲粮中添加175和350 mg·kg^-1 SQ均能显著提高肉鸡平均日增重,并显著降低料重比（P＜0.05）,同时提高肉鸡血清中超氧化物歧化酶（superoxide dismutase,SOD）、谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）、过氧化氢酶（catalase,CAT）活性及总抗氧化力（total antioxidant capacity,T-AOC）（P＜0.05）,显著降低血清丙二醛（malonyldialdehyde,MDA）含量（P＜0.05）,且350 mg·kg^-1SQ 添加量在改善肉鸡血清过氧化氢酶活性和总抗氧化力方面,效果显著优于175 mg·kg^-1（P＜0.05）。（2）饲粮中添加175和350 mg·kg^-1 SQ均能显著提高肉鸡血清中高密度脂蛋白、补体C3和C4水平（P＜0.05）,显著降低血清中低密度脂蛋白水平（P＜0.05）,且350 mg·kg^-1 SQ 添加量在降低血清低密度脂蛋白和提高补体C3和C4水平方面效果显著优于175 mg·kg^-1（P＜0.05）。（3）饲粮中添加175和350 mg·kg^-1 SQ均能显著提高肉鸡免疫器官指数（P＜0.05）。综上所述,饲粮中添加 SQ能有效改善1~21日龄白羽肉鸡生长性能、抗氧化能力和免疫功能,其中350 mg·kg^-1 SQ在改善肉鸡血清过氧化氢酶、总抗氧化力、补体C3和C4方面更具优势。     

Effect of dietary supplementation with mulberry (Morus alba L.) leaves on the growth performance,meat quality and antioxidative capacity of finishing pigs

The present study was conducted to evaluate the effect of dietary mulberry(Morus alba L.) leaves powder(MLP) supplementation on meat quality of finishing pigs.A total of 40 Duroc×Landrace×Yorkshire pigs(initial body weight of(40.5±0.63) kg) were randomly allotted into two treatments,fed either with control diet or 15% MLP diet for 85 d.The results showed that MLP diet decreased(P≤0.05) average daily gain(ADG) and increased(P0.05) feed/gain ratio(F/G) in the finishing and whole period.MLP diet also decreased(P0.05) carcass weight,dressing percentage,last rib and average backfat depth.However,MLP diet increased(P0.05) intramuscular fat(IMF) content,decreased(P0.05) shear force,cooking loss and drip loss.In addition,MLP diet increased(P0.05) total antioxidative capacity,glutathione peroxidase and tended(P0.10) to increase total superoxide dismutase in serum.In longissimus thoracis,myosin heavy chain(MyHC) I and IIa mRNA levels were increased(P≤0.05) for MLP diet.In conclusion,15% MLP supplementation reduced the growth performance and carcass traits,but improved meat quality of finishing pigs possibly through the change of myofiber characteristics,enhancement of antioxidative capacity and increase of IMF.     

锌氨基酸螯合物对断奶仔猪补饲效果的研究

试验选用杜洛克×长白×约克夏29日龄断奶仔猪45头,随机接受基础饲粮相同、添加100 mg/kg(以锌计)由无机锌(ZnSO4)和有机锌(Zn-AAC)组成的5种处理饲粮,研究不同配合比例的Zn-AAC与ZnSO4对断奶仔猪生长性能和血液指标的影响。28 d试验,分前期(1~14 d)和后期(15~28 d)两阶段。结果表明:用Zn-AAC分别取代ZnSO4的40%、60%、80%和100%,与对照组(ZnSO40%)比较,试验前期ADG分别提高22.0%(P>0.05)、38.5%(P<0.01)、32.6%(P<0.05)、26.2%(P<0.05),ADFI分别提高24.6%(P<0.05)、25.3%(P<0.05)、23.5%(P<0.05)、23.8%(P<0.05);试验后期所有含Zn-AAC组ADFI增加(P>0.05);FCR Zn-AAC 60%组全期提高4.2%(P<0.05);80%和100%的Zn-AAC组,血清锌浓度分别比对照增加1.63倍(P<0.01)和1.46倍(P<0.01),随着Zn-AAC取代量提高,血清IgG含量增加(P>0.05),各组血清ALP活性无显著差异。结论:断奶仔猪补饲常规剂量的锌氨基酸络合物,与ZnSO4比较,能够提高仔猪ADG和ADFI,增加血清锌浓度;有机锌与无机锌合用时饲喂效果优于单一使用,其最佳配合比例为Zn-AAC 60%加ZnSO440%。     

Effects of Maternal Dietary Energy Restriction on Fat Deposition of Offspring

The study was carried out to investigate the effects of maternal dietary energy restriction on growth performance, serum indices and fat deposition of offspring. A total of 400 female Arbor Acres （AA） broiler breeders were studied. These female birds involved three experimental treatments and a control group with normal dietary energy diets （ND, 11.7 MJ of ME. kgt during the laying）. In treatments 2, 3 and 4, the energies of diets were 20%, 30% and 50% （LD20, LD30 and LD50） lower than those of the control, respectively. The study commenced at the beginning of the laying period when the total egg production reached 5% of the flock. All the broiler offspring were fed the same diets. The results showed that in low energy diets, offspring showed decreased 1-day-old weight, but 49-day-old weight was higher in LD20 diet （P〈0.05）. For offspring during days 1-49, the average daily gain （ADG） in LD20 group and the feed conversion ratio in LD50 group were improved as compared with those of the control （P〈0.05）. Compared with the control, abdominal fat percentage increased in 49-day-old offspring from LD30 diet （P〈0.05）; the fat content of breast muscle in offspring increased in broilers fed low energy diets （P〈0.05）. In 28-day-old offspring from breeders given LD20 and LD50 diets, liver fat percentages were higher compared with ND （P〈0.05）. The subcutaneous fat thickness in 28-day-old offspring from LD50 group and 49-day-old offspring from LD30 group was higher （P〈0.05）. On day 49, the serum cholesterol （CHO） of offspring from breeders fed LD20 diet and serum high-density lipoprotein （HDL） of offspring from breeders fed LD50 diet reduced compared with those of the control （P〈0.05）. In addition, a higher triiodothyronine （T3） content in serum was found in offspring from broiler breeders given LD20 and LD30 diets （P〈0.05）. Serum thyroxine （T4） in offspring significantly decreased with the decrease of diet energy （P〈0.05）. In conclusion, to a certain extent, dietary energy restriction in breeders could improve growth performance and promote lipid metabolism of offspring.     

Regulation of bone phosphorus retention and bone development possibly by BMP and MAPK signaling pathways in broilers

The bone morphogenetic protein(BMP) and mitogen-activated protein kinase(MAPK) signaling pathways play an important role in regulation of bone formation and development,however,it remains unclear that the effect of dietary different levels of non-phytate phosphorus(NPP) on these signaling pathways and their correlations with bone phosphorus(P) retention and bone development in broilers.Therefore,this experiment was conducted to investigate the effect of dietary P supplementation on BMP and MAPK ...     

饲喂褪黑激素(MT)对生长猪生产性能及饲料养分消化率的影响

选用15头体重为35kg左右的长大二元杂交猪,考查饲喂褪黑激素(MT)对生长猪生产性能和饲料养分消化率的影响。试验设两个水平MT添加组[低MT组1·5mg/(kg·d),高MT组3·0mg/(kg·d)]和1个对照组,每组5个重复,每个重复1头猪。结果为,高MT组猪平均日增重和日采食量比对照组分别下降11·31%(P<0·01)和13·53%(P<0·01),料肉比(F/G)有下降趋势,但差异还未达到显著水平。低MT组日增重和采食量与对照组没有显著差异,但饲料转化率显著提高,料肉比(F/G)较对照组下降了5·85%(P<0·05)。与对照组相比,两个MT水平组对饲料消化能和总有机养分表观消化率均没有显著影响,而降低粗脂肪表观消化率,其中高MT组比对照组降低了6·19(P<0·05),低MT组比对照组降低了5·27%(P=0·056)。高MT组降低粗蛋白的表观消化率,而低MT组则提高蛋白质的表观消化率,高MT组与低MT组差异达到显著水平。本试验表明,饲喂低水平的MT可提高生长猪的饲料利用率。     

Long term effects of artificial rearing before weaning on the growth performance,ruminal microbiota and fermentation of fattening lambs

Early life intervention is important to shape the gut microbiome profiles of adult animals due to the tremendous alteration of diet components. Nevertheless, there is still no unified understanding about its long-term effects in lambs. In this study, sixty 20-day-old lambs were assigned into ewe-rearing (ER) and artificial-rearing (AR) treatments to evaluate the effects of AR strategy on ruminal microbiota, fermentation, and morphology of pre-weaning lambs (from 20 to 60 days of age) and its long-term effects in the fattening stage (from 61 to 180 days of age). During the pre-weaning stage, ER lambs were breastfed and supplemented starter, while AR lambs were artificially fed with milk replacer and starter. During the fattening stage, all lambs in both treatments were fed with the same fattening diets. At 60, 120 and 180 days of age, 6 lambs from each group were slaughtered to collect rumen content and tissue samples. Compared with ER lambs, the dry matter feed intakes of AR lambs increased (P<0.05) from 20 to 180 days of age, companying an increased average daily gain (ADG) from 61 to 120 days of age (P<0.05) and from 121 to 180 days of age (0.05<P<0.1). Although there was no difference in short-chain fatty acid (SCFA, including acetate, propionate, and butyrate) between treatments before weaning (P>0.05), it was higher (P<0.05) in AR lambs compared with ER lambs at the fattening stage. The rumen keratin layer of AR lambs was thinner (P<0.05) than that of ER lambs. Along with lamb growth from 60 to 180 days of age, the differences in rumen bacterial diversity between AR and ER treatments grew more distinct (P<0.05). Compared with ER lambs, AR lambs increased (P<0.05) rumen bacteria abundance, such as phylum Spirochaetes and genus Treponema at 60 days of age, phylum Actinobacteria and genus Succiniclasticum at 120 days of age, and phylum Proteobacteria at 180 days of age, but decreased genus Selenomonas from 60 to 180 days of age, and Anaerovibrio at 180 days of age. In summary, the early interventions before weaning could improve dry matter feed intake of lambs, which triggered robust rumen development and produced positive long-term effects on rumen fermentation and noticeable weight gain of fattening lambs. It suggests that the artificial rearing strategy is effective in improving rumen fermentation and microbial maturity of intensive fattening lambs.     

沙棘叶粉对AA肉鸡生产性能和钙代谢的影响

为了检测沙棘叶粉作为一种饲料添加剂对爱拔益加(AA)肉鸡生产性能和钙代谢的作用效果,试验选择健康的1日龄AA肉仔鸡公雏240只.按体重相近的原则,随机分成4组:对照组(玉米-豆粕型基础饲粮)、基础饲粮+0.25%沙棘叶粉组、基础饲粮+0.5%沙棘叶粉组、基础饲粮+1%沙棘叶粉组.每组6个重复,每个重复10只.饲养试验共...