基于Faster-RCNN的肉鸡击晕状态检测方法

为了准确识别屠宰加工中肉鸡的击晕状态,提出了一种基于快速区域卷积神经网络的肉鸡击晕状态检测方法。对输入图像进行归一化处理,通过卷积神经网络（VGG16）提取肉鸡的卷积特征图,利用区域建议网络提取预测框,在卷积特征图上采用非极大值抑制算法去除重复表述的预测框;将所得的各预测框映射到卷积特征图上,得到预测框在卷积特征图上的候选区域,将其输入感兴趣区域池化层;通过感兴趣区域池化层将大小不一的候选区域进行池化操作、得到统一的输出数据,最后通过全连接层与柔性最大值分类器,输出各击晕类别的概率和预测框的坐标。将2319个样本图像按2∶1的比例随机分为训练集与测试集,对模型进行训练与实验验证。结果表明,本文建立的基于Faster-RCNN的肉鸡击晕状态分类模型对773个测试集肉鸡样本击晕状态分类的总准确率达到96.51%,对肉鸡击晕状态的预测速度可达每小时37000只,基本满足肉鸡屠宰生产线要求。     

野山杏总黄酮对三黄肉鸡屠宰性能的影响

[目的]研究不同剂量野山杏总黄酮对三黄肉鸡屠宰性能的影响。[方法]采用单因素试验设计,将96羽1日龄雌性三黄肉鸡随机分为4组,每组24羽。于14日龄开始,野山杏总黄酮低、中、高剂量组肉鸡分别灌服50、100、200 mg/（kg·BW·d）的野山杏总黄酮,对照组肉鸡灌服生理盐水,试验期42 d。28、35、42日龄时每组分别选取8羽肉鸡进行屠宰试验,测定并比较相同日龄下各组肉鸡的屠宰性能指标。[结果]高剂量野山杏总黄酮可显著或极显著（P<0.05或P<0.01）提高28、35、42日龄肉鸡宰前体重,中剂量野山杏总黄酮可极显著（P<0.01）提高35日龄肉鸡宰前体重。高剂量野山杏总黄酮分别显著（P<0.05）和极显著（P<0.01）提高35日龄和42日龄肉鸡屠宰率。中、高剂量野山杏总黄酮极显著（P<0.01）提高28日龄肉鸡半净膛率。低剂量野山杏总黄酮可极显著（P<0.01）提高28日龄肉鸡全净膛率,显著（P<0.05）提高35日龄肉鸡全净膛率;中剂量野山杏总黄酮可极显著（P<0.01）提高35日龄肉鸡全净膛率;低、中、高剂量野山杏总黄酮可极显著（P<0.01）提高42日龄肉鸡全净膛率。低、中、高剂量野山杏总黄酮可显著或极显著（P<0.05或P<0.01）降低35、42日龄肉鸡皮下脂肪厚度。高剂量野山杏总黄酮可显著（P<0.05）降低28日龄肉鸡肌间脂肪宽度,极显著（P<0.01）降低35日龄肉鸡肌间脂肪宽度;低、中、高剂量野山杏总黄酮可极显著（P<0.01）降低42日龄肉鸡肌间脂肪宽度。低剂量野山杏总黄酮可显著（P<0.05）降低28、42日龄肉鸡腹脂率,中剂量野山杏总黄酮可显著（P<0.05）降低28、35、42日龄肉鸡腹脂率,高剂量野山杏总黄酮可极显著（P<0.01）降低42日龄肉鸡腹脂率。高剂量野山杏总黄酮可显著或极显著（P<0.05或P<0.01）提高35、42日龄肉鸡胸肌率,可显著或极显著（P<0.05或P<0.01）提高28、35、42日龄肉鸡腿肌率。[结论]灌服不同剂量的野山杏总黄酮能够明显改善三黄肉鸡的屠宰性能。     

Short- and Long-Term Effects of Feed Form on Fast- and Slow-Growing Broilers

Three experiments were conduced to quantify the potential negative effect of fine particles (<0.5 mm diameter) in the feed on fast- and slow-growing broiler growth performance. In the first experiment, chickens were fed mash or pellets of 2.5 and 4 mm diameter between 15 and 35 d of age. During this period, fast-growing broiler fed pelleted feed had a 19% higher final BW, a 12% higher feed intake, and a 12% lower (improved) feed conversion ratio than those fed mash. Feed form had no significant effect on feed intake, BW gain, or final BW of slow-growing chickens. Feed conversion ratio, however, was 6% lower with pellet than mash. In the second and the third experiments, fast and slow-growing chickens weighed 1.2 kg at the beginning of the experiment. In the second experiment, the effects of a transition from pelleted feed to mash or a mixture between the 2 feed forms on the short-term feed intake and growth was investigated. After the transition from pellet to mash or the mixture, both fast- and slow-growing chickens adapted their feed intake in less than 10 min. The mixture between mash and pellets led to a 25% higher feed intake and an 18% lower feed conversion ratio for fast-growing chickens. There was no significant difference between mash and the mixture on slow-growing feed intake, but feed conversion ratio was 9% lower. In the third experiment, the effect of fine particles concentration in the feed on short-term growth response was measured. Increase in the concentration of fine particles in the feed linearly reduced feed intake and BW gain of both fast- and slow-growing chickens. However, the slope was 5 times greater for fast-growing chickens than for slow-growing chickens. These 3 experiments showed that fast-growing chickens are more sensitive to feed form than slow-growing chickens. Therefore, physical form of the feed can be a major limiting factor of performance.     

Combinatorial Effect of Dietary Oregano Extracts and 3,4,5-Trihydroxy Benzoic Acid on Growth Performance and Elimination of Coccidiosis in Broiler Chickens

We aimed to compare the combinatorial effect of 3,4,5-trihydroxybenzoic acid (THB) and oregano extracts (OE) with THB alone on the growth performance and elimination of deleterious effects in coccidiosis-infected broilers. A total of 210 one-day-old broilers were randomly assigned to one of five dietary treatments, with six replicates each, for 35 days. Dietary treatments were: 1) non-challenged, non-treated (NC); 2) challenged, non-treated (PC); 3) PC+ Salinomycin (0.05 g/kg; AB); 4) PC+THB (0.1 g/kg; THB); and 5) PC+THB+OE (0.1 g/kg; COM). On day 14, all groups except for NC were challenged with a 10-fold dose of Livacox^® T anticoccidial vaccine to induce mild coccidiosis. All treatments significantly improved (P<0.05) body weight, average daily gain, and average daily feed intake, compared to PC, on days 21, 28, and 35. However, all treatments significantly reduced (P<0.05) the feed conversion ratio of PC by more than 14.60% on day 35, 11.76% during growing period, and 10.36% through the entire period. Broilers receiving anticoccidial treatments had 54.23% and 51.86% lower lesion scores (P<0.05) at 4 and 7 days post-infection, respectively, compared to PC. Additionally, the villus height of COM was significantly longer (P < 0.05) than that of THB. Although the molecular action of COM remains unclear, OE addition to THB reduced the shedding of oocysts better than THB alone (P<0.05, 9-11 days post-infection). Most importantly, COM effectively minimized the mortality of challenged birds from as high as 11.90% (PC) to 0%, a level similar to NC and AB, while THB maintained a mortality of 2.38%. In conclusion, the anticoccidial effect of THB can be enhanced by the addition of OE for better animal performance and the elimination of deleterious effects from coccidiosis-infected broilers for 35 days.     

Influence of Age and Sex on Footpad Quality and Yield in Broiler Chickens Reared on Low and High Density Diets

The effect of age and sex on live performance, processing yields, and footpad quality of broiler chickens was evaluated by rearing 2 commercial strain-crosses (SC) to 56 d of age on 2 diets varying in nutrient density. Each strain cross was placed in 10 replicate pens of 50 birds (25 males and 25 females per pen). Equally distributed among the replicate pens were high- and low-density starter (0 to 21 d) and grower (22 to 42 d) diets with a common finisher fed from 43 to 56 d to all birds. Body weights, adjusted feed conversion, and mortality were determined at 21, 42, and 56 d of age. Processing yields, foot weights, and yields, and the incidence and severity of footpad dermatitis were evaluated on d 35, 42, 49, and 56.No differences (P > 0.05) were seen in mortality between the SC and diet density treatments throughout the course of the study. Strain-cross had a significant effect on body weights at d 21 and feed conversion at d 42, but no differences remained at d 56. Significant SC effects were present for carcass without giblets at d 35, 42, and 56. Diet density effects were limited to carcass without giblets at d 35 and abdominal fat content at d 56. As expected, females had higher abdominal fat yields than males at all ages examined.Foot weight and yields were significantly affected (P < 0.05) by SC and sex at d 42, 49, and 56. As expected, foot weights increased with age. The proportion of birds with footpad dermatitis tended to increase until 49 d of age after which they started to decline. Male broilers had significantly higher incidence of footpad dermatitis than female broilers at d 49 and 56. Footpad dermatitis response to diet density and pigmentation of the feet was dependent on SC.     

日粮中添加酶制剂对樱桃谷肉鸭

选用1 200羽刚出壳的樱桃谷肉鸭,依性别随机分为 2组,每组设4个重复(每个重复150羽鸭,公母各半),一组为对照组,饲喂基础日粮,另一组为试验组,在基础日粮中添加0.1%华芬1511型肉鸭用复合酶.试验结果表明华芬1511型肉鸭用复合酶可以极显著地提高樱桃谷肉鸭的日增重(P<0.01),0～45日龄日增重提高7.44%;能显著提高饲料利用率(P<0.05),0～45日龄饲料效率提高7.38%;能获取较好的经济效益(提高毛利润47.54%).     

紫外线缺乏时肉用仔鸡维生素D3的需要量

将400只1日龄AA肉鸡随机分成8组，第I组接受紫外线光照，饲喂不添加维生素D3(WD3)的基础日粮；第Ⅱ—Ⅷ组不接受紫外线光照，分别饲喂添加0、50、100、200、400、800和1600国际雏鸡单位(ICU)／kg VD3的基础日粮。结果表明：与接受紫外线光照的鸡相比，缺乏紫外线光照的鸡(第Ⅱ组)具有较低的28日龄体重(P＜0．05)，较高的料重比(P＜0．05)；骨灰分、血钙和血浆磷含量也显著低于前者(P＜0．05)。在日粮中添加200 ICU／kg VD3可以基本满足肉用仔鸡缺乏紫外线照射时增重的要求；但对于骨灰分和血浆钙、磷含量而言，需要添加更高水平的VD3。     

免疫应激对肉仔鸡苏氨酸、赖氨酸需求比例的影响

选用300只16日龄的AA肉公鸡,研究了免疫应激对内源氨基酸损失和日粮氨基酸消化率的影响.选用750只1日龄AA肉公鸡,采用2×5因子设计,研究了免疫应激和日粮苏氨酸/赖氨酸比例对1～21日龄期间生长性能、内分泌激素水平和血清尿酸浓度的影响.结果表明,免疫应激直接增加肉仔鸡内源氨基酸损失,同时又通过降低干物质采食量显著减少内源损失,但没有影响日粮氨基酸消化率.免疫应激也降低了肉仔鸡生长性能,日粮苏氨酸/赖氨酸比例对肉仔鸡增重的影响与免疫状态有关.对照组获得最大增重和最低耗料/增重比需要的日粮苏氨酸/赖氨酸比例均为64/100,应激组相应的需求比例分别为70/100和71/100.