Effect of mastitis during the first lactation on production and reproduction performance of Holstein cows

The aim of this study was to evaluate the effect of postpartum mastitis between first calving and subsequent conception on production and reproduction performance as well as culling of Holstein cows. A data set of 9,183 first lactation cows was used. Results showed that the first cumulative 100?days' milk production and the milk yield standardized to 305?days were affected by the interval from calving to first mastitis (P??0.05). Calving year, calving difficulty score, and cumulative first 60?days milk production had significant impacts on mastitis risk (P?相似文献   

日粮添加鱼粉和n-3多不饱和脂肪酸对泌乳初期奶牛产奶量及机体代谢的影响

本试验旨在研究添加鱼粉和特殊n-3脂肪酸对泌乳初期奶牛产奶量、乳成分、干物质采食量和血浆中代谢产物和代谢有关的激素含量以及甘油三酯在肝脏中累积的影响。从产奶第5～50 d,给奶牛饲喂等氮、等能、等脂肪日粮,其中处理分别为0%(对照组)以及1.25%、2.5%、5%的鱼粉和2.3%的鱼油脂肪酸钙盐,在产奶第25 d和第50 d饲喂前(离饲喂后间隔11 h)采集血液样品。试验结果表明:不同处理影响产奶量(分别为48.2、49.8、48.6、53.5、52.2±1.0 kg)和干物质采食量(分别为22.7、22.8、23.0、23.8、24.7±0.5 kg)。各处理间血浆葡萄糖平均浓度分别为53.4、55.3、51.1、57.6、57.3±1.3mg/dl);在添加5%鱼粉和添加2.3%鱼油脂肪酸钙盐处理组中血浆胰岛素浓度均有上升趋势。试验结果也显示在第25 d所有处理奶牛血浆中葡萄糖含量相一致;但在第50 d时存在着差异,其含量分别为54.6、54.4、52.4、60.5、58.3±1.4 mg/dl)。在第25 d时,5%鱼粉和2.3%鱼油脂肪酸钙盐处理中血浆胰岛素含量有所增加,但在第50 d时含量又相一致。各日粮处理对乳成分、能量平衡和血浆非酯化脂肪酸、β-羟基丁酸盐以及尿素浓度均无显著影响。在第21 d时,各日粮处理血浆中天冬氨酸盐转氨酶和肝脏甘油三酯浓度也无较大变化。因此本研究结果显示:在泌乳初期奶牛日粮中添加鱼粉或n-3多不饱和脂肪酸可显著增加产奶量和干物质采食量,但并不改变乳组成。     

Removal of sodium dodecyl sulfate in an intermittent cycle extended aeration system

The objective of this study was to investigate the removal of an anionic surfactant from wastewater in ICEAS. The surfactant considered here was anionic SDS being widely used in the household and industrial detergents. Basic wastewater COD was 260 mg L(-1) and SDS surfactant added in range 20 to 400 mg L(-1). The effect of the inlet SDS concentration and reaction time on COD and SDS removal was investigated. The results from this study indicated that the aeration time of 2 h was sufficient for removal of SDS ranged 20 to 400 mg L(-1). Obtained data showed low effluent SDS concentrations of 0.3 to 5 mg L(-1) and removal of SDS was more than 98%. These results revealed that biological treatment using ICEAS process is capable to treating wastewaters containing high concentration of SDS surfactant.     

Computer vision systems (CVS) for moisture content estimation in dehydrated shrimp

This paper presents a method based on computer vision systems (CVS) to estimate shrimp dehydration level by analyzing color during drying process. Since the most commonly used color space in food industry is L*a*b, transformation of RGB digital images to L*a*b units was carried out using direct two steps model with γ factor. Experimental data obtained from images captured at different drying temperatures (100–130 °C) and several time intervals (15–180 min) were analyzed with a complete randomized block design (CRBD), and the means were compared with Duncan's multi-range test. Multiple linear regression (MLR) and artificial neural networks (ANN) were applied for correlating the color features to moisture content of dried shrimp determined chemically. Results obtained with these two models lead to 0.80 and 0.86 correlation coefficients in MLR and ANN models, respectively. While there is no statistical difference at p < 0.05 between the two modeling approaches, both approaches indicate successful prediction of shrimp dehydration with high correlation to those found by the more expensive and intrusive chemical method. The automated vision based system, therefore, has the advantage over conventional subjective methods and instrumental ones for being objective, fast, non-invasive, inexpensive and precise.