Effects of feeding different levels of concentrate on growth and carcass characteristics in younger Japanese Black cattle

The effects of a higher concentrate feed during the raising period on the growth and carcass of Japanese Black cattle being fattened at a younger age were investigated using three pairs of artificially bred identical twins and three pairs of full‐sibs. The animals were fed the concentrate at 2.4%/day (2.4% group) and 1.2%/day (1.2% group) comparative bodyweight (BW) during the raising period. The BW and subcutaneous fat thickness were measured every month using ultrasonic equipment. The animals were slaughtered at the age of 24 months. The BW of the 2.4% group from the age of 6–10 months appeared to be higher than that of the 1.2% group (P < 0.1). The subcutaneous fat of the 2.4% group from the age of 7–11 months was thicker than that of the 1.2% group (P < 0.1). After those ages, the BW and subcutaneous fat of the two groups did not differ and there was no difference in the carcass characteristics between the two groups. Using a higher concentrate feed during the raising period for younger fattening of Japanese Black cattle influenced growth from the late half of the raising period to the early part of the fattening period.     

Effect of diet composition and slaughter weight on animal performance, carcass and meat quality, and fatty acid composition in veal calves

The effect of true milk use in the diet of Spanish Brown Swiss male calves on animal performance, carcass and meat quality, and fatty acids composition was studied. In experiment 1, the effect of milk intake [ad libitum continuous (ADLIB) feed vs. restricted 0.7 during 75 days followed by ad libitum feed (RESTR)] and slaughter endpoint (225 kg vs. 5 month) were studied. In experiment 2, ad libitum concentrate feeding [grain-fed (GF)] was compared with milk supplementation until slaughter [milk-fed (MF)] in calves slaughtered at 345 kg. As regards to milk intake, carcass weight and degree of fatness were higher in the ADLIB group (P<0.05). The RESTR group revealed a higher percentage of saturated fatty acids (P<0.05). In experiment 2, the MF group exhibited a higher fat percentage (P<0.05), lower press and cooking losses (P<0.05), and higher scores for tenderness and juiciness (P<0.05) than the GF group. The percentage of saturated fatty acids was higher in the MF group (P<0.05). The results suggest that true milk use in veal production could be an advantageous alternative in terms on production costs, animal performance, and carcass and meat quality.     

苜蓿饲喂肉牛育肥效果试验研究

[目的]为进一步探讨苜蓿草饲喂肉牛育肥效果。[方法]选择临床健康的1.5~2岁的西门塔尔杂种公牛60头、按年龄、体重、相同或相近的原则,配对分为试验组和对照组,每组30头。试验组饲喂养殖场周边地区的苜蓿草,经80d饲喂。[结果]表明:实验组日均增重1 320g/头,对照组日均增重1 170g/头,试验组比对照组提高12.82%(P0.05);每增加1kg净肉成本试验组14.39元、对照组为15.78元。试验组比对照组成本费减少9.67%。[结论]表明:苜蓿草饲喂肉牛增重效果显著。     

宁夏干旱风沙区5种灌木保水剂造林试验与饲用价值研究

选择红柳(Tamarix ramosissima)、紫穗槐(Amorpha fruticosa)、柠条(Caragana korshinskii)、梭梭(Haloxylon ammodendron)、花棒(Hedysarum scoparium)5种宁夏干旱风沙区的主要造林灌木,采用法国SNF(爱森)保水剂和北京"清华绿宝"高效抗旱保水剂,通过蘸根法进行田间造林种植试验,以筛选出在干旱条件下提高苗木成活率的最佳方法,并对5种灌木的粗蛋白(crude protein,CP)、中性洗涤纤维(neutral detergent fiber,NDF)、酸性洗涤纤维(acid detergent fiber,ADF)、全量钙和全量磷的含量进行了测定。试验结果表明,使用SNF保水剂蘸根处理的成活率为39.60%,与CK相比提高了79.27%,与"清华绿宝"保水剂相比提高了44.90%。采用SNF保水剂蘸根处理,不仅可以提高造林成活率还可以节省保水剂用量,操作简单,适宜大面积的造林推广。5种灌木的粗蛋白与纤维比顺序为:柠条(0.46)紫穗槐(0.35)梭梭(0.24)花棒(0.22)红柳(0.17)。柠条、紫穗槐、梭梭都是优质的饲料资源。     

运输应激对比格犬血常规及生化指标的影响

为了研究运输应激伴随的冷应激、驱赶、捕捉及饲料改变等多重应激对比格犬血常规和血液临床生化指标造成的影响,并且评估1周适应性饲养时间的合理性。以30只比格犬作为试验对象,对其适应性饲养前后的血常规和血液临床生化指标进行检查,并对数据进行分析发现,适应性饲养前犬的血常规和生化指标都有显著变化,1周的常规适应性饲养后,犬应激症状消失,血常规和生化检查指标均回复正常;这说明应激对比格犬造成了显著的影响,1周的适应性饲养是合理且必须的。     

６种豆科饲用灌木中酚类物质动态变化与体外消化率的关系

 通过对云南省几种主要豆科饲用灌木不同生育期酚类化合物含量的分析研究,结果表明,单宁的含量变化范围从银合欢的枯黄期（４２．９ｇ／ｋｇ）到假大青蓝的开花期（１２３．６ｇ／ｋｇ）之间;简单酚的含量变化范围从银合欢的营养期（１１．６ｇ／ｋｇ）到结荚期（５８．７ｇ／ｋｇ）之间;总酚的含量在各生育期的变化范围依次为１０９．１～１７３．３,１０４．１～１６９．２,１０３．７～１５３．０和８６．６～１５５．６ｇ／ｋｇ。４种酚类化合物含量都较高的灌木有假大青蓝,含量均较低的有多花木蓝和假木豆。４种酚类化合物的含量总体表现为总酚＞单宁＞缩合单宁＞简单酚。缩合单宁与总酚和单宁之间呈极显著正相关（犘＜０．０１）,与简单酚之间呈不显著的负相关（犘＞０．０５）。体外干物质消化率（ＩＶＤＭＤ）在同一生育期不同灌木间差异显著（犘＜０．０５）,体外有机物消化率（ＩＶＯＭＤ）在同一生育期不同灌木间差异显著（犘＜０．０５）。体外消化率和体内消化率与总酚、单宁和缩合单宁呈极显著负相关（犘＜０．０１）,且相关系数绝对值大于０．７。     

饲用油腊的加工技术及应用

本文介绍了近几年在饲料工业生产中不同饲用油脂添加技术应用及研究,重点对常规喷涂技术、真空喷涂技术和固态油脂喷雾干燥技术进行综述、分析,并对饲料中应用的固态油脂生产加工和应用技术进行了展望。     

The effect of exogenous purine supply on the endogenous excretion of purine derivatives in the urine of growing lambs

An experiment was made to determine the absorption of purine metabolites in dietary nucleic acids through the digestive tract, and also to determine the utilization of nucleic acids absorbed in the body, using growing lambs. Two pairs of 120‐ and 180‐day‐old twin female lambs with a bodyweight of 18.2–19.0 kg were kept in metabolism crates and fed on purine‐free milk replacement (MR) with supplements of exogenous purine (purine base or purine nucleoside) at a level of 0.2 mmol/BW^0.75/d for 5 consecutive days, and thereafter they were maintained in the crates for 4 days. The daily amount of exogenous purine supply was calculated based on the urinary excreted purine derivatives (PD) in lambs fed on milk replacement alone. A urine sample was collected daily for 9 consecutive days, and the urinary excretion of PD was determined daily. Urinary PD excretion opened to increase within 24 h after the dose of purine bases, and the level was recovered on 3 days after ceasing the exogenous purine supply. The recovery of PD in the urine was about 70% of the purine supplement. When purine nucleosides were added to the feed, urinary PD excretion was initiated within 24 h after dosing, and the values were recovered after ending the purine nucleoside supply. The recovery rate of PD in the urine was only 30% of the supplemented purine. The plasma allantoin levels were almost similar after feeding purine bases and purine nucleosides, and the values were mostly in the range (40–60 µmol/L). These findings indicate that an exogenous purine can be directly incorporated into the body, and the purine as nucleoside is more effectively utilized for the synthesis of nucleic acids than as a purine base in the body of growing lambs.     

Growth,Meat Yield,and Economic Responses of Broilers Provided Three- and Four-Phase Schedules Formulated to Moderate and High Nutrient Density During a Fifty-Six-Day Production Period

This study examined growth responses and meat yield of broilers provided a 3- or 4-phase feeding schedule formulated to moderate or high nutrient density. Four dietary treatments were implemented consisting of high or moderate nutrient density diets that were provided for the duration of 3 phases (1 to 17, 18 to 35, and 36 to 56 d) or 4 phases (1 to 17, 18 to 35, 36 to 46, and 47 to 56 d).Provision of a 3-phase schedule did not alter growth performance, meat yield, or diet cost per final BW. Broilers receiving high nutrient diets had improved growth rate and feed conversion from 1 to 35 d. In the 3-phase schedule, birds given the high nutrient density diets had advantages in BW gain and pectoralis minor breast weight. Market changes in meat prices impact differences in gross feeding margins between diets formulated to high or moderate nutrient density more than variation in diet cost.     

浅论优质牧草在肉牛饲养中的利用

针对我国肉牛饲养在饲料利用中的误区,结合肉牛的消化及代谢特点,分析了牧草的鲜喂、青贮、干草饲喂以及综合利用4种不同的利用方式及其营养特点,指出优质牧草用于肉牛饲养能充分发挥牧草的优良特性,而且符合我国畜牧业发展要求,值得广泛推广.