Evaluation of Content and Source of Phosphorus Fed to Dairy Calves

Twenty-four Holstein bull calves, 12 Holstein heifer calves, and 6 Jersey bull calves were assigned to a 2 × 3 factorial experiment at 8 to 9 wk of age. Three concentrations (.26, .34, and .41%) and two sources (feed grades monoammonium phosphate and dicalcium phosphate) of dietary P were fed during a 10-wk trial. The biological availability of monoammonium phosphate was equal to dicalcium phosphate as a supplemental P source. Increasing dietary P from .26 to .34% increased feed intake, body weight gain, plasma inorganic P, plasma Mg, bending moment of the tibia and ninth rib, percentage ash, and ash content (P and Mg) of the 7th and 10th ribs and lowered plasma Ca. Only plasma inorganic P increased from .34 to .41%. Treatment means for .26, .34, and .41% P, respectively, were feed intake (kg.d⁻¹) 2.98, 3.48, and 3.34; daily body weight gain (kg.d⁻¹) .83, .94, and .92; wk 9 and 10 plasma inorganic P (mg-100 ml⁻¹) 6.08, 8.38, and 9.05; bending moment (kg.cm) of the 9th rib 31.6, 47.6, and 40.7 and tibia 1314.84, 1783.94, and 1751.00. These results indicate a requirement for calves greater than the .26% P currently recommended.     

Effects of Feeding High Magnesium to Young Dairy Calves

Holstein bull calves were fed 1, 2, and 4% supplemental magnesium as magnesium oxide. The control diet contained .3% magnesium and consisted of ground corn, soybean meal, cottonseed hulls plus mineral, vitamin, and antibiotic supplements. Diarrhea was the most obvious effect of high intake of magnesium. The extent and intensity of the diarrhea was related closely to the dietary magnesium content. High (2 and 4%) magnesium reduced feed consumption and weight gains. Although there were traces of blood in feces, no abnormalities were observed at autopsy. Large tubular sections of mucus were voided in the feces with a greater prevalance among calves fed 2 and 4% supplemental magnesium. Magnesium in plasma rose sharply in response to the increased intake of magnesium. In calves receiving the 4% added magnesium, the plasma values were triple those of controls. When high magnesium was fed, magnesium increased much more in urine than in plasma. Within 1 wk after calves were returned to control diet, magnesium in urine and plasma declined to control.     

乳品市场终端调查

《中外食品》记者在北京沃尔玛超市进行了调查,对购买婴幼儿奶粉的消费者进行了采访,结果超过半数的被采访者都表示不会选择国产品牌的奶粉。采购超市导购时得知,由于消费者对国产奶粉的信心不足。导致大部分超市中进口奶粉的销量都明显好于国产奶粉。     

中国荷斯坦奶公犊不同部位肉的品质特性

为分析比较中国荷斯坦奶公犊不同部位肌肉品质间的差异,选取6 头遗传背景一致、7 月龄左右的荷斯坦奶公犊,经商业屠宰厂宰后排酸48 h。分别采集6 个部位（外脊、半腱肌、半膜肌、股内侧肌、股直肌和股外侧肌）的肌肉样品,测定其营养成分、理化指标及感官品质,并利用主成分分析法研究犊牛肉品质性状之间的关系。结果表明：半膜肌中蛋白质含量显著高于股内侧肌（P＜0.05）,股内侧肌水分含量和红度值最高,但嫩度最差（P＜0.05）,股直肌的滴水损失最大（P＜0.05）,外脊和半腱肌具有更低的红度值（P＜0.05）,外脊与股直肌总体可接受性评分显著高于股外侧肌（P＜0.05）;主成分分析结果表明,感官特性因子、持水力因子和营养成分因子累计贡献率达59.79%,可基本反映6 个部位犊牛肉的品质评价信息。综上所述,奶公犊不同部位肉间的各指标差异较大,可依据各部位肉的典型特征提升奶公犊部位肉的市场价值,达到优质优价的市场效果。     

乳制品设备专用清洗剂的研制与应用

乳制品加工企业中设备的清洗是生产中必不可少的部分,传统的化学清洗一般采用碱洗和酸洗的方法,其清洗枯实际应用中存在着各种各样的问题,特别是针对奶牛垢中的焦化物无法有效地清除,且清洗工艺复杂,清洗时间长。ＨＱ－４００乳制品专用清洗剂成功地解决了这一清洗技术上的难题,并已应用于大规模生产;产品具有清洗效果好,工艺简单,清洗时间短,成本低等特点。     

奶牛饲料中磷需求量研究进展

反刍类动物如奶牛饲料中需要添加一定量的磷以供动物瘤胃中的微生物生长和代谢,但现行标准中推荐的磷的添加量高于奶牛对磷的实际生理需求量。饲料中添加过量的磷不但增加了饲料成本,而且造成了环境污染。文章对美国、法国、荷兰等奶牛养殖先进国家关于奶牛饲料中磷需求量的最新试验研究成果进行了分析对比,介绍了现行奶牛饲料标准中磷的添加量可以降低的新模式,并且强调了奶牛饲料中应用谷物配料时应该注意的实际问题。     

Dairy Ration Formulation and Evaluation Program for Microcomputers

An interactive ration evaluation and formulation computer program for lactating and nonlactating dairy cows was developed using electronic spreadsheet software (Lotus 123). The program has five subunits: 1) a nutrient requirement section; 2) a feed bank section that stores nutrient composition of available feeds; 3) a computational section where rations are evaluated or formulated; 4) a feeding recipe section, which displays or prints grain mix, mineral mix, total mixed ration, or stanchion barn feeding recommendations; and 5) a comparative economic evaluator, which ranks feeds by a nutritional cost and benefit algorithm. Up to 12 fixed feed ingredients are able to be selected by the operator from a bank of up to 100 feeds on the basis of evaluation, farm availability, and nutrient constraints. Selected variable ingredients are used to balance the ration for dry matter, net energy, crude protein, bypass protein, and acid detergent fiber. Calcium and phosphorus are balanced using a combination of mineral sources. Trace mineral mixes may be either custom formulated or selected from a bank of proprietary supplements on the basis of limiting trace elements in the ration. Individualized farm data storage and retrieval capability facilitates regular nutritional monitoring and reformulation procedures.     

鲜切甘蓝生物保鲜剂配方优化和评价

鲜切甘蓝易造成机械损伤,导致品质恶化,选择合适的保鲜剂配方尤为重要。该文通过研究木瓜蛋白酶、菠萝蛋白酶和ε-聚赖氨酸保鲜剂的不同质量分数对鲜切甘蓝品质的影响,采取真空包装,以色泽、质地、外形、气味为筛选指标,对鲜切甘蓝感官品质进行评价;通过单因素和响应面优化实验确定了鲜切甘蓝的生物保鲜剂的最佳配方为0.3%(m/m)木瓜蛋白酶、0.3%(m/m)菠萝蛋白酶和0.1%(m/m)ε-聚赖氨酸。由响应面方差分析对鲜切甘蓝的感官品质的影响顺序为：ε-聚赖氨酸>菠萝蛋白酶>木瓜蛋白酶。根据贮藏实验,证明了优化后的生物保鲜剂配方,能有效延缓鲜切甘蓝维生素C、还原糖和叶绿素含量的下降。贮藏12 d时,生物保鲜剂处理组鲜切甘蓝维生素C含量为26.23 mg/100 g,还原糖含量为18.92 mg/g,叶绿素a含量为6.08 mg/kg,叶绿素b含量为12.25 mg/kg。结果证明了经优化的生物保鲜剂能有效维持鲜切甘蓝的感官品质和营养指标,较单一保鲜剂具有明显优势,可用于鲜切甘蓝的商品保鲜。     

安全性复合预混料及日粮电解质平衡对奶牛生产性能的影响

试验结果显示,奶牛生产中应用安全性复合预混料以及对基础日粮进行电解质平衡调节,可显著提高奶牛产奶性能,改善牛奶品质。利用电解质平衡日粮,可提高奶牛产奶量5.60%(P<0.01),提高牛奶密度0.29%;在电解质平衡日粮基础上,使用安全性复合预混料,可进一步提高奶牛产奶量6.26%(P<0.01),提高牛奶密度0.19%;二者综合考虑,可提高奶牛产奶量12.24%(P<0.01),提高牛奶密度0.49%。     

饲料防霉剂富马酸二甲酯合成工艺研究

对富马酸二甲酯的应用和合成方法进行了介绍 ,重点对富马酸二甲酯合成中异构化反应和酯化反应进行了研究 ,得到了适宜的工艺参数。     

樱桃仁的小鼠饲喂安全性评价

研究中国樱桃仁的饲用安全性,为樱桃仁的综合加工利用提供一定的参考依据。用添加不同量(10%,20%和30%)樱桃仁的饲料饲喂小鼠28 d,以普通饲料饲喂的小鼠为对照组,通过称重法分析小鼠的体重变化和脏器系数、用血细胞分析仪分析小鼠血液组分(白细胞数量、红细胞数量、红细胞压积、平均红细胞体积、血红蛋白浓度、平均血红蛋白浓度、平均血红蛋白含量、血小板计数、血小板压积、平均血小板体积、血小板分布宽度)、用化学分析法分析血液中谷丙转氨酶和谷草转氨酶活性以评价樱桃仁的饲用安全性。结果表明:在饲喂周期内,小鼠无异常症状和体征,除少数指标所测结果与对照组有所差别,大部分指标结果都不存在显著性差异,所有指标测得值均在小鼠正常生理指标范围内,未发现毒害作用,鉴于此,初步可以认为樱桃仁作为饲料添加是安全的。