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牛奶挥发性成分的GC-MS分析 总被引:21,自引:0,他引:21
研究4种牛奶挥发成分,经水蒸气蒸馏所得的油状物,采用GC-MS法对4种牛奶的挥发性成分进行了分离鉴定.经气质连用检出4种牛奶中含有苯并噻唑、丁化羟基甲苯、二苯胺、十二烷、十六烷、十八烷、十九烷、二十一烷、2-壬酮、2-呋喃甲醇、戊酸等. 相似文献
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南京奶业集团为巩固4年来在国际牛奶日和开展"牛奶与健康"宣传月期间的宣传效果,决定从8月起在全国同行业中第一个向全国消费者开通国内首条"牛奶与健康"热线-025-4873583。仅20多天来就受到南京市和苏、皖等省市广大牛奶订户和消费者的欢迎。据悉,这条热线每天由国内知名的营养学家、省营养学会专家、乳品卫生专家和医护技术人员轮流在线,认真接受咨询和圆满解答消费者提出的有关牛奶、牛初乳与人体健康关系的各种问题。国内首条“牛奶与健康”热线在宁开通——025-4873583 受到消费者的欢迎@桑万邦 相似文献
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随着人民生活水平的不断提高 ,牛奶消费者越来越多 ,其消费主体已从原来的婴幼儿、老弱病者逐步扩展到工薪阶层及普通市民 ,甚至农民。因此 ,在城市居民的食物消费结构中 ,牛奶的消费比例逐日上升。按国家“十五”计划 ,到 2 0 0 5年 ,全国年人均牛奶占有量将从目前的 6 8千克 ,提高到 9千克。特别是 2 0 0 0年由农业部牵头、国家六个部委联合颁发的“学生饮用奶计划”的实施方案现已在全国各直辖市、省会城市及有条件的中小城市试点和启动 ,这意味着今后我国食品市场对牛奶的需求量将与日俱增 ,展示着奶业广阔的发展前景。在政府关心青少年… 相似文献
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近几年来,我国奶牛业发展迅速,成效显著。牛奶生产、乳品加工和市场消费实现了快速增长。在新时期,我国奶牛业的发展对带动农业和农村经济结构的战略性调整,发展第二产业和第三产业,增加农民收入,提高国民素质都具有重要意义。据统计,2003年全国奶牛存栏893.2万头,牛奶总产量17 相似文献
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对我区城市奶牛业应如何发展,谈两点意见: 一、我区奶牛生产和牛奶供应现况据85年统计,我区奶牛5,000头,牛奶产量600万公斤,人均占有奶0.17公斤,奶牛头数和牛奶产量是全国倒数第一位。据南宁、柳州、桂林、梧州、北海等五市统计有奶牛3,300头,挤奶1.718头,年产鲜奶518.5万公斤,商品奶445.35万公斤,五个城市奶类总耗量946.5万公斤,自给率仅 相似文献
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本试验旨在分析水牛乳成分中乳脂肪、乳蛋白、乳糖和乳尿素氮含量及其与乳能量的相关性,建立产奶净能的预测模型,用于奶水牛泌乳期科学的饲养管理。试验采取云南省主要奶水牛养殖场和养殖小区的2014—2015年9—12月份送达昆明市奶牛生产性能测定中心的304个原料乳样本,水牛乳的乳成分由昆明市奶牛生产性能测定中心用MilkoScan FT+FC乳成分体细胞联用仪和MilkoScan FT 120乳成分分析仪测定,鲜乳经真空干燥箱恒温烘干后用氧弹式热量计测定乳能量。结果表明:乳脂肪、乳蛋白、乳糖、乳尿素氮、乳总固形物含量和乳能量分别为6.45%、4.55%、5.31%、13.60 mg/dL、18.77%和4.02 MJ/kg;乳能量分别与乳脂肪和乳蛋白含量呈现极显著正相关(r=0.896 0、r=0.563 0,P0.01),乳能量受乳脂肪和乳蛋白含量的影响较大。分别以乳脂肪(F),乳脂肪和乳蛋白(F和P),乳脂肪、乳蛋白和乳糖(F、P和La),乳脂肪、乳蛋白、乳糖和乳尿素氮含量(F、P、La和MUN)为预测因子,建立的预测乳能量(E)的一元、二元、三元及四元回归方程的拟合度均在0.90以上,方程分别为:E=0.388F+1.540(R~2=0.933 6,P0.01);E=0.373F+0.221P+0.460(R~2=0.926 7,P0.01);E=0.396F+0.186P+0.105La-0.104(R~2=0.954 0,P0.01);E=0.397F+0.187P+0.106La+0.002MUN-0.146(R~2=0.958 0,P0.01)。由此可见,可通过水牛乳中的乳脂肪、乳蛋白、乳糖及乳尿素氮含量预测水牛乳产奶净能。 相似文献
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Ch. Milis 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(4):191-195
Abstract This study was conducted in order to develop equations for the prediction of ewe's milk energy content via milk composition. Twenty-four multiparous Chios breed ewes were examined in a eight-week study that started at parturition. Animals were fed in groups (12 ewes), with two, highly concentrated (forage to concentrate ratio 30:70 DM), rations differing in undegradable protein (UP) content. The following equations are proposed: (i) when fat content (F; g/kg) is the only variable: EVL(kJ/kg)=39×F+2090 (SE 0.30 kJ/g), (ii) when total solids (TS; g/kg) is the only variable: EVL(kJ/kg)=33×TS–1222 (SE 0.26 kJ/g) whilst the following equation is proposed when solids non fat content (SNF; g/kg) is an additional known variable: EVL (kJ/kg)=39×F+36×SNF–1990 (SE 0.27 kJ/g). Fat corrected milk (FCM) yield can be calculated by the following equation: Y (FCM 6%; kg/d)=L (kg/d)×[0.472+0.0088×F (g/kg)], where L is milk yield. 相似文献
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Sletmoen-Olson KE Caton JS Olson KC Redmer DA Kirsch JD Reynolds LP 《Journal of animal science》2000,78(2):456-463
Hereford x Angus cows (n = 36; initial wt 568+/-59 kg) were used to evaluate the effects of undegradable intake protein (UIP) supplementation on plasma hormone and metabolite concentrations. Treatments were control (unsupplemented) or one of three protein supplements. Supplements were fed at 1.3 kg DM/d and included UIP at low, medium, or high levels (53, 223, or 412 g UIP/kg supplement DM, respectively). Supplements were formulated to be isocaloric (1.77 Mcal NEm/kg) and to contain equal amounts of degradable intake protein (DIP; 211 g DIP/kg supplement DM). Prairie hay (5.8% CP) was offered for ad libitum consumption. Jugular blood samples were collected daily from each cow during six 7-d collection periods (corresponding to mo 7, 8, and 9 of gestation and to mo 1, 2, and 3 of lactation). Plasma glucose concentrations were similar between control and supplemented cows during mo 2 and 3 of lactation; however, the low UIP treatment group had consistently higher plasma glucose (P< or =.02) than cows fed medium or high UIP supplements during gestation and the last month of lactation. During gestation, cows fed the high UIP supplement had higher (P< or =.08) plasma glucose than cows fed the medium UIP supplement. During gestation, plasma insulin concentration was increased (P = .01) by supplementation; insulin also increased (P<.01; mo 8 and 9) as supplemental UIP increased. During lactation, plasma insulin was greater (P = .01) in supplemented than in control cows. During mo 2 and 3 of lactation, insulin was lower (P< or =.04) in cows fed low UIP supplement compared with cows fed medium or high UIP supplements. Growth hormone concentration was higher (P< or =.03) in control cows than in supplemented cows in all periods measured except mo 7 of gestation. Plasma nonesterified fatty acid concentrations were higher (P< or =.03) in control cows than in supplemented cows in all periods measured except the 1st mo of lactation. These data are interpreted to suggest that protein supplementation and level of UIP can alter plasma concentrations of hormones and metabolites in gestating and lactating beef cows consuming low-quality hay. 相似文献
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应用纤维素酶+胃蛋白酶法评定了6种秸秆饲料在绵羊体内的消化率。试验结果表明:酶解的消化率(X)与体内干物质消化率(DMD),有机物消化率(OMD),和能量消化率(ED)之间有显著的相关性,求出估测方程为: 体内:DMD(%)=6.95+0.75X r=0.89(P<0.01),RSD=1.81 OMD(%)=9.39+0.80X r=0.76(P<0.05),RSD=3.25 ED(%)=0.92X-1.75 r=0.78(P<0.05).RSD=3.54 酶解法具有良好的重演性和稳定性(变异系数平均4.66%)。 相似文献
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The effects of supplemental carbohydrate (CHO) sources on milk yield and composition,nitrogen (N) balance,and ruminal fermentation were evaluated in lactating dairy cows fed energy-deficient total mixed rations (TMR).Fifty-six lactating Holstein cows (36.8 ±3.4 kg/d of milk yield; 152 ±26days in milk [ DIM ] ) were randomly assigned to one of four diets:( 1 ) basal TMR ( control ) ; ( 2 ) basal TMR + 1.25 kg/d sucrose (SUC) ; ( 3 ) basal TMR + 2.12 kg/d steam-flaked corn ( SFC ) ; ( 4 ) basal TMR + 2.23 kg/d wheat (WHE).The trial lasted 70 days,including the first 10 days of adaptation.Simultaneously,a 4 × 4 Latin square trial was conducted with four ruminally cannulated cows of similar DMI (Dry Matter Intake) fed on the above four diets.Each testing period lasted 18 days:15 days for adaptation and 3 days for sampling.Cows fed SUC-,SFC-,and WHE-supplemented diets produced 1.6,2.9,and 0.8 kg/d,respectively,more milk than those on the basal TMR control diet,but the difference was not significant (P =0.160).However,the production of energy-corrected milk of cows fed CHO-supplemented diets improved significantly (P =0.020),and the yield of 4% fat-corrected milk tended to be higher (P =0.063 ) than in control animals.Percentages of milk protein,lactose and solidsnot-fat (SNF) increased significantly in cows fed CHO-supplemented diets ( P < 0.05 ),and yields of milk protein and SNF were significantly higher (P<0.05); yields of milk fat and lactose were somewhat higher ( P < 0.10 ).Cows receiving supplementary CHO diets consumed more DM (Dry Matter) ( P =0.023 ) ; however,there was no significant difference in N retention,digestibility,or utilization efficiency among the treatments (P > 0.10 ).The average ruminal pH was lowest in cows supplemented with SUC,while that in cows supplemented with SFC and WHE was only slightly reduced (P =0.025 ).Ruminal NH3-N concentration was highest with no supplementary CHO ( P =0.017 ),and changes in postfeeding time were similar across the diets.Total volatile fatty acid concentration was significantly lower in control animals than in those on SUC- and WHE-supplemented diets ( P =0.001 ) ; significant dietary responses were observed in the concentrations of acetate,butyrate,and branched-chain fatty acids and in the acetate-to-propionate ratio ( P < 0.001 ).These results indicate that supplementation with different CHO sources in energy-deficient diets substantially improved the balance of energy and N in the rumen,altered ruminal fermentation,and improved lactation performance in dairy cows. 相似文献
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Effect of dietary energy on milk production and metabolic hormones in thin, primiparous beef heifers
Thirty-six primiparous heifers were used to determine the effect of dietary energy on postpartum interval, milk production, serum concentrations of insulin, insulin-like growth factor I (IGF-I), growth hormone, and cerebrospinal fluid (CSF) concentrations of neuropeptide-Y (NPY). Low-quality hay was fed during the last trimester of pregnancy to achieve suboptimal calving weight (370 +/- 5 kg) and condition score (4.0 +/- .1). After calving, cows were allotted to one of four dietary treatments that differed in metabolizable energy. Experimental diets were fed at 2.5% of shrunk body weight and formulated to provide 1.8 (low), 2.1 (maintenance), 2.4 (maintenance high), or 2.7 (high) Mcal of ME/kg DM. Daily milk production was estimated at approximately 30, 60, and 90 d postpartum. Condition score change and weight change were defined as change from calving to d 90 postpartum. As energy intake increased, condition score change (P < .001), IGF-I (P < .001) and insulin (P < .01) increased and postpartum interval decreased (P = .04). No relationship existed between postpartum interval and CSF concentration of NPY (P > .1). Condition score change was positively associated with IGF-I and insulin (r = .71, P < .001; r = .38, P = .02, respectively) and negatively associated with GH (r = -.67, P < .001). Weight change and serum concentrations of GH did not differ (P > .10) among treatments. Increasing dietary energy intake was associated with a curvilinear increase in milk yield (P = .04) and percentage milk fat (P = .03) and a linear increase (P = .04) in energy available for milk production. Greater milk yield at d 30 was associated with a longer postpartum interval (r = .34, P < .05). In conclusion, a greater proportion of net energy is partitioned to maternal tissue realimentation when cows receive high compared to low-, maintenance-, or moderate-energy diets. 相似文献
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Feed intake and weight gain of growing goats fed diets of various energy and protein levels 总被引:4,自引:0,他引:4
Growing goats, 45 Alpine and 45 Nubian, were used in a 3 x 3 factorial arrangement to quantify the influence of dietary energy and protein levels on daily DM intake and nutrient utilization for growth. Goats had ad libitum access to complete mixed diets containing either 2.46, 2.77 or 3.05 Mcal/kg ME plus 11.2, 12.7 or 15.1% CP for 16 wk. Dry matter intake decreased curvilinearly as dietary ME density increased (P less than .001). Dry matter intake increased linearly (P less than .05) as dietary CP level increased during all growth intervals except wk 25 to 28 of age. Average daily gain was 115, 113 and 99 g/d for goats fed diets containing 2.46, 2.77 and 3.05 Mcal/kg ME, respectively. Average daily gain was 104, 106 and 117 g/d for goats fed diets with 11.2, 12.7 and 15.1% CP, respectively. Dry matter intake was higher (P less than .01) for Alpine than for Nubian goats, whereas ADG was similar between breeds. Intake of ME was 248, 260 and 198 kcal/(kg.75.d) for goats fed the low- medium- and high-energy diets, respectively. Intake of CP was 9.1, 10.7 and 13.2 g/(kg.75.d) for goats fed low-, medium- and high-protein diets, respectively. Average requirements for growth derived from regression analysis of all data points were 4.6 kcal ME and .26 g CP/g ADG. The prediction equation for intake of growing goats of 4 to 8 mo of age was: DMI, g/d = 1,749 - 496 DE, kcal/g + 18 live weight, kg + 3 ADG, g/d; r2 = .73 (Sy.x = 127, P less than .0001, n = 90). The requirement of ME for growth was 33% lower than the value recommended in 1981 by the National Research Council. 相似文献
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Thirty-two wethers were used to compare the nutritive value of Climax timothy (Phleum pratense L.) and quackgrass (Agropyron repens L. Beauv.) harvested at two stages of maturity, joint and early heading, and fed as hay. Crude protein was higher for quackgrass than for timothy (P less than .01). As maturity advanced, CP decreased (P less than .01), but NDF and ADL increased (P less than .01). Dry matter intake was similar between species but decreased by 8% with increasing maturity (P less than .01). Intake of NDF (g/kg.75) was similar for all hays. With increasing plant maturity, apparent digestibility decreased, the effect being more pronounced for quackgrass. Apparent digestibilities of DM and energy were slightly higher (P less than .06) for timothy, and those of CP and hemicellulose were higher for quackgrass (P less than .01). Apparent digestibilities of NDF, ADF, ADL, crude fiber and cellulose were similar between species. Dry matter intake and digestibility were correlated negatively with the ADL/ADF ratio of the hay (r = -.99, P less than .01), whereas CP intake and CP digestibility were correlated with CP of the hay (r = .99, P less than .01). The Lucas test estimated true protein digestibility at 88.1% and metabolic fecal protein at 29.4 g per kg of DM intake. During the growth trial, DM intake was similar between hays, but ADG of sheep was lower (P less than .01) for those fed hays at early heading vs those receiving hays at the joint stage of maturity. The feed to gain ratio was slightly lower for hays at joint (P less than .08). Under the climatic conditions of the 1988 growing season, the nutritive value of quackgrass was similar to that of Climax timothy. 相似文献
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为了研究我国黑白花生长母牛的能量代谢规律和探讨运动对奶牛能量代谢的影响,笔者用传统开路式面具装置对6、9、12、15、18月龄(各3头)的青年母牛在中立温度区内进行了绝食代谢试验,并对3头22月龄青年母牛运动状态下的产热量进行了测定。结果表明,黑白花青年母牛中立温度区内的绝食代谢产热量FHP(kcal/24hr)=277.5w~(0.653);不同速度水平行走的能量消耗分别为0.3316±0.0101cal/kgm(V=0.95±0.04米/秒)和0.4625±0.0462cal/kgm(V=1.54±0.03米/秒)。 相似文献
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Tomohiro MITANI Makoto TAKAHASHI Koichiro UEDA Hiroki NAKATSUJI Seiji KONDO Masahiko OKUBO 《Animal Science Journal》2005,76(4):331-337
The effects of supplementary corn silage (CS) of either 2 or 4 kg of dry matter (DM; S + 2 and S + 4, respectively) above the energy requirement for milk production and maintenance for grazing dairy cows (S) were determined. Time‐restricted grazing was used to compare the feed intake, milk production, and nitrogen and energy use of lactating cows. The experiment was carried out on two different pastures using a 3 × 3 Latin square design for each pasture. Cows were grazed for 5 h on a rotational grazing system and were fed concentrate (1 kg per 5 kg of milk yield). Herbage intake was measured using a weighing technique. To calculate the energy and nitrogen use, whole feces and urine were collected. There was no statistical effect of the pastures. Herbage intake decreased by the addition of CS (P = 0.02). The reduction of herbage DM intake per unit consumption of supplementary CS towards the S group were 0.80 and 0.45 kg for the S + 2 and S + 4 groups, respectively. The total DM intake for the S + 4 group was higher than that for the S and S + 2 groups (P = 0.02). Milk yield did not differ among treatments, even though the total DM intake for the S + 4 group was higher than that of the S and S + 2 groups. Nitrogen and energy use did not differ with the addition of CS. 相似文献