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1.
试验旨在研究日粮不同能量蛋白质水平和赖氨酸水平对5~10周龄扬州鹅生长性能的影响。试验采用3×4二因子设计,3个能量蛋白质水平分别为:10.83 MJ/kg、15%,11.29 MJ/kg、16%,11.75 MJ/kg、17%,其蛋白质能量比均约为14 g/MJ,4个赖氨酸水平分别为:0.65%、0.80%、0.95%和1.10%。结果表明:①日粮能量蛋白质水平对6、8、10周龄扬州鹅体重没有显著影响(P>0.05),日粮赖氨酸水平显著影响扬州鹅6、8、10周龄体重(P<0.05),但能量蛋白质水平和赖氨酸水平对其没有显著交互作用(P>0.05);②日粮能量蛋白质水平显著影响5~10周龄扬州鹅的平均日采食量和料重比(P<0.05),赖氨酸水平显著影响平均日增重和平均日采食量(P<0.05),能量蛋白质水平和赖氨酸水平对其没有显著交互作用(P>0.05);③中能蛋水平和最低赖氨酸水平下,5~10周龄扬州鹅可获得较佳生长性能。试验认为5~10周龄扬州鹅能量蛋白质和赖氨酸适宜需要量分别为11.29 MJ/kg、16%和0.65%。  相似文献   

2.
The effect of feeding varying dietary lysine to energy levels on growth and haematological values of indigenous Venda chickens aged 8 – 13 weeks was evaluated. Four hundred and twenty Venda chickens (BW 362 ± 10 g) were allocated to four dietary treatments in a completely randomized design. Each treatment was replicated seven times, and each replicate had fifteen chickens. Four maize–soya beans‐based diets were formulated. Each diet had similar CP (150 g/kg DM) and lysine (8 g lysine/kg DM) but varying energy levels (11, 12, 13 and 14 MJ ME/kg DM). The birds were reared in a deep litter house; feed and water were provided ad libitum. Data on growth and haematological values were collected and analysed using one‐way analysis of variance. Duncan's test for multiple comparisons was used to test the significant difference between treatment means (p < 0.05). A quadratic equation was used to determine dietary lysine to energy ratios for optimum parameters which were significant difference. Results showed that dietary energy level influenced (p < 0.05) feed intake, feed conversion ratio, live weight, haemoglobin and pack cell volume values of chickens. Dry matter digestibility, metabolizable energy and nitrogen retention not influenced by dietary lysine to energy ratio. Also, white blood cell, red blood cell, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration in female Venda chickens aged 91 days were not influenced by dietary lysine to energy ratio. It is concluded that dietary lysine to energy ratios of 0.672, 0.646, 0.639 and 0.649 optimized feed intake, growth rate, FCR and live weight in indigenous female Venda chickens fed diets containing 8 g of lysine/kg DM, 150 g of CP/kg DM and 11 MJ of ME/kg DM. This has implications in diet formulation for indigenous female Venda chickens.  相似文献   

3.
This study aimed to determine the net energy requirement of Holstein cows in mid‐lactation under heat stress. Twenty‐five multiparous Holstein cows were randomly allocated to five groups corresponding to five isonitrogenous total mixed rations, with net energy for lactation (NEL) content of 6.15 (NE‐6.15), 6.36 (NE‐6.36), 6.64 (NE‐6.64), 6.95 (NE‐6.95), 7.36 (NE‐7.36) MJ/kg of dry matter (DM), respectively. Throughout the experimental period the average temperature humidity index at 07.00, 14.00 and 22.00 hours was 72.1, 88.7, and 77.6, respectively. DM intake decreased significantly with the elevated dietary NEL concentration. Fat corrected milk increased quadratically, and milk fat content and milk energy (MJ/kg) reached the greatest in the NE‐6.95 group with increasing dietary NEL content. Strong correlations were found between dietary NEL content and: (i) DM intake; (ii) NEL intake; (iii) milk energy (El); (iv) El/metabolizable energy intake (MEI); (v) El/NEL intake, as well as between NEL intake and fat corrected milk yield (FCM). The suitable net energy required for dairy cows producing 1 kg FCM ranged from 5.01 to 5.03 MJ, was concluded from the above‐stated regressions. Correlation between heat production (HP) and MEI could be expressed as: Log (HP) = ?0.4304 + 0.2963*MEI (n = 15, R2 = 0.99, Root Mean Square Error (RMSE) = 0.18). Fasting HP was 0.3712 MJ/kg0.75 when extrapolating MEI to zero.  相似文献   

4.
The effects of three dietary protein levels on growth, meat, and carcass traits were studied in organic pigs fed a three-phase diet. Assuming lysine was the first limiting amino acid, feeds were formulated to ileal digestible (ID) lysine content, with the ID lysine:crude protein ratio set at a constant of 4%. Feeds were also formulated to an isocaloric rate (net energy: 9.4 MJ/kg during the first feeding phase, 9.25 MJ/kg during the second feeding phase and 9.1 MJ/kg during the finisher phase), with a high (HP), a medium (MP) or a low (LP) protein content ranging from 20% to 14% crude protein (CP). ID lysine content of the LP and MP feed was, respectively, 80% and 90% of the ID lysine content of the HP feed. The nutrient formulation of the HP feed was similar to nutrient levels commonly used in conventional Belgian pig farming. From 20 to 40 kg liveweight, the pigs showed better feed conversion ratios, with an increasing dietary protein concentration (r(2)=0.84). This effect was not observed in the second and third phases, although a significant effect of protein concentration on voluntary feed intake in the second phase did occur (P=0.018), probably as a compensation for the lower protein concentration in the LP diet. Analysis of the carcasses showed a lower meat percentage with lower protein concentration (P<0.05), whereas influences on meat quality were limited. It was concluded that whereas during the first phase of growth, higher protein concentration leads to better performance, from the second phase onwards (45 kg), at least with isocaloric diets, a decrease in protein content (corresponding to a 10% reduction in dietary ID lysine levels compared to conventional pig fattening) may be used in organic growing-finishing pig nutrition.  相似文献   

5.
Eighteen Chinese Holstein heifers average age 230 ± 14 days were allocated to 1 of 3 dietary crude protein (CP) to metabolizable energy (ME) ratios to examine the effects on growth performance, blood metabolites and rumen fermentation parameters with 90‐days experiment. Three different dietary CP:ME ratios were targeted based on the formulation of dietary CP contents of 10.85%, 12.78% and 14.63% on dry matter (DM) basis with similar ME contents (10.42 MJ/kg DM), which were categorized as low, medium and high dietary CP:ME ratios. The actual CP:ME ratios obtained in this study significantly increased from low to high CP:ME ratio groups with a value of 10.59, 11.83 and 13.38 g/MJ respectively. Elevated CP:ME ratios significantly increased CP intake (kg/day) and feed efficiency (FE) which was defined as dry matter intake as a proportion of average daily gain (ADG), whereas little difference was observed in body weight (kg), ADG (kg/day), DM intake (kg/day) and ME intake (MJ/day) among the three different CP:ME ratio groups. Increasing dietary CP to ME ratios significantly increased CP digestibility, whereas digestibility of DM and gross energy remained constant in the current experiment. Blood urea nitrogen and insulin‐like growth factor‐1 linearly increased with increasing dietary CP:ME ratios. There was significantly dietary treatment effect on rumen fermentation parameters including acetate, propionate, butyrate and total volatile fatty acids. Therefore, this study indicated that increasing dietary CP levels with similar energy content contributed to increased protein intake and its digestibility, as well as FE. Holstein heifers between 200 and 341 kg subjected to 13.38 dietary CP:ME ratio showed improved feed efficiency, nutrient digestibility, some blood metabolites and rumen fermentation characteristics for 0.90 kg/day rate of gain.  相似文献   

6.
Fifty-nine multiparous Large White x Landrace sows were used to determine the effects of high ambient temperature and level of dietary heat increment on lactation and reproductive performance. During a 28-d lactation and the 14-d postweaning period, ambient temperature was maintained constant at 20 or 29 degrees C. Experimental diets fed during lactation were a control diet (NP; 17.6% crude protein) and two low-protein diets obtained by reduction of CP level (LP; 14.2% CP) and both reduction of CP and addition of 4% fat (LPF; 15.2% CP); the NE:ME ratio was 74.3, 75.6, and 75.8% for NP, LP, and LPF diets, respectively. All diets provided 0.82 g of digestible lysine/MJ of NE, and ratios between essential amino acids and lysine were above recommendations. During the ad libitum period (i.e., between d 7 and 27 of lactation), ADFI and NE intake decreased, respectively, from 7.63 to 4.22 kg and 82.0 to 43.3 MJ of NE when the temperature increased from 20 to 29 degrees C. Exposure to 29 degrees C reduced litter BW gain (2,152 vs 2,914 g/d) and increased lactation BW loss (34 vs 16 kg) but increased postweaning BW gain (2 vs - 4 kg). Expressed per kilogram of feed intake, water intake increased from 4.0 to 7.5 L between 20 and 29 degrees C. Compared with the NP diet, low-CP diets (LP or LPF) maintained performance and reduced total N excretion (-22.5%) in lactating sows at thermoneutrality and attenuated the negative effects of high temperature on NE intake and BW loss (40.9 vs 47.9 MJ of NE/d and 41 vs 30 kg for NP and LP + LPF diets, respectively). Temperature and diet composition did not affect the reproductive performances, and the mean weaning-to-estrus interval was 4.9 d. The respiratory rate and skin, udder, and rectal temperatures increased markedly at 29 degrees C (105 vs 33 breaths per min and 37.8 vs 36.1 degrees C, 38.9 vs 38.2 degrees C, and 39.5 vs 38.8 degrees C, respectively) without any effect of diet. In conclusion, low heat increment diets (i.e., with reduced CP/NE ratio) did not affect lactation performance of sows at thermoneutrality and attenuated the effects of high ambient temperature on energy intake and BW loss. At any ambient temperature, N excretion can be markedly reduced.  相似文献   

7.
1～3周龄黑羽公番鸭代谢能和粗蛋白质需要量的研究   总被引：3，自引：0，他引：3  
本试验旨在确定1～3周龄黑羽公番鸭代谢能和粗蛋白质的需要量.采用3×3双因子试验设计,设3个代谢能水平( 11.72、12.14、12.55 MJ/kg)和3个粗蛋白质水平(17％、19％、21％),配制9种试验饲粮.选取1日龄黑羽公番鸭378羽,随机分为9个处理,每处理设6个重复,每重复7只鸭,每组试鸭随机饲喂1种试...  相似文献   

8.
The net and metabolizable energy (NE and ME) requirements of Dorper cross‐bred female lambs with BWs of 20–35 kg were assessed in a comparative slaughter trial. Thirty‐five Dorper × thin‐tailed Han cross‐bred female lambs weaned at ~50 days of age (20.3 ± 2.15 kg BW) were used. Seven randomly selected lambs were slaughtered at the start of the trial (baseline group). An intermediate group consisting of seven randomly selected lambs fed ad libitum was slaughtered when the lambs reached an average BW of 28.5 kg. The remaining 21 lambs were allotted randomly to three levels of dry matter intake: ad libitum or restricted to 70% or 40% of the ad libitum intake. All the lambs were slaughtered when the sheep fed ad libitum reached a BW of 35 kg. Total body energy, nitrogen, fat, ash and moisture content were determined. In a digestibility trial, an additional 15 Dorper × thin‐tailed Han cross‐bred female lambs (28.7 ± 1.75 kg BW) were housed in metabolism cages and used in a completely randomized design experiment to evaluate the ME value of the diet at the three feed intake levels. The maintenance requirements for NE and ME were 245.5 and 380.3 kJ/kg metabolic shrunk body weight (SBW0.75) respectively. The partial efficiency of energy use for maintenance was 0.645. The NE requirements for growth ranged from 1.18 to 5.18 MJ/d for the lambs gaining 100–350 g/d from 20 to 35 kg BW. Partial efficiency of ME for growth was 0.44. In conclusion, the current study suggests that the NE requirement for maintenance and growth of Dorper early‐weaned cross‐bred female lambs is lower than the current AFRC and NRC recommendations.  相似文献   

9.
本试验旨在通过研究饲粮不同代谢能、粗蛋白质水平对新杨绿壳蛋鸡产蛋后期(44~56周龄)生产性能、蛋品质及血清生化指标的影响,得出其产蛋后期饲粮代谢能和粗蛋白质的适宜配比。选取768羽体重相近的43周龄末新杨绿壳蛋鸡,随机分为6组,每组4个重复,每个重复32羽。采用2×3因子(代谢能水平为10.87和11.08 MJ/kg,粗蛋白质水平为15.00%、15.50%和16.00%)设计试验,共设计6种饲粮。试验预试期1周,正试期12周。结果表明:1)饲粮不同代谢能、粗蛋白质水平对绿壳蛋鸡产蛋后期产蛋率和料蛋比有显著影响(P0.05),饲粮代谢能和粗蛋白质水平在产蛋率上表现出极显著的交互作用(P0.01),其中,高能低蛋组(代谢能为11.08 MJ/kg,粗蛋白质为15.00%)产蛋率最高,料蛋比最低。2)饲粮较高粗蛋白质水平(16.00%)能显著提高绿壳蛋鸡产蛋后期鸡蛋的哈氏单位(P0.05);饲粮较高代谢能水平(11.08 MJ/kg)能显著提高绿壳蛋鸡产蛋后期鸡蛋的蛋黄颜色(P0.05);饲粮代谢能和粗蛋白质水平在蛋品质上未表现出显著的交互作用(P0.05)。3)高能低蛋组绿壳蛋鸡血清尿素氮含量最低;饲粮较高代谢能水平(11.08 MJ/kg)能显著降低绿壳蛋鸡血清总胆固醇含量(P0.05)。综上,在本试验条件下,饲粮代谢能、粗蛋白质水平分别为11.08 MJ/kg和15.00%时,更有利于绿壳蛋鸡产蛋后期生产性能的发挥和蛋品质的改善。  相似文献   

10.
生长前期丝羽乌骨鸡饲粮适宜能量、蛋白水平研究   总被引：7，自引：0，他引：7  
两因子设计 ,以1日龄丝羽乌骨鸡504只为材料 ,进行饲养试验结合代谢试验考察了饲粮代谢能(ME)、粗蛋白质(CP)对生长前期(0～8周)丝羽乌骨鸡生产性能的影响规律。结果表明 ,通过饲粮营养调控可显著改善生长前期丝羽乌骨鸡的生长速度和生产性能 ,ME显著(P<0.05)或极显著(P<0.01)影响各阶段平均日采食量(ADFI)和饲料转化率(FCR) ,CP显著影响3周龄前的生产性能指标(P<0.05) ,二者互作影响不显著(P>0.05) ;增加营养素摄入量有利于改善丝羽乌骨鸡对营养素的表观利用率。推荐3周龄前饲粮ME为13.40MJ/kg、CP为20 % ,整个生长前期(0～8周)推荐使用ME为12.35MJ/kg、CP为18 %饲粮以获得较好生产成绩和经济效益  相似文献   

11.
The present study was performed to quantify the energy and nutrient metabolism of pregnant sows fed high (HP) or low (LP) dietary protein [18.3 vs. 13.5% of dry matter (DM)]. A total of nine sows (four on HP and five on LP diet) were subjected to balance and respiration trials four times during their second pregnancy (approximately on days 30, 61, 80 and 104 of gestation). The digestibility of protein (83.0 vs. 79.9) (p < 0.01) and energy (84.9 vs. 83.7%) (p < 0.05) was higher for the HP diet. Daily intake of metabolizable energy (ME) and retained energy (RE) were similar for the two groups, with an average of 28.37 MJ ME and 3.94 MJ RE, respectively. Heat production (HE) measured according to the respiratory quotient (RQ) and carbon-nitrogen (CN) method was similar (464 vs. 454 kJ/kg 0.75/day, respectively). Sows fed HP retained more energy in protein (3.33 vs. 2.00 MJ/day) (p < 0.001) and tended to retain less energy in fat (1.59 vs. 2.50 MJ/day) than LP sows. Retained nitrogen (N) (22.3 vs. 13.4 g/day) (p < 0.001) and utilization of N (retained/digested) (45.2 vs. 38.1%) was higher for HP sows compared with LP sows. In late pregnancy, retained N, retained fat, HE and oxidation of carbohydrates increased, while oxidation of fat was reduced to zero. In conclusion, both diets provided adequate N for retention in maternal tissue and conception products. In spite of the lower utilization of N in LP sows, the N excretion was depressed by 5.6 g/day compared with HP sows, because of the lower N intake.  相似文献   

12.
The aim of this study was to investigate whether dietary protein intake during gestation less than or greater than recommendations affects gilts growth and body composition, gestation outcome, and colostrum composition. German Landrace gilts were fed gestation diets (13.7 MJ of ME/kg) containing a low (n = 18; LP, 6.5% CP), an adequate (n = 20; AP, 12.1%), or a high (n = 16; HP, 30%) protein content corresponding to a protein:carbohydrate ratio of 1:10.4, 1:5, and 1:1.3, respectively, from mating until farrowing. Gilts were inseminated by semen of pure German Landrace boars and induced to farrow at 114 d postcoitum (dpc; Exp. 1). Energy and protein intake during gestation were 33.3, 34.4, and 35.8 MJ of ME/d (P < 0.001) and 160, 328, and 768 g/d, respectively, in LP, AP, and HP gilts (P < 0.001). From insemination to 109 dpc, BW gain was least in LP (42.1 kg), intermediate in HP (63.1 kg), and greatest in AP gilts (68.3 kg), whereas increase of backfat thickness was least in gilts fed the HP diet compared with LP and AP diets (3.8, 5.1, 5.0 mm; P = 0.01). Litter size, % stillborn piglets, and mummies were unaffected (P > 0.28) by the gestation diet. Total litter weight tended to be less in the offspring of LP and HP gilts (14.67, 13.77 vs. 15.96 kg; P = 0.07), and the percentage of male piglets was greater in litters of HP gilts (59.4%; P < 0.01). In piglets originating from LP and HP gilts, individual birth weight was less (1.20, 1.21 vs. 1.40 kg; P = 0.001) and birth weight/crown-rump length ratio was reduced (45.3, 46.4 vs. 50.7 g/cm; P = 0.003). Colostrum fat (7.8, 7.4 vs. 8.1%) and lactose concentrations (2.2, 2.1 vs. 2.6%) tended to be reduced in LP and HP gilts (P = 0.10). In Exp. 2, 28 gilts (LP, 10; AP, 9; HP, 9) were treated as in Exp. 1 but slaughtered at 64 dpc. At 64 dpc, LP gilts were 7% lighter than AP gilts (P = 0.03), whereas HP gilts were similar to AP gilts. Body composition was markedly altered in response to LP and HP feeding with less lean (P < 0.01) and greater fat content (P = 0.02 to 0.04) in LP and less fat content (P = 0.02 to 0.04) in HP gilts. Fetal litter weight and number, and embryonic survival at 64 dpc were not affected by the diets. These results indicated that gestation diets containing protein at 50 and 250% of recommendations and differing in protein:carbohydrate ratio led to marked changes in protein and fat metabolism in gilts resulting in fetal growth retardation of 15%, which mainly occurred during the second half of gestation.  相似文献   

13.
日粮能量和蛋白水平对肉鸡腹脂和血脂的影响   总被引：29，自引：2，他引：29  
对７０８只（公、母各半）５～９周龄黄羽肉鸡进行３个代谢能水平（１３．４,１２．５,１１．６ＭＪ／ｋｇ）和３个粗蛋白水平（２２．４％,１９．４％,１６．４％）交叉的饲养试验,以探讨日粮代谢能和粗蛋白水平时黄羽肉鸡腹脂和血脂水平的影响。日粮代谢能和粗蛋白水平对腹脂有明显影响,腹脂随日粮代谢能水平的升高而升高（Ｐ＜０,０１）。随粗蛋白水平的升高而降低（Ｐ＜０．０５）。日粮能量和蛋白水平对板油的影响与腹脂相似。日粮代谢能水平对肌胃脂无明显影响;日粮粗蛋白水平对肌胃脂重无明显影响,但对肌胃脂率有一定影响（Ｐ＝０．０７）。日粮粗蛋白和代谢能水平对血浆极低密度脂蛋白（ＶＬＤＬ）、甘油三酯、胆固醇及总脂浓度均有显著影响（Ｐ＜８．０５）,８周龄血浆ＶＬＤＬ浓度随日粮代谢能的升高而降低（Ｐ＜０．０００１）;血浆总脂和胆固醇浓度均随日粮代谢能、粗蛋白水平的升高而降低（Ｐ≤０．００１）。肉鸡８周龄血浆ＶＬＤＬ水平明显存在日粮能量和蛋白的互作效应（Ｐ＜０．０１）,而血浆甘油三酯、胆固醇和总脂水平不存在明显的能量和蛋白的互作（Ｐ＞０．０５）。  相似文献   

14.
本文旨在研究日粮不同代谢能和粗蛋白质水平对合浦鹅日粮干物质、粗蛋白质、粗脂肪、粗纤维、钙和磷等养分的消化率及生长性能的影响.将120只28日龄的合浦鹅随机分成6个组,进行2个饲养和消化试验:试验1组饲喂粗蛋白质水平为15.10%,代谢能水平分别为10.03、11.00和11.85 MJ/kg的3种日粮;试验2组饲喂代谢能水平为11.50 MJ/kg,粗蛋白质水平分别为12.50%、14.85%和17.83%的3种日粮.用4 mol/L HCI ALA方法测定日粮的养分消化率.结果表明:粗蛋白质水平为15.10%和代谢能水平为10.03 MJ/kg的日粮,具有较高的养分消化率,但不同代谢能水平对试鹅的生长性能影响差异不显著(P>0.05);代谢能水平为11.50 MJ/kg和粗蛋白质水平为12.50%的日粮也具有较高的养分消化率,但不同粗蛋白质水平对试鹅的生长性能影响差异也不显著(P>0.05).因此,28日龄以后的合浦鹅的日粮粗蛋白质和代谢能水平分别为15.10%和10.03 MJ/kg,或分别为12.50%和11.50 MJ/kg时,均具有较高的养分消化率,但对合浦鹅的生长性能无显著影响.  相似文献   

15.
为研究22~42日龄肉鸡WOD168公鸡适宜的能量、蛋白质水平,以1 350只22日龄健康的肉鸡WOD168公鸡为试验对象,采用2×3因子设计,研究代谢能水平(ME分别为12.98、13.19 MJ/kg)、粗蛋白水平(CP分别为17.5%、18.5%、19.5%)及其交互作用对鸡生长性能与屠宰性能的影响。结果显示:CP水平为17.5%时42日龄体重显著降低(P<0.01);采食量、料肉比、营养摄入量等均表现出ME、CP的交互作用(P<0.05);屠体率随日粮能量水平提高而降低(P=0.057),而翅膀相对重随蛋白水平提高而提高(P=0.091)。研究提示,22~42日龄肉鸡WOD168公鸡在ME为13.19 MJ/kg、CP为19.5%时可获得最佳生长性能,而ME为12.98 MJ/kg、CP为17.5%时可获得较低料肉比及最佳屠宰性能。  相似文献   

16.
1. An experiment was conducted to determine the effect of different dietary protein contents on the performance of naked neck (Na/na) and normally feathered (na/na) broilers.

2. Chicks from the two genotypes were reared in wire‐floored cages and divided at random into 3 groups. Birds were fed on high protein (HP, 12.99 MJ ME, 238 g crude protein/kg and 12.94 MJ ME, 216 g crude protein/kg from 0 to 3 and 3 to 7 weeks, respectively), medium protein (MP, 12.99 MJ ME, 219 g crude protein/kg and 12.87 MJ ME, 201 g crude protein/kg from 0 to 3 and 3 to 7 weeks), and low protein (LP, 12.94 MJ ME, 205 g crude protein/kg and 12.75 MJ ME, 184 g protein/kg from 0 to 3 and 3 to 7 weeks) diets.

3. The LP diets resulted in a significantly lower daily body weight gain of males from 0 to 3 weeks. Dietary protein content had no effect on body weight gain from 3 to 7 weeks, body weight at 7 weeks, and the food intake of birds. Carcase composition of birds from both genotypes was unaffected by dietary protein.

4. Naked neck birds had significandy higher body weights at 7 weeks. Yields of carcase and breast of Na/na males were significantly higher than those of na/na males. There were no significant differences between females from the two genotypes as regards carcase yield.

5. It was concluded that the dietary protein requirements of naked neck birds were similar to those for normally feathered birds.  相似文献   


17.
魏明  崔志浩  陈志强  郑月  颜培实 《草业学报》2017,26(11):113-122
旨在应用直接法和回归法测定肉牛玉米青贮的消化能、代谢能和净能值,并探讨精料回归法用于估测肉牛单一粗饲料原料能值的可行性。试验选取12头体况良好、体重相近[(259±14.08)kg]的生长期公牛,随机分为3组,每组4头牛。分两期试验进行,试验一按试验牛自由采食量的95%、80%和60%3个水平饲喂全玉米青贮日粮;试验二在固定玉米青贮投喂量的基础上,各组分别按青贮饲喂量的15%、25%和50%(干物质基础)添加精料补充料。试验每期14d,其中前10d为预饲期,后4d为正试期。正试期消化代谢和呼吸代谢试验同期进行,测定玉米青贮对肉牛能量代谢规律。结果表明:1)肉牛对全玉米青贮日粮的各种营养物质消化率和能量消化率及代谢率随饲喂水平的提高总体逐渐降低;肉牛能量采食量(总能、消化能、代谢能和净能)随饲喂水平的提高逐渐升高,组间差异显著(P0.05)。2)玉米青贮对肉牛的消化能、代谢能和净能值随着饲喂水平的提高呈下降趋势,各有效能值变化范围分别为10.58~11.48 MJ/kg,8.33~9.44 MJ/kg和5.20~6.21 MJ/kg。3)添加精料补充料显著提高了肉牛对日粮的干物质采食量和粗蛋白消化率(P0.05),而洗涤纤维消化率精料添加比例组间差异不明显(P0.05);随着精料添加比例的增加,肉牛对日粮的能量采食量(总能、消化能、代谢能和净能)和能量消化率及代谢率逐渐上升,消化能代谢率各组之间无显著差异(P0.05)。4)根据试验日粮有效能值与精料添加量之间的关系建立线性回归方程后,外推估测得玉米青贮的消化能、代谢能和净能值分别为10.53 MJ/kg、8.29 MJ/kg和5.35MJ/kg,与95%饲喂水平组直接测定结果(10.58 MJ/kg、8.33 MJ/kg和5.20 MJ/kg)差异不显著(P0.05)。综上所述,回归法测定玉米青贮对肉牛的有效能值与直接法测定结果差异不明显,精料回归法可以用于估测肉牛单一粗饲料的有效能值。  相似文献   

18.
The possible roles of dietary protein level and feed restriction in regulating mammary development of prepubertal gilts were investigated. Cross-bred gilts were fed a commercial diet until 90 d of age and then divided into four nutritional regimens based on two pelleted diets (as-fed basis): a high-protein diet (HP = 13.8 MJ of ME, 1.0% total lysine, 18.7% CP) and a low-protein diet (LP = 13.8 MJ of ME, 0.7% total lysine, 14.4% CP). Nutritional regimens were as follows: 1) HP ad libitum until slaughter (n = 22, T1); 2) HP ad libitum until 150 d of age followed by LP until slaughter (n = 20, T2); 3) LP ad libitum until slaughter (n = 21, T3); and 4) HP with a 20% feed restriction until slaughter (n = 19, T4). Gilts were weighed, their backfat thickness was measured, and jugular blood samples were obtained on d 90, 150, and at slaughter to determine concentrations of prolactin, IGF-I, leptin, and glucose. Gilts were slaughtered 8+/-1 d after their first or second estrus (202.7+/-14.5 d of age). Mammary glands were excised, parenchymal and extraparenchymal tissues were dissected, and composition of parenchymal tissue (protein, fat, DM, DNA, protein/DNA) was determined. The T4 gilts weighed less (P < 0.01) and had less backfat (P < 0.01) than did gilts on other treatments on d 150 and at slaughter. Treatments had no significant effects on prolactin, IGF-I, or glucose concentrations, but there was a treatment x day interaction (P < 0.01) for leptin, with concentrations being lower at slaughter in restricted-fed (T4) vs. LP (T3) gilts (P < 0.05). There was less extraparenchymal mammary tissue (P < 0.01) in T4 gilts than in gilts from the other groups and a tendency (P = 0.13) for the amount of parenchymal tissue to be lower in T4 gilts. In conclusion, a lower lysine intake during prepuberty did not hinder mammary development of gilts, but a 20% feed restriction decreased mass of parenchymal and extraparenchymal tissues. The effect of feed restriction on extraparenchymal tissue is most likely associated with the lower fat deposition.  相似文献   

19.
本试验旨在研究1~21日龄爱拔益加(AA)×罗曼肉杂鸡饲粮代谢能、粗蛋白质、蛋氨酸和赖氨酸的适宜水平。采用L_9(3~4)正交试验设计,饲粮代谢能水平分别为11.70、12.12、12.54 M J/kg;粗蛋白质水平分别为19.00%、20.00%、21.00%;蛋氨酸水平分别为0.45%、0.50%、0.55%;赖氨酸水平分别为1.00%、1.10%、1.20%。选取1日龄AA×罗曼肉杂鸡864只,随机分为9组,每组6个重复,每个重复16只,试验期21 d。通过饲养试验、屠宰试验等方法检测不同营养水平饲粮的饲喂效果。结果表明:1)饲粮粗蛋白质、蛋氨酸和赖氨酸水平对试验鸡平均日增重有显著影响(P0.05),21.00%粗蛋白质水平组显著高于20.00%粗蛋白质水平组(P0.05),0.50%蛋氨酸水平组显著高于0.55%蛋氨酸水平组(P0.05),1.20%赖氨酸水平组显著高于1.10%赖氨酸水平组(P0.05)。2)饲粮代谢能水平对21日龄试验鸡活体总能含量有显著影响(P0.05),12.12 MJ/kg代谢能水平组显著高于12.54 MJ/kg代谢能水平组(P0.05);饲粮蛋氨酸水平对试验鸡活体粗脂肪含量有显著影响(P0.05),0.50%和0.55%蛋氨酸水平组显著高于0.45%蛋氨酸水平组(P0.05)。3)饲粮代谢能和粗蛋白质水平对21日龄试验鸡活体能量沉积率有显著影响(P0.05),11.70和12.12 MJ/kg代谢能水平组显著高于12.54 MJ/kg代谢能水平组(P0.05),21.00%粗蛋白质水平组显著高于20.00%和19.00%粗蛋白质水平组(P0.05);1.10%赖氨酸水平组的试验鸡活体赖氨酸沉积率显著高于1.20%赖氨酸水平组(P0.05)。4)饲粮赖氨酸水平对试验鸡血清葡萄糖、尿酸、尿素氮水平有显著影响(P0.05),1.00%赖氨酸水平组血清葡萄糖水平最高,显著高于1.20%赖氨酸水平组(P0.05),1.10%赖氨酸水平组血清尿酸水平最高,显著高于1.20%赖氨酸水平组(P0.05),1.20%赖氨酸水平组血清尿素氮水平最高,显著高于1.10%赖氨酸水平组(P0.05)。5)由回归分析得出1~21日龄AA×罗曼肉杂鸡饲粮代谢能、粗蛋白质、蛋氨酸和赖氨酸适宜水平的计算公式分别为ME=45.33W~(0.75)+183.84△W,CP=19.77 W~(0.75)+626.47△W,Met=1.44 W~(0.75)+10.31△W,Lys=3.01 W~(0.75)+21.28△W(M E为代谢能,W~(0.75)为代谢体重,△W为平均日增重,CP为粗蛋白质,Met为蛋氨酸,Lys为赖氨酸),根据公式计算得出饲粮代谢能、粗蛋白质、蛋氨酸和赖氨酸的适宜水平分别为11.90 MJ/kg、21.08%、0.51%和1.05%。  相似文献   

20.
A post hoc analysis of the metabolizable energy (ME) intake of privately owned pet dogs from the authors' nutrition consultation practice (Years 2007–2011) was carried out to identify if current ME recommendations are suitable for pet dogs. Data on 586 adult dogs were available (median age 5.5, median deviation from ideal weight 0.0), 55 of them were healthy; the others had various diseases. For ration calculation, a standardized questionnaire and the software diet‐check Munich? was used. ME was predicted according to NRC (2006). Data were evaluated for the factors disease, breed, size, age, gender and type of feeding. The mean ME intake of all adult dogs amounted to 0.410 ± 0.121 MJ/kg metabolic body weight (BW0.75) (n = 586). There was no effect of size and disease. Overweight dogs ate 0.360 ± 0.121 MJ/kg BW0.75, and underweight dogs ate 0.494 ± 0.159 MJ/kg BW0.75. Older dogs (>7 years, n = 149, 0.389 ± 0.105 MJ/kg BW0.75) had a lower ME intake than younger ones (n = 313, 0.419 ± 0.121 MJ/kg BW0.75), and intact males had a higher ME intake than the others (p < 0.001). Some breeds were above average: Jack Russell Terrier, Dalmatian, small Munsterlander and Magyar Viszla, Bearded Collies, Sight Hounds, German Boxers, English foxhounds, Rhodesian Ridgebacks and Flat‐Coated Retrievers with a mean ME intake of 0.473 ± 0.121 MJ/kg BW0.75. The following breeds were below average: Dachshunds, Bichons, West highland White Terrier, Collies except Bearded Collies, Airedale Terriers, American Staffordshire terriers and Golden Retrievers with a mean ME intake of 0.343 ± 0.096 MJ/kg BW0.75. The mean maintenance energy requirements of pet dogs are similar to that of kennel dogs which do not exercise very much. These results suggest that opportunity and stimulus to exercise provided for pet dogs are lower than for kennel dogs. Lower activity in pet dogs may reduce part of potential effects of breed, medical history and age groups.  相似文献   

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