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本试验选用山西太谷绵羊为试验动物,在自由采食玉米秸秆的条件下,研究不同精料补饲水平对育肥羊生产性能和日粮消化率的影响。 相似文献
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在羔羊舍饲育肥中 ,营养水平、饲粮配合与实际采食饲粮的全价性对营养物质的利用和肥羔生产水平起决定作用。动物所需要的能量来源于饲料中的三大有机物质 ,即碳水化合物、脂肪、蛋白质。能量在动物体内的转化过程是这三种有机物质转化的综合体现。因此 ,饲料能量的消化与利用效率反映该饲粮总的营养价值。饲粮有机物质在动物体内的消化率 ,也具有概括性。本试验通过测定羔羊对于不同营养水平全饲粮颗粒饲料能量和有机物质的消化率 ,以其为确定羔羊肥育最佳营养水平提供部分依据。1 材料与方法1 1 试验时间与地点 于 2 0 0 0年 8月 1日… 相似文献
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1.高钙饲粮对单胃动物锌的利用有拮抗作用,钙不仅影响锌的吸收,而且影响锌在体内的分配.2.植酸在钙与锌拮抗关系中起一定的介导作用,植酸本身也不利于锌的利用.3.钙与锌除了其本身的拮抗关系和植酸的介导作用之外,还与饲粮磷水平、锌水平、球虫感染因素有关.单胃动物对饲粮锌的利用受许多饲粮因素影响,饲粮的钙水平是其重要的影响因素之一.关于钙如何影响锌的利用,前人做了广泛的研究. 相似文献
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断奶仔猪饲粮能量水平和饲粮组成对小肠黏膜形态的影响 总被引：3，自引：1，他引：2
该试验研究了低能量水平饲粮对断奶仔猪肠黏膜形态的影响，同时观测饲粮组成(通过改变乳糖／蛋白质比)与肠黏膜形态的关系。试验分三个处理组，分别是令断奶仔猪采食低乳糖／高蛋白质饲粮(LL/HP)、对照饲粮(C)和高乳糖／低蛋白质饲粮(HL/LP)，三种饲粮能量水平相同。仔猪断奶后第四天剖杀取小肠前段、中段、后段作组织切片，在显微镜下观察其绒毛高度和隐窝深度。结果表明，采食三种低能量饲粮的仔猪，其绒毛都有不同程度的缩短，隐窝都表现加深。与采食其它两种饲粮的仔猪相比，采食HL/LP饲粮的仔猪小肠前段有较高的绒毛高度(P＜0．01)和较浅的隐窝深度(P＜0．01)。说明断奶仔猪饲粮的能量水平和饲粮组成对其肠黏膜形态都有影响。 相似文献
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本试验先后进行2次试验研究饲粮棉籽粕水平对不同生长阶段肉鸭屠宰性能的影响,并进一步根据屠宰性能探讨肉鸭饲粮棉籽粕的适宜水平。试验1、2均采用单因素试验设计,试验1饲粮棉籽粕水平分别为0、8.28%、16.56%、24.83%、33.11%;试验2饲粮棉籽粕水平分别为0、5.83%、11.60%、17.50%、23.30%。试验1肉鸭1~21日龄采食试验饲粮,22~35日龄采食无棉籽粕的玉米-豆粕型饲粮;试验2肉鸭1~14日龄采食无棉籽粕饲粮,15~35日龄采食试验饲粮。35日龄时每个试验的每个重复屠宰1只肉鸭测定其屠宰性能。结果表明：1)在试验1中,随饲粮棉籽粕水平的增加,肉鸭半净膛率与全净膛率线性增加( P<0.05),16.56%棉籽粕组肉鸭腹脂重和腹脂率显著低于其他各组( P<0.05)。2)在试验2中,随饲粮棉籽粕水平的增加,饲粮棉籽粕水平线性或二次影响肉鸭活体重、半净膛重、全净膛重和胸肌重( P<0.05),二次影响肉鸭的屠体重( P<0.05),23.30%棉籽粕组肉鸭活体重、半净膛重、全净膛重、胸肌重及胸肌率显著低于其他各组(P<0.05)。3)基于不同的屠宰指标肉鸭饲粮棉籽粕适宜水平为7.51%~14.78%。以上结果提示,在以可消化氨基酸平衡模式配制饲粮时,1~21日龄肉鸭采食棉籽粕高达33.11%饲粮,22~35日龄采食玉米-豆粕型饲粮对35日龄屠宰性能无显著影响;结合35日龄屠宰性能来考虑,15~35日龄肉鸭饲粮棉籽粕水平不宜超过14.78%。 相似文献
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Y. Henry 《Livestock Production Science》1985,12(4):339-354
The objective of the present review was to consider the dietary factors involved in the adjustment of voluntary feed or energy intake in the growing pig. Energy concentration was the primary factor to be taken into account, in relation to growth potential and lean-tissue gain as affected by age, sex and genotype, as well as climatic environment. The effect of protein level and amino acid balance on voluntary feed intake is reviewed in the second part of the paper, by considering the compensatory increase in feed consumption following a moderate deficiency in the limiting amino acid or total protein, and the performance benefit to be expected from correcting amino-acid excesses in common diets. Finally, the separate regulations of energy and protein intakes are analyzed through self-selection of two dietary portions with different protein-energy ratios. The results obtained are further evidence that protein intake is separately regulated from energy intake and that both controlling mechanisms interact in determining overall feed intake. 相似文献
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Interactions between dietary crude protein and essential amino acid intake on performance in broilers 总被引：1，自引：0，他引：1
1. The effect of diets with increasing concentrations of crude protein at either fixed essential amino acid concentrations or at fixed essential amino acid:dietary crude protein ratios on performance was examined in 1- to 4-week-old male Cobb chicks. Increasing crude protein intakes at constant essential amino acid concentrations was carried out at two dietary energy contents. 2. Increasing crude protein resulted in a linear decrease in feed intake while weight gain and feed efficiency changed quadratically with a smaller positive effect at the highest crude protein intakes. Feed intake decreased and feed efficiency increased with higher dietary energy and interactions between protein and energy were significant. Abdominal fat content and the efficiency of protein retention decreased with increasing dietary protein intake. 3. Using constant essential amino acid:crude protein ratios at increasing crude protein intakes resulted in (Trial 3) feed intake, weight gain and feed efficiency all increasing before reaching a plateau. Abdominal fat decreased with protein intake and the efficiency of protein retention was quadratic, decreasing at the higher protein intakes. 4. Multiple regression analysis of the results of the three trials indicated that partition of energy intake into maintenance, fat-free tissue growth, fat and the energy required to transform protein intake in excess of retention explained more than 98% of variation. 5. It is proposed that broiler performance at the lower protein intakes was limited by either non-essential amino acid (Trials 1 and 2) or essential amino acid (Trial 3) intake whereas at high protein intakes the decreased efficiency of amino acid utilisation after growth requirements are fulfilled resulted in poorer performance. 相似文献
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《畜牧与生物技术杂志(英文版)》2018,(4)
Background: The feed conversion ratio(FCR) and residual feed intake(RFI) are common indexes in measuring feed efficiency for livestock. RFI is a feed intake adjusted for requirements for maintenance and production so these two traits are related. Similarly, FCR is related to feed intake and weight gain because it is their ratio. Cholecystokinin type A receptor(CCKAR) plays an important role in animal digestive process. We examined the interplay of these three parameters in a local Chinese chicken population.Results: The feed intake(FI) and body weights(BW) of 1,841 individuals were monitored on a daily basis from 56 to 105 d of age. There was a strong correlation between RFI and average daily feed intake(ADFI) and a negative correlation between the FCR and daily gain(r_g=-0.710). Furthermore, we identified 51 single nucleotide polymorphisms(SNPs) in the CCKAR and 4 of these resulted in amino acid mutations. The C334A mutation was specifically associated with FI and the expected feed intake(EFI)(P 0.01) and significantly associated with the average daily gain(ADG)(P 0.05). G1290A was significantly associated with FI and EFI(P 0.05).Conclusion: FCR is apply to weight selecting, and RFI is more appropriate if the breeding focus is feed intake. And C334A and G1290A of the CCKAR gene can be deemed as candidate markers for feed intake and weight gain. 相似文献
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M Hegedüs 《Acta veterinaria Hungarica》1992,40(3):133-143
Utilization of dietary protein depends not only on the amino acid composition and the digestibility of the protein itself, but also upon the level of protein, feed intake, energy, fibre, and other constituents in the feed. On the other hand, the animal species, sex, age and health status may also play an important role. A deeper understanding of these factors helps to utilize feedstuffs as a protein source more efficiently. 相似文献
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H.O. Gravert 《Livestock Production Science》1985,13(2):87-99
The direct control of feed efficiency is feasible only in test stations and experimental farms. Here coefficients of heritability were found below those for milk yield. Between milk yield and feed efficiency there exist strong genetic correlations, while the correlations between feed intake and feed efficiency are smaller. In spite of these favourable correlations, breeding for higher milk yield entails a serious energy deficit during the first part of lactation. The feed intake reaches its maximum not earlier than 10 to 12 weeks post partum, but peak daily milk yield has already been reached by two to four weeks post partum. Due to energy deficiency the feed efficiency during the first part of lactation seems to be very high, but in fact the feed intake at this time does not cover the energy demand of the high yielding dairy cow.In future more research on genetic factors controlling the feed intake during the first 10 weeks of lactation is required. As potential single factors the capacity of the digestive tract, the production of saliva, the ruminal fermentation, the rate of passage and the overall physiological status of the animal should be investigated. To estimate the real feed efficiency one should observe not only the direct production in milk, milk fat, protein and lactose but also the metabolism of depot fat, growth, nutrition of the foetus, maintenance requirements and a genetically affected resistance against metabolic disorders. Higher feed intake at beginning of lactation can reduce the feed costs, increase the protein content in milk and improve the conception rate in dairy cows. For breeding purposes we need indirect parameters for feed intake under field conditions, e.g. changes in body measurements, urea content in milk, oleic acid proportion in milk fat or content of ketone bodies. 相似文献
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Bruininx EM van der Peet-Schwering CM Schrama JW Vereijken PF Vesseur PC Everts H den Hartog LA Beynen AC 《Journal of animal science》2001,79(2):301-308
Feed intake characteristics of 192, 27-d-old weanling pigs housed in groups and given ad libitum access to feed and water were measured individually with the use of computerized feeding stations. The groups were either homogeneous or heterogeneous as to BW distribution; pigs of three defined initial BW classes were used (mean BW of 6.7, 7.9, or 9.3 kg). The effects of BW distribution, BW class, and sex were studied with regard to average performance traits, latency time (interval between weaning and first feed intake), initial feed intake (intake during the first 24 h following first feed intake), and daily increase in feed intake during the interval between first feed intake and the day on which energy intake met or exceeded 1.5 times the maintenance requirement. Homogeneous and heterogeneous groups had similar latency times, initial feed intakes, and daily increases in feed intake. For the period 0 to 34 d after weaning, ADFI and ADG were also similar for homogeneous and heterogeneous groups, but gain:feed ratio was greater (P < 0.05) in the homogeneous groups. Gilts had higher (P < 0.05) initial feed intakes than barrows and also had greater (P < 0.05) ADFI and ADG during the period 0 to 13 d after weaning. Pigs with average BW of 6.7 kg had higher (P < 0.05) initial feed intakes than their counterparts with average BW of 7.9 kg and 9.3 kg, but the daily increase in feed intake was similar for the three groups. The lighter pigs had more daily visits and a lower feed intake per visit and tended to have a shorter postweaning latency to the onset of feeding than the heavier pigs. This study indicates that the high variability in early feeding behavior among group-housed weanling pigs may be related to BW and sex. 相似文献
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In three experiments with two Black-and-White dairy cows the influence of soybean oil and coconut fat as well as that of rations rich in roughage and concentrated feed on the production of fatty acids were determined with the isotope dilution method. A change in the method of sampling from the rumen in the course of the investigations resulted in distinctly different absolute production quotas, which can presumably be traced back to the disproportionate mixing in of the isotope and/or different production quotas in various regions of the rumen. The relative differences between the production quotas dependent on the rations, however were approximately the same with both sampling methods, so that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation o that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation o that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation between the relation of acetic and propionic acid in the rumen fluid and the quotient from acetic and propionic acid produced. In contrast to this, a significant relation between the concentration of fatty acids and the production of fatty acids could not be ascertained. Soybean oil and coconut fat brought about a slightly better utilisation of the fat-free organic matter for the production of fatty acids in the rumen. This could mainly be traced back to the increased production of propionic acid. The production of acetic acid per kg fat-free organic matter was insignificantly reduced. A reduced quota of roughage in the ration as well as the use of feed fats resulted in a decrease in the production of acetic acid and an increase in the production of propionic acid. The influence of the quota of roughage, however, was bigger than that of the use of fats. When rations rich in roughage were given, the share the energy contained in the total fatty acids has in the total of the digested energy was, on an average of both animals, slightly lower in comparison to rations rich in concentrated feed. However, the reason for this is not to be found in a lower share the energy digested in the stomachs has in the total of digested energy but in a higher amount of fermentation losses with a nutrition rich in roughage. 相似文献
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In order to investigate the effects of benzoic acid on growth performance, nutrient digestibility, nitrogen balance and gastrointestinal microflora of piglets, we conducted a performance experiment and a separate balance study. The performance experiment involved four different dietary treatments: (1) basal diet (negative control); (2) basal diet supplemented with benzoic acid at 5 g/kg; (3) basal diet supplemented with benzoic acid at 10 g/kg; (4) basal diet supplemented with potassium diformate at 12 g/kg. Each dietary treatment was assigned to nine replicate groups, each consisting of two piglets. Live weight, daily weight gain, feed intake and feed conversion ratio were monitored as performance parameters over a 35-day period. Supplementation of the diet with benzoic acid resulted in a dose-dependent increase in feed intake and body weight gain and an improved feed conversion ratio. Piglets fed the diet supplemented with benzoic acid at 10 g/kg outperformed the control piglets in mean feed intake, body weight gain and feed conversion ratio by 9%, 15% and 6% respectively. Growth performance of the piglets fed the diet with benzoic acid at 10 g/kg was similar to that of piglets fed the diet supplemented with potassium diformate. In the balance experiment three groups of six piglets each were fed either a control diet or diets supplemented with benzoic acid at 5 or 10 g/kg respectively. Benzoic acid did not significantly affect nutrient digestibility but increased nitrogen retention. Piglets fed the diets supplemented with benzoic acid at 5 or 10 g/kg retained 5% and 6% more nitrogen, respectively, than control piglets. Supplementation of benzoic acid did not influence the pH value or the concentration of ammonia in the gastrointestinal tract but reduced the number of bacteria in the digesta. In the stomach the number of total aerobic, total anaerobic, lactic acid forming and gram-negative bacteria was reduced; in the duodenum the presence of benzoic acid reduced the number of gram-negative bacteria and in the ileum the number of total aerobic bacteria in a dose-dependent manner. Benzoic acid also considerably reduced the concentration of acetic acid in the duodenum. In conclusion, the data of this study suggest that benzoic acid exerts strong antimicrobial effects in the gastrointestinal tract of piglets and therefore enhances growth performance and nitrogen retention. 相似文献