Influence of dietary lysine and energy intakes on body protein deposition and lysine utilization in the growing pig

A serial slaughter study was conducted to determine the effects of true ileally digestible lysine (IDLys) intake and metabolizable energy intake (MEI) on whole-body protein deposition (PD) and dietary lysine utilization in pigs between 45 and 75 kg live weight (LW). Conventional N balances were determined at the start and end of the serial slaughter study. Semisynthetic diets based on casein and cornstarch provided protein-bound lysine to support protein depositions of approximately 70% (Lys70%, IDLys 11.1 g/d) or 90% (Lys90%, IDLys 13.2 g/d) of a determined maximum PD. During the serial slaughter study and at Lys70%, pigs were fed one of six levels of MEI ranging from 14.1 to 23.5 MJ/d; at Lys90%, pigs were fed one of seven levels of MEI ranging from 15.6 to 26.4 MJ/d. The serial slaughter study and N balances indicated that MEI and IDLys had independent effects on PD and lysine utilization. Lysine utilization (calculated as the fraction of absorbed available lysine, over and above maintenance lysine requirements, that was retained in body protein) and PD increased with increasing MEI until plateau values were reached. At the plateaus, PD was determined by lysine intake. When lysine intake determined PD, lysine utilization did not decline (P > 0.10) with increasing lysine intake. Based on the N balance study, there was no effect (P > 0.1) of LW on lysine utilization. The marginal efficiency of using absorbed available lysine for PD was 0.75 and was not affected by LW, MEI, or IDLys.     

Effect of diet composition on water consumption in growing pigs

Concerns relating to use of water resources by the livestock industry, combined with the rising cost of manure management, have resulted in greater interest in identifying ways to reduce drinking water utilization by pigs while maintaining animal well-being and achieving satisfactory growth performance. The objective of this experiment was to determine if increasing the dietary CP or mineral concentrations increases water intake and excretion and, conversely, if reducing the dietary CP content reduces water intake and excretion. Forty-eight barrows (34.3 +/- 4.6 kg of BW; 12/treatment) were given free access to diets containing a low protein (16.9% CP), high protein (20.9% CP), or excess protein (25.7% CP) level, or a diet with excess levels of Ca, P, Na, and Cl. Water was available to each pig on an ad libitum basis via dish drinkers that were determined to waste less than 3% of total water flow. The excess CP diet tended to increase average daily water intake (ADWI) and urinary excretion (P < 0.10) and increased the water:feed ratio (P < 0.05); lowering dietary CP did not lower water intake or excretion. The excess mineral diet did not increase ADWI or urinary excretion but did increase water excretion via the feces. Daily nutrient intake and dietary nutrient concentration were poor predictors of ADWI; only daily intake of N and K were significantly correlated with ADWI (P < 0.05), and the r-values were low (0.39 and 0.32, respectively). There was no relationship between ADFI and ADWI. The average water:feed ratio was 2.6:1. Any study of water utilization is complicated by behavioral as well as nutritional and physiological influences, and isolating physiological need from so-called luxury intake is a significant experimental challenge. Because the impact of dietary treatment on water utilization was small, we conclude that factors other than dietary protein and mineral concentration and daily protein and mineral intake have a relatively large effect on water intake and excretion. Consequently, strategies to reduce water intake must recognize, understand, and manage these additional behavioral and physiological factors. Diet composition may be a part of strategies designed to reduce excessive water utilization by the pig industry but may have a limited effect if other important factors are ignored.     

利舒宝乳化剂对生长猪能量利用效率的影响

脂肪是一种高能量的饲料原料．代谢能为7000-9000Kcal／kg。远比碳水化合物和蛋白质的代谢能高，而且脂肪的体增热较低，动物直接分解日粮中的脂肪产生脂肪酸比从葡萄糖合成脂肪酸更节约能量，因此在畜禽养殖中广泛用来提高生产效率。但是脂肪的来源和饱和度等因素又影响脂肪的消化能力，一般从提高脂肪的乳化能力和利用率两个方面来提高消化能力．而在日粮中添加外源乳化剂就能起到上述作用。本试验旨在探讨利舒宝乳化剂对生长猪能量利用效率的影响。     

日粮不同能量水平对中卫山羊育成母羊增重与屠宰性能的影响

选11月龄、健康、体重相近的中卫山羊育成母羊24只,随机分为3组,分别饲喂不同能量水平和精粗比的日粮,通过梯度饲养试验与屠宰试验结合的方法,研究日粮能量水平与精粗比对其增重与产肉性能的影响。结果表明:试验羊增重、日增重、屠宰率、净肉率、眼肌面积等产肉性能指标随日粮能量水平的增加而提高。     

Interaction between energy level in the diet and environmental temperature on the utilization of energy in growing pigs

Thirty-two pigs weighing approximately 50 kg were maintained in respiration chambers to measure their heat production and the partition of energy retention between protein and fat deposition at two environmental temperatures (23 and 13 C) and with two energy levels in the diet: 3.39 (HE) and 2.92 (LE) Mcal ME/kg. From energy balance data, maintenance requirements (MEm) and the efficiency (k) of energy (ME) utilization for energy deposition were calculated for each treatment. For both diets, MEm averaged 122 kcal ME/kg.75 at 23 C, the rate of increase of MEm being 3.7 kcal ME/kg.75 for each 1 C decrease in the environmental temperature. At 23 C, k was higher with the HE diet (.81 vs .55) and similar for both diets (.78) at 13 C. At comparable ME intakes, heat production was higher with the LE diet at 23 C, and the rate of increase of heat production between 23 and 13 C was lower with the LE diet (1 kcal/kg.75) than with the HE diet (3 kcal/kg.75), resulting in similar heat production at 13 C for both diets. This resulted in an interaction (P less than .01) between temperature and diet on heat production. Protein retention was lower (P less than .01) at 13 C but unaffected by diet at both temperatures. This resulted in an interaction (P less than .01) between temperature and diet on fat retention. Consequently, energy of LE and HE diets was similarly utilized at 13 C, while at 23 C, the HE diet was better utilized. The comparison between these results and those obtained in growth experiments is discussed.     

日粮成分对生长猪饮水量的影响

1前言历史上,人们一直把水看成是充裕而廉价的资源,所以缺乏确定猪需水量或对影响水利用情况因素进行研究(Fraser等,1990)的积极性。现在,人类社会正越来越意识到水是有限的资源,而家畜生产行业却又是一个主     

杜长大中猪饲粮适宜蛋白质及赖氨酸水平试验

试验采用1×3因子设计,选取杜长大三元杂种中猪60头,阉公和母猪各半,随机分为3个处理组,每个处理组设2个重复(阉公和母猪各一个重复),每个重复10头猪,同性别的猪饲养在一个栏内。按3种粗蛋白质水平(17.5%,16.1%,15.1%)、3种赖氨酸水平(0.92%,0.83%,0.75%)组合配制3种试验饲粮(能量水平一致,消化能均为13.5MJ/kg),分别饲喂3个处理组。试验结果表明,40～70kg的混养猪群,饲粮以粗蛋白质15.1%、总赖氨酸0.75%的水平为适宜。40～70kg杜长大阉公猪,饲粮以粗蛋白质15.1%、总赖氨酸0.75%的水平为适宜;同阶段青年母猪,饲粮以粗蛋白质17.5%、总赖氨酸0.92%的水平为适宜。     

猪不同生长阶段连续使用赖氨酸强化低蛋白日粮的效果研究

选取40头25kg左右的仔猪,随机分为2组,探讨在其25～50kg、50～80kg和80～100kg3 个生长阶段连续使用低蛋白日粮,并添加赖氨酸对其各阶段生长性能的影响。结果表明,将日粮粗蛋白含量降低2个百分点,补加适量的赖氨酸,其第一阶段和第二阶段的日增重均低于对照组,料重比均高于对照组。但差异不显著(P>0.05)。第三阶段的日增重与对照组接近,料重比略高于对照组,但差异仍不显著(P>0.05)。     

Effect of oat particle size on energy and nutrient utilization in growing pigs

An experiment was conducted to determine the energy content of oats and to investigate the effects of oat particle size on nutrient and energy balance in growing pigs. Eighteen barrows (23.56 ± 0.94 kg initial body weight) were randomly assigned to one of the three dietary treatments with six replicates per treatment. Whole oats were ground with a hammermill fitted with 4.8- and 3.2-mm screens to make coarse and medium particle size oats, respectively. Medium oats were further ground with a rotary steel cutting grinder fitted with a 2.0-mm screen, and the further ground oats were mixed with medium oats in a 1:3 ratio to make fine oats. Three experimental diets consisted of 96.3% of the coarse, medium, or fine oats as a sole source of energy were used. Pigs were fed diets for 16 d, including 10 d for adaptation and 6 d for total fecal and urine collection. Pigs were then moved into indirect calorimetry chambers to determine 24-h heat production and 12-h fasting heat production. All data were analyzed using the MIXED procedure of SAS with the individual pig as the experimental unit. The geometric mean particle sizes for coarse, medium, and fine oats were 765, 619, and 569 μm, respectively. Pigs fed the medium oats diet tended to have (P < 0.10) greater apparent total tract digestibility (ATTD) of starch, neutral detergent fiber, and gross energy than those fed coarse oats diet. The medium oats diet contained greater (P < 0.05) digestible energy (DE), metabolizable energy (ME), and net energy (NE) than the coarse oats diet. Pigs fed the fine oats diet had lower (P < 0.05) ATTD of Ca and P than those fed the coarse oats diet. The DE, ME, and NE contents of fine oats were comparable with those of coarse oats. The determined NE contents for coarse, medium, and fine oats were 2,335, 2,615, and 2,521 kcal/kg on a dry matter basis, respectively. The NE content in medium oats was greater (P < 0.05) than the NE values predicted using published equations. In conclusion, it was suggested to grind whole oats for 619 μm concerning energy utilization. Further grinding to 569 μm reduces Ca and P digestibility.     

Protein utilization in lysine-supplemented barley protein and effectiveness of the limiting amino acid lysine in growing pigs

In 57 N-balance experiments with castrated male pigs (20 ... 65 kg live weight) the influence of graded lysine supplements to crushed barley enriched with energy, minerals and vitamins on nitrogen metabolism and lysine effectiveness was tested. Close correlative relations between lysine concentration and the b-value, the NPU-value, N-balance and N-excretion in urine could be detected. In agreement with the law of minimum a constant lysine effectiveness could be observed within the limiting range. The supplemented synthetic lysine distinguished itself by the same effectiveness as the protein-bound barley lysine. When barley supplemented with lysine is used, an amount of lysine supplement should be chosen from the point of view of nutrition physiology which raises the total lysine content to a maximum level of 6.3 g/16 g N because lysine supplementation exceeding this value without the simultaneous supplementation of limiting threonine remains ineffective.     

Effects of energy intake and body weight on physical and chemical body composition in growing entire male pigs

Two experiments were conducted to determine independent effects of BW and DE intake on body composition and the partitioning of retained body energy between lipid and protein in pigs with high lean tissue growth potentials and when energy intake limited whole-body protein deposition. In a preliminary N-balance experiment involving 20 entire male pigs at either 30 or 100 kg BW, it was established that whole-body protein deposition increased linearly (P < 0.05) with DE intake at both BW. These results indicate that DE intake controlled whole-body protein deposition and that these pigs did not achieve their maximum whole-body protein deposition when fed semi-ad libitum. In the main serial slaughter experiment, 56 pigs, with a BW of 15 kg, were assigned to one of four DE intake schemes and slaughtered at 40, 65, 90, or 115 kg BW. Within DE intake schemes, DE intake was increased linearly (P < 0.05) with BW, allowing for an assessment of effects of DE intake and slaughter BW on chemical and physical body composition (carcass, viscera, blood). Between 15 and 90 kg BW, average DE intake of 16.1, 20.9, 25.2, and 28.8 MJ/d supported average BW gains of 502, 731, 899, and 951 g/d, respectively. The proportion of whole-body protein present in the carcass increased with BW and decreased with DE intake (P < 0.05), whereas the distribution of whole-body lipid between carcass and viscera was not influenced by BW and DE intake. A mathematical relationship was developed to determine the relationship between DE intake at slaughter (MJ/d) and chemical body composition in these pigs: whole-body lipid-to-protein ratio = 1.236 - 0.056 x (DE intake) + 0.0013 x (DE intake)2, r2 = 0.71. The data suggests that absolute DE intake alone was an adequate predictor of chemical body composition in this population of entire male pigs over the BW and DE intake ranges that were evaluated, simplifying the characterization of this aspect of nutrition partitioning for growth in different pig populations.     

Effects of protein deprivation on subsequent growth performance,gain of body components,and protein requirements in growing pigs

Forty-eight barrows were used in a 2 x 6 factorial arrangement to test a hypothesis that feeding a protein-deficient diet affects subsequent growth response by altering the efficiency of protein utilization. Barrows were individually fed either a 9% crude protein (CP) diet or an 18% CP diet from 20 to 30 kg of body weight (BW) (depletion phase). From 30 to 45 kg BW (realimentation phase), pigs were fed one of six experimental diets with CP levels of 11.8, 13.1, 14.3, 15.6, 18.8, and 21.8%. Four pigs were slaughtered at 20 kg BW to determine initial body composition. Four pigs from each treatment in depletion phase (a total of eight) were slaughtered at 30 kg BW, and all pigs from each treatment in realimentation phase (a total of 36) were slaughtered at 45 kg BW for subsequent compositional analysis. Pigs were bled at 20, 30, and 40 kg BW for blood urea nitrogen (BUN), insulin-like growth factor (IGF)-I, and IGF-binding protein (IGFBP) assays. Pigs were given three times the maintenance digestible energy requirement (3 x 120 kcal BW(-0.75) x d(-1)) in three equal meals daily. The feed allowance was adjusted every 3 d. During the depletion phase, pigs fed the 18% CP diet grew faster and more efficiently (P < 0.01) and gained more (P < 0.01) water and protein than did pigs fed the 9% CP diet. Pigs fed the 18% CP diet showed higher (P < 0.01) BUN values, IGF-I concentrations, and IGFBP ratios than pigs fed the 9% CP diet. During the realimentation phase, pigs fed the 9% CP diet during the depletion phase grew faster (P < 0.05), tended to grow more efficiently (P = 0.066), gained more water (P < 0.01), and tended to gain more protein (P = 0.068) than pigs fed the 18% CP diet during the depletion phase. Pigs fed the 9% CP diet during the depletion phase tended (P = 0.069) to have a higher protein requirement during the realimentation phase than pigs fed the 18% CP diet during the depletion phase. When measured at 40 kg BW, pigs fed the 9% CP diet had a lower (P < 0.05) BUN than pigs fed the 18% CP diet during the depletion phase. However, the plasma IGF-I concentration and IGFBP ratio at 40 kg BW were not affected by dietary CP level fed during the depletion phase. This study indicates that pigs fed a protein-deficient diet exhibit compensatory growth. During the period of compensatory growth, the requirement of CP for those pigs is higher than that of pigs previously fed an adequate diet. This study also suggests BUN can be used as an indicator of protein utilization efficiency and compensatory growth.     

Increasing dietary pectin level reduces utilization of digestible threonine intake, but not lysine intake, for body protein deposition in growing pigs

Two N balance studies were conducted to investigate the effects of feeding graded levels of pectin (a soluble nonstarch polysaccharide, NSP) on the utilization of ileal digestible threonine (Thr; Thr study) and lysine (Lys; Lys study) intake for body protein deposition (PD) in growing pigs. In each study, eight Yorkshire barrows with an average initial BW of 17.2 +/- 1.3 (Thr study) and 14.3 +/- 1.4 kg (Lys study) were fed each of five experimental diets during five subsequent experimental periods, according to a crossover design. Pigs were fed twice daily at 2.6 times maintenance energy requirements. The soybean- and cornstarch-based diets, in which either Thr or Lys was the first-limiting nutrient, were formulated to contain (as-fed basis) 0, 4, 8, or 12% pectin or 8% cellulose (water-insoluble NSP), respectively, and with NSP substituting cornstarch. Across treatments, the mean daily Thr and Lys intake were 5.42 +/- 0.04 g/d (Thr study) and 7.98 +/- 0.12 g/d (Lys study), respectively. Apparent and standardized ileal digestibilities of Thr and Lys were determined in a separate study. Mean PD was 93.4, 90.2, 82.1, 76.7, and 87.9 g/d (SEM = 1.3; Thr study) and 90.7, 88.6, 87.8, 85.3, and 88.1 g/d (SEM = 1.1; Lys study) for the five respective treatments. Utilization of ileal digestible Thr intake, but not of ileal digestible Lys intake, for PD decreased linearly with dietary pectin level, and was not influenced by diet cellulose level. The current study indicates that apparent and standardized ileal digestibility values do not provide an accurate predictor of dietary effects on the utilization of ileal digestible Thr intake for protein deposition in growing pigs fed diets containing soluble NSP.     

The chemical composition of the live-weight gain and the performance of growing pigs

Investigations carried out in Poland are reviewed on the crude chemical body composition of growing pigs. The material comprises about 300 analyses of the bodies of females and castrated males, fed on different levels and slaughtered within the live-weight range from 2.5 to about 90 kg. Straight correlations between all body components are high, while partial correlations, with the content of protein held constant, between the body fat and the lean body mass and between the contents of fat and water in the body are very low and insignificant. This leads to the conclusion that in the animals investigated the growth of the lean body was independent of the fat content, the latter being merely a function of the energy surplus given to the animals. Regression equations are quoted that enable the total body composition to be estimated, if the live weight and the content of any individual component, preferably protein, are known. An attempt is also made to demonstrate, by a mathematical model, that the efficiency of feed conversion, as well as the ratio of fat to protein deposited in the growing body, depends mainly on the level of feeding applied and the ability of the animals to deposit protein in their tissues at a faster or slower rate. The practical application of this model is demonstrated, using an example taken from the reports of the Danish progeny testing stations. Assuming that the rate of protein deposition in the body is a highly inheritable trait it is also shown how the genotype and the level of feeding jointly affect the fat to protein ratio in the live-weight gain.     

Effects of feed restriction and subsequent refeeding on energy utilization in growing pigs

An experiment was carried out to evaluate the metabolic utilization of energy in crossbred barrows during feed restriction and subsequent refeeding. Ten pigs, initially weighing 52 kg, were used in 5 blocks of 2 littermates each. A 7-d adaptation period (P1) was used in which pigs were offered feed at 2.60 MJ of ME.kg of BW(-0.60).d(-1). This adaptation period was followed by a 7-d period (P2), in which 1 pig of each block continued to receive feed at the same level of feeding, whereas for its littermate a 40% reduction in feed intake was imposed (i.e., 1.55 MJ of ME.kg of BW(-0.60).d(-1)). During the subsequent 7-d period (P3), both pigs were offered feed at 2.60 MJ of ME.kg of BW(-0.60).d(-1). After P3, pigs were fasted for 1 d. Heat production (HP) was measured for all pigs during the last 3 d of P1 and on all days for P2 and P3. Heat production was measured using an open-circuit respiration chamber. Energy and N balances were determined for P1, P2, and P3. The HP was partitioned into HP due to physical activity, the short-term thermic effect of feeding, and resting HP. Feed restriction during P2 decreased (P < 0.01) total HP, resting HP, short-term thermic effect of feeding, and retained energy, whereas HP due to physical activity was not affected by feed restriction (P = 0.50). Likewise, fecal and urinary N loss, protein gain, lipid gain, and ADG were reduced during feed restriction (P < 0.01). There were no differences in components of HP and metabolic utilization of energy between the 2 groups during P1 and P3. Nevertheless, urinary N loss was decreased (P < 0.05) and ADG increased (P < 0.01) during P3 for pigs that were restricted in P2. Compensatory growth after a period of feed restriction does not seem to be related to a change in the metabolic utilization of energy for gain but more likely is due to gain in water and gut contents.     

Effects of dietary lysine levels and lighting conditions on intramuscular fat accumulation in growing pigs

This study was conducted to test our hypothesis that intramuscular fat (IMF) accumulation increases in pigs fed on a low lysine diet during the dark period than those fed on the same diet during the light period. Using barrows aged 6 weeks, we monitored whether serum glucose and insulin levels were affected by light conditions. Two diets with different levels of lysine, 0.78% (LL diet) and 1.37% (control diet) were prepared. Eight pigs were fed on the diet during the light period, while the remaining pigs were fed during the dark period. The pigs were fed either the LL diet or the control diet. Although IMF contents of Longissimus dorsi (LD) muscle were higher in the pigs fed on a LL diet (p < .05), the light conditions had no effect. Low dietary lysine caused reduction in serum glucose levels (p < .05) and serum insulin levels (p = .0613). However, they were also unaffected by the lighting conditions. To gain further insights, we determined the messenger RNA levels of insulin receptor, insulin receptor substrate 1, acetyl CoA carboxylase, and fatty acid synthase in LD and Rhomboideus muscles and in the liver.     

饲料能量和蛋白水平对乌鳢生长、饲料利用和体组成的影响

选择健康的体质量为(10.92±0.42)g的乌鳢为试验鱼,采用3×3双因子试验,设计了3种不同蛋白质水平[含34.7%、38.3%和41.8%可消化蛋白(DP)]和三个能量水平(14.5、16.0和17.5 MJ/kg)的可消化能(DE)的9种试验饲料,探讨饲料能量和蛋白水平对乌鳢生长、饲料利用和体组成的影响。结果表明:饲料蛋白质水平极显著地影响乌鳢的平均增重率、蛋白质效率和饲料系数(P<0.01),随着蛋白质水平的增加,乌鳢的特定生长率呈先升高后稳定的趋势。饲料蛋白水平显著影响乌鳢白肌蛋白质与脂肪含量(P<0.05),饲料能量水平极显著影响脂肪含量(P<0.01)。在本试验条件下,乌鳢人工饲料促进生长和饲料利用的最适蛋能比为23.3 g/MJ,可提高乌鳢对饲料的利用率,从而促进生长。