Nutrition physiology effects of dietary fats in rations for growing pigs. 5. Effects of soy bean oil and lard on protein retention in piglets

In two experiments with 30 and 26 castrated male pigs of the German Landrace breed, weight range 15-30 kg, the influence of isoenergetic changes in the carbohydrate and fat fractions of the diet were examined. The effect of the addition of soya oil (SO) and lard (LA) to the diet on the utilization of protein and on the blood urea concentration was also examined. The apparent digestibilities of the crude nutrients and energy were determined using different methods. The following were examined: experiment I: ration I (control), ration II (+7% SO), ration III (+7% LA) experiment II: ration I (control), ration II (+2% SO), ration III (+2% SO + 5% LA), ration IV (+7% LA) In all experiments the animals were fed a similar amount of digestible crude protein of constant quality at constant ME-intake. In both experiments the apparent digestibility of crude protein in the groups with 7% added fat was 4% higher (p less than 0,05) than in the corresponding control groups. The apparent digestibility of crude fat in experiment I and II (in groups II and III and in groups III and IV, respectively) was approximately 87%, when calculated on the basis of faecal fat which was determined by a simple ether extract procedure. When the faeces was treated with HCl before determination, these values for experiment I and II were approximately 6% (p less than 0,001) and 1% (NS) lower, respectively. In both experiments the utilization of protein and the blood urea concentration were not significantly influenced by the amount or form of fat included in the rations.     

Nutritional-physiological effects of dietary fats in rations for growing pigs. 4. Effects of sunflower oil and coconut oil on protein and fat retention, fatty acid pattern of back fat and blood parameters in piglets

Rations containing 12% sunflower oil (Ration II) and 12% coconut fat (Ration III) were compared with a control ration (Ration I) in a 34 day experiment with growing boars of the German Landrace breed (12-30 kg body weight). The relationships between DP and ME were held constant for all 3 rations, and because of the higher ME contents of the two fat rations, this was achieved by reducing the feed intake, relative to that of the control ration. Parameters measured were growth, composition at slaughter, the apparent digestibility of the crude nutrients and energy, the N-balance and the concentrations of urea, insulin, glucose, triglyceride and cholesterol in the blood. In comparison to Ration I, the apparent digestibilities of crude protein in Rations II and III were 5 and 4% (p less than 0,05) higher, respectively. There was little difference in the apparent digestibility of crude fat between the Rations II and III. However, large differences in the values were determined depending upon method of extraction. There were little differences in the productive performance of the animals fed the fat diets. The control animals had, however, a 13% lower growth rate (p less than 0,05) when compared at similar ME-intakes. As the energy concentration and the growth rate were higher in groups II and III, the feed conversion efficiency and the ME required per kg growth were approximately 30 and 13% lower than that of the control animals. The efficiency of protein utilization of the animals in group III was 4% higher (p greater than 0.05) and the blood urea concentration 20% lower (p less than 0.05) than that in group II. The values for the control animals were intermediate. A similar result was obtained concerning the fat content of the animals. The fat content of the animals in group III was 15.9% and this was significantly lower (p less than 0.001) than that of 21.1% measured in group II. That of the control animals, 18.6%, was not significantly different from the above values. The differences in feeding over the relatively short period of 34 days lead to marked differences in the fatty acid pattern of the backfat. The contents of myristic acid and linoleic acid were significantly different between group II and III; for the former values of 0.8% and 16.9% were determined, respectively, with corresponding values of 48.7 and 11.3% for the latter.(ABSTRACT TRUNCATED AT 400 WORDS)     

Nutritive physiological effect of dietary fats in growing swine rations. 3. Effect of sunflower and coconut kernels on protein and fat retention, backfat fatty acid pattern and various blood parameters in piglets

Two groups, each of 9 castrated male piglets of the German Landrace breed, body weight 13-29 kg, were fed ad libitum for a 5 week period in order to determine the influence of the fatty acid composition of the dietary fat on protein and fat retention. The concentrations of urea, insulin, glucose, free glycerol and triglycerides were also determined. That fat in ration I (derived from 27% sunflower seed) contained 50% linoleic acid while that of ration II (derived from 12,5% coconut kernels) had a maximum lauric acid content of 41,8%. The relationship between digestible crude protein and ME-content was calculated to be similar in both rations. In addition protein quality was calculated to be similar in both rations. Protein deposition was determined from both nitrogen and comparative slaughter procedures. The results can be summarized as follows: The animals fed ration I had a higher daily ME-intake and growth rate than those fed ration II, although no great difference was observed in ME required per kg body weight gain. The efficiency of protein utilization was significantly better in group I and this was associated with a lower blood urea concentration. The concentrations of insulin and glucose in the blood, measured before as well as 20, 45, 60 and 120 minutes following feeding, showed little differences between the groups. The triglyceride concentration measured before and 1 and 5 hours following feeding was significantly higher (p less than 0,01) in group II. There was no significant difference in the protein and fat content of the body as well as in the daily protein and fat deposition. The fatty acid composition of the back fat was significantly influenced by the fatty acid pattern of the dietary fat. In group I the linoleic acid content was 3,6 times higher and the lauric- and myristic acid content 11,7 times lower compared to that of group II.     

Estimation of quantitative oxidation and fat retention from carbohydrate,protein and fat in growing pigs

Die Oxidation von Nährstoffen und Retention von Kohlenhydraten, Protein und Fett hei wachsenden Schweinen Die Oxidation von Nährstoffen sowie deren Beitrag zur Fettretention wurde an Hand von 185 individuellen Bilanzstudien mit wachsenden Schweinen (40–100 kg Lebendgewicht) beurteilt. Der Respirationskoeffizient ohne Berücksichtigung des Proteins (RQnp) lag entweder unter oder über 1. Die beschriebene Methode basierend auf Gasaustausch sowie Kohlenstoff-Stickstoffbilanz zur Berechnung der Oxidation von Nährstoffen und Lipogenese ist in beiden Fällen gültig (RQnp > 1 und RQnp < 1). Bei einer den Wachstumsbedarf deckenden Energiezufuhr (ME ≥ 1,2 MJ/kg^0.75) ist die Oxidation von Nährstoffen im Bezug auf die Proteinretention abhängig von der Menge und Qualität des verdauten Proteins. Weiterhin besteht eine Abhängigkeit von der Menge an verdaulichen Kohlenhydraten. Die Versorgung mit Fett spielt dagegen keine Rolle. Die Oxidation von Kohlenhydraten trägt mit 85%, die von Protein mit 15% zur anfallenden Wärmeenergie bei. Eine Fettoxidation findet auch bei hohem Fettgehalt der Nahrung nicht statt. Die Lipogenese aus Kohlenhydraten stellt die Hauptquelle für die Körperfettretention dar. Da keine Fettoxidation stattfindet, wird das gesamte Nahrungsfett im Körper reteniert. Bei einer für das Wachstum zu geringen Energiezufuhr werden Nahrungsfett und Körperfett oxidiert. Um Protein für die Retention zu erhalten, ist die Oxidation von Protein vermindert. Selbst bei Mobilisierung von Körperfett und Oxidation von Nahrungsfett wird ein Teil der Kohlenhydrate und des Proteins für die Lipogenese vermutlich zum Aufbau von Strukturfett verwendet.     

Difference in energy metabolism and protein retention of limit-fed growing pigs of several breeds

Energy metabolism and protein retention of four pig breeds were studied in three experiments comparing Norwegian (N) landrace with either Finnish (F) landrace (Exp. 1), Great Yorkshire (Y, Exp. 2) or Dutch landrace (D, Exp. 3). An increasing or decreasing temperature regimen (11 to 26 degrees C) was used. The animals were kept at a constant feeding level (about 93 g.kg -.75.d -1). Energy and protein balances were measured at increasing and decreasing temperature conditions separately. The three landrace breeds utilized their dietary energy and protein with similar efficiencies. However, large differences were observed between Y and N pigs in Exp.2. The Y pigs had a higher growth rate, lower feed/gain, lower heat production, and higher protein deposition than the N pigs. These differences were related to a lower level of activity of the Y pigs. This lower activity level resulted in lower maintenance requirements of the Y pigs compared with the N pigs. Growth rate and feed conversion differed between balance periods. When the temperature within a period was being increased, growth rate was higher and feed/gain was lower compared with periods in which the temperature was being decreased. Breeds differ with respect to energy and protein utilization.     

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。     

Effect of dietary energy restriction on retention of protein,fat and energy in broiler chickens

1. Broiler chickens were fed 60–100% of recommended energy intakes to study the effects of energy restriction on protein and fat retention.

2. At an energy retention of 179 kJ/kg W ^0·75 d, only protein was retained. At higher energy intakes, each increment in retention had a rather constant composition: about 85% energy in fat and 15% in protein. At lower energy intakes body fat was mobilised whereas protein was deposited.

3. The efficiencies of energy retention in protein and fat were estimated to be 0·66 and 0·86 respectively.

4. The rather constant composition of additional retained energy after additional energy supply provides an explanation for a linear relationship between energy intake and energy retention.     

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.     

Impact of seasonal thermal stress on physiological and blood biochemical parameters in pigs under different dietary energy levels

The present study was formulated to find out the status of important season related thermal stress biomarkers of pure-bred (Hampshire) and crossbred (50% Hampshire × 50% local) pigs under the agro-climatic condition of Assam State, India. The experiment was also aimed to study the role of different level of energy ration (110, 100, and 90% energy of NRC feeding standard for pig) in variation of physiological and biochemical parameters in two genetic groups of pigs in different seasons. The metabolizable energy value were 3260, 2936.5, and 3585.8 kcal/kg in grower ration and 3260.2, 2936.6, and 3587 kcal/kg in finisher ration for normal energy (NE), low energy (LE) and high energy (HE), respectively. Both the genetic group of animals were housed separately under intensive system of management. Each pen was measuring 10′ × 12′ along with an outer enclosure. Six weaned piglets (almost similar body weight of average 10.55 kg) of each group were kept in a separate pen. However, after attainment of 35 kg body weight, the animals of a group were divided in two pens of three animals each. The present experiment indicated that average ambient temperature during summer months (27.33–29.51 °C) was above the comfort zone for pigs (22 °C). The significantly (P?<?0.01) higher relative humidity (RH) (%) was recorded in outdoor environment (87.26–91.10%) and in the morning time (86.60–91.10%). The temperature humidity index (THI) during the study period was found to be indicative of thermal stress to the experimental animals during summer (79.55–82.56). Physiological parameters viz., respiration rate (RR) and rectal temperature (RT) were significantly (P?<?0.01) higher in summer season (43.75–72.12 breaths/min. and 102.29–103.23 °F) and non-significantly higher values were recorded in Hampshire pigs. It was also found that the significantly (P?<?0.01) lower RR as well as RT was recorded in the pigs fed with high energy (HE) ration during summer season. Serum triiodothyronine (T₃) and thyroxine (T₄) concentrations were significantly (P?<?0.01) lower during summer, while both the genetic groups showed significantly (P?<?0.01) higher concentration of serum cortisol during summer season. It was also observed that thyroid hormone and cortisol concentrations were maintained in groups of pig fed vegetable oil incorporated HE diet during summer. From the present study, it is found that the increasing the energy level of the ration might be helpful to minimize the effects of thermal stress during summer.     

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.     

Influence of the amount of dietary fiber on the available energy from hindgut fermentation in growing pigs: use of cannulated pigs and in vitro fermentation

Available energy from hindgut fermentation to pigs fed various amounts of dietary fiber was investigated using an in vivo-in vitro methodology. Six growing pigs fitted with a simple T-shaped cannula at the terminal ileum, and following a Latin-square design, were fed 3 diets differing in the content of non-starch polysaccharides (NSP): a low fiber diet (LFD, 77 g/kg of DM), a standard fiber diet (SFD, 160 g/kg of DM), and a high fiber diet (HFD, 240 g/kg of DM). After adaptation to the diet for 10 d, samples from feces and ileum were collected and analyzed for DM, energy, NSP, and chromic oxide; feces were also analyzed for short chain fatty acids (SCFA). Freeze-dried ileal samples (10 g/L) were fermented in vitro in a fecal slurry consisting of an anaerobic mineral salt medium and feces (50 g/L) from cannulated pigs fed the same diets. Available energy was calculated from the amount of SCFA produced in vitro after 48 h of incubation. Nonstarch polysaccharide content in the fermented material was measured to assess the in vitro degradation of this fraction. Increasing dietary NSP from 77 to 240 g/kg of feed DM increased (P < 0.001) ileal flow from 199 to 468 g/kg of feed, leading to a reduction in the energy digested at the terminal ileum, from 15 to 11 MJ/kg of feed DM and an increment in energy digested in the hindgut, from 1.6 to 3.5 MJ/kg of feed DM. Total in vitro production of SCFA/kg of feed DM was dependent on the amount of ileal substrate available for fermentation; that is, increased concentrations of NSP in the diet led to an increase in the SCFA that may be available to the animal (P < 0.001). The molar ratio of SCFA produced in vitro was affected by diet; the high fiber diet showed the greatest (P = 0.004) proportion of acetic acid, and the low fiber diet showed a tendency (P = 0.081) to an increased butyric acid proportion compared with the other 2 diets. Net disappearance of NSP during fermentation in vivo and in vitro were compared and showed a close relationship (P < 0.001, slope = 0.906, r = 0.960). In our experimental conditions, available energy as SCFA to the animal from hindgut fermentation increased with the concentration of dietary NSP (P < 0.001) and provided between 7.1 and 17.6% of the total available energy.     

杜仲提取物对猪生长性能及血液指标的影响

探讨杜仲提取物在猪生产中的作用,试验选用基本同质的42日龄杜×长×大三元杂交猪300头,平均初始质量为（9．96±0．05）kg,随机分成5个处理,每个处理6个重复,每重复10头猪。试验分3个阶段,第1阶段9．96—20kg,第2阶段20—60kg,第3阶段60-90kg。试验日粮分别在基础日粮中添加杜仲提取物0、1500、2000和2500mg／kg及黄霉素12mg／kg（阶段1）或8mg／kg（阶段2和阶段3）。试验结果表明,1500mg／kg杜仲提取物显著降低阶段1和阶段2日均腹泻评分（P〈0．05）,显著提高了阶段2猪群日均增质量（P〈0．05）,降低了阶段2和阶段3料重比（P〈0．05）。杜仲提取物（除2000mg／kg）和黄霉素组均能显著提高试验全期动物日增质量（P〈0．05）,而杜仲提取物与黄霉素间不存在显著差异,动物日均采食量存在增加趋势（0．05〈P〈0．10）。杜仲提取物能显著降低血清尿素氨水平（P〈0．05）,显著提高阶段2和阶段3血清球蛋白水平（P〈0．05）。这说明,杜仲提取物的添加能影响动物机体蛋白质代谢,提高猪体免疫能力,对猪生长性能产生影响,添加量以1500mg／kg最佳。     

不同能量水平日粮对深县猪生长性能、养分消化率和血液生化指标的影响

为了研究不同消化能水平日粮对深县猪生长性能、养分消化率和血液生化指标的影响,选用体重(15. 54±2. 25) kg的健康深县猪48头,随机分成3组,每组4个重复,每个重复4头猪,试验Ⅰ、Ⅱ、Ⅲ组饲粮消化能水平分别为11. 20、11. 70、12. 20 MJ/kg,预试期7 d,正式期28 d。结果显示:试验Ⅲ组的平均日增重显著高于试验Ⅰ组15. 56%(P<0. 05),试验Ⅲ组的料重比(F/G)显著低于试验Ⅰ组(P<0. 05);试验Ⅲ组粗蛋白、总能与粗脂肪表观消化率均显著高于试验Ⅰ组9. 89%、7. 29%、7. 21%(P<0. 05)。综合各项指标,在本试验条件下,生长期深县猪适宜的消化能水平为12. 20 MJ/kg。     

Assessment of chromium tripicolinate supplementation and dietary energy level and source on growth, carcass, and blood criteria in growing pigs

Two experiments were conducted to evaluate potential interactive effects of supplemental Cr and dietary energy supply in growing pigs. Experiment 1 used 36 individually penned barrows, 25 to 65 kg, in a 2 x 3 factorial arrangement of supplemental Cr (0 or 200 ppb) and energy level (70, 80, or 90% of ME requirement). A corn-soybean meal basal diet was designed to supply all protein, mineral, and vitamin needs and 70% of the estimated ME need at 70% of ad libitum feed intake. Additional energy to 80% or 90% of the ME requirement was provided by a cornstarch/corn oil blend. In Exp. 2, 30 individually penned barrows, 23 to 68 kg, were used in a 2 x 4 factorial arrangement of supplemental Cr (0 or 200 ppb) and added energy source (none, cornstarch, corn oil, or choice white grease) with basal diets identical to Exp. 1. The various energy sources were added to 90% of the ME requirement. In both experiments, growth data were collected over a 50-d period and pigs were killed at 70.1 kg. Increasing energy levels increased (linear, P < 0.01) ADG, average backfat thickness, 10th rib backfat thickness, and cooler shrink and decreased (linear, P < 0.01) longissimus muscle area in Exp. 1. Carcass composition increased (linear, P < 0.01) in lipid and decreased in protein, water, and protein:lipid ratio in response to increasing ME levels. Similar results were observed in Exp. 2 in response to added energy, regardless of the energy source used. In response to ME, linear increases (P < 0.05) in plasma insulin concentration before feeding and after feeding were observed in Exp. 1. In Exp. 2, plasma insulin concentration was lower for the basal diet before feeding (P < 0.05) and higher for the starch diet after feeding (P < 0.01); insulin:glucose ratio increased (P < 0.01) after feeding for starch compared to oil and fat. No consistent effect of Cr or Cr x ME level on performance or carcass was observed (P > 0.10) in these experiments. Similarly, no Cr effect or Cr x ME interaction (P > 0.10) was observed in plasma glucose or insulin levels. Dietary energy levels markedly affected growth criteria in growing pigs (23 to 68 kg) in these experiments, as anticipated, but supplemental Cr was without effect on performance or carcass responses.     

Infleuce of dietary levels of vitamin E and selenium on tissue and blood parameters in pigs.

Eighteen barrows approximately three weeks of age were used in a 3 X 3 factorial arrangement to investigate the effect of level of supplemental vitamin E and selenium on tissue and blood parameters. Tissue selenium concentrations increased in a quadratic manner with increased selenium intake with kidney tissue containing considerably greater concentrations than liver, heart or muscle. Supplementation of the diet caused a three-fold increase in serum selenium within the first week with a slight tendency to further increases in subsequent weeks. Serum vitamin E of unsupplemented pigs declined by fifty percent during the experiment, whereas supplemental vitamin E resulted in increased serum vitamin E. There was a considerable viration in percent peroxide hemolysis. Correlation of -0.63 between percent peroxide hemolysis and vitamin E intake and -0.85 between percent peroxide hemolysis and serum vitamin E were observed.     

Nutritive physiological effects of dietary fats in rations of growing swine. 6. Effect of soya oil and lard on growth performance and carcass characteristics and various blood parameters in fattening swine

Groups of each 10 boars, weight range 20-60 kg, were fed ad libitum the following 4 rations of similar protein: energy ratio: Ration I (control), Ration II (+ 2% soyaoil ), Ration III (+ 2% soyaoil + 5% lard), Ration IV (+ 7% lard). When the animals reached 60 kg body weight each group was halved. One half had free access to the above rations, while the other half were fed ad libitum on the control ration. At body weights of 50 and 100 kg the concentrations of urea, insulin, glucose and cholesterol were measured, in addition the fatty acid composition of the backfat. At the end of the experiment (100 kg) the content of fat in the carcass was calculated by determining the specific gravidity of the carcass. There was little difference in the intake of metabolizable energy (ME) of the different groups of animals at both body weight ranges as a result of the reduction in feed intake of the fat supplemented diets on account of the higher ME-content. There were little differences in the glucose and urea concentrations in the blood of the animals fed the different rations. The highest cholesterol and the lowest insulin levels were measured in groups III and IV, when 5 and 7% lard was added, respectively. The animals, continuously fed Rations III and IV over the whole period of experiment, had a significantly higher fat content (p less than 0,05) than the control animals. There was a very marked influence of the fatty acid intake on the fatty acid pattern of the backfat. Following the change of feed to the control ration at 60 kg body weight, the linoleic acid content of the animals in Groups III and IV was significantly reduced (p less than 0,001) from 15.7 to 11.2%. However this was higher than the 7.3% linoleic acid measured on the animals continuously fed the control ration.     

不同蛋白水平对早期断奶仔猪生产性能、血液生化指标的影响

试验采用单因子试验设计,选用21(±2)日龄断奶、体质量约6.4kg、80头DLY杂交仔猪,随机分为5个处理,每个处理4个重复,每个重复4头猪,各处理分别饲喂粗蛋白水平为26%、23%、20%、17%、14%的等能(14448kJ/kg)等氨基酸模式(Dlys:D-SAA:DThr:DTrp=100∶57∶62∶18)的玉米-小麦-豆粕型饲粮,进行28d的试验,研究5种不同蛋白水平日粮对早期断奶仔猪生产性能、血液生化指标的影响。结果表明,随着蛋白水平的提高,ADG、ADFI、饲料转化率先增加后降低;粗蛋白水平为26%组的腹泻率、腹泻频率、腹泻指数都极显著的高于其他各组(P<0.01),其他各组之间的差异不显著;其中以第4组粗蛋白水平为23%时,仔猪的生产性能最佳。随着蛋白质水平的增加血液中的总蛋白、白蛋白含量以及白蛋白/球蛋白的值先增加后下降,粗蛋白为23%时的总蛋白、白蛋白含量最高;然而,血液中血红蛋白和尿素氮各组间差异不显著。     

饲粮中添加植酸酶对猪生长性能和血清生化指标的影响

选用体重约30kg的杜长大三元杂交生长猪96头,随机分成4个处理组,每组6个重复,每重复4头猪,公母各半。A组为对照组,饲喂基础饲粮,B、C、D组为试验组(每千克饲粮分别以250、500、750U植酸酶取代基础饲粮中的40%、60%、80%磷酸氢钙)。以研究玉米-豆粕型饲粮中添加植酸酶对生长猪生长性能和血液生化指标的影响。42d的饲养试验结果表明:与对照组相比,B、C、D组的平均日增重分别提高了1.05%(P>0.05)、4.09%(P<0.05)、2.64%(P>0.05);料重比与对照组相比分别降低了2.18%、2.62%、1.75%;每千克增重的饲料成本分别是对照组的97.38%、97.03%和97.73%。血清中钙含量分别提高了4.22%、4.22%、8.12%(P<0.05);血清中磷含量分别提高了1.46%、0.36%、14.23%(P<0.05),其它生化指标各试验组间无明显差异。     

Effect of protein and lysine levels in the diet on body gain composition and energy utilization in growing pigs

Eight replicates of four Large White littermate female pigs were used to evaluate the effect of protein and lysine levels in the diet on the efficiency of protein and energy utilization. In each replicate, one pig was slaughtered at about 20 kg live weight and the others received three diets that contained (per Mcal digestible energy) 37.5 and 2.00 g (diet pl), 37.5 and 2.35 g (diet pL) or 45.0 and 2.35 g (diet PL) of digestible protein and lysine, respectively. Pigs were slaughtered after a 7-wk period. Tissue and chemical composition of the gain and energy and nitrogen gain were determined by using the comparative slaughter technique. Metabolizable energy (ME) intakes were similar in the treatments. Pigs fed the pl diet had a smaller body weight and muscle gain and retained less nitrogen and more lipids than pigs fed pL and PL diets. The decrease in the level of nonessential nitrogen in the diet (pL vs PL) did not affect body weight and muscle gain and the amount of nitrogen retained in muscle tissues. However, pigs given the PL diet had a higher total nitrogen retention and a lower fat deposition and exhibited a higher heat production. For each gram of additional protein catabolized for energy purposes (PL vs pL), heat production was increased by 1.8 kcal. The amount of lysine per unit of muscle gain (38 g/kg) or protein deposited (120 g/kg) was independent of protein and lysine levels in the diet. Estimates of energy (indirect calorimetry) and nitrogen (balance technique) retention were also obtained on the same animals; results were comparable with data obtained by direct measurements.