Significance of quality of truly digestible protein on performance of ewes at late pregnancy and early lactation

Two trials were conducted in ewes at late pregnancy and early lactation in order to evaluate the effects of substituting the moderate degradable protein of soy bean (SBM), with a low degradable protein of corn gluten meal (CGM), accordingly that both diets were calculated to provide equal truly digestible protein (PDI). At the first trial thirty multiparous ewes were examined in an 8-week study that started at parturition. Animals were fed in groups (15 ewes), with two isocaloric-isonitrogenous-isofibrous rations. Treatments were: (A) SBM, (B) CGM. Diets were different at PDIA/PDI ratio (0.52 versus 0.63). The second trial lasted 7 weeks, 5 weeks pre partum till 2 weeks post partum. Three rations were tested by the use of 48 pregnant ewes. Ewes were allotted to three equivalent groups: (A) SBM and wheat bran, (B) CGM and corn gluten feed, (C) CGM and corn gluten feed plus additional lysine (CGML). Data from both trials were analyzed as repeated measures. CGM compared to SBM decreased milk yield and fat corrected milk (FCM) yield (2.25 and 1.98 kg of milk; 2.47 and 2.17 kg of FCM), while tended to decrease milk's protein content (5.45 and 5.36%, for the SBM and CGM group). The daily production of fat, protein and lactose were higher in SBM than in CGM. CGM ration decreased body weight (BW) gain of ewes during late pregnancy and mean birth BW of litter, and also caused a 30% increase of abortions-dead births. CGM cannot totally replace SBM, in ewes’ diets at early lactation, because of the decrease in milk yield as well as the milk's protein content, even when equal PDI is provided, due to low lysine content. This trial has extended the knowledge from cattle, that supplementation of lysine, usually the first limiting amino acid, is also crucial in ewes during pregnancy and lactation.     

Plant products affect growth and digestive efficiency of cultured Florida pompano (Trachinotus carolinus) fed compounded diets

Costs of compounded diets containing fish meal as a primary protein source can be expected to rise as fish meal prices increase in response to static supply and growing demand. Alternatives to fish meal are needed to reduce production costs in many aquaculture enterprises. Some plant proteins are potential replacements for fish meal because of their amino acid composition, lower cost and wide availability. In this study, we measured utilization of soybean meal (SBM) and soy protein concentrate (SPC) by Florida pompano fed compounded diets, to determine the efficacy of these products as fish meal replacements. We also calculated apparent digestibility coefficients (ADCs) for canola meal (CM), corn gluten meal (CGM), and distillers dried grains with solubles (DDGS), following typical methods for digestibility trials. Juvenile Florida pompano were fed fish-meal-free diets containing graded levels of SBM and SPC, and weight gain was compared to a control diet that contained SBM, SPC, and fish meal. Fish fed diets that contained 25-30 percent SBM in combination with 43-39 percent SPC had weight gain equivalent to fish fed the control diet with fish meal, while weight gain of fish fed other soy combinations was significantly less than that of the control group. Apparent crude protein digestibility of CGM was significantly higher than that of DDGS but not significantly different from CM. Apparent energy digestibility of DDGS was significantly lower than CGM but significantly higher than CM. Findings suggested that composition of the reference diet used in a digestibility trial affects the values of calculated ADCs, in addition to the chemical and physical attributes of the test ingredient.     

麦瑞加拉鲮幼鱼对12种原料表观消化率的比较研究

试验以麦瑞加拉鲮（Cirrhinus mrigala）幼鱼（3.88±0.06）g为试验对象,研究其对国产鱼粉、白鱼粉、花生粕、白酒糟、鸡肉粉、米糠、棉粕、菜粕、豆粕、玉米蛋白粉、玉米酒糟和羽毛粉的干物质、粗蛋白、粗脂肪、总能、磷、钙、镁、锌、铜、铁和锰的表观消化率。结果表明:12种试验原料的干物质、粗蛋白质、粗脂肪、总能、磷、钙、镁、锌、铜、铁和锰的表观消化率范围分别为24.93%-85.68%、50.02%-97.40%、51.89%-94.02%、39.18%-96.39%、9.72%-87.37%、3.47%-25.92%、26.11%-88.25%、12.63%-66.35%、41.33%-104.86%、10.69%-91.84%、4.42%-85.49%。其中包括干物质、粗蛋白和总能在内的主要营养物质的表观消化率以国产鱼粉和白鱼粉最高。除鱼粉外的其他原料中,干物质以花生粕、豆粕和玉米蛋白粉最高;粗蛋白以花生粕最高;粗脂肪以米糠和花生粕最高;总能以花生粕和鸡肉粉最高;白酒糟的干物质、粗蛋白、粗脂肪、总能的消化率最低。在矿物质元素表观消化率中,羽毛粉的磷、铜、铁和锰的表观消化率最高;米糠的锌表观消化率最高;钙的表观消化率以白鱼粉、豆粕和羽毛粉最高;镁的表观消化率以豆粕、羽毛粉和玉米酒糟最高;鸡肉粉的磷、钙、镁和铁表观消化率最低;花生粕和棉粕中锌的表观消化率最低;菜粕中铜的表观消化率最低;白酒糟中锰的表观消化率最低。因此,花生粕、豆粕和玉米蛋白粉是麦瑞加拉鲮幼鱼配合饲料中较优质的蛋白源,可进一步开发用于适量替代饲料中的鱼粉;米糠可作为较好的能量饲料;羽毛粉可作为饲料中较好的矿物质元素来源;白酒糟对麦瑞加拉鲮幼鱼而言营养价值最差。     

Effect of different protein sources on the concentrations of small peptides in the rumen of sheep

The experiment was conducted to determine the effect of different protein sources on concentration of small peptides (Pro-Ala, Val-Val, Pro-Leu, Met-Met) in the rumen fluid of sheep. Four Inner Mongolia Sunite sheep fitted with permanent cannulas were used in a 4 x 4 Latin square design, and fed four different protein sources including soybean meal (SBM), casein (Casein), fish meal (FM) and corn gluten meal (CGM), respectively. The results showed that the concentration of Pro-Ala peaked in Casein, FM, CGM groups at 2 h after feeding, whereas the highest level was measured at 6 h after feeding in SBM group. Val-Val and Pro-Leu production were highest at 6 h after feeding Casein and CGM diets and 4 h after feeding SBM and FM diets, respectively. During 6 h after feeding the accumulative concentration of Pro-Ala (1.74 mg/l) and Pro-Leu (25.78 mg/l) in rumen was highest for the Casein diet. During the total sampling time, the highest amount of accumulated small peptides was measured for Pro-Leu, and lowest amount for Met-Met, which was independent of treatment groups. Experimental results proved that small peptides with N-terminal Pro and a hydrophobic structure could inhibit rumen degradation and may be available for post-ruminal absorption.     

Preovulatory follicular status and diet affect the insulin and glucose content of follicles in high-yielding dairy cows

Insulin and glucose may be limiting factors for ovarian function in dairy cows genetically selected for high milk yield. The effects of nutrition on the intrafollicular content of insulin and glucose were investigated in Israeli Holstein dairy cattle fed a basic total mixed ration and producing 34-39kg of milk daily. In experiment 1, carried out in 11 oestrus-synchronised cows, little variation in insulin concentration was found in plasma sampled during the luteal phase, but high variation was found in plasma sampled during the follicular phase. Therefore, in order to prevent confounding the effects of diet and of phase in cycle in the following experiments, experimental diets were fed during the luteal phase of synchronised oestrus cycles. In experiment 2, designed as Latin-Square, six cows received sequentially diets containing 17.1 (control) or 19.7% of crude protein, using two sources of supplementary protein, i.e. soyabean meal (SBM) and corn gluten meal (CGM), differing in ruminal degradability and leucine content. When dry matter intake was used as covariant, plasma insulin on day 16 was 29.5 and 26.4% higher in cows fed diets containing SBM and CGM than in the control (P<0.05). In experiment 3, 17 cows were individually fed the basic diet and then switched to isoenergetic diets containing SBM (n=5), CGM (n=6) or corn grain (CG, n=6) given from day 10 to 16 of the synchronised oestrus cycle. On the eve of day 16, and in the morning of day 17, they were administered PGF(2alpha) and the content of 26 largest follicles was aspirated by using the transvaginal ovum pick-up technique. Follicles were sorted into two classes (preovulatory and subordinate) according to oestradiol concentration and the progesterone:oestradiol ratio in follicular fluid (FF). Higher concentrations of insulin (0.282 versus 0.127ng/ml, P<0.0001) and of glucose (0.614 versus 0.386g/l, P<0.002), were found in FF from preovulatory follicles. The insulin concentration in the FF of cows fed the CG diet was 26% higher than in their counterparts fed CGM (P<0.04), SBM being intermediate. Dietary effects did not reach significance in subordinate follicles.The finding that preovulatory follicular status is associated with increased intrafollicular insulin and glucose suggests that insulin is involved in follicular maturation. The nutritional effect on intrafollicular glucose and insulin may have practical implications to optimise feeding in dairy cows during phases of the oestrus cycle.     

Effects of excess metabolizable protein on ovarian function and circulating amino acids of beef cows: 1. Excessive supply from corn gluten meal or soybean meal

In the dairy industry, excess dietary CP is consistently correlated with decreased conception rates. However, the source from which excess CP is derived and how it affects reproductive function in beef cattle is largely undefined. The objective of this experiment was to determine the effects of feeding excess metabolizable protein (MP) from feedstuffs differing in rumen degradability on ovulatory follicular dynamics, subsequent corpus luteum (CL) development, steroid hormone production and circulating amino acids (AA) in beef cows. Non-pregnant, non-lactating mature beef cows (n=18) were assigned to 1 of 2 isonitrogenous diets (150% of MP requirements) designed to maintain similar BW and body condition score (BCS) between treatments. Diets consisted of ad libitum corn stalks supplemented with corn gluten meal (moderate rumen undegradable protein (RUP); CGM) or soybean meal (low RUP; SBM). After a 20-day supplement adaptation period, cows were synchronized for ovulation. After 10 days of synchronization, gonadotropin releasing hormone (GnRH) was administered to reset ovarian follicular growth. Starting at GnRH administration and daily thereafter until spontaneous ovulation, transrectal ultrasonography was used to diagram ovarian follicular growth, and blood samples were collected for hormone, metabolite and AA analyses. After 7 days of visual detection of estrus, CL size was determined via ultrasound. Data were analyzed using the MIXED procedures of SAS. As designed, cow BW and BCS were not different (P⩾0.33). Ovulatory follicular wavelength, antral follicle count, ovulatory follicle size at dominance and duration of dominance were not different (P>0.13) between treatments. Cows supplemented with CGM had greater post-dominance ovulatory follicle growth, larger dominant follicles at spontaneous luteolysis, shorter proestrus, and larger ovulatory follicles (P⩽0.03) than SBM cows. No differences (P⩾0.44) in peak estradiol, ratio of estradiol to ovulatory follicle volume, or plasma urea nitrogen were observed. While CL volume and the ratio of progesterone to CL volume were not affected by treatment (P⩾0.24), CGM treated cows tended to have decreased (P=0.07) circulating progesterone 7 days post-estrus compared with SBM cows. Although total circulating plasma AA concentration did not differ (P=0.70) between treatments, CGM cows had greater phenylalanine (P=0.03) and tended to have greater leucine concentrations (P=0.07) than SBM cows. In summary, these data illustrate that excess MP when supplemented to cows consuming a low quality forage may differentially impact ovarian function depending on ruminal degradability of the protein source.     

Growth performance, carcass characteristics and bioavailability of isoflavones in pigs fed soy bean based diets

A growth trial with 38 weaners (castrated male pigs) was designed to compare the growth performance and carcass quality of pigs fed diets containing either soy bean meal or soy protein concentrate in a pair-feeding design. Soy bean meal (SBM) and soy protein concentrate (SPC) differed in isoflavone (daidzein plus genistein) content (782 microg/g in SBM and 125 microg/g in SPC, respectively). During the experiment, all pigs were fed four-phases-diets characterized by decreasing protein concentrations with increasing age (weaner I, weaner II, grower, finisher diets). Rations of control and experimental groups were isoenergetic, isonitrogenous, and isoaminogen. The weanling pigs with an initial live weight of 8.4 +/- 1.1 kg were allotted to flat deck boxes. During the growing/finishing period (days 70-170 of age), the pigs were housed in single boxes. Both, the weaning and the grower/finishing performances (daily body weight gain, feed intake, feed conversion ratio) were similar in both groups. No differences were found between the groups in carcass composition (percentages of cuts, tissues, and protein/fat), and meat quality of pigs. Moreover, the IGF-1R mRNA expression in longissimus muscle was not influenced by the kind of soy product. However, circulating levels of isoflavones were clearly different between pigs fed SBM (genistein 239 +/- 44; daidzein 162 +/- 42; equol 12 +/- 4 ng/ml plasma) and animals fed SPC (genistein 22 +/- 9 and daidzein 8 +/- 3, and equol 10 +/- 3 ng/ml plasma). The results confirm the expected differences in the bioavailability of soy isoflavones, yet, there were no significant differences in performance of pigs fed either soy bean meal or soy protein concentrate.     

Growth performance,carcass characteristics and bioavailability of isoflavones in pigs fed soy bean based diets

A growth trial with 38 weaners (castrated male pigs) was designed to compare the growth performance and carcass quality of pigs fed diets containing either soy bean meal or soy protein concentrate in a pair-feeding design. Soy bean meal (SBM) and soy protein concentrate (SPC) differed in isoflavone (daidzein plus genistein) content (782?μg/g in SBM and 125?μg/g in SPC, respectively). During the experiment, all pigs were fed four-phases-diets characterized by decreasing protein concentrations with increasing age (weaner I, weaner II, grower, finisher diets). Rations of control and experimental groups were isoenergetic, isonitrogenous, and isoaminogen. The weanling pigs with an initial live weight of 8.4?±?1.1?kg were allotted to flat deck boxes. During the growing/finishing period (days 70?–?170 of age), the pigs were housed in single boxes. Both, the weaning and the grower/finishing performances (daily body weight gain, feed intake, feed conversion ratio) were similar in both groups. No differences were found between the groups in carcass composition (percentages of cuts, tissues, and protein/fat), and meat quality of pigs. Moreover, the IGF-1R mRNA expression in longissimus muscle was not influenced by the kind of soy product. However, circulating levels of isoflavones were clearly different between pigs fed SBM (genistein 239?±?44; daidzein 162?±?42; equol 12?±?4?ng/ml plasma) and animals fed SPC (genistein 22?±?9 and daidzein 8?±?3, and equol 10?±?3?ng/ml plasma). The results confirm the expected differences in the bioavailability of soy isoflavones, yet, there were no significant differences in performance of pigs fed either soy bean meal or soy protein concentrate.     

A combination of corn gluten and soybean meal as a substitute for fishmeal in diets of turbot (Scophthalmus maximus Linnaeus, 1758) in brackish water

This study was conducted to test the replacement of fishmeal (FM) with a combination of corn gluten meal (CGM)‐soybean meal (SBM) (at a ratio of 58 : 42, respectively) fortified with lysine, taurine and monocalcium phosphate (MCP) in turbot (Scophthalmus maximus) diets. FM as the main protein source in the control diet (FM100) was replaced in 15% decrements while increasing the combination of replacement material: 85% FM (FM85), 70% FM (FM70), 55% FM (FM55) and 40% FM (FM40). The diets were fed to triplicate groups (n = 25 per group) for 9 weeks (water temperature, dissolved oxygen, pH and salinity of 18.59 ± 0.06°C, 7.32 ± 0.02 mg L^?1, 7.73 ± 0.01 and 8.46 ± 0.04 g L^?1, respectively). Initial weight of fish was 286.1 ± 0.1 g. At the end of the experiment, growth, feed and nutrient utilization performance of fish fed FM85 and FM70 were similar to FM100, but a further increase in plant protein led to a significant reduction of these parameters. Whole body, fillet, viscera and liver nutrient compositions were not affected significantly; however, whole body lipid levels were significantly lower in fish on FM55 and FM40 than those on FM100. The fish in–fish out ratio in the diets decreased from 2.12 in FM100 to 1.00 in FM40. The results suggest that the FM level could be reduced by 30% with a combined use of CGM‐SBM supplemented with lysine, taurine and MCP.     

Peas (Pisum sativum L.) as an alternative protein source in lamb diets: growth performances,and carcass and meat quality

Thirty weaned Barbaresca lambs were divided into three groups and fed diets that differed in their protein supplement source; the main protein source was soybean meal in SBM diet treatment, totally or partially replaced by peas in P39 and P18 diet treatments, respectively. Soybean meal and peas were present in the diets in the following proportions (on as fed basis): 16:0% (SBM), 0:39% (P39), 9:18% (P18).The diets were of different crude protein content: higher in SBM diet (16.96% DM) than in P39 (14.27% DM) and P18 (15.37% DM). Soluble protein was higher in P39 diet than in the other treatments (36.2, 27.4 and 23.14% CP in P39, P18 and SBM treatments, respectively) while the B₂-protein fraction was lower. The NDF-bound nitrogen was 17.36, 16.87 and 15.06% of crude protein in P39, P18 and SBM diet, respectively. The NDF content was similar among the diets. Growth and slaughter performances were similar among groups (250 g per day versus 219 and 218 g per day respectively in P18, P39 and SBM groups). Carcass fatness was comparable among treatments. Meat pH, colour parameters and cooking losses were comparable among groups. Drip losses were significantly higher (P<0.001) in meat from P39 and P18 than from SBM group. In the present trial, the replacement of soybean meal with peas did not significantly affect growth and slaughter performances and preserved meat quality.     

四种植物蛋白对中华绒螯蟹幼蟹生长性能、氨基酸沉积率和抗氧化酶活性的影响

为了筛选适宜于养殖中华绒螯蟹幼蟹的饲料植物蛋白源,探究不同植物蛋白源饲料对幼蟹生长性能、氨基酸沉积率和抗氧化性能等方面的影响,以50%的鱼粉配制基础饲料（记为FM）,分别采用30.5%发酵豆粕、32.5%豆粕、28%棉粕和39%菜粕替代基础饲料中鱼粉总量的50%,配制成4种等氮等能的饲料（分别记为FSBM、SBM、CSM和RSM）,投喂初始体重为（0.249±0.003）g的中华绒螯蟹幼蟹8周。结果表明:（1）与FM组相比,FSBM、SBM和CSM组的增重率、特定生长率、饲料系数、蛋白质效率和蛋白质沉积率均没有显著性差异;RSM组的增重率与FM组相比差异不显著（P>0.05）,但显著低于SBM组（P < 0.05）,而其饲料系数则显著高于FM、FSBM及SBM组（P < 0.05）,蛋白质效率显著低于其他各组（P < 0.05）,蛋白质沉积率显著低于SBM和CSM组（P < 0.05）。（2）不同植物蛋白组的总必需氨基酸沉积率和FM组相比差异不显著（P>0.05）,而RSM组总必需氨基酸沉积率显著低于FSBM和CSM组（P < 0.05）。（3）与FM组相比,不同植物蛋白组蟹的血清和肝胰腺中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-PX）活性和肝胰腺丙二醛（MDA）含量并没有显著的影响,而RSM组血清丙二醛（MDA）含量显著的高于其他各组（P < 0.05）。结果表明,在幼蟹饲料中,豆粕、发酵豆粕和棉粕替代基础配方中鱼粉的50%后并未对幼蟹的生长性能、氨基酸沉积率及抗氧化能力造成负面的影响,发酵豆粕、豆粕和棉粕可以作为替代鱼粉的适宜蛋白源,且添加水平约在30%左右。菜粕替代后降低了饲料的利用和氨基酸沉积效率,这可能是由于菜粕的蛋白质消化率低、含有相应的抗营养因子和添加水平过高所致,建议使用前应适当进行脱毒处理,并与或和其他植物蛋白配伍使用。     

Renal Excretion of Urea in Reindeer Effect of Nutrition

Renal reabsorption of urea was studied in 8 9-month old reindeer calves fed low protein (19–34 g crude protein, mostly lichens) and high protein (68–69 g crude protein, lichens + soybean meal) diets. Low protein diets fed for a 3-month period resulted in an average renal reabsorption of 93% of the filtered urea, while only 50 % was reabsorbed on the high protein ration. It was calculated that if the reabsorbed urea was used completely for protein synthesis in the rumen, 4 g crude protein could be made daily in the lichen fed animals. This amount would be a very significant contribution to the nitrogen economy of animals which are usually in a negative nitrogen balance when lichens are the main food consumed.     

Partial replacement of triticale for corn grain in starter diet and its effects on performance,structural growth and blood metabolites of Holstein calves

The primary objective of this study was to examine the effects of different inclusion rates of dietary triticale replacing corn grain in starter rations of dairy calves on feed intake, average daily gain (ADG), feed efficiency, skeletal growth, fecal score, and selected blood and ruminal parameters. In all, 30 4-day-old Holstein calves (15 female and 15 male) were blocked by gender and birth weight, and then randomly allotted to three treatment groups (n=10 calves/treatment) and received either a corn-based diet without triticale (T0), or a diet containing 16% (T16) or 32% (T32) triticale (25% and 50% corn replaced by triticale, respectively) for 10 weeks. Calves were weaned on day 43 of study and remained on the study until day 70. During post-weaning period, calves fed T32 had the lowest starter intake (1.78 kg/day; P=0.02). In contrast, ADG was not affected in pre-weaning and overall periods, but calves fed T32 had a lower ADG (P=0.04) as compared with calves fed T0 in post-weaning period. No dietary effect was detected for feed efficiency. Dietary treatment did not affect heart girth and body length; however, height at wither and hip at weaning increased in calves fed triticale compared with T0. No detectable effects were observed in serum glucose and β-hydroxybutyrate. No difference was detected in blood urea nitrogen on day 35 either but on day 50 and day 70 the greatest concentration was recorded for calves fed T16. Compared with the control, ruminal ammonia concentration was increased for calves fed T32 (4.34 v. 7.50 mmol/l) and T16 (4.01 v. 8.12 mmol/l) on day 35 and day 50. No difference was detected in ruminal pH on day 35 or day 50; however, calves fed T32 had the lowest pH (6.11) at 70 days. No significant effect was detected in days scoured, respiratory score and general appearance. Under our experimental conditions, it appears that triticale at 16% dry matter (i.e. replacing corn grain up to 25%) in the starter diet does not have adverse effects on the performance and intake of calves. Therefore, substituting corn partially with triticale in calf starter diets may prove beneficial in places where corn is less abundant or its price is prohibitive. The low number of calves per treatment however may have limited the statistical power to detect significant differences among treatments, possibly affecting the results, which should be interpreted with caution.     

Estimation of protein digestibility—IV. Digestive proteinases from the pyloric caeca of coho salmon (Oncorhynchus kisutch) fed diets containing soybean meal

The goal of this study was to better understand why dietary soybean products are poorly utilized by salmonids. The influence of dietary intake on coho salmon fingerling weight gain and specific properties of pyloric caeca enzymes was investigated. Fingerlings were fed diets containing heated or unheated soybean meal (SBM) or Promoveal™, as 15–25% herring meal replacer, for 8–12 weeks. Fish fed to apparent satiation with diets containing heated SBM replacer gained more weight than those fed unheated SBM at the same level. Fish increased in body weight at the same rate when fed restricted rations containing either 15% SBM replacer that was variously heated up to 20 min, 15% Promoveal™ replacer or the herring meal basal diet. After the experimental diets were fed, digestive proteinases were isolated from the pyloric caeca. Yield of pyloric caeca enzymes (PCE), recovery of trypsin in PCE, soybean trypsin inhibitor (SBTI) sensitivity of PCE trypsin, specific activity of PCE trypsin and in vitro casein digestibility by PCE were determined for each dietary group. Weight gain vs in vitro casein digestibility by PCE was linear for animals fed unheated SBM to apparent satiation (r² = 0.71, P < 0.1) but not for animals fed either heated SBM to apparent satiation or variously heated SBM as 15% replacer at restricted levels. Trypsin from fish fed diets with heated or unheated SBM, but not Promoveal™ replacer, was less sensitive to SBTI than fish fed no SBM. For fish fed diets with variously heated SBM as 15% replacer, the SBTI activity of the SBM and SBTI inhibition of PCE trypsin were inversely related (r² = 0.88, P < 0.05). The yield of PCE was higher for fish fed 25% of heated SBM replacer than it was for diet groups fed less SBM. The yield of PCE trypsin was higher from animals fed 25% heated SBM replacer than those fed diets with a lower percentage of heated SBM replacer. Feeding coho fingerlings rations with SBM replacer appears to promote physiological compensation of PCE. Heat stable and/or heat-activated factor(s) and SBTI appear to cause the compensation of salmon digestive proteinases from coho salmon fed diets with SBM.     

Candida utilis and Chlorella vulgaris Counteract Intestinal Inflammation in Atlantic Salmon (Salmo salar L.)

Intestinal inflammation, caused by impaired intestinal homeostasis, is a serious condition in both animals and humans. The use of conventional extracted soybean meal (SBM) in diets for Atlantic salmon and several other fish species is known to induce enteropathy in the distal intestine, a condition often referred to as SBM induced enteropathy (SBMIE). In the present study, we investigated the potential of different microbial ingredients to alleviate SBMIE in Atlantic salmon, as a model of feed-induced inflammation. The dietary treatments consisted of a negative control based on fish meal (FM), a positive control based on 20% SBM, and four experimental diets combining 20% SBM with either one of the three yeasts Candida utilis (CU), Kluyveromyces marxianus (KM), Saccharomyces cerevisiae (SC) or the microalgae Chlorella vulgaris (CV). Histopathological examination of the distal intestine showed that all fish fed the SC or SBM diets developed characteristic signs of SBMIE, while those fed the FM, CV or CU diets showed a healthy intestine. Fish fed the KM diet showed intermediate signs of SBMIE. Corroborating results were obtained when measuring the relative length of PCNA positive cells in the crypts of the distal intestine. Gene set enrichment analysis revealed decreased expression of amino acid, fat and drug metabolism pathways as well as increased expression of the pathways for NOD-like receptor signalling and chemokine signalling in both the SC and SBM groups while CV and CU were similar to FM and KM was intermediate. Gene expression of antimicrobial peptides was reduced in the groups showing SBMIE. The characterisation of microbial communities using PCR-DGGE showed a relative increased abundance of Firmicutes bacteria in fish fed the SC or SBM diets. Overall, our results show that both CU and CV were highly effective to counteract SBMIE, while KM had less effect and SC had no functional effects.     

Nitrogen in vivo digestibility and in situ degradability data for estimation of lower tract N digestibility with or without correction for microbial contamination

In situ degradability and in vivo (by difference) digestibility trials were conducted to estimate lower tract residual N digestibility (LTRND) of five protein supplements. Efforts were also made to improve the in situ method of measuring protein degradability. For in situ degradability trials, soybean meal (SBM), corn gluten meal (CGM), cotton seed cake (CSC), wheat bran (WB) and corn gluten feed (CGF) were weighed into Dacron bags and incubated in the rumen of three cannulated Chios ewes. SBM, CGF and WB were degraded significantly, while CGM and CSC were least degraded. Microbial contamination (MC) resulted in a 5.3–28.3% artificially decrease in effective ruminal protein degradation of supplements. Total tract digestibility was measured using five rams in an in vivo, by difference, trial using a 5 × 5 Latin-square design. SBM had higher CP digestibility compared to WB, CGF and CSC, and higher N free extract (NFE) digestibility compared to the other feeds. CGM showed higher CP digestibility compared to WB, CGF or CSC, while CGF had higher organic matter (OM) and crude fibre (CF) digestibility compared to WB. CSC was the protein source with the lowest digestibility of OM, CP and NFE in comparison with the other feeds. LTRND was predicted as 0.928, 0.806, 0.227, 0.540, and 0.498 for SBM, CGM, CSC, WB, and CGF, respectively, or 0.931, 0.803, 0.147, 0.364, and 0.316 when the correction for MC was applied. Lower tract N digestibility could be predicted via a combination of in situ degradability and in vivo apparent digestibility data. This approach yields significant data regarding LTRND estimation of protein supplements, while diminishing animal suffering by avoiding small intestinal fistulation.     

不同添加方式植酸酶处理豆粕对牙鲆生长和饲料利用率的影响

以初始平均体重(2.02±0.02)g的牙鲆(Paralichthys olivaceus)为实验对象,进行为期70d的摄食生长实验,研究不同添加方式的植酸酶对牙鲆生长和饲料利用的影响。在5000.0g豆粕中添加2.5g植酸酶,然后用产朊假丝酵母(Candidautilis)进行发酵预处理,得到植酸酶预处理豆粕。共制作4种等氮等能(粗蛋白49.7%、总能20.9kJ/g)饲料,对照饲料主要以鱼粉为蛋白源;在对照饲料的基础上,用豆粕蛋白替代45%的鱼粉蛋白配制成豆粕组饲料;在每千克豆粕组饲料中添加1000IU植酸酶,配制成植酸酶组饲料;用植酸酶预处理豆粕蛋白替代45%的鱼粉蛋白配制成植酸酶预处理豆粕组饲料。结果表明,与对照组相比较,用豆粕蛋白替代饲料中45%的鱼粉蛋白,若不添加植酸酶则显著降低牙鲆的特定生长率(P0.01)、饲料效率、蛋白质效率和氮贮积率(P0.05);直接添加植酸酶组、植酸酶预处理豆粕组牙鲆的特定生长率、饲料效率、蛋白质效率和氮贮积率与鱼粉对照组相比较没有出现显著差异(P0.05);与不添加植酸酶的豆粕组相比较,在含豆粕饲料中添加1000IU/kg饲料的植酸酶显著提高牙鲆的特定生长率(P0.01)、氮贮积率(P0.05)和磷贮积率(P0.01),显著降低氮排放率(P0.05)和磷排放率(P0.01),但饲料效率和蛋白质效率没有显著变化(P0.05);在豆粕中添加植酸酶进行发酵预处理,降低了豆粕中植酸含量,在饲料中添加植酸酶预处理豆粕显著提高牙鲆的特定生长率(P0.01)、饲料效率、蛋白质效率和氮贮积率(P0.05),显著降低氮(P0.05)、磷和钙的排放率(P0.01)。       

Digestibility of phosphorous in cereals and co-products for animal feed

Feed ingredients used in swine diets contain various levels and availabilities of nutrients. Nutritional precision evaluation of each ingredient is necessary for formulating diets of pigs. Especially, phosphorous (P) is one of important nutrients for metabolism. However, current data of P digestibility were most apparent digestibility. Therefore, this study was aimed to estimate the coefficient of total tract standardized digestibility (CTTSD) of P in cereals and various co-products used in pig diet. Twelve barrows (initial BW?±?SD, 46.70?±?3.21?kg) were used in this experiment. The experimental design was a 12?×?8 incomplete Latin square with 12 diets and 8 periods. Experimental diets were consisted of barley, wheat, lupine kernel (LK), soybean meal (SBM), almond meal (AM), corn gluten meal (CGM), corn gluten feed from China (CGF-C), corn gluten feed from Korea (CGF-C), wheat bran (WB), rice bran (RB), lupine hull (LH) and P-free diet. The CTTAD of Ca was higher in AM than RB and CGF-K. The LK and CGM showed greater CTTSD of P than RB and LH. In conclusion, our results indicated that the cereals and co-products as P sources were the ideally used as an ingredient in mixed diets of the growing-finishing pigs.     

Dietary protein source affects lipid metabolism in the European seabass (Dicentrarchus labrax)

The study was undertaken to evaluate the effects of dietary protein sources on lipogenesis and fat deposition in a marine teleost, the European seabass (Dicentrarchus labrax). Four isonitrogenous (crude protein (CP, Nx6.25), 44% DM) and isoenergetic (22-23 kJ/g DM) diets were formulated to contain one of the following as the major protein source: fish meal (FM), one of two soy protein concentrates (SPC) and corn gluten meal (CGM). Apparent digestibility coefficients of the diets and raw ingredients, as well as soluble nitrogen (ammonia and urea) and phosphorus excretion were measured. Growth rates of seabass fed plant protein-based diets were significantly lower than those fed fish meal based diet. The protein utilisation was strongly correlated to the dietary essential amino acids index. Measurements of N excretion (ammonia and urea nitrogen) confirmed these data. Daily fat gain at the whole body level ranged between 1.1 to 1.7 g/kg BW, with the highest values being recorded in fish fed the fish meal based diet. Levels of plasma triglycerides and cholesterol were lower in fish fed soy protein diets than in those fed the diet solely based on fish meal. Soy protein rich diets decreased the activities of selected hepatic lipogenic enzymes (glucose 6-phosphate dehydrogenase, malic enzyme, ATP-citrate lysase, acetylcoenzyme A carboxylase and fatty acid synthetase). Highest lipogenic enzyme activities where found in fish fed the fish meal diet, except for fatty acid synthetase which was increased in seabass fed the corn-gluten meal based diets. Overall data suggest that dietary protein sources affects fat deposition and the lipogenic potential in European seabass.