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1.
Abstract

The aim of this study was to evaluate the influence of the yeast Yarrowia lipolytica growing on industrial glycerol on the protein nutritional value of cereal grains. We prepared six isonitrogenous diets. Three diets were based on cereal grains (wheat, barley, or triticale) plus the yeast Y. lipolytica (consisting of 60% cereal protein and 40% yeast protein). For comparison, three diets were prepared in which the only sources of protein were wheat, barley, or triticale. The tested yeast Y. lipolytica has 46.7% crude protein in dry matter, is rich in lysine (6.22 g/16 gN) and threonine (4.18 g/16 gN), but contains little methionine (1.44 g/16 gN). In our experiment, diets consisting of 40% Y. lipolytica protein +60% wheat, barley, or triticale protein had higher (p<0.01) protein efficiency ratio and net protein ratio than diets based on cereals only. Cereal+yeast diets also have higher biological value and true digestibility (significantly for barley+yeast and triticale+yeast, at p<0.05) compared with diets based only on cereals.  相似文献   

2.
ABSTRACT

1. The influence of the age of broiler chickens on ileal amino acid (AA) digestibilities in three cereals was examined. The digestibility estimates, including both apparent (AID) and standardised (SID) coefficients, for wheat, triticale and barley samples were determined using 14 and 28 d old broilers of mixed sex, fed diets containing the test grains as the only source of protein.

2. Each assay diet was offered to five replicate cages of 14 and eight birds respectively, for the 14 and 28 day samplings. On both sampling days, the contents from the lower half of the ileum were collected for determination of the AID coefficients. The SID coefficients were calculated using ileal endogenous amino acid (EAA) losses previously determined from birds fed an N-free diet.

3. The average AID for essential AA (EAA) in triticale and barley were significantly higher at 28 day compared to those at 14 days. In contrast, the magnitude of AID coefficients of AA in wheat was found to be in larger in the younger chickens.

4. Correction of AID for EAA losses increased the values of digestibility coefficients by an average of about 7%. The SID values of AA in wheat was not influenced by the age of broilers. The SID of most AA in triticale, and of all the AA in barley, were higher in 28-day-old chickens compared with their 14-day-old counterparts. The results suggested that the SID coefficients of EAA in wheat determined at day 28 could be applied to feed formulations for 14-day-old broilers, but in the case of triticale and barley, the values obtained in older chickens were not applicable in younger birds and vice versa.  相似文献   

3.
To gain further insights into temperate and tropical grass ensiling, fermentation products and bacterial communities were examined at both the initial and late stages of ensiling of wilted Italian ryegrass and wilted guinea grass silages. 2,3‐Butanediol and ethanol fermentation were observed in wilted Italian ryegrass silage. Enterobacteria such as Rahnella sp. and Enterobacter sp. may have been involved in fermentation; however, alcohol production was intensified after the silage enterobacterial community overwhelmed the pre‐ensiled enterobacterial community. Pediococcus spp. appeared in silage stored for 4 months, when a significant increase in lactic acid content was seen compared with that at 2 months. Prolonged storage enhanced acetic acid fermentation in wilted guinea grass silage. The disappearance of Enterococcus sulfureus and appearance of Lactobacillus plantarum may have been associated with the increased acetic acid content. Although many species of enterobacteria were found in common between the pre‐ensiled crop and silages of Italian ryegrass and guinea grass, marked differences were seen in the type of fermentation from the initial stages. These results indicate that the bacterial community of pre‐ensiled crops may be immediately replaced by one that is adapted to ensiling environments, although metabolic changes may continue over the course of ensiling.  相似文献   

4.
Two experiments were conducted to measure the energy and nutrient digestibilities in NutriDense corn and other cereal grains. An additional objective was to evaluate the effect of balancing diets with AA on the values measured for DE and ME of corn varieties. In Exp. 1, 6 growing pigs were fitted with a T-cannula in the distal ileum and allotted to a 6 x 6 Latin square design to measure apparent ileal digestibility (AID) and standardized ileal digestibility (SID) values for CP and AA in NutriDense corn, yellow dent corn, barley, wheat, and sorghum. Diets based on each of the 5 cereal grains were formulated, along with a N-free diet. Results of this experiment showed that the AID for most indispensable AA were greater (P < 0.05) in NutriDense corn and wheat than in the other cereal grains. The SID for Lys in NutriDense corn (77.6%) was greater (P < 0.05) than in yellow dent corn (68.5%), and sorghum (56.9%), but not different from wheat (75.1%) and barley (71.7%). The SID for Arg and Met in NutriDense corn also were greater (P < 0.05) than in yellow dent corn (88.1 and 87.2% vs. 84.5 and 82.8%, respectively). For the remaining indispensable AA, no differences in SID between NutriDense corn and yellow dent corn were observed. For all AA, the lowest values (P < 0.05) for AID and SID were obtained for sorghum. If calculated as grams of standardized ileal digestible AA per kilogram of DM, concentrations of all indispensable AA in NutriDense corn were greater (P < 0.05) than in yellow dent corn, but barley and wheat had greater concentrations of most AA than yellow dent corn and NutriDense corn. In Exp. 2, 12 growing barrows were placed in metabolism cages, and the DE and ME of NutriDense corn and yellow dent corn were measured. Both grains were used in diets without or with crystalline AA supplementation. Each diet was fed to 6 pigs in a 2-period, changeover design. The DE and the ME in NutriDense corn (4,004 and 3,922 kcal/kg of DM, respectively) were greater (P < 0.01) than in yellow dent corn (3,878 and 3,799 kcal/kg of DM, respectively). Values for DE and ME were not affected by the addition of crystalline AA to the diets. It is concluded that NutriDense corn has a greater value than yellow dent corn in diet formulations due to increased concentrations of digestible, indispensable AA and energy. However, barley and wheat have greater concentrations, whereas sorghum has lower concentrations, of many digestible AA than NutriDense corn.  相似文献   

5.
SUMMARY: Weaner pigs on a farm near Beaudesert in south eastern Queensland refused to eat feed comprised largely of wheat and barley. Older pigs consumed small amounts and some prepubertal gilts subsequently displayed enlarged and reddened vulvas. Wheat, barley and triticale were grown on the farm during 1983, which was unusually and persistently wet. The wheat and triticale were harvested and stored for about 3 weeks with moisture contents above 14% before being fed. Samples of the wheat and triticale contained pale pink grains, which can indicate infection by the fungus Fusarium graminearum Schw. On analysis 2 mycotoxins known to be produced by F. graminearum were detected, deoxynivalenol (vomitoxin) which causes feed refusal and vomiting, and zearalenone which causes oestrogenic effects. Concentrations of deoxynivalenol in the wheat, triticale and barley were 34, 10, and < 0.1 mg/kg respectively. Concentrations of zearalenone were 6.2, 2.8 and 0.1 mg/kg respectively. Subsequently, F. graminearum was isolated from grains and crop residues. Although the wet weather contributed to F. graminearum infection of the crops before harvest, most of the toxins probably developed during storage.  相似文献   

6.
This study was conducted to estimate the effect of fermented persimmon extract (FPE) supplementation levels on chemical composition and fermentation characteristics of barley silage. Barley forage was harvested at 25% dry matter and chopped to 5 cm lengths. The FPE was applied at 0, 0.4, 0.8 and 1.6 g/kg of barley forage (fresh weight basis). After sub‐sampling of barley forages (0 day), a total of 64 laboratory mini silos (5 kg capacity) were ensiled to generate quadruplicate data from each of four treatments for four ensiling durations (2, 6, 40 and 120 days). The chemical compositions and in vitro digestibility of barley forage (0 day) were not affected by FPE supplementation. However, the content (L, P = 0.035) and in vitro digestibility (L, P = 0.041) of neutral detergent fiber on 120‐day barley silage decreased by increasing FPE supplements. Acetate content of barley silage ensiled for 120 days increased (Q, P = 0.004) by increasing FPE supplements, whereas pH (L, P < 0.001), lactate content (Q, P < 0.001) and lactate‐to‐acetate ratio (Q, P < 0.001) decreased. These results indicate that addition of FPE can increase the acetate content which has potential to increase aerobic stability.  相似文献   

7.
Forty-eight barrows and forty-eight gilts (PIC 337 sires x PIC C22 dams) were evaluated to determine the effects of feeding ractopamine hydrochloride (RAC) and different cereal grains on the carcass and fat quality in late finishing pigs. The study was carried out using four replicates with 24 animals in each replicate (four pigs per pen, six pens per replicate, two replicates per slaughter date, 12 pens per slaughter date). Treatments for the experiment included corn, wheat, and barley (early finisher period); and corn, corn + RAC, wheat, wheat + RAC, barley, and barley + RAC for the late finisher period. Ractopamine was fed at the level of 10 mg/kg (as-fed basis) of feed. Pigs were allotted to early finisher period treatments at approximately 45 kg BW. Pigs were then given late finisher period treatments at approximately 80 kg BW and fed for 28 d. The dietary digestible lysine level for all diets was maintained at 2.7 g/Mcal of ME. Pigs fed the wheat and corn diets during the late finisher period had a greater (P <0.05) G:F than those fed the barley diets. Pigs fed diets with RAC had lower (P <0.05) leaf fat weights, 10th-rib fat, last-rib fat, and belly firmness and had improved (P <0.05) dressing percents and loin muscle areas compared with those not receiving RAC. Pigs fed the wheat diets had a greater (P <0.05) dressing percent than those receiving the barley diets, but pigs fed the barley diets had a higher (P <0.05) Minolta L* for fat color than pigs fed wheat. Pigs fed diets containing RAC produced pork that was less tender (P <0.05) compared with pigs that did not receive RAC. Linoleic acid percent values were higher (P <0.05) for pigs fed diets with RAC than in those that did not. Feeding RAC improved G:F and lowered feed intake of pigs during the late finisher period (P <0.05). Feeding diets equal in lysine (2.7 g/Mcal of ME) but varying in ME, whether based on corn, wheat, or barley with or without RAC, had little to no effect on carcass, meat, or fat quality attributes.  相似文献   

8.
An investigation of the dry matter degradability (DMD) and effective dry matter degradability (EDDM) was performed for barley, wheat, rye, corn, triticale and oat samples, using the Nylon-bag technique. Gas production (GP), metabolizable energy (ME) and in vitro organic matter digestibility (IVOMD) were also studied by using Hohenheim gas test. The DM from barley, wheat, rye and triticale was digested rapidly in the rumen, and, at the 48 h of incubation, degradability was found to be approximately about 80%. The higher degradability observed for these grains than for oats and corn was attributable to the structure of these grains. In contrast, DM of corn and oats was degraded very slowly and reached 66.7 and 66.5 at 48 h, respectively. Effective degradability values of barley, wheat, rye, corn, triticale and oats were determined to be 61.4, 69.0, 64.0, 41.7, 66.7 and 58.6% in 5% rumen outflow rate, respectively. At the end of the 48 h incubation, total gas productions in barley, wheat, rye, corn, triticale and oats were estimated to be 83.6, 87.2, 87.5, 83.5, 85.8 and 63.9 ml/200 mg DM, respectively. The mean ME values of these grains calculated from cumulative gas amount at 24 h incubation were 11.8, 12.1, 12.3, 10.9, 12.4 and 10.2 MJ/kg DM, respectively. In vitro digestible organic matter of barley, wheat, rye, corn, triticale and oats were estimated to be 85.0, 87.3, 88.2, 79.5, 89.0 and 72.6%. Percentage overall EDDM (k=5%) of barley, wheat, rye, triticale and oats was positively correlated with in vitro GP at 6 h, cumulative GP at 24 h and total GP at 48 h (p<0.05). As a result, in situ dry matter degradation of grains showed great differences depending on the chemical compositions. In situ EDDM of grains may be predicted from in vitro gas production parameters.  相似文献   

9.
Effects of different chemical additives on peptide composition in ensiled alfalfa (Medicago sativa L.) were investigated by using gel filtration and determination of N characteristics. The alfalfa silages were prepared untreated (control) or with formic acid, formaldehyde or tannic acid as additives at ensiling. All additives reduced non‐protein N (NPN), ammonia nitrogen (NH3‐N) and amino acid N (AA‐N) in the ensiled forage, and the most effective reduction of NPN and AA‐N was observed in the formaldehyde‐treated silages. Peptides in the control silage were mainly dipeptides to peptides with five amino acid residues. Most peptides in the formic acid‐treated silage contained 4–12 amino acid residues. Although most peptides in the formaldehyde‐treated silages contained 4–6 amino acid residues, there was a considerable proportion of peptides with 7–11 amino acid residues. Tannic acid had little effect on peptide size of ensiled alfalfa extract in which most peptides contained 5–6 amino acid residues. Peptide size in formic acid‐treated alfalfa silage was greater than that in the other treatments. Addition of formic acid and formaldehyde not only increased the peptide concentration in alfalfa silage, but enlarged the peptide size.  相似文献   

10.
The effects of ensiling temperature and duration of ensiling on the feeding quality of whole‐crop maize (Zea mays L.) silages were investigated. Samples of one cultivar of maize plants were collected from two different fields, grown in different years on sandy soils. Samples were collected when the whole‐plant dry matter content was approximately 330 g/kg. Maize plants were chopped and ensiled in mini silos at three different ambient temperatures (5, 12 and 18 °C). The ensiling temperature affected the ensiling fermentation processes, causing different rates of pH decline and different final pH values. Samples from the silos were taken after 0 (not ensiled, i.e. control), 4, 8 and 16 weeks of ensiling. The silage samples were not dried, but ground‐frozen under liquid nitrogen to pass a 1‐mm sieve. The gas production technique was used to evaluate the influence of the ensiling temperature and the duration of ensiling on the degradation of the silage samples in rumen fluid. The gas production was highest when the maize was ensiled at 12 °C (p < 0.0001). An increase in ensiling duration caused a decrease in silage pH, accompanied by a decrease in gas production (p < 0.0001). The decrease in gas production was linearly related to the decrease in pH at the three temperatures. The present study shows that both ensiling temperature and ensiling duration play a significant role in the rumen degradability of maize silage.  相似文献   

11.
Rice straw and sweet potato vines are the main by‐products of agricultural crops, and their disposal creates problems for the environment in the south of China. In order to establish an easy method for making rice straw silage successfully, experiments were conduct to evaluate fermentation quality and nutritive value of rice straw silages ensiled with or without sweet potato vine. Paddy rice straw (PR) and upland rice straw (UP) were ensiled alone or with sweet potato vines (SP) by a ratio of 1:1 (fresh matter basis), over 3 years. Compared with rice straw silages ensiled alone, the mixed‐material silages (PR + SP, UR + SP) showed higher fermentation quality with lower propionic acid content and NH3‐N ratio of total N, and higher (P < 0.05) concentrations of lactic acid and acetic acid, resulting in decrease (P < 0.05) of dry matter loss and higher (P < 0.05) in vitro ruminal dry matter digestion. When the fermentation quality, chemical composition and in vitro rumen fermentation characteristics were considered, ensiling would be an effective way of utilization of rice straw and sweet potato vines in the regions where rice and sweet potato are harvested at same season, and the sweet potato vines have the potential to improve rice straw fermentation quality with low water soluble carbohydrate content in south of China.  相似文献   

12.
Amino acid (AA) composition of body protein is considered constant although there are evidences that AA pattern in pigs may be altered by different factors. Pigs with different body composition and protein deposition rates—like fatty and lean pigs—may differ in AA composition, with possible consequences on their AA requirements. This work investigates effects of genotype and dietary lysine deficiency on AA composition of carcass and muscles of Iberian and Landrace × Large White pigs. Twenty‐eight barrows (10 kg body weight [BW]), 14 from each breed, were used. They were randomly assigned to two experimental diets according to a factorial arrangement (two breeds × two diets). Diets were isonitrogenous and isoenergetic (200 ± 1 g CP/kg dry matter (DM); 14.7 ± 0.1 MJ ME/kg DM) and with identical chemical composition except for lysine concentration (10.9 and 5.20 g lysine/kg DM, for lysine‐adequate (AL) diet and lysine‐deficient (DL) diet respectively). Pigs were individually housed, and daily feed allowance was adjusted on a weekly basis according to BW. Pigs were slaughtered at 25 kg BW. Isoleucine, valine and phenylalanine concentration were higher in carcass protein of Iberian pigs (p < .01). In longissimus muscle, higher concentration of arginine, isoleucine, phenylalanine, lysine and valine (p < .001–p < .05), and lower of methionine (p < .001) were detected in Iberian pigs, whereas phenylalanine, leucine, lysine, threonine and methionine concentration decreased and arginine increased (p < .001–p < .05) when pigs were fed DL diet. Genotype and lysine deficiency effects were moderate in the AA composition of protein of biceps femoris muscle. The results show that AA proportions in protein of carcass and longissimus muscle can be influenced by pig genotype and conditions of lysine shortage. The biceps femoris muscle, with different functional and metabolic properties, shows more constant AA composition than longissimus, which seem to prevail independent from genotype or nutritional challenges.  相似文献   

13.
To study the effects of feeding fermented cereals or just fermentation end‐products on performance and energy metabolism, 18 restrictedly fed groups of eight pigs each were assigned to one of three dietary treatments: (i) a liquid control diet (C) containing 40% of a mixture of barley and wheat; or (ii) a liquid diet (F) containing 40% fermented barley and wheat; or (iii) a liquid diet as C with the addition of some important fermentation end‐products (FP; organic acids and ethanol) in concentrations similar to those in the fermented F‐diet. Energy and nitrogen balances, heat production, and performance traits were measured during two consecutive periods (days 1–5 and days 6–14). There was a considerable increase in average dry matter intake that tended (p = 0.06) to be higher in the FP‐group than in the other groups. Apparent fecal digestibility of dry matter, ash, nitrogen and energy during period 2 were not affected (p > 0.1). Averaged over both periods, none of the energy metabolism parameters were affected by the diets (p > 0.1). However, there were diet × period interactions for metabolizable energy‐intake (p = 0.07), energy retention (p < 0.05), the respiratory quotient (RQ; p < 0.01) and activity‐related heat production (HACT, p = 0.05). Additionally, there were some differences between the diets in the average hourly patterns in RQ and HACT. In conclusion, restricted feeding of either 40% fermented cereals nor their fermentation end‐products affected performance and energy metabolism traits in weanling pigs. Nevertheless, lower postprandial activity‐related heat production by pigs given the fermented cereals suggest a stimulating effect of fermented cereals on short term satiety that was not seen in pigs given fermentation end‐products only.  相似文献   

14.
The effects of inclusion of persimmon peel (PP) in total mixed ration (TMR) silage on its nutrient composition, tannin content, and in vitro ruminal fermentation were studied. Four types of TMR silages containing 0, 50, 100, and 150 g/kg of PP on a dry matter basis were prepared. The dietary contents of non‐fiber carbohydrate (NFC) decreased, while soluble protein fraction increased after ensiling of the TMR. In the TMR silages, the content of insoluble tannin increased (p < .05) with increasing PP level. The fraction of soluble protein decreased linearly (p < .01), while that of neutral detergent insoluble protein increased linearly (p < .01) with increasing the PP level in the TMR silages. The total gas and methane yields from the in vitro rumen fermentation of the TMR silages were lower (p < .01) than those of pre‐ensiled TMR and declined linearly (p < .01) with increasing PP level. These results indicate that adding PP to TMR silage may resist the breakdown of dietary protein during the ensiling process, although the ruminal fermentability of TMR possibly decreased after ensiling due to the loss of NFC.  相似文献   

15.
Ensiling legume grain may be an inexpensive and ecologically interesting method to produce a high‐protein feed of local origin. The typically patchy maturation recommends harvesting and ensiling the seeds in moist condition. Developing a method for preserving legume grains harvested before maturation by lactic acid fermentation would have several advantages. Under laboratory conditions, crushed legume seeds of beans, peas and lupines with high moisture content of 35 % were ensiled with different additives (molasses and lactic acid bacteria). To characterize the final silages, contents of proximate nutrients and antinutritional factors (alkaloids, oligosaccharides, tannins) were analysed. The addition of lactic acid bacteria ensured a fast and pronounced lactic acid production and decreased contents of undesired fermentation products like ethanol. An additional use of molasses for ensilage did not provide a remarkable additional benefit. Excluding sugar and starch, the contents of proximate nutrients were not remarkably altered after ensiling. As an overall effect, lactic acid fermentation reduced tannins and oligosaccharides. It can be supposed that the oligosaccharides after breakdown of the complex molecules acted as a source of fermentable carbohydrates. A relevant reduction of alkaloids did not occur. The lactic acid fermentation of legume grains can be recommended as an appropriate method for conservation. With respect to the economic advantages and compared with methods of chemical preservation, the lactic acid fermentation of legume grains under anaerobic conditions is an environmentally compliant procedure and therefore also an option for organic farming.  相似文献   

16.
The ruminal degradation of amino acids (AA) of a green Italian rye-grass (GRG) and its silage (ERG) was determined on three wethers cannulated in rumen and duodenum using in situ and particle passage techniques. Wethers were fed a diet of ERG, corn silage and concentrate (1:1:1, DM basis) at 40 g DM/kg BW0.75. Two rumen incubations (at 0, 2, 4, 8, 16, 24, 48 and 72 h) with freeze-dried samples (3 g) in nylon bags were performed for each feed. The microbial contamination of incubated residues was corrected using 15N enriched solid associated bacteria isolates as reference. Two different estimates of undegraded AA were established: UPp, considering the particle rumen outflow rate (kp) of the ERG, and UPcp, considering additionally the rate of comminution and mixing (kc) of these particles. Microbial contamination resulted in large errors in the degradation kinetic parameters of all AA. As a result, non corrected UPp and UPcp included a large fraction of microbial origin. For essential AA plus cysteine these microbial proportions ranged 0.365–0.555 (UPp) and 0.461–0.710 (UPcp) in GRG. In ERG these values ranged: 0.403–0.666 (UPp) and 0.481–0.804 (UPcp). Cysteine always supplied minimum values whereas lysine showed maximum values in GRG or very close to these in ERG. Ensiling was associated with large changes in the AA profile. These variations conditioned, in turn, large differences in the changes made by the rumen microorganisms on the AA profile of both forages. However, ensiling only led to little changes in the profile of the rumen undegraded protein, especially when kc was considered. Results show the need to correct for this contamination to obtain accurate AA valuations and also that the AA profile of the undegraded protein of a green forage may serve as a guide for this profile in its silages.  相似文献   

17.
Protein degradation during ensiling is a major problem. Tannins are known to prevent or decelerate protein degradation in the rumen and may be able to do so in silages as well. Therefore, the present evaluation aimed to analyse the influence of tannins on silage quality. This was done by integrating from all suitable experiments found in literature on the topic in a meta‐analysis approach. A total of 122 datasets originating from 28 experiments obtained from 16 published articles and one own unpublished experiment were included in the database. Tannins in the silages originated either from the plants ensiled or from supplementations of tanniferous plants or tannins extracted from such plants. Tannin concentrations ranged from 0 to 57.8 g/kg dry matter, and the ensiling period varied from 30 to 130 days. The analysis was based on the linear mixed model methodology in which the different studies were considered as random effects and tannin‐related properties (either concentration or type of tannins) were treated as fixed effects. Results revealed that greater concentrations of tannins were associated with a decrease of butyrate concentration in the silages (p < 0.05). An increasing tannin concentration was also accompanied with smaller proportions of soluble N, free amino acid N, non‐protein nitrogen and NH3‐N in total silage N (p < 0.05). The relationships between hydrolysable and condensed tannins and the decline in butyrate and NH3‐N concentrations in the silages were of different magnitude (p < 0.05). A higher tannin concentration was associated with a decline in in vitro dry matter digestibility. It was concluded that tannins apparently have the ability to limit extensive proteolysis which may occur during ensiling and thus may improve the fermentative quality of silages. A desired side effect seems to be given by the tannins' apparent property to limit the activity of the butyrate‐producing microbes.  相似文献   

18.
N balance experiments were conducted to derive age‐dependent model parameters for modelling of lysine (Lys) requirements in growing pigs. Modern genotype barrows from 16 litters were utilized (four piglets/litter) at 15, 30, 50, 70, 90 and 110 kg body weight respectively. Six diets provided graded dietary protein supply (40 to 320 g/kg) by a constant mixture of barley, wheat, potato protein, wheat gluten, soybean protein concentrate and crystalline amino acids. Lys was set as the first limiting dietary amino acid. Each age period provided 24 N balance data (n = 4) to derive N maintenance requirement (NMR) and theoretical maximum for daily N retention (NRmaxT) by non‐linear regression analysis. At high dietary Lys efficiency, 17–18 g daily Lys intake was required for 170 g daily protein deposition. To achieve similar daily protein deposition, pigs need 21–23 g Lys if the Lys efficiency is 20% lower. For higher daily protein deposition (195–200 g) and varying dietary Lys efficiency, between 22 and 29 g Lys was required. The Lys requirement data yielded by modelling were in line with current recommendations. Further developments of the approach are discussed to improve age‐independent applications.  相似文献   

19.
We explored the suitability of Goettingen Minipigs as models to measure ileal AA digestibility and evaluate dietary proteins for conventional pigs. Further, a potential for secondary ileal microbial colonization 5 mo after establishing end-to-end ileorectal anastomosis was investigated. Goettingen Minipigs (BW 18 kg) and Saddleback pigs (BW 27 kg) fitted with end-to-end ileorectal anastomosis were fed six diets based on barley and oilseed meals and three diets based on wheat and milk powder differing in total and ileal digestible lysine. Apparent ileal digestibilities of CP (N x 6.25) and of 20 AA were determined. No differences (P = 0.062 to 0.982) were found in AA apparent ileal digestibilities between breeds. Therefore, Minipigs are a reasonable model to estimate apparent ileal digestibility of AA for evaluation of dietary proteins. However, the apparent ileal digestibility of CP (P = 0.048) was higher in Minipigs than in Saddleback pigs (barley and oilseed meals-based diets 70% vs. 66%; wheat and milk powder-based diets 80% vs. 77%), which is probably due to a smaller contribution of non-AA-nitrogen in the ileal effluent of Goettingen Minipigs. For lysine, the apparent ileal digestibilities (means of both breeds) ranged from 78 to 85% in wheat and milk powder-based, and 70 to 78% in barley and oilseed-based diets. Experimentally derived concentrations of ileally digestible lysine confirmed the values predicted from a published table. Microbial counts were not affected by breed as shown for lactobacilli, with 9.1+/-0.2 and 9.1+/-0.2 (P = 0.977), enterococci with 4.8+/-0.3 and 5.6+/-0.4 (P = 0.162), and yeasts with 4.6+/-0.3 and 4.6+/-0.4 (P = 0.906) log cfu/g effluent for Goettingen Minipigs and Saddleback pigs, respectively. The counts did not change over 5 mo, suggesting that no secondary microbial colonization occurred in pigs with end-to-end ileorectal anastomosis.  相似文献   

20.
Two experiments were conducted using laboratory mini-silos to study the effect of ensiling and silage additives on fatty acid (FA) composition, including minor or unusual FA, of ryegrass and corn silages. Ryegrass was ensiled for 12 wk with no additives, with the addition of a bacterial inoculant or formic acid. Corn was ensiled for 9 wk without additives, with the addition of a bacterial inoculant or calcium formate. Ensiling affected both total FA content and FA composition of ryegrass silages. Total FA concentration increased (P < 0.001) during ryegrass ensiling. The proportions (g/100 g of total FA) of the major unsaturated FA, 18:3n-3 and 18:2n-6, were not affected (P > 0.05) by ensiling. However, their concentration (mg/g of DM) in silages was greater (P=0.017 and P=0.001, respectively) than in fresh ryegrass. Two 18:2 FA (trans-11,cis-15 and cis-9,cis-15) that were not originally present in the fresh ryegrass were detected in silages. Silage additives affected the FA composition of ryegrass silages, mostly by increasing the proportions of SFA, but not on total FA concentration. Ensiling did not affect (P=0.83) total FA content of corn silages; however, FA composition was affected, mostly by decreasing the proportions of 18:2n-6 and 18:3n-3. Silage additives had no effect on corn silage FA composition. Exposing corn silages to air resulted in no oxidation of FA or reduction in total FA content or composition.  相似文献   

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