Effect of graded levels of rapeseed oil in isonitrogenous diets on the development of the gastrointestinal tract,and utilisation of protein,fat and energy in broiler chickens

The effect of feeding 0, 4, 8 and 16% rapeseed oil from 12–42 days of age was studied in broiler chickens on performance, digestibility of nutrients, and development of gastrointestinal tract, protein and energy metabolism. Thirty six female chickens (Ross 208) with initial body weight average 246 g were allocated to the four groups and kept pair-wise in metabolism cages. The chickens were fed similar amounts of metabolisable energy (ME) per day and similar amounts of essential amino acids relative to ME by adjusting with crystalline amino acids. The chickens were subjected to four balance periods each of five days with two 24 h measurements of gas exchange in two open-air-circuit respiration chambers inserted on the second and third day of each period. The addition of rapeseed oil increased the amount of gutfill indicating a reduced rate of passage and causing a hypertrophy of the gastrointestinal tract. There was a positive effect on feed utilisation as well as on digestibility especially of dietary fat together with higher utilisation of protein with addition of rapeseed oil. The partial fat digestibility of rapeseed oil estimated by regression was 91.1% and the partial metabolisability (ME/GE) of the rapeseed oil was estimated to 85% yielding an apparent metabolisable energy value of 34.30 MJ/kg.     

Effect of dehulling of rapeseed on feed value and nutrient digestibility of rape products in pigs

In the presented study the influence of dehulling rapeseed on the composition of rapeseed meal (RM) and rapeseed cake (RC) and on its feed value for piglets and growing-finishing pigs was investigated. Before withdrawal of oil, rapeseed (variety Express) was dehulled applying a procedure developed by SKET GmbH Magdeburg and the Section Food-Technology of the University Essen. The steps of the dehulling procedure were described. For RM the oil was removed by the prepress-solvent procedure till a crude fat content of 2.1% in DM. RC was produced by pressing only resulting approximately 13% crude fat in DM. The RM and RC from not dehulled (ND) and dehulled (D) rapeseed were examined analytically. Crude nutrients, sugar and fibre substances, amino acids, some minerals and trace elements, fatty acids, glucosinolates and sinapine, and phytate were determined. By dehulling the seed the crude fibre content was decreased in RM and RC by approximately 40%. The ADF content declined by 35 and 39%, and the NDF content by 28% and 40% in RM and RC, respectively. The decrease in ADL content amounted to 50% and 65% for RM and RC, respectively. On the other hand, the CP content of RM and RC was increased by 7% and 13%, respectively, by dehulling the seed while the amino acid content of rape protein increased only slightly. The contents of glucosinolates and sinapine were also increased by dehulling, while the contents of phytate and phytate P were decreased. In digestibility and balance experiments with piglets and intact hybrid breeds of growing-finishing pigs, the digestibility of organic matter and of crude nutrients and the contents of digestible energy and metabolizable energy were estimated. Furthermore, the precaecal digestibility of crude nutrients and amino acids was determined with fistulated mini-pigs. By dehulling the seeds the digestibility of organic matter from RM and RC was improved in piglets and adult pigs by approximately 10%, and the ME contents increased by 13-15%. The precaecal digestibility of the sum of amino acids was increased by approximately 3 and 6 units in RM and RC, respectively. The precaecal digestibility of lysine in RM and RC reached that of soybean oil meal from not dehulled beans.     

Metabolisable energy value of fats in chicks and adult cockerels

The metabolisable energy (ME) values of beef tallow, animal fat and poultry fat were determined by various methods using two- or six-week-old chicks and adult cockerels. The ME value of tallow increased with the age of the bird, but no parallel changes in either digestibility or ME of unsaturated fats were observed. The difference between ME values obtained by digestibility studies and those obtained directly showed that added fat may increase the absorbability of other constituents of the diet, hence the ME obtained by difference may exceed gross energy in some cases.     

Digestibility and energy value of non-starch polysaccharides in young chickens, ducks and geese, fed diets containing high amounts of barley

The purpose of the present investigation is to compare the ability of chickens, ducks and geese to digest and utilise a diet containing a relatively large amount of barley (40%) rich in beta-glucan (18 g kg(-1)) and NSP (137 g kg(-1)) of which 35 g kg(-1) were soluble non-starch polysaccharides (NSP). The diets were offered to the birds (50 chickens, 40 ducks and 30 geese) in the period from hatching to 42 days of age. The digestibility of NSP was measured during the last week of the growth period using chromic oxide as an indigestible marker. Emphasis was on total NSP, soluble and insoluble NSP and their constituent sugar residues (rhamnose, fucose, arabinose, xylose, mannose, galactose, glucose and glucuronic acid). The degradation of NSP to short chain fatty acids (SCFA) was determined in the small intestine, caeca and large intestine. Although significant differences were found between species to the extent of degradation of individual soluble, insoluble and total NSP residues in the small intestine and caeca, the overall apparent digestibility of total NSP was similar (39-42%). On the basis of the digestibility of the NSP sugar residues and the formation of SCFA in the gut, the energy value of NSP was estimated on 2.8, 3.2 and 2.7 kJ g(-1) NSP ingested (P>0.05) in chickens, ducks and geese, respectively. On average, NSP contributed approximately 3.5% of metabolisable energy (ME) in the three poultry species.     

Effects of glyceryl polyethylene glycol ricinoleate on nutrient utilisation and performance of broiler chickens

A completely randomised design study with a 2 × 2 factorial arrangement was conducted to observe effects of an emulsifier (glyceryl polyethylene glycol ricinoleate (GPR)) on nutrient utilisation and performance of broiler chickens. A total of 384 male broiler chickens were used to determine the influence of GPR (without addition or added at 0.04% of diet) and two levels of apparent metabolisable energy (AME_N) (according to standard requirements (Diets SE) or energy reduced by 0.4 MJ/kg diet (Diets LE)) on birds’ performance and apparent total tract digestibility (ATTD). ATTD of ether extract (EE) and AME_N were measured on d 14 and 35, and ATTD of neutral detergent fibre (NDF) was measured on d 35. All diets were based on wheat–maize–soybean meal with rapeseed oil and lard (blend of 50:50) as fat sources. During the grower period and the whole trial, birds fed Diets supplemented with GPR were characterised by higher body weight gain (BWG) and lower feed conversion ratio (FCR) compared to chicken receiving diets without GPR (p < 0.05). At the end of experiment, birds fed Diet LE without GPR were characterised by lower BWG and higher FCR (p < 0.05). Supplementation with GPR caused a higher ATTD of EE for diets SE and LE at d 14 and 35 (p < 0.05). Moreover, the GPR addition to Diet LE improved ATTD of NDF at d 35 (p < 0.05). In conclusion, the findings suggest that GPR effects the digestion of a blend of animal fat/rapeseed oil positively, even in a practical maize–wheat-based broiler diet with decreased AME_N level.     

Synchronising the availability of amino acids and glucose increases protein retention in pigs

Effects of synchronising the availability of amino acids and glucose within a day on protein and energy metabolism were studied in growing pigs. Ten pigs of on average 54 (s.e. 1.0) kg live weight were assigned to each of two dietary treatments (synchronous v. asynchronous nutrient supply) in a change-over design. On the synchronous treatment (SYN), pigs received two balanced meals: one at 0800 h and one at 1600 h. On the asynchronous treatment (ASYN), pigs received virtually all protein at 0800 h and all carbohydrates at 1600 h. The dietary supply of ingredients and nutrients to pigs was similar for both treatments. Pigs were housed individually in respiration chambers. Faecal apparent nutrient digestibility was determined and nitrogen and energy balances were measured. Faecal apparent digestibility of energy, organic matter and non-starch polysaccharides was higher ( P < 0.05) for SYN than for ASYN. The efficiency of utilisation of digestible protein with protein gain was higher ( P = 0.001) for SYN (56.7%) than for ASYN (47.1%). The substantial decrease ( P < 0.05) in respiratory quotient and ¹³C enrichment of the expired CO₂ after the morning meal indicated higher amino acid oxidation for ASYN than for SYN. Heat production and energy retention as fat were not affected by nutrient synchrony. In conclusion, an asynchronous availability of glucose and amino acids within a day increases amino acid oxidation, resulting in a substantial reduction in protein utilisation but with virtually no effect on fat retention.     

Determination of energy and amino acid digestibility in growing pigs fed corn distillers' dried grains with solubles containing different lipid levels

Two experiments were conducted to estimate the digestibility of energy, nitrogen and amino acids (AA) in growing pigs fed diets containing one of five corn distillers' dried grains with solubles (DDGS), including three normal oil DDGS (NO-DDGS) and two low oil DDGS (LO-DDGS) samples. Exp. 1 was conducted to determine the digestible energy (DE) and metabolisable energy (ME) content. Six growing barrows (initial body weight [BW]: 35.1 +/- 2.2 kg) were allotted to a 6 x 6 Latin square design, with six periods and six diets. One diet was a corn soybean meal basal diet and the other five diets were based on corn, soybean meal and 28.8% DDGS. The average DE and ME values for the three NO-DDGS samples were 16.0 and 14.9 MJ/kg dry matter (DM). These values were 9 and 13% greater than the LO-DDGS values of 14.7 and 13.2 MJ/kg DM respectively. Exp. 2 was conducted to determine and compare apparent (AID) and standardised (SID) ileal digestibility for crude protein and AA in the five DDGS samples. Six growing barrows (initial BW, 32.2 +/- 1.9 kg) fitted with a simple T-cannula were allotted to a 6 x 6 Latin square design with six periods and six diets. Five of the diets were based on the five DDGS samples, and the remaining one diet was nitrogen-free diet based on cornstarch and sucrose. Titanium dioxide (0.1%) was used as inert marker. The results of the experiment showed the largest variation among the different samples in AID and SID for lysine (from 41.8 to 65.8% and 53.8 to 73.9% respectively) and threonine (from 54.3 to 73.8% and 65.2 to 79.5% respectively). Also, among the indispensable AA, the SID values for arginine, histidine, threonine and tryptophan observed in LO-DDGS were not different from the values derived from NO-DDGS. In conclusion, LO-DDGS may have decreased energy compared with NO-DDGS because of its lower fat content. However, oil removal during the production of DDGS may not affect amino acid digestibility.     

Nutritional value of 15 corn gluten meals for growing pigs: chemical composition, energy content and amino acid digestibility

The objectives of this study were to determine the chemical composition, energy content and amino acid digestibility for corn gluten meals (CGM) and to develop prediction equations for estimating energy content and amino acid digestibility for growing pigs based on the chemical characteristics of these meals. The 15 CGM tested were obtained from seven Chinese companies. Experiment 1 was conducted to determine the digestible (DE) and metabolisable energy (ME) of the 15 CGM. The 18 growing barrows (38 +/- 4 kg) were assigned to three 6 x 6 Latin square designs. The 15 CGM test diets were formulated to contain 19.20% CGM, which replaced 20% of the energy supplied by corn and crystalline amino acid in the basal diet. Experiment 2 was conducted to determine the apparent (AID) and standardised (SID) ileal digestibility of the crude protein (CP) and amino acids in the 15 CGM using chromic oxide as an inert marker. The 18 growing barrows (25 +/- 2 kg) fitted with a simple T-cannula were assigned to three 6 x 6 Latin square designs. The 15 test diets contained 35% of one of the 15 CGM as the sole source of amino acids in the diet. The results showed a considerable variation in the chemical composition of CGM within and among plants. On dry matter basis, the DE and ME content of the CGM ranged from 18.8 to 21.0 MJ/kg and from 18.0 to 19.9 MJ/kg, respectively. There were no significant differences in the AID and SID for CP, arginine, lysine, glycine and proline among the 15 CGM, however, for all the other amino acids, significant differences were found for their AID and SID. With R2 values exceeding 0.50, the DE of CGM can be predicted accurately from CP and fibre content and ME from starch and fibre content. Suitable prediction equations for SID of methionine were also developed.     

Ileal and total tract digestibility and nitrogen utilisation in blue fox (Vulpes lagopus) fed low-protein diets supplemented with DL-methionine and L-histidine

ABSTRACT

To formulate low-protein diets for blue foxes with sufficient amounts of amino acids (AA), AA digestibility and AA requirements of the animals are crucial information. Therefore, a digestibility and nitrogen (N) balance trial was conducted with 20 blue foxes to determine the macronutrient and AA digestibility and N utilisation in low-protein diets supplemented with DL-methionine (Met) and L-histidine (His). In addition, plasma urea and plasma AA were measured. The diets were designated as P24 (control), P20, P20M, P16M and P16MH and contained energy from digestible crude protein (DCP) at 24%, 20% or 16% of total dietary metabolisable energy (ME). The 20% protein level was fed with or without Met and the 16% protein level was fed with Met and with or without His. The apparent total-tract digestibility (ATTD) of crude protein linearly decreased with decreasing dietary protein level. The ATTD of dry matter, organic matter and crude carbohydrates increased when wheat starch was added as a replacement for protein. The apparent ileal digestibility (AID) and ATTD methods were compared to determine the AA digestibility. The decreasing dietary protein supply decreased the ATTD of most of the AA: threonine, tryptophan (Trp), valine, alanine (Ala), aspartic acid (Asp), glutamic acid, glycine (Gly), proline (Pro), serine (Ser) and total AA. The AID of the AA was constant between diets. Diverging AA showed higher or lower digestibility when determined in the AID or ATTD methods. Isoleucine, lysine, Met, Ala and tyrosine showed higher levels of AID. Arginine, His, cysteine (Cys), Trp, Asp, Gly, Pro and Ser showed higher levels of ATTD, which may reflect the net loss of these AA in the large intestine. Met and His supplementation improved the ATTD and AID of the AA in question, respectively, but did not affect the other variables examined. N retention did not differ between diets and renal N excretion decreased with decreasing protein level; thus N utilisation improved. It was concluded that the protein supply and AA composition in low-protein diets with supplemented Met were adequate for adult blue foxes, since the lower protein supply improved N utilisation and did not affect N retention. However, His supplementation failed to reach the designed level and therefore showed no clear results.     

Determination and prediction of the energy content and amino acid digestibility of peanut meals fed to growing pigs

Two experiments were conducted to determine the content of digestible energy (DE) and metabolisable energy (ME) as well as the apparent ileal digestibility (AID) and standardised ileal digestibility (SID) of amino acids in peanut meal (PNM) for growing pigs. In Experiment 1, 78 growing pigs (46.8 ± 2.6 kg) were randomly allotted to 1 of 13 diets, including a corn–soya bean meal basal diet and 12 PNM test diets. In Experiment 2, 12 growing barrows (48.7 ± 2.8 kg) were allotted to one of two 6 × 6 Latin squares. The treatments include a N-free diet and 10 PNM test diets. The results of Experiment 1 showed that the DE and ME differed (p < 0.05) among the 12 PNM samples. On a dry matter basis, the DE and ME content ranged from 14.5 to 16.4 MJ/kg (mean 15.6 MJ/kg) and from 12.7 to 15.5 MJ/kg (mean 13.9 MJ/kg), respectively. The apparent total tract digestibility (ATTD) of gross energy (GE) was 82.2%. The DE of PNM could be precisely predicted by equations including NDF combined with GE or crude protein (CP) with an R² value of 0.91 and 0.92, respectively. For the AID and SID for lysine, the results of Experiment 2 indicated variations among PNM sources ranging from 59.6% to 76.7% and 64.8% to 80.9%, respectively. However, for CP, variations for AID and SID were lower and ranged from 70.2% to 81.9% and 75.7% to 85.6%, respectively. The results indicate that the concentration of lysine was the best single predictor to estimate the digestibility of amino acids. However, further work is needed to investigate the reason for the variation in the digestibility of lysine and avoid processing procedures that are detrimental to lysine digestibility.     

Nutrition and energetics of the canary (Serinus canarius)

Canaries appear to be primarily seed-eaters, although there are no reports of their feeding ecology in the wild. In captivity, they are offered seed-based diets, preferring to consume seeds such as canary, rapeseed and millet. The mean daily dry-matter intake ranges from 3 to 4 g, which corresponds to a mean gross energy intake of approximately 70 kJ per bird per day. The efficiency of dietary metabolism is high (0.85), which equates to individual metabolizable energy intakes of 45-75 kJ per bird per day. For a canary of average body weight (22 g) the data can be fitted to a regression equation to predict a requirement of 62 kJ ME per day. This corresponds to published information on the energy requirements of other passerine species, but deviates from the predictive equation for poultry. The digestibility values for protein, fat and carbohydrate are similar to those obtained for the budgerigar, although it is likely that the digestibility coefficient is dependent upon the seed type and alimentary tract lipase and amylase activities. Nutrient requirements of canary chicks have not yet been determined, although recent studies have provided data on the nutrient intakes of developing chicks. The newly-hatched canary chick has a rapid growth rate, achieving 90% of its asymptotic body mass by 11 days of age. Gross energy intake is approximately 3 kJ per day following hatching and by day 10 is equivalent to that of an adult canary. It appears that the protein intake should lie between 16.5 and 21.9% of the diet (as is), with peak intake occurring between 8 and 10 days of age.     

Clostridium perfringens challenge and dietary fat type affect broiler chicken performance and fermentation in the gastrointestinal tract

The aim of the present work was to examine how different fats commonly used in the feed industry affect broiler performance, nutrient digestibility and microbial fermentation in the gastrointestinal tract of broiler chickens challenged with virulent Clostridium perfringens strains. Two experiments were carried out, each including 480-day-old male broilers (Ross 308), which were randomly distributed to eight experimental groups using six replicate pens per treatment and 10 birds per pen. In Experiment 1, birds were fed diets containing soybean oil, palm kernel fatty acid distillers, rendered pork fat and lard. In Experiment 2, birds were fed diets containing rapeseed oil, coconut oil, beef tallow and palm oil. In both experiments, the birds were either not challenged or challenged with a mixture of three C. perfringens type A strains. Irrespective of the fat type present in the diet, C. perfringens did not affect broiler chicken body weight gain (BWG) and mortality in either of the two experiments. The BWG was affected by dietary fat type in both experiments, indicating that the fatty acid composition of the fat source affects broiler growth performance. In particular, the inclusion of animal fats tended to improve final BW to a greater extent compared with the inclusion of unsaturated vegetable oils. In Experiment 2, irrespective of the dietary fat type present in the diet, C. perfringens challenge significantly impaired feed conversion ratio in the period from 14 to 28 days (1.63 v. 1.69) and at 42 days (1.65 v. 1.68). In both experiments apparent metabolizable energy values were affected by dietary fat type. Irrespective of the fat type present in the diet, C. perfringens challenge decreased the digesta pH in the crop and ileum, but had no effect in cecal contents. Moreover, in Experiment 1, total organic acid concentration in the ileum was two to three times lower on soybean oil diets as compared with other treatments, indicating that C. perfringens as well as dietary fat type significantly affects microbiota activity in the broiler chicken gastrointestinal tract.     

Nutritional value of 15 corn gluten meals for growing pigs: chemical composition,energy content and amino acid digestibility

The objectives of this study were to determine the chemical composition, energy content and amino acid digestibility for corn gluten meals (CGM) and to develop prediction equations for estimating energy content and amino acid digestibility for growing pigs based on the chemical characteristics of these meals. The 15 CGM tested were obtained from seven Chinese companies. Experiment 1 was conducted to determine the digestible (DE) and metabolisable energy (ME) of the 15 CGM. The 18 growing barrows (38 ± 4 kg) were assigned to three 6 × 6 Latin square designs. The 15 CGM test diets were formulated to contain 19.20% CGM, which replaced 20% of the energy supplied by corn and crystalline amino acid in the basal diet. Experiment 2 was conducted to determine the apparent (AID) and standardised (SID) ileal digestibility of the crude protein (CP) and amino acids in the 15 CGM using chromic oxide as an inert marker. The 18 growing barrows (25 ± 2 kg) fitted with a simple T-cannula were assigned to three 6 × 6 Latin square designs. The 15 test diets contained 35% of one of the 15 CGM as the sole source of amino acids in the diet. The results showed a considerable variation in the chemical composition of CGM within and among plants. On dry matter basis, the DE and ME content of the CGM ranged from 18.8 to 21.0 MJ/kg and from 18.0 to 19.9 MJ/kg, respectively. There were no significant differences in the AID and SID for CP, arginine, lysine, glycine and proline among the 15 CGM, however, for all the other amino acids, significant differences were found for their AID and SID. With R ² values exceeding 0.50, the DE of CGM can be predicted accurately from CP and fibre content and ME from starch and fibre content. Suitable prediction equations for SID of methionine were also developed.     

Effects of inclusion with blue lupins (Lupinus angustifolius) in broiler diets and enzyme supplementation on production performance, digestibility and dietary AME content

An experiment with broiler chickens was conducted to study the effect of inclusion of blue lupins and exogenous enzyme to broiler diets on the apparent metabolisable energy (AME), digestibility and performance. Two basal diets were formulated: a non-lupin diet A based on soya bean meal and maize, and a diet B where parts of soya bean meal and maize were substituted with blue lupin (200 g/kg). The two basal diets were fed either alone or, for diet B in combination with different enzyme preparations (Bio-Feed Plus, lactase, two galactanases (Gal-I and Gal-II)). The experiment was performed in battery cages with 648 male broiler chickens, where eight experimental diets were fed to the chickens from 7 to 21 days of age and weight gain and feed intake were measured during the period. At the end of the experiment, three chickens from each pen were slaughtered and the content from jejunum and ileum was separately collected and pooled and used for measurement on intestinal viscosity. For measurements of the apparent metabolisable energy and the apparent digestibility, excreta were collected at 22–24 days of age and ileal contents collected at 25–26 days from the remaining chickens.

Substitution of soya bean meal and maize with blue lupin depressed weight gain (9%) and feed conversion ratio (12%) significantly. Feed intake of the lupin-based diets was not decreased. The protein in lupin was digested to the same extent as the protein from soya bean meal, the coefficient of ileal apparent digestibility being on average 0.75. However, the high content of the non-starch polysaccharides (NSP; 450 g/kg) in lupin depressed the apparent digestibility of the organic matter by approximately 10%. The AME_n of the non-lupin diet was 14.01 MJ/kg dry matter (DM) compared to a value of 13.11 MJ/kg DM in the lupin control diet. Improvements in the measured parameters were seen with some of the enzymes. Gal-I, and Gal-II in combination with lactase were the most efficient enzymes concerning improvement in AME_n and performance. Weight gain was increased by 3.5–5.5% by addition with these enzymes. Gal-I increased the AME_n significantly to 13.65 MJ/kg, a value not significantly different from the AME_n of the non-lupin diet. There was no effect of addition with the different enzymes on the coefficients of apparent digestibility of organic matter measured in the ileum, whereas addition with Gal-I to the lupin diet increased the apparent digestibility of organic matter over the total tract by 3%. The mode of action of the galactanases has been to hydrolyse the galactan in the NSP cell wall of lupins to galactose and dimers of galactose, which are energy-yielding to poultry. From the results obtained, it can be indicated that Gal-I increased the energy utilisation of the lupin-based diet, confirmed by the improved AME_n content and performance.     

Effects of feeding intact,ground and/or pelleted rapeseed on nutrient digestibility and growth performance of broiler chickens

ABSTRACT

In this study, the effect of grinding or pelleting of rapeseed on the digestibility, apparent metabolisable energy (AME_N), growth performance and gizzard weight of broiler chickens was evaluated. In Exp. 1, four treatments were tested (240 broiler chickens, 20 replications, 3 birds per cage). Birds received either a basal diet or were fed with rapeseed of different sized particles (fine, medium and coarse ground, respectively). In Exp. 2, 10 treatments were assessed (360 chickens, 12 replications, 3 birds per cage), where five different diets (a basal diet and four diets with intact rapeseed, fine ground, medium ground or coarse ground rapeseed, respectively) were fed non-pelleted or pelleted. In Exp. 3, two treatments were compared (224 broiler chickens, 14 replications, 8 birds per floor pen): fine ground rapeseed (FG) and intact rapeseed (IS). Compared with medium and coarse ground rapeseed, fine grinding increased in Exp. 1 the AME_N of rapeseed and the precaecal digestibility (PD) of dry matter and ether extract (EE) (p < 0.05). In Exp. 2, the content of AME_N and the PD of EE and crude protein (CP) increased as the degree of grinding increased when diets were not pelleted (p < 0.01). In contrast, the significantly highest values for these parameters were measured after pelleting without effect of grinding, resulting in a significant interaction between pelleting and grinding (p < 0.001). In Exp. 3, performance of chickens was not affected by dietary treatments, but gizzard weight and the PD of CP were higher when IS were included in the diet (p < 0.05). The results suggested that fine grinding may be used to increase the feeding value of full-fat rapeseed for broiler chickens. Nevertheless, pelleting of diets with rapeseed seemed to be much more effective in the reduction of particle size than grinding.     

Effects of pressed beet pulp silage inclusion in maize-based rations on performance of high-yielding dairy cows and parameters of rumen fermentation

Beet pulp contains high amounts of pectins that can reduce the risk of rumen disorders compared to using feedstuffs high in starch. The objective was to study the effects of inclusion of ensiled pressed beet pulp in total mixed rations (TMR) for high-yielding dairy cows. Two TMR containing no or about 20% (on dry matter (DM) basis) beet pulp silage were used. The beet pulp silage mainly replaced maize silage and corn cob silage. The TMR were intentionally equal in the concentrations of energy and utilisable crude protein (CP) at the duodenum. TMR were fed to 39 and 40 dairy cows, respectively, for 118 days. The average daily milk yield was about 43 kg/day. No significant differences in milk yield and milk fat or milk protein content were detected. DM intake of cows was significantly reduced by the inclusion of beet pulp silage (23.0 v. 24.5 kg/day). However, a digestibility study, separately conducted with sheep, showed a significantly higher organic matter digestibility and metabolisable energy concentration for the TMR that contained beet pulp silage. In vitro gas production kinetics indicated that the intensity of fermentation was lower in the TMR that contained beet pulp silage. In vitro production of short-chain fatty acids, studied using a Rusitec, did not differ between the TMR. However, the inclusion of beet pulp silage in the ration caused a significant reduction in the efficiency of microbial CP synthesis in vitro. The amino acid profile of microbial protein remained unchanged. It was concluded that beet pulp silage has specific effects on ruminal fermentation that may depress feed intake of cows but improve digestibility. An inclusion of beet pulp silage of up to 20% of DM in rations for high-yielding dairy cows is possible without significant effects on milk yield and milk protein or milk fat.     

Effect of L-Carnitine Supplementation on Utilisation of Energy and Protein in Broiler Chicken Fed Different Dietary Fat Levels

Effects of a supplementation of 80mg L-carnitine perkg diet were studied in broiler chicken at two dietary levels of fat (4 and 8 %) and different feeding levels (ad libitum in a growth trial, 95 and 85 % of ad libitum in a balance trial). A low-carnitine basal diet adequate in amino acid concentration was used. In the growth trial, each diet was fed to 9 groups of 10 birds each for 16 days from day 5 of live onwards. Growth and feed intake were determined. At the end of the trial, birds were killed and homogenised for subsequent empty body analysis. Accretion of protein and energy was determined using a representative blank group killed at the beginning of the trial. In the balance trial, 8 individual birds were used per treatment. Birds were offered the feed at approximately 85 and 95% of ad libitum intake, which was determined with separate birds for both fat levels. Excreta were quantitatively collected three times daily for 8 consecutive days beginning on day 17 individually for each bird. Supplemented L-carnitine did not significantly affect any response criterion. However, growth and feed conversion tended to be improved by about 5% in the carnitine supplemented diets when fed ad libitum. An interaction between carnitine and fat level occurred with regard to feed conversion, indicating that carnitine had a positive effect at the high fat level, but not at the low fat level. L-carnitine did not positively affect the metabolisability of energy (ME/GE) and the efficiency of energy utilisation (RE/GE or RE/ME). Similarly, no significant carnitine effect was determined with regard to N accretion and the efficiency of utilisation of dietary protein in both trials. It is concluded that endogenous carnitine synthesis is not the limiting factor for energy utilisation in broiler chicken, even at high dietary fat concentration. Occasionally reported positive effects of supplemental carnitine were likewise caused by reasons other than improved energy or protein utilisation. Further studies on amino acid utilisation and catabolism should consider marginal amino acid supply.     

Soybean oil and beef tallow in dry extruded diets for adult dogs

The aim of the study was to determine the effects of two different fat sources (soybean oil (SO) and beef tallow (BT)) in dry extruded dog diets on the intake of food and metabolizable energy (ME), on faecal characteristics and apparent total tract digestibility (ATTD) of nutrients and energy. Ten adult dogs of different breeds were used in a Latin square design. Five experimental diets were designed from a basal diet. A Control diet was coated with 1% SO and four other diets were obtained by coating the basal diet with 6.5% and 13% of SO or BT. The Control, 6.5% and 13% coated diets contained approximately 8.5%, 15% and 20% fat, respectively. The dogs had similar dry matter (DM) intakes and, consequently, higher ME intakes with an increased fat content for both sources (p < 0.05). Fat digestibility was highest for Diet SO13% (p < 0.05). The ATTD of DM and organic matter was highest (p < 0.05) for Diets SO13% and BT13%. Fat coating improved the faecal score, especially for Diet BT13%. The dietary ratios of protein:fat:carbohydrate [% of ME] were close to AAFCO’s estimates. For SO a higher ATTD (99.1%) and ME content (38.88 MJ/kg) was estimated than for BT (ATTD 92.9% and 36.37 MJ ME/kg). Both SO and BT can comprise up to 13% of the diet. However, SO was more susceptible to leaking from the kibbles with the coating method applied.     

Effect of silver nanoparticles on growth performance, metabolism and microbial profile of broiler chickens

This study evaluated the potential of silver nanoparticles (AgNano) as an antimicrobial growth-promoting supplement for broiler chickens. One hundred forty-four seven-day-old broiler chicks were distributed randomly to AgNano treatments at 0, 10 and 20 mg/kg (Control, Group AgNano10, and Group AgNano20, respectively) provided via the drinking water from day 7 to 36 post-hatching. Body weight and feed consumption were measured weekly. In addition, balance and respiration experiments were carried out to determine nitrogen (N) utilisation and energy retention. At days 22 and 36, blood samples and intestinal content were collected to evaluate the effects of AgNano on plasma concentration of immunoglobulins and the intestinal microflora, respectively. The provision of water solutions containing different concentrations of AgNano had no effect on postnatal growth performance and the energy metabolism of broiler chickens. However, in Group AgNano10 N intake (p = 0.05) and retention (p = 0.03) was increased, but N excretion and efficiency of utilisation was not affected. The populations of bacteria in the intestinal samples were not affected by AgNano supplementation. The concentration of immunoglobulin (IgG) in the blood plasma of broilers supplemented with AgNano decreased at day 36 (p = 0.012). The results demonstrated that AgNano affects N utilisation and plasma IgG concentration; however, it does not influence the microbial populations in the digestive tract, the energy metabolism and growth performance of chickens.     

Increasing levels of rapeseed expeller meal in diets for pigs: effects on protein and energy metabolism

The heavy reliance on imported soybean meal (SBM) as a protein source makes it necessary for the European pig industry to search for alternatives and to develop pigs that perform efficiently when fed such ingredients. Digestion and metabolism are major physiological processes contributing to variation in feed efficiency. Therefore, an experiment was conducted to assess the effects of replacing SBM with increasing levels of rapeseed meal (RSM) in diets for young pigs on apparent total tract digestibility (ATTD) of energy and nutrients, nitrogen (N) balance, energy metabolism and carbohydrate, protein and fat oxidation. Four diets were fed to 32 pigs (22.7±4.1 kg initial BW) for three weeks. The diets consisted of a control cereal grain-SBM basal diet and three test diets where SBM and wheat were partially replaced with 10%, 20%, and 30% of expeller RSM. Increasing level of RSM in the diets linearly reduced ATTD of organic matter, CP, total carbohydrates, dietary fiber and energy. Utilization of digested nitrogen (DN) for N retention and total N excretion were not affected by RSM inclusion, however, RSM inclusion induced a shift in N excretion from urine to feces. Despite a linear increase in liver to metabolic BW ratio, heat production and utilization of metabolizable energy (ME) for retention were not affected by increasing RSM inclusion. In conclusion, replacing SBM with up to 30% of expeller RSM in nutritionally balanced diets for young pigs reduced the ATTD of most nutrients and energy, but did not affect N and energy retention in the body or efficiency of utilization of DN or ME for retention.