Significant Differences In Digestibility Research Articles

Glycation of goat milk with different casein-to-whey protein ratios and its effects on simulated infant digestion

This research compared the effects of dry heating on the digestion of goat milk proteins with different casein-to-whey ratios (40% casein, C40 and 80% casein, C80). The glycation markers of heated samples were determined by LC-MS. Heating at 60 °C for 8 h induced early glycation while heating at 60 °C for 72 h induced advanced glycation. Unheated C80 samples showed a higher digestibility than unheated C40 samples, which may be due to their higher protein solubility. After dry heating for 72 h, no significant difference in digestibility was observed between C80 and C40 samples. Heating for 72 h decreased the digestibility of C40 samples compared to unheated samples, probably due to glycation, while protein aggregation was the main reason for the reduced digestibility of heated C80 samples. Overall, this study showed that dry heating for 72 h induced a lower digestibility of C80 and C40 samples, although with different underlying mechanisms.

Caecal digestibility as an approximation of ileal protein digestibility evaluation in rats.

The rat model can be used to assess ileal protein digestibility rapidly and in first intention, but no standardised method exists. Our objective was to compare methods to assess protein digestibility, depending on collection site (ileum/caecum) and use of a non-absorbable marker. A meal containing either casein, gluten or pea protein and chromium oxide as non-absorbable marker was given to male Wistar rats and the entire digestive content was collected 6 h later. Total chromium recovery was incomplete and variable, depending on protein source. We observed no significant difference in digestibility between the methods for any of the protein sources tested. Although none of the methods tested is optimal, our results suggest that caecal digestibility can be used as a proxy of ileal digestibility in rats without using a non-absorbable marker. This simple method makes it possible to evaluate protein digestibility of new alternative protein sources for human consumption.

PSXIII-12 Exploring nutritional differences of canola seeds and bio-processing co-products (meals, pellets) from different processing plants/companies in Canada and China for dairy cattle

Abstract Canola was created as a low erucic acid and low glucosinolate seed, to produce high quality oil for human consumption and meal for use in livestock feed. China is an important user of Canadian canola products (seeds, oil, and meal). The extraction of the oil from the seed produces a co-product called canola meal. This meal is rich in protein and is used as a protein source in animal diets. However, differences in the characteristics of the seeds, or processing methods during oil extraction may affect the quality of this co-product. Plus, the synthesis of tissues and milk is related to the amino acids available to the animal for absorption in the small intestine. This study aimed to determine if there are significant differences in the intestinal digestibility (in vitro) of CP and DM between canola seeds and meals from different companies in Canada and to determine if there are significant differences between them in Canada and China. The three-step procedure was applied on residues from a 12-hour rumen incubation in fistulated dairy cows to estimate the intestinal digestibility of CP and DM. There were significant differences (P < 0.05) for TDDM (Total digestible dry matter) and IDP (intestinal digestibility of protein) of the meals between countries. The samples from China had higher TDDM (83.76% versus 81.53%, P = 0.018), while Canada’s had higher IDP (68.51% versus 65.28%, P = 0.016). No significant differences were observed within countries. Based on the material analyzed during this study, it is safe to affirm that there are no significant differences in the digestibility of DM and CP between Canada and China. It was concluded that the quality of the canola seeds or meals produced in both Canada and China were similar when used in dairy rations. Key words: canola seeds and bio-processing co-products (meals, pellets), nutritional differences, dairy cows

In vitro digestibility of Paspalum notatum in ruminal fluid of buffaloes and bovines

<p>El objetivo de la investigación fue evaluar los coeficientes de digestibilidad in vitro de la materia seca (DIVMS) y digestibilidad in vitro de la materia orgánica (DIVMO) del pasto Paspalum notatum maduro en búfalos (Bubalus bubalis) y cebúes (Bos indicus). Para la digestibilidad in vitro se utilizó líquido ruminal de un animal de cada especie, los cuales tuvieron previamente un período de adaptación a la dieta. La digestibilidad in vitro se evaluó por el método Tilley y Terry (1963). Diferencias significativas en la digestibilidad fueron encontradas para ambas especies: DIVMS: 20,31% vs 17,91%, error estándar de la media (EE): 0,6448 y DIVMO: 20,30% vs 15,68%, EE: 1,7429 para búfalos y cebúes respectivamente.</p>

Effect of Phlorotannins from Brown Seaweeds on the In Vitro Digestibility of Pig Feed.

Simple SummaryIn large-scale pig farming, alternative and safe antimicrobials are needed to enhance pig nutrition. Seaweed bioactives, and in particular phlorotannins, have been reported to have antimicrobial properties. However, their effect on the digestibility of pig feed is not well understood. This study investigates the effect of these phenolics on the in vitro dry matter digestibility of seaweed using an in vitro pig digestibility model. The effect of the phenolics when extracted into their purified phlorotannin form, and blended directly into pig feed, was also tested using the same model. The results found that, when added to the pig feed, purified phlorotannins had a more pronounced effect on digestibility than seaweeds containing phenolics. In addition, the results showed that given the seasonal variation within seaweeds, inclusion of whole seaweeds should be based on phenolic concentration as opposed to percentage inclusion of seaweeds.Phlorotannins have been reported to have positive effects on pig health, including improved gut health and digestibility. In this study, we investigate the effect of phenolics found in two brown seaweeds, Ascophyllum nodosum and Fucus serratus, on in vitro dry matter digestibility of seaweeds and commercial pig feed. Phlorotannin extracts and whole seaweeds were supplemented into pig feed to test their effect on digestibility. Solid-phase extraction was used to purify the phenolics to phlorotannins. The results showed a slight decrease in the digestibility of pig feed that was found to be significant when phlorotannin extracts were added from either seaweed. However, when whole A. nodosum was added to the pig feed, the effect on digestibility was less pronounced. Specifically, no significant difference in digestibility was observed at inclusion rates up to 5%, and thereafter results varied. A difference in digestibility was also observed in the same species at the same inclusion rate, collected from different seasons. This suggests that other compounds, e.g., polysaccharides, are having an effect on digestibility when whole seaweeds are supplemented to animal feed. This research has also highlighted the need to base supplementation on phenolic concentration as opposed to a standardised percentage inclusion of seaweeds to ensure that digestibility is not adversely affected.

The effect of Syphacia muris on nutrient digestibility in laboratory rats.

This study was carried out to investigate how pinworm infection in rats affects nutrient digestibility in the hosts. Twenty-four male outbred Wistar rats were randomly divided into two groups of 12 rats each. The rats from the first group (GI) were kept in cages with bedding containing pinworm eggs, and the second (control) group (GII) were kept in a separate room in clean, uncontaminated filter-top cages. The animals were put into individual metabolic cages later. Metabolic trials lasted five days and records of animal weight, food ingestion, and faecal weight were taken daily. Based on laboratory analysis of the feed and faecal nutrient content, digestibility values were determined. On day 15 of the experiment, the animals were euthanized. Although Syphacia muris were found in all rats from the GI group, animals exhibited no clinical signs. In our experiment, S. muris infection reduced the overall digestibility of all measured nutrients (P < 0.01). The most significant differences in digestibility were observed in the case of crude fibre and mineral matter (P < 0.01).

Use of re-esterified palm oils, differing in their acylglycerol structure, in weaning-piglet diets

Re-esterified oils are new fat sources obtained from chemical esterification of acid oils with glycerol (both economically interesting by-products from oil refining and biodiesel industries, respectively). The different fatty acid (FA) positional distribution and acylglycerol composition of re-esterified oils may enhance the apparent absorption of saturated fatty acids (SFA) and, thus, their overall nutritive value. The aim of the present study was to investigate the potential use of re-esterified palm oils, in comparison with their corresponding acid and native oils, and also with an unsaturated fat source in weaning-piglet diets. The parameters assessed were: FA apparent absorption, acylglycerol and free fatty acid (FFA) composition of feces, and growth performance. One-hundred and twenty weaning piglets (average weight of 8.50±1.778 kg) were blocked by initial BW (six blocks) and randomly assigned to five dietary treatments, resulting in four piglets per pen and six replicates per treatment. Dietary treatments were a basal diet supplemented with 10% (as-fed basis) of native soybean oil (SN), native palm oil (PN), acid palm oil (PA), re-esterified palm oil low in mono- (MAG) and diacylglycerols (DAG) (PEL), or re-esterified palm oil high in MAG and DAG (PEH). Results from the digestibility balance showed that SN reached the greatest total FA apparent absorption, and statistically different from PN, PA and PEL (P<0.05). There were no statistical differences among palm-oil sources (P>0.05), but PEH achieved the greatest total FA apparent absorption. Animals fed PEL, despite the fact that PEL oil contained more sn-2 SFA, did not show an improved absorption of SFA (P>0.05). Animals fed PA and PN showed similar apparent absorption coefficients (P>0.05), despite the high FFA content of PA oil. The acylglycerol and FFA composition of feces was mainly composed of FFA. There were no significant differences in growth performance (P>0.05). Results of the present study suggest that, despite the different acylglycerol structure of re-esterified oils, there were no significant differences in digestibility or performance with respect to their corresponding PN and PA oils in weaning-piglet diets.

Effect of addition of high fiber ingredients on protein quality of casein and gluten diets assessed by bioassays in growing rats (540.8)

The food industry has responded to consumer demand for foods with higher fiber content, developing products with high‐fiber ingredients. These ingredients have unique properties that raise the level of fiber. Excessive consumption of high‐fiber products can have an impact on the digestibility and protein quality. The aim of this study was to evaluate the effect of three commercial products used to increase fiber content of food on the protein quality of diets based on casein and gluten bioassays, employing Sprague Dawley rat as an experimental model. Six synthetic diets were prepared, three of casein, and three of gluten with three different ingredients high in fiber: insoluble fiber from wheat bran, soluble fiber with resistant maltodextrins and fiber obtained from orange pulp formed by similar amounts of fiber soluble and insoluble. Biological indicators were determined, Net Protein Ratio (NPR) and % Apparent and true digestibility of nitrogen (ADN, VDN). Results were analyzed by a statistical program with 95% significance. ADN and VDN of casein diets with high fiber ingredients ranged from 83.7 to 86.2% and from 86.6 to 89.1% respectively. In gluten diets with different fiber ADN and VDN ranged from 88.0 to 90.5% and from 91.1 to 94.8% respectively and NPR results ranged from 1.44 to 1.77. The results showed that commercial fibers showed significant differences in digestibility and RNP gluten diets.

EGG YOLK CHOLESTEROL AND PRODUCTIVE PERFORMANCE OF LAYING HENS INFLUENCED BY DIETARY CRUDE FIBER LEVELS UNDER DRINKING NATURAL SALINE WATER

This study was conducted to investigate the influenced of four levels of dietary crude fibers (CF) on egg yolk cholesterol, productive and physiological performance of laying hens under drinking natural saline water (2000 ppm total dissolved solids). A total number of 120 White Leghorn layers from 44 to 56 weeks of age randomly divided into four equal groups (30 hens of each). Four levels of CF (3, 4, 5 and 6 %) as substitution of alfalfa meal. The treatments were tested for 12 weeks. The results showed that under condition of drinking natural saline water (2000 ppm total dissolved solids), feeding laying hens control diet which contained 3 % crude fiber had (P<0.05) highest egg number, egg mass and feed consumption (g/day) (17.97, 30.99 g and 67.80 g, respectively) compared with other three groups which recorded no significant differences among each other's.Hens fed the highest-fiber diet (6 %) laid eggs with greatest shell, albumin and yolk weights % (4.53, 58.00 and 36.19, respectively) compared with other experimental groups. Feeding hens diet contained higher crude fiber level above 3 % had higher (P<0.05) values of albumen height (mm) and shape index values with no significant differences in yolk index (%) and Haugh units. There were a gradual (P<0.05) decrease in digestion coefficients of DM, OM, CP, ash, CF, NFE and EE with increasing crude fiber levels in hens diets; while, there were no significant differences in digestibility of fiber fractions (NDF, ADF and hemicelluloses). Water intake (ml/ bird/day) and water/feed intake increased (P<0.05) with increasing crude fiber levels. So, hens fed 6 % CF consume more water being 236.00 ml/bird/day and 3.45 ml/g feed intake. Inclusion of graded levels of CF in laying hen diets tended to decrease (P<0.05) concentrations of total lipids, triglycerides, phospholipids, cholesterol, total cholesterol, and low-density lipoproteins (LDL) in egg yolk. Hens fed diet contained 6 % CF decreased the egg yolk concentrations of the same respective parameters by 25.10, 22.22, 26.61, 22.38, 19.51 and 23.33 %, respectively compared to the control group. There were a significant decrease in serum total lipids (g/dl), cholesterols (mg/dl), triglyceride (mg/dl) and HDL values with increasing CF levels; however, AST and ALT activity was within a normal physiological range. Gizzard (%), edible giblets (%), digestive tract weight and digestive tract length had significantly increased with increasing dietary CF level; while, there were non-significant increases in carcass, liver and heart (%). The best value for economic efficiency and relative economic efficiency (117 %) had been recorded by hens fed diet contained 6 % CF as compared with the control (3 % CF). It was concluded that, we can used crude fiber by up to 6 % in laying hens diets (44 to 56 weeks of age) reared under drinking natural saline to achieve acceptable productive and physiological performance and reduce the egg yolk cholesterol.

Use of spray‐dried porcine blood by‐products in diets for young chickens

Spray-dried porcine blood plasma (SDBP) or blood cells (SDBC) at amounts of 20 or 40 g/kg were included to the feed mixtures that were given to young chickens within 1-28 (Exp. 1) or 1-30 (Exp. 2) days post-hatch. In comparison with the group fed mixtures containing plant components, chickens fed mixtures supplemented with 40 g/kg of SDBP significantly (p < 0.01) increased the body weight estimated on 14 day of life (Exp. 1). At the age of 28 or 30 days post-hatch, the body weight was improved significantly (p < 0.01 or 0.05) in both experiments. Significant differences (one-factorial anova) in feed conversion among particular feeding groups were stated in Exp. 1 only; however, calculations using two-factorial anova show insignificant differences depending on the used animal meal. In selected blood parameters (IgG, Ht, Hb), insignificant differences between feeding groups were stated. The use of SDBP in feed mixture significantly increased the Na retention in both experiments, and K accretion in Exp. 1 only. Application of SDBC and 40 g/kg of SDBP significantly or insignificantly improved Fe retention. Insignificant diversification of apparent ileal digestibility of nutrients was stated; the crude fat was significantly better digested in treatments fed mixtures with animal meals but kind of animal meal was without any significant effect. Significant differences in digestibility of amino acids were recorded for Pro, Cys, Val, His, Lys and Arg. In chickens fed mixture with SDBC, higher coefficients of apparent digestibility of Cys, Val and His (Exp. 1) and Cys and His (Exp. 2) than in other feeding groups were obtained. The kind of used blood by-products has not affected the histological structure of intestine wall.

Limits to sustained energy intake. XI. A test of the heat dissipation limitation hypothesis in lactating Brandt's voles (Lasiopodomys brandtii)

The maximum rate of sustained energy intake (SusEI) may limit reproductive effort, thermoregulatory capability and other aspects of an animal's energy expenditure. Consequently, factors that limit SusEI are of interest. The ;heat dissipation limitation hypothesis' suggests that maximum SusEI during lactation is limited by the capacity to dissipate body heat generated as a by-product of processing food and producing milk. In the present study, we tested the heat dissipation limitation hypothesis in lactating Brandt's voles (Lasiopodomys brandtii). Female voles were mated and pregnant at 21(+/-1) degrees C. A random sample of animals was transferred into a hot room 30(+/-1) degrees C on the day of parturition. The energy intake of lactating voles at 30 degrees C was always lower than that at 21 degrees C. At peak lactation food intake was 3.3 g day(-1) lower at 30 degrees C than at 21 degrees C. There was no significant difference in digestibility. With similar mean litter sizes (7.26+/-0.46 pups at 21 degrees C and 7.78+/-0.39 pups at 30 degrees C at the beginning of parturition, 6.83+/-0.51 pups at 21 degrees C and 7.73+/-0.50 pups at 30 degrees C at weaning), the milk energy output of mothers, evaluated from the difference between metabolizable energy intake and daily energy expenditure measured by doubly labelled water, at 30 degrees C was 23.3 kJ day(-1) lower than that at 21 degrees C on days 14-16 of lactation. As for reproductive performance, there was a difference in the response to the higher temperature between mothers raising large and those raising small litters. For small litters (<7) there was no significant change in litter mass, but for large litters (<or=7) there was a significant decrease at the higher temperature. On average, in larger litters the pups were 15.5 g heavier on day 12 of lactation when raised at 21 degrees C. Our data from Brandt's voles support the suggestion that SusEI at peak lactation is limited by heat dissipation capacity, particularly for those voles raising large litters. In smaller litters the peripheral limitation hypothesis may be more relevant. The importance of heat dissipation limits in species raising exclusively small litters needs to be investigated.

Effects of Dietary Fat Levels on Nutrient Digestibility at Different Sites of Chicken Intestines

The present study was conducted to investigate the effects of varying dietary fat levels (3%-10%) on the digestibilities of crude protein, crude fat (CF), nitrogen-free extract and ash at different sites of fistulized chicken intestines. Chickens were fistulized to either the middle part of the jejunum (MJ), the distal end of the jejunum (DJ), the middle part of the ileum, the distal end of the ileum or the distal end of the rectum. Intestinal digesta were collected from each site of intestine, and contents of crude protein, crude fat, nitrogen-free extract and ash were measured. The true digestibility of crude protein in intestinal digesta at MJ in the 10% CF group was significantly lower than that in other groups. The digestibility of crude fat in intestinal digesta at MJ in the 10% CF group was also significantly lower than that in other groups. The digestibility of nitrogen-free extract at MJ and DJ in the 10% CF group was significantly lower than that in other groups. There were no significant differences in digestibility of ash among groups. These results clearly demonstrate that dietary fat levels influence the digestibility of protein, fat, and carbohydrate at MJ in chicken.

Growth, Nutrient Utilization and Amino Acid Digestibility of Dairy Calves Fed Milk Replacers Containing Different Amounts of Protein in the Preruminant Period

This study was designed to examine the effects of different dietary protein levels on growth performance, nutrient utilization, amino acid (AA) digestibility and serum biochemical parameters of preruminant dairy calves. Fifteen healthy new-born calves were randomly allotted to three experimental groups and fed with different milk replacer that contained 18% (LP), 22% (MP) or 26% (HP) of protein. The results showed that final BW, net gain and ADG were significantly higher in the MP group than in LP and HP groups (p 0.05). BUN concentration, on the other hand, decreased as calves grew but increased following the increase of dietary CP content. Furthermore, no significant differences in digestibility of amino acids were observed among these three groups of animals (p>0.05). We concluded that calves fed with milk replacer containing 22% of protein had better growth performance and nutrient utilization as compared to animals treated with milk replacer containing either 18% or 26% of protein.

Nutritional assessment of genetically modified rapeseed synthesizing high amounts of mid-chain fatty acids including production responses of growing-finishing pigs

The nutritive value of genetically modified myristic acid-rich rapeseed, in which a acyl-thioesterase gene inserted, was studied. Crude nutrients, amino acid and fatty acid profiles as well as mineral and glucosinolate contents were determined and compared with those of the non-transgenic parental cultivar. The concentration of crude nutrients, minerals and amino acids were found to be within the range of natural variance. The myristic and palmitic acid content increased from 0.1 – 11.4% and from 3.6 – 20%, respectively, at the expense of oleic acid, which decreased from 68.6 – 42.6% of total fatty acids. The glucosinolate contents increased from 12.4 µmol/g in the parental plant to 19 µmol/g DM in the GM-plant. Full-fat rapeseed of both cultivars was incorporated in pig diets at a level of 15%, and the digestibility and the production efficiency were tested under ad libitum feeding conditions with ten pigs each over the growing finishing period from 32 – 105 kg BW. The experimental diets did not show significant differences in digestibility and energetic feeding value. However, feed intake and weight gain decreased presumably due to the increasing glucosinolate intake associated with the feeding of transgenic rapeseed. The dietary fatty acids profile influenced the fatty acid profile of body fat. Myristic acid accumulated in back fat and intramuscular fat while the oleic acid content decreased. The increased glucosinolate intake affected the weight of thyroid glands and their iodine concentration.

이유자돈에 있어 대두유, 우지 및 코코넛 오일의 첨가가 생산성, 혈청 지질변화 및 영양소 소화율에 미치는 영향

ABSTRACT This experiment was conducted to determine the effect of soybean oil, tallow and coconut oil supplementation on growth performance, serum lipid changes and nutrient digestibility in weaned pigs. One hundred twenty cross-bred [(Yorkshire × Landrace) × Duroc, 6.92 ± 0.01 kg average initial BW] were used in a 35 d growth trial. Dietary treatments included CON (5% soybean oil), T0.5 (4.5% soybean oil + 0.5% tallow), C0.5 (4.5% soybean oil + 0.5% coconut oil) and C1.0 (4.0% soybean oil + 1.0% coconut oil). For the whole period and from d 14 to 35, G/F was increased in C0.5 and C1.0 treatments compared with T0.5 treatment (P<0.05). ADG and ADFI were not affected by treatments. On d 14, C1.0 treatment was higher in serum HDL-cholesterol than C0.5 treatment and atherogenic index was increased in C0.5 treatment compared to T0.5 and C1.0 treatments. Digestibility of fat was improved for pigs fed C1.0 diet compared with those fed T0.5 diet on d 35. However, there were no significant differences in digestibilities of DM, N and DE. In conclusion, feeding diets containing soybean and coconut oils in weaned pigs increased feed efficiency and fat digestibility than feeding those containing soybean oil and tallow.(

이유자돈에 있어 대두유, 건조팜유분말과 Monoglyceride의 첨가가 성장 및 혈청 지질변화에 미치는 영향

본 실험은 이유자돈에 있어 대두유, 건조팜유분말과 monoglyceride의 첨가가 성장 및 혈청 내 콜레스테롤 변화에 미치는 영향을 조사하기 위하여 실시하였다. 3원 교잡종[(Y×L)×D] 자돈 125두(개시시 체중 6.00±0.79kg)를 공시하여 21일간 사양시험을 실시하였다. 시험설계는 기초사료 내 일반대두유 5%를 함유한 처리구(SOY), 건조팜유분말 5.5%를 함유한 처리구(PALM), 일반대두유 2.5%와 0%, 12.5%, 25%의 monoglyceride를 각각 첨가한 건조팜유분말 2.7%를 함유한 처리구(SOPM0, SOPM12.5, SOPM25)의 5개 처리를 두었다. 0－21일간의 총 사양시험기간동안, 일당사료섭취량은 monoglyceride를 함유한 SOPM 구와 PALM 구가 SOY 구, monoglyceride를 함유하지 않은 SOPM 구와 비교하여 증가하였다(P<0.05). 일당증체량 및 사료효율에 있어서는 처리구간 차이를 보이지 않았다. 지방소화율에 있어서는 SOY 구가 가장 높았으며(P<0.05), monoglyceride를 함유한 SOPM 구는 PALM 구와 비교하여 유의적으로 소화율이 증가하였다(P<0.05). SOPM12.5 구와 SOPM25 구는 SOY 구와 비교하여 통계적인 차이를 보이지 않았다(P>0.05). 그러나, DM, N 및 DE의 소화율에 있어서는 처리구간 차이를 보이지 않았다(P>0.05). 등지방 두께는 처리구간 유의적인 차이를 나타내지 않았다(P>0.05). 혈청 내 콜레스테롤 농도에 있어서는 SOY 구는 다른 처리구와 비교하여 혈청 내 total cholesterol, HDL- cholesterol과 total lipid 함량에 있어서는 유의적으로 감소하였으며(P<0.05), free fatty acid 함량에 있어서는 증가하였다(P<0.05). 또한, triglyceride 함량에 있어서는 PALM 구가 SOPM 구와 비교하여 증가하였다(P=0.06). 결론적으로, 이유자돈에 있어 대두유의 급여는 건조팜유분말의 단일 급여보다 높은 지방 소화율을 나타내었으며, 혈청 콜레스테롤 및 triglyceride 함량에 있어서도 감소하는 것으로 나타났다. 또한, monoglyceride가 함유된 건조팜유분말은 건조팜유분말만을 급여한 처리구와 비교하여 이유자돈의 지방 소화율을 개선하는 효과를 가지는 것으로 사료된다.(색인: 건조팜유분말, 모노글리세라이드, 성장율, 혈청 지질, 이유자돈) This experiment was conducted to determine the Effect of soybean oil, dried palm oil powder and monoglyceride supplementation on growth performance and serum lipid changes in weaned pigs. One hundred twenty five cross-bred pigs((Y×L)×D, 6.00±0.79kg average initial BW) were used in a 21 d growth trial. Dietary treatments included SOY(containing 5% soybean oil), PALM(containing 5.5% dried palm oil powder) and SOPM0, 12.5 and 25(containing 2.5% soybean oil and 2.7% dried palm oil powder containing 0%, 12.5% and 25.0% monoglyceride, respectively). For the whole period, ADFI was increased in dried palm oil powder containing monoglyceride and PALM treatments compared with SOY and SOPM0 treatment(P<0.05). ADG and G/F were not affected by treatments. Digestibility of fat was higher(P<0.05) for pigs fed SOY diet than fed other diets. SOPM diets containing monoglyceride showed increased fat digestibility compared with PALM diet(P<0.05). SOPM12.5 and SOPM25 treatments were no difference with SOY treatment. However, there were no significant differences in digestibilities of DM, N and DE(P>0.05). Backfat thicknesses were not significantly different among treatments. Pigs fed SOY diet was decreased in serum total cholesterol, HDL-cholesterol, total lipid and was increased in free fatty acid than those fed other diet. Also, triglyceride concentration in serum was increased in PALM treatment compared with SOPM treatment(P=0.06). In conclusion, feeding soybean oil in weaned pigs showed higher fat digestibility and lower cholesterol and triglyceride concentration in serum than feeding only dried palm oil powder. Also, pigs fed monoglyceride were improved fat digestibility compared with those fed dried palm oil powder only.

Partial compensatory growth in hybrid tilapia Oreochromis mossambicus x O. niloticus following food deprivation

The capacity of hybrid tilapia Oreochromis mossambicus x O. niloticus [23.2 +/- 0.2 g (mean +/- SE)] to show compensatory growth was assessed in an 8-week experiment. Fish were deprived of feed for 1, 2 and 4 weeks, and then fed to satiation for 4 weeks; fish fed to satiation during the experiment served as control. Water temperature gradually declined from 28.1 to 25.5 degrees C throughout the experiment. Specific growth rate (SGR) decreased with progressive food deprivation. At the end of deprivation, body weight was lower in the deprived fish than in the control. Fish deprived for 4 weeks exhibited lower contents of lipids and energy in whole body, and higher moisture content and ratio of protein to energy (P/E) than those of the control; they also consumed feed faster than the control when normal feeding was resumed. All deprived fish showed higher food intake (FI) than that of the control during re-alimentation; however, enhanced SGR was only observed in the fish deprived for 4 weeks. There were no significant differences in digestibility of protein and energy, food efficiency (FE) or energy retention efficiency between the control and deprived fish. At the end of re-alimentation, deprived fish failed to catch up in body weight with the control, while content of moisture, lipids and energy, and P/E in whole body of the deprived fish did not significantly differ from that of the control. The results of the experiment revealed that the hybrid tilapia reared in freshwater showed partial capacity for compensatory growth following food deprivation of 4 weeks, and that growth compensation was due mainly to increased FI, rather than to improved FE.

Apparent digestibility coefficients of feed ingredients and their prediction in diets for tilapia Oreochromis niloticus x Oreochromis aureus (Teleostei, Cichlidae)

Apparent digestibility of crude protein (CP), lipid, carbohydrate, energy and fatty acids was measured in various feed ingredients fed to hybrid tilapia (Oreochromis niloticus×Oreochromis aureus) including fish and poultry meals, corn gluten, soybean meal, rapeseed meal, sunflower seed meal, wheat, corn, sorghum, barley and wheat bran. Chromic oxide was used as a non-absorbed marker. A diet compounded from a mixture of these ingredients was then used to examine the possibility of predicting the digestibility of formulated diets. In addition, the effect of pelleting or extrusion on digestibility of a compound diet was examined. Apparent digestibility of CP ranged from 75% to 97%, lipids from 72% to 90% and energy from 39% to 89% in the different ingredients. Apparent digestibility of carbohydrates was lower and ranged from 32% to 80%. Digestibility of fatty acids ranged from 75% to 90% with saturated fatty acids exhibiting digestibilities lower than unsaturated fatty acids. In a full-fat soy diet containing 19% fat, digestibility of lipids did not decrease. There were no significant differences in digestibility between a diet that was either pelleted or extruded. Tests conducted using a compound diet indicated that ingredient digestibility was additive for protein, lipids carbohydrates and energy. Diets for the hybrid tilapia may thus be formulated on the basis of digestibility of individual ingredients, for the nutrients examined in this study.

Effects of astaxanthin-rich algal meal ( Haematococcus pluvalis) on growth performance, caecal campylobacter and clostridial counts and tissue astaxanthin concentration of broiler chickens

The effects of a dietary astaxanthin from the microalgae Haematococcus pluvalis on broiler performance during an experimental infection with Campylobacter jejuni were studied. The experiment included 960 female broiler chickens, divided into 48 floor pens with free access to food and water. Half the number of birds were inoculated at 10 days of age with C. jejuni. The experimental diets were supplied with either 0, 7, 36, or 179 mg astaxanthin/kg feed (0, 350, 1 800 and 8 950 mg algae meal/kg feed, respectively), giving an intake of approximately 0, 1, 5 or 25 mg astaxanthin per bird and per day at 5 weeks of age. In addition, two different application methods of the astaxanthin were studied. The first method mixed the algal meal into the mash prior to pelleting. The second method mixed the meal with oil and was then sprayed on top of the pellets. Generally, there were no differences in bird live weight, feed intake or feed conversion ratio between different inclusion levels of astaxanthin or application methods. The results indicated that algal meal could reduce caecal colonization of Clostridium perfringens, whereas caecal colonization of C. jejuni was unaffected. Tissue astaxanthin and carotenoid concentrations increased with increasing levels of algal meal inclusion. The algal meal mixed with oil and sprayed onto the pellet resulted in higher tissue concentrations than the algal meal added prior to pelleting. Inoculation with C. jejuni significantly increased tissue astaxanthin concentrations in the kidney, intestine and breast muscle compared to non-inoculated birds. Coefficient of total tract apparent digestibility of astaxanthin was calculated to 0.882±0.048 for the upper intestine (between the end of the duodenal loop and Meckel’s diverticulum), 0.925±0.032 for the lower intestine (between Meckel’s diverticulum and the ileo-caecal junction), and 0.938±0.018 for the total tract. There were no significant differences in digestibility between application methods of the algal meal.

The effect of dietary protein content and hay intake level on the true and apparent digestibility of hay

The digestibility of concentrate feeds has been determined by difference using hay as a basal forage in many institutions. The objective of this experiment was to examine the effect of hay intake level and dietary crude protein (CP) content on hay digestibility. Groups of wether lambs (1 year old) were fed three levels (600, 700 and 800 g/day) of hay each at two CP contents (103 and 182 g CP/kg DM), achieved by using a urea solution. An extra group of lambs were fed hay unsupplemented with urea (42 g CP/kg DM) at a level of 800 g/day. The true organic matter digestibility (True OMD, calculated using two methods: True OMD 1 and 2) and apparent OMD of all treatments fed the 182 g CP/kg DM diets were significantly higher ( P<0.05) than treatments fed the 103 g CP/kg DM diet (OMD: 632.8 g/kg vs. 604.2 g/kg; True OMD 1: 720.6 vs. 694.1 g/kg; True OMD 2: 711.8 vs. 681.0 g/kg). Apparent and true digestibility also increased as hay allowance increased and a significant linear effect was observed for GED. For the three groups fed 800 g/day of hay, significant differences in digestibility due to CP content only occurred between the 182 and the 42 g CP/kg DM diets (with the exception of CP digestibility). Although the effect of CP content was significant in some cases, the magnitude of the observed digestibility response is of little consequence for concentrate feed evaluation.