Digestibility Coefficients Research Articles

An Accurate Estimate of the Amino Acid Content of Human Milk Collected from Chinese Women Adjusted for Differences in Amino Acid Digestibility

BackgroundThe amino acid (AA) composition of human milk is used to define the AA requirements of the infant. Thus, it is important that estimates of composition be as complete and accurate as possible. When determining AA composition using standard hydrolysis methods, some AAs are progressively destroyed while others are incompletely released. For accuracy, AA composition needs to be determined using multiple hydrolysis times. The true ileal digestibility of AAs also needs to be taken into consideration. ObjectiveThe objective was to bring together AA compositional (determined using multiple hydrolysis intervals) and digestibility data determined using the piglet to give an estimate of the absorbed AA profile of human milk with reference in particular to Asian females. MethodsMature milk was collected from Chinese females. AA analysis using multiple hydrolysis intervals and a nonlinear regression model was used to accurately estimate AA composition. Human milk, as well as a protein-free diet, were fed to piglets (n = 6), and ileal digesta were collected (piglet age, 21 d) to determine the true ileal AA digestibility of AAs in human milk. ResultsTrue ileal AA digestibility coefficients ranged from (mean ± standard error of the mean) 0.61 ± 0.081 for tyrosine to 1.01 ± 0.030 for tryptophan, with a digestibility for total nitrogen of 0.90 ± 0.013. Convergence criteria were met for the modeling for each AA, and the model had a level of significance of P < 0.0001 for each AA. The amount of available AAs (total AA content as per the model prediction multiplied by the true ileal AA digestibility coefficient determined in the piglet) are reported. ConclusionsAn estimate of the absorbed AA profile of mature milk collected from Chinese females is provided. For the first time, data is presented for cysteine.

Spirulina in diets of Japanese quail: Productive performance, digestibility, and egg quality

The present study evaluated the effects of dietary inclusion of spirulina on productive performance, nutrient utilization, and egg quality of Japanese quails. One hundred twenty quails were included in a completely randomized design with four treatments and five replicates. Treatments consisted of a control diet and three diets containing 0.3, 0.6, or 0.9% of spirulina powder. Spirulina inclusion had no effect (p &gt; 0.05) on the productive performance, digestibility coefficients of dry matter and ether extract, calcium and phosphorus retention, weight and pH of the eggs, yolk index, albumen quality, and eggshell thickness when compared with the control diet. However, crude protein consumption was higher (p &lt; 0.05) and the digestibility coefficient of crude protein was lower (p &lt; 0.05) in birds in the 0.9% and 0.3% spirulina inclusion groups, respectively. The weights of the yolk and eggshell were improved (p &lt; 0.007) by the inclusion of 0.6% and 0.9% and 0.9% spirulina, respectively. Quails fed diets containing 0.3% and 0.6% spirulina exhibited lower specific gravity of eggs (p &lt; 0.019) than those fed diets containing 0.9% spirulina. Therefore, spirulina inclusion at 0.9% improved the eggshell quality and reduced the total lipid levels in the yolks.

Effect of age on the standardized ileal amino acid digestibility of soybean meal and canola meal in broilers

Standardized ileal digestibility coefficients (SIDC) of nitrogen (N) and amino acids (AA) in two protein sources (soybean meal [SBM] and canola meal [CM]) were investigated at six broiler ages (d 7, 14, 21, 28, 35, and 42). Two assay diets were formulated to contain either SBM (413 g/kg) or CM (553 g/kg) as the sole dietary AA source. Titanium dioxide (5 g/kg) was added as an indigestible marker. A total of 696 male broilers at 1 d old were allotted to 12 replicate cages per age group. Each assay diet was offered to birds for 4 d prior to the ileal digesta collection on d 7 (14 birds/cage), 14 (12 birds/cage), 21 (10 birds/cage), 28 (8 birds/cage), 35 (8 birds/cage) and 42 (6 birds/cage), respectively. The apparent digestibility coefficients were standardized using age-specific basal endogenous AA flows. In the SBM group, though the SIDC of N tended to be influenced (quadratic; P = 0.075) by age, no linear or quadratic response of age effect was observed on the average SIDC of indispensable (IAA) and total AA (TAA). An age effect (quadratic; P < 0.05) was observed on the average SIDC of dispensable AA (DAA) in SBM with the highest value recorded at d 7, followed by a decrease from d 14 to 28, which increased beyond d 35. The SIDC of some individual AA (Arg, Thr, Trp, Cys, Pro) were affected (P < 0.05 or P < 0.001) in a quadratic manner by age. In the CM, the SIDC of N, average SIDC of IAA, DAA and TAA were influenced (quadratic; P < 0.05 or P < 0.001) by age. The SIDC of N and average SIDC of DAA and TAA were higher from d 7 to 14, declined at d 21, and then increased beyond d 28. The average SIDC of IAA was low between d 7 and 28 and increased thereafter. The SIDC of individual AA were affected (linear or quadratic; P < 0.05 or P < 0.001) by different magnitudes by age. The age influence on the SIDC AA was variable, depending on the protein source and AA. The results demonstrate that age-specific SIDC AA data might need consideration in broiler feed formulations.

Effect of different energy, protein levels and their interaction on productive performance, egg quality, digestibility coefficient of laying Japanese quails

For the evaluation of the effects of various quantities of crude protein (CP) and metabolizable energy (ME) (kcal/kg diet) in Japanese quail lay chicken meals on performance, digestion coefficients, and nutritional value. An experiment was undertaken in the summer season; 216 eight-wk-old Japanese quail laying hens were allocated at random to 1 of 9 groups in a factorial design (3×3) experiment involving 3 levels of CP (18, 20, and 22%) plus 3 levels of ME (2,800, 2,900, or 3,000 kcal/kg ME diet). The testing period lasted from 8 to 20 wk. The findings demonstrated that the relationship between protein and energy levels significantly impacted all productive outcomes except the feed conversion ratio (P < 0.01). Throughout the overall period 8 to 20 wk of age, the greatest measurements of egg weight (11.9 g) and egg mass (8.33 g) occurred in hens fed 20% CP with 2,900 kcal/kg diet, yet the lowest values of egg weight (11.2 g) and egg mass (6.72 g) were noticed in hens fed 22% CP with 2,900 kcal/kg diet. The data showed that the combination of dietary energy and protein levels had a substantial (P < 0.05 and P < 0.01) effect on all egg quality trials evaluated. The results indicated that the interaction between dietary energy and protein concentrations substantially impacted DM and EE digestion ratios (P < 0.01). Finally, when feeding layer Japanese quail between the ages of 8 and 20 wk during the summer, a dietary energy content of 2,900 kcal ME/kg with 20% CP is recommended.

Impact of β-glucan dietary supplementation on productive, reproductive performance and physiological response of laying hens under heat stress conditions

The exploration for effective in-feed additives is growing owing to the global climatic change trend to alleviate the negative effects of heat stress in laying hens. This research assessed the potential of using B-glucan (G) as an antiheat stress agent in Matrouh laying hens subjected to early heat shock programs during the growing period. Factorial design (3 × 3) was used, including 3 levels of heat stress (control, heat shock at 3 d and at 3 d and 8 wk of age) and 3 levels of β-glucan (0, 100, and 200 mg β-glucan /kg diet). During the first 12 wk of egg production (EP), treatments were exposed to heat challenge. The results revealed that heat shock program applications at 3 d and 8 wk of age significantly decreased body weight at 36 wk of age (P < 0.05) and reduced (P < 0.05) feed intake (FI). While significantly (P < 0.05) improved feed conversion ratio (FCR), hemoglobin, RBCs, WBCs, immunoglobulin M (IgM), immunoglobulin G (IgG), and Heat shock protein (HSP70) of the Liver (P < 0.01) as compared with the control group. At the same time, there was a decrease in lymphocyte%, H/L ratio, cortisol, and T3 compared to the thermo-neutral control. When compared to the control group, hens fed a diet containing 200 mg of βG significantly (P < 0.05) improved body weight at 16 wk and final weight at 36 wk, feed conversion (FCR) (g. feed/g. egg mass), hen-day egg production, and egg mass, as well as the digestibility coefficients of crude protein (CP), dry matter (DM), metabolizable energy (ME), and cortisol. The interactions between heat chock programs and βG levels were nonsignificant for the most studied traits except daily feed intake. Therefore, the early heat shock exposure 2 times and supplementation of Β-glucan (βG) at 200 mg/kg diet during the growth period for laying hens that are exposed to heat stress during the reproductive period could improve productive, reproductive performance, HSP70 level and enhance immunity responses.

Fecal amylase-treated neutral detergent fiber and ash contents as independent variables can predict metabolizable energy and coefficient of energy digestibility of diets for growing pigs without dietary information

The objectives of the present study were to develop prediction equations for digestible energy (DE), metabolizable energy (ME), and coefficient of energy digestibility (ED) of swine diets using fecal nutrients as independent variables without dietary information and to validate the prediction equations. A total of 262 fecal samples obtained from growing pigs fed 27 diets in 4 experiments were used to develop prediction equations for DE, ME, and ED. These equations were validated using 95 fecal samples obtained from growing pigs fed 12 diets in an additional experiment. The diets were based mainly on corn, soybean meal, and other plant-originated feed ingredients. In the digestibility experiments, feces and urine were quantitatively collected using the marker-to-marker procedure. Diet and fecal samples were analyzed for dry matter (DM), crude protein, ash, and amylase-treated neutral detergent fiber (aNDF). The DE of the 27 diets ranged from 12,164 to 18,301 kJ/kg DM and ME of 24 diets ranged from 11,603 to 16,657 kJ/kg DM. Coefficients of ED for the 27 diets ranged from 0.667 to 0.919. Fecal ash was positively correlated with DE (r = 0.81; P < 0.001), ME (r = 0.66; P < 0.001), and coefficient of ED (r = 0.67; P < 0.001) whereas fecal aNDF was negatively correlated with DE (r = –0.66; P < 0.001), ME (r = –0.74; P < 0.001), and coefficient of ED (r = –0.67; P < 0.001). The prediction equations developed using fecal nutrients were: DE (kJ/kg DM) = 15,077 + (13.72 × ash) – (4.65 × aNDF) (R2 = 0.71; P < 0.001); ME (kJ/kg DM) = 17,067 + (6.54 × ash) – (7.56 × aNDF) (R2 = 0.63; P < 0.001); and coefficient of ED = 0.881 + (0.00037 × ash) – (0.00028 × aNDF) (R2 = 0.57; P < 0.001) where nutrients are expressed as g/kg DM. Based on the regression analysis for validation of the equations, the prediction equations for DE and coefficient of ED using only fecal aNDF did not have mean bias or linear bias. In conclusion, DE values, ME values, and coefficient of ED for swine diets are correlated with fecal ash and aNDF concentrations and the energy values can be predicted using fecal ash and aNDF concentrations without dietary information.

Dietary citric acid improves phosphorus and calcium availability and intestinal morphology of Nile tilapia Oreochromis niloticus

Citric acid is an organic acid, which has been used as a feed additive because it has a reasonable cost, pleasant taste, and fast assimilation, showing positive effects on the growth and health of some livestock and aquatic species. This study aimed to evaluate the effects of increased levels of citric acid (0, 10, 20, 30, and 40 g/kg) in an isonitrogenous (280.00 g/kg of digestible protein) and isoenergetic diet (12.98 MJ/kg of digestible energy) on growth performance, body composition, apparent digestibility of nutrients and minerals, hematology, pH in stomach and intestine, and intestinal histomorphometry of Nile tilapia juveniles. Fish (n = 200, initial average weight of 14.59 ± 0.81 g) were randomly distributed in 25 experimental tanks (five replicates per treatment) and fed experimental diets over a 40-day period. Increasing levels of citric acid supplementation resulted in a decrease in the pH of the experimental diets (P = 0.021). However, no significant differences in pH levels were observed in the stomach and intestine among the treatments (P > 0.05). Citric acid supplementation did not significantly (P > 0.05) affect the growth performance variables, body composition, or the apparent digestibility coefficients (ADC) of dry matter, crude protein, gross energy, ether extract, and ash of the diets. Fish fed diets with 10 and 30 g/kg citric acid exhibited higher values for total leukocytes (P = 0.043) and total plasma protein (P = 0.019) compared to the control group. Diets supplemented with 20 g/kg citric acid showed a higher ADC value for phosphorus (P = 0.027) and calcium (P = 0.032) compared to the control. Additionally, fish fed with diets containing 20 g/kg citric acid demonstrated higher values for villus height (P = 0.002) and width (P = 0.048), crypt depth (P = 0.035), and villus: crypt ratio (P = 0.014) compared to the control group. In conclusion, the supplementation of 20 g/kg citric acid improved the availability of phosphorus and calcium and positively influenced the intestinal morphology of Nile tilapia juveniles.

Effect of acetic acid addition to rice straw pre-treated with urea on performance of dairy ewes.

This experiment was carried out to study the effect of acetic acid addition to rice straws that had been already treated with urea on chemical composition, digestibility, nutritive value, and productive performance of ewes. Thirty ewes with an initial body weight of 44 ± 0.41 kg were chosen 7 days after parturition and divided into 3 groups (10 of each) for 3 months. Each group was assigned randomly to receive one of the three experimental rations composed of concentrate feed mixture and untreated rice straw as a control group (G1), urea-treated rice straw (G2), and urea-acetic acid-treated rice straw (G3). Digestibility coefficients and nutritive value were determined using fifteen mature rams andblood samples were obtained at the end of the collecting period. Findings indicated that the crude protein of rice straw was increased, and crude fiber content was decreased by either urea or urea-acetic acid rations(i.e., G2 and G3). Digestibility of most nutrients was increased (P < 0.05) for animals fed either G2 or G3 rations. There were no significant differences in nutritive value astotal digestible nutrients (TDN) among tested groups; however, digestible crude protein(DCP) increased (P < 0.05) for G2 and G3 rations. Plasma total protein, AST, creatinine, and urea were increased (P < 0.05) by feeding on G2 or G3 ration; however, plasma ALT was not affected. The average daily intake ofdry matter (DM), TDN, and DCP was higher for G2 and G3 rations. Actual milk yield, fat-corrected milk(FCM), percentages of fat, and total solids and constituents yield were increased (P < 0.05) by feeding on treated rice straw rations (i.e.,G2 and G3); however, the percentages of protein, lactose, solids not fat, and ash were not affected. In the 1st month after parturition, the changes in ewes body weight were less (P < 0.05) when they fed on G2 and G3 rations than the control one(G1)). Dams' production and offspring performance were improved (P < 0.05) by feeding on G2 and G3 rations. Feed conversion as kg DMI/kg FCM, kg TDN/kg FCM, and economic efficiency was improved for G2 and G3. Inconcluded, adding acetic acid to urea-treated rice straw may improve the performance of ewes fed on it and increase their milk production and profitability. The same trend was observed with (G2) which received urea-treated rice straw ration.

Effect of replacing fish meal with chicken gut meal on growth, immune parameters, and metabolism of juvenile Fat Greenling Hexagrammos otakii

AbstractObjectiveChicken gut meal (CGM) is reasonably priced and rich in nutrients and can become a new source of protein in the diets of major aquatic products, such as fish and shrimp.MethodsAn 8‐week feeding trial was conducted to comprehensively investigate the beneficial effects of CGM on juvenile Fat Greenling Hexagrammos otakii. Juveniles (1.58 ± 0.06 g [mean ± SE]) were fed with different levels of CGM in replacement of fish meal (FM) in the basal diet: 0% (CGM0), 25% (CGM25), 50% (CGM50), 75% (CGM75), and 100% (CGM100) replacement, representing a dietary CGM level of up to 40 g/kg.ResultThe results showed that the percent weight gain; specific growth rate; feeding rate; feed conversion ratio; hepatosomatic index; and apparent digestibility coefficients of dry matter, protein, and lipid were significantly improved among the experimental groups. Moreover, the activities of superoxide dismutase and catalase were significantly increased in the CGM25 and CGM50 groups, respectively. The activities of acid phosphatase and alkaline phosphatase were significantly decreased in the CGM75 and CGM100 groups. Triglycerides and total cholesterol were significantly increased in the CGM50 and CGM75 groups, respectively. Fish in the CGM100 and CGM75 groups had significantly higher activities of aspartate aminotransferase and alanine aminotransferase than the control. Moreover, the relative expression levels of the fatty acid synthase and acetyl‐coenzyme A carboxylase alpha genes were significantly increased in the CGM75 and CGM100 groups, while the gene expression levels of hormone‐sensitive lipase and peroxisome proliferator‐activated receptor alpha were significantly decreased.ConclusionIn summary, the optimal replacement level of FM with CGM was shown by curve equation analysis to be 61.30%, and their dosages were 24.52 and 15.48 g/kg, respectively.

Performances and nutritional values of a new hooded barley (cv. Mochona) and a high yield triticale (cv. Titania) as hay or silage for sheep under Mediterranean conditions

The hooded barley phenotype produces an extra sterile flower in spikelets instead of awns. Hence, it might improve the nutritive value of the whole plant. The aim of this work was to evaluate a new variety of hooded barley (cv. Mochona) and a high yield triticale (cv. Titania) harvested and processed as hay and silage during 2 consecutive years for sheep. Digestibility was determined using 32 ewes which were distributed in 2 balanced groups by treatment, and fed with hay and silage sequentially. Results showed differences in the chemical composition of hay and silage according to harvesting year, but no differences were found on voluntary intake by year, species, or their interaction. Both forages showed high sheep fill values (sFV) either as hay or as silage (2.65 ± 0.030 and 3.09 ± 0.042 sFV/kg DM, on average, respectively). Impact on apparent nutrient digestibility coefficients varied according to preservation method, the digestibility of hays being mainly affected by the harvesting year, and that of silages by species. Digestible undegradable protein values were greater in hooded barley than in triticale for silages. In conclusion, marked compositional differences between years, but slight differences between species, were observed. Consequently, intake was similar, although triticale revealed slightly greater nutritive values than hooded barley. The obtained values for hooded barley as forage were greater than those reported in the literature for common fodder barley.

Dietary calcium requirement of bullfrog (Lithobates catesbeiana)

This study was conducted to determine dietary calcium (Ca) requirement of bullfrog (Lithobates catesbeiana). Six diets were formulated to contain 0.55% (control), 0.96%, 1.30%, 1.72%, 2.02% and 2.53% Ca. Each diet was fed to triplicate tanks of bullfrogs (24.96 ± 0.03 g), and each tanks was stocked with 13 bullfrogs. Bullfrogs were fed twice daily (8:30 and 17:30) to apparent satiation for 8 weeks. Weight gain rate of bullfrogs fed the 1.72% Ca diet was significantly higher than the control group (P < 0.05). The content of Ca was significantly increased in the whole body and vertebrae of bullfrogs fed the 1.72%, 2.02% and 2.53% diets compared to those fed the 0.55%, 0.96% and 1.30% Ca diets (P < 0.05). Furthermore, bullfrogs fed the 1.30%, 1.72% and 2.02% diets had higher activity of trypsin than those fed the 0.55% and 2.53% Ca diets (P < 0.05). Apparent digestibility coefficient of dry matter was higher in bullfrogs fed the 1.72% Ca diet than those fed the 0.55% and 2.53% diets (P < 0.05). Bullfrogs fed the 1.72% Ca diet had higher activity of superoxide dismutase in the serum than those fed the 0.55% and 2.53% diets (P < 0.05). Compared to the control group, contents of 1,25 dihydroxyvitamin D3 and parathyroid hormone in the serum as well as vitamin D receptor and sodium-calcium exchanger genes expression in the kidney were significantly decreased in bullfrogs fed the 1.72%, 2.02% and 2.53% Ca diets (P < 0.05). Compared to the control group, intestinal sodium-calcium exchanger gene expression was significantly decreased in bullfrogs fed the 1.72% and 2.02% Ca diets (P < 0.05). Based on second order polynomial analysis of weight gain rate, dietary Ca requirement of bullfrog was 1.89%.

Feeding Black Pepper (Piper nigrum) or Exogenous Xylanase Improves the Blood Lipid Profile of Broiler Chickens Fed Wheat-Based Diets.

This study aimed to determine the impact of dietary black peppercorn (BP) and xylanase (XYL) alone or in combination on growth performance, dietary energy, nutrient digestibility and blood lipid profile when fed to male Ross 308 broiler chickens from the ages of 7 to 21 d. A wheat-soy-based basal feed that was formulated to be 0.42 MJ lower in metabolizable energy (ME) was mixed. The basal feed was then split into four batches, with the first batch set aside as the basal control; the second batch was supplemented with freshly milled BP; the third batch was supplemented with XYL; the fourth batch was supplemented with both BP and XYL, as in the previous two batches. Each diet was fed to eight pens, with two birds in a pen, following randomization. Feeding BP reduced bird growth and most of the digestibility coefficients but increased blood high-density lipoprotein (p < 0.05). Dietary XYL increased bird growth, dietary ME and nutrient digestibility (p < 0.05). In addition, XYL increased hepatic carotenoids and coenzyme Q10, but reduced blood low-density lipoprotein (p < 0.05). There were no BP by XYL interactions (p > 0.05) observed. Further research is needed to identify the optimum level of BP in broiler diets.

Effects of two phosphorous sources in the diet on the growth performance, digestibility, and plasma physiological parameters of Pelodiscus sinensis juveniles

Phosphorus is an essential mineral for aquatic animals to maintain the health of the skeletal system and many physiological functions. This study assessed the effects of two inorganic phosphorus sources on growth performance, apparent phosphorus digestibility, whole-body proximate composition, and physiological status in juvenile Pelodiscus sinensis. Two experimental diets were supplemented with 4% calcium phosphate monobasic (MCP) and 5.47% calcium phosphate dibasic (DCP), respectively, to obtain equal total dietary phosphorus (2.20%). 96 turtles (initial body weight: 5.40±0.03g) were randomly distributed into 12 tanks and fed the corresponding diets for 60d. Results showed that phosphorus sources have not significantly influenced the growth parameters, including the specific growth rate, feeding rate, and feed conversion ratio (P&gt;0.05). No significant differences were observed in the hepatosomatic index and whole-body proximate compositions between MCP and DCP groups (P&gt;0.05). The apparent digestibility coefficients of dry matter and phosphorus in MCP group (53.22%) are slightly higher than that in DCP group (48.98%) but did not reach the statistically significant level (P &gt; 0.05). Turtles in MCP and DCP groups are the same in plasma physiological parameters and have equal alkaline phosphatase activities in plasma and liver (P&gt;0.05). In conclusion, calcium phosphate monobasic and calcium phosphate dibasic had the same biological phosphorus availability in diet for juvenile Pelodiscus sinensis.

Effect of dietary supplementation of inulin with low and high concentrate diet on growth performance and nutrient digestibility in Barbari goats

This study aimed to determine the effect of dietary supplementation of inulin on growth performance, feed conversion and nutrient digestibility in Barbari goats fed high and low concentrate diet for a period of 90 days. Twenty four yearling female Barbari goats were randomly divided into four equal groups (n=6) according to average body weight (18.24±1.16 kg). Treated animals in Group 1 were fed low concentrate diet (LCD; concentrate roughage ratio 40:60) and Group 2 (LCIN) with 2% inulin supplementation (% DM basis). Similarly, Group 3 was fed high concentrate diet (HCD; concentrate roughage ratio 60:40) and Group 4 (HCIN) with 2% inulinsupplementation. Results showed that average daily gain (ADG) and feed conversion efficiency (FCE) were higher in inulin supplemented groups than the non-supplemented group. There was no increase in mean live body weight (BW) and dry matter intake (DMI) with inulin supplementation either in LCD or HCD treatment groups.The mean body condition score (BCS) was also similar in all groups. However, faecal score (FS) was superior in inulin supplemented group observed after 30 days of feeding trial. There was significant improvement in the digestibility coefficient of crude protein and DCP intake. It was concluded that inulin supplementation either in high concentrate and low concentrate diet of growing goats resulted in improvement in growth performance, faecal score and nutrient digestibility.

The influence of non-bound amino acid inclusions and starch-protein digestive dynamics on growth performance of broiler chickens offered wheat-based diets with two crude protein concentrations

The primary objective of this study was to investigate the influence of high and low inclusions of non-bound amino acid (NBAA) in standard and reduced-crude protein (CP), wheat-based diets on growth performance in broiler chickens. Dietary treatments were formulated to either 210 or 180 g/kg CP. The 210 g/kg CP diets contained either 12.1 or 21.1 g/kg NBAA and 180 g/kg CP diets contained either 44.0 or 55.5 g/kg NBAA. The formulations also generated different dietary starch:protein ratios which impacted on starch-protein digestive dynamics. Each of the four dietary treatments were offered to 7 replicates of 15 birds housed in floor pens from 14 to 35 days post-hatch or a total of 420 male Ross 308 chickens. Growth performance, relative abdominal fat-pad weights, breast muscle and leg shank yields were determined. Ileal starch and protein (N) digestibility coefficients, disappearance rates and starch:protein disappearance rate ratios were defined. Apparent ileal digestibility coefficients and disappearance rates of 16 amino acids were determined at 35 days post-hatch and free concentrations of 20 amino acids in systemic plasma were determined at 34 days post-hatch. The transition from 210 to 180 g/kg CP diets depressed weight gain by 11.3% (1742 versus 1964 g/bird) and FCR by 10.4% (1.606 versus 1.455), although both parameters were subject to treatment interactions. The treatment interaction (P < 0.001) observed for FCR was because high NBAA inclusions significantly improved FCR by 4.17% (1.424 versus 1.486) in birds offered 210 g/kg CP diets, but significantly depressed FCR by 3.36% (1.632 versus 1.579) in 180 g/kg CP diets. A quadratic relationship (r = 0.860; P < 0.001) between dietary NBAA inclusions and FCR was detected, which indicated that when NBAA inclusions exceed 18.5 g/kg efficiency of feed conversion deteriorated. However, a multiple linear regression (r = 0.913; P < 0.001) was detected for FCR where both NBAA inclusions and analysed dietary starch:protein ratios were significantly (P < 0.001) related to FCR. This relationship indicates that growth performance of broiler chickens offered wheat-based diets is strongly influenced by dietary NBAA inclusions coupled with dietary starch:protein ratios and consideration is given to the possible underlying mechanisms.

The influence of dietary crude protein concentrations, grain types and arginine:lysine ratios on the performance of broiler chickens.

The objective of this study was to investigate the effects of dietary crude protein (CP) concentrations, grain types and arginine:lysine ratios on performance parameters of broiler chickens. The 2×2×2 factorial array of dietary treatments harnessed two CP concentrations (210 and 170g/kg), two feed grains (wheat and sorghum), and two arginine:lysine ratios (104 and 110). Each dietary treatment was offered to 7 replicates of 14 birds per floor pen, a total of 784 off-sex male, Ross 308 broilers, from 14 to 35d post-hatch. The dietary CP reduction compromised weight gain by 10.0% (2078 versus 2310g/bird) as a main effect and FCR by 7.51% (1.474 versus 1.371), subject to an interaction. In a three-way interaction (P=0.008), expanded arginine:lysine ratios improved FCR by 2.30% in 170g/kg CP, sorghum-based diets but compromised FCR by 2.12% in corresponding wheat-based diets. Sorghum was the more suitable feed grain in reduced-CP diets as sorghum generated significant advantages in weight gain of 7.59% (2154 versus 2002g/kg) and FCR of 6.94% (1.421 versus 1.527) in birds offered 170g/kg CP diets. Both dietary CP and feed grain generated significant and divergent impacts in apparent ileal digestibility coefficients for the majority of 16 assessed amino acids. Dietary CP reductions increased non-bound amino acid inclusions (NBAA) in wheat-based diets (48.96 versus 9.80g/kg) to a greater extent than sorghum-based diets (35.3 versus 9.50g/kg) and increasing dietary NBAA inclusions were linearly associated with compromised weight gain (r=-0.834; P<0.001) and FCR (r=0.862; P<0.001). Increasing ratios of free arginine to lysine plasma concentrations were linearly (r=-0.466; P=0.004) related to improvements in FCR. The implications of the observed outcomes are discussed and possible explanations are advanced.

Fecal NIRS to estimate intake and diet composition in Sarda dairy ewes fed mixed diets or part-time grazing forage crops

Knowledge on the intake and diet composition is a key to efficiently and sustainably drive ruminant production systems. Near infra-red spectroscopy of fecal samples (F.NIRS) has been proposed as a tool to estimate intake, diet composition and digestibility of ruminants. This study was aimed at ascertaining if F.NIRS can precisely and accurately predict 1) individual dietary intake and composition in dairy sheep fed mixed diets in confinement; 2) group dietary intake and composition in grazing dairy ewes using spot sampled faeces. We used two main datasets consisting of pairs of NIRS fecal spectra and reference values for intake, nutrient digestibility and composition of the diet: STALL, based on the results of digestibility trials carried out on a total of 120 sheep individually fed mixed diets including fresh forages, hays and concentrates (29 diets) and GRAZE based on results of already published grazing experiments. GRAZE encompassed a total of 102 pairs of group fecal spectra and group reference values regarding 6 grazing treatments differing in forage species, supplementation type and access time to pasture, in which reference data were obtained by double weighing procedure for herbage intake and hand-plucking for herbage composition. Group fecal samples were collected the day after. Data of the two datasets were separately used to calibrate F.NIRS using partial least square regression analysis and subsequent cross-validation. The quality of calibrations was evaluated using the ratio performance deviation (RPDcv). The diet attributes showing RPDcv in a range good to excellent (RPD > 3) in cross-validation were submitted to a validation exercise, on a subset of data previously excluded from calibration. Validation performance were evaluated as RPDval. Under confined conditions, individual herbage intake was predicted with good precision R2val = 0.90 and accuracy, SEP = 11.6% (RDPval = 3.2). The intake of hay was also well predicted (R2val = 0.97, SEP = 9.9%, RPDval = 4.6), whereas that of concentrates was just fairly predicted with R2val = 0.88 but a lower accuracy (SEP = 26.7%, RPDval = 2.9). The estimation of individual diet composition (% ingredients) was excellent for herbage and hay and good for concentrate, with R2val = 0.97, SEP = 11.2% and RPDval = 4.9 for hay; R2val = 0.97, SEP = 6.7% and RPDval = 5.5 for herbage; and R2val = 0.95, SEP = 26.7% and RPDval = 4.5 for concentrates. Prediction of nutrient proportion in the diet (% DM) was good for NDF, ADF, EE (RPDval ≥ 3) but inadequate for NFC (RPDval = 1.5). Cross-validation models were rather imprecise for CP and OM. Individual digestibility coefficients were poorly estimated in cross-validation, being the best models those estimating the digestibility of NFC (R2cv = 0.83, SECV% = 2.3, RPDcv = 2.4) and ADF (R2cv = 0.81, SECV% = 9.3, RPDcv= 2.3). Under grazing conditions, after cross-validation all models showed RPD < 3. The group intake of herbage was estimated with a modest precision and accuracy (R2cv = 0.75, SECV% = 14.2, RPDcv = 2.0). The proportion of herbage in the diet and its NDF content showed a higher accuracy, and equal or better precision, although models were adequate only for rough screening (RPDcv = 2 and 2.3, respectively). To conclude, this research confirms for dairy sheep the usefulness of F.NIRS to estimate individual intake and individual diet composition in ruminants fed mixed diets in confinement. Moreover, this study shows a modest cross-validation performance of F.NIRS for estimating group average proportion of herbage and NDF in the diet of grazing ewes by spot-sampling their faeces. Further validation of these models is needed to assess the applicability of the above results to farm conditions.

Solid-State Fermentation as Green Technology to Improve the Use of Plant Feedstuffs as Ingredients in Diets for European Sea Bass (Dicentrarchus labrax) Juveniles.

This study aimed to evaluate the utilization by juvenile European sea bass of a SSFed PF mixture with Aspergillus niger CECT 2088. A 22-day digestibility and a 50-day growth trial were performed testing four diets, including 20 or 40% of an unfermented or SSFed PF mixture (rapeseed, soybean, rice bran, and sunflower seed meals, 25% each). SSF of the PF added cellulase and β-glucosidase activity to the diets. Mycotoxin contamination was not detected in any of the experimental diets except for residual levels of zearalenone and deoxynivalenol (100 and 600 times lower than that established by the European Commission Recommendation-2006/576/EC). In diets including 20% PF, SSF did not affect growth but increased apparent digestibility coefficients of protein and energy, feed efficiency, and protein efficiency ratio. On the contrary, in diets including 40% PF, SSF decreased growth performance, feed intake, feed and protein efficiency, and diet digestibility. SSF decreased the intestinal amylase activity in the 40% SSFed diet, while total alkaline proteases decreased in the 20% and 40% SSFed diets. Hepatic amino acid catabolic enzyme activity was not modulated by SSF, and plasma total protein, cholesterol, and triglyceride levels were similar among dietary treatments. In conclusion, dietary inclusion of moderate levels of the SSFed PF, up to 20%, improves the overall feed utilization efficiency without negatively impacting European sea bass growth performance. The replacement of PF with the SSFed PF mixture may contribute to reducing the environmental footprint of aquaculture production.

Effects of urea-treated rumen digesta pellet concentrate on digestibility, growth performance and blood profile of Djallonké sheep

Rumen digesta is a waste product from the abattoir and slaughterhouse. In most developing countries, it discarded in a manner that causes pollution in the environment. It contains partially fermented feedstuff with a CP ranging from 9 to 20%. Addition of urea and pelleting of feed has been proven to further enhance the nutrient quality and digestibility of the feed. The study sought to evaluate the effects of dried rumen digesta pellets (DRDP) concentrate on intake, apparent digestibility, growth performance and blood profile of Djallonké sheep in the savanna agro ecological zone of Ghana. Four levels of DRD (0%, 5%, 10% and 15%) were incorporated into a concentrate diet and fed to sixteen (16) Djallonké rams with mean initial weight of 9.± 0.37 kg. The four concentrates were pelleted and fed with rice straw as the basal diet and replicated four times in a completely randomized design (CRD) for 84-d. The CP content of the concentrate was in the range of 101.0 to 131.4 g/kg DM. The NDF and ADF were in the range of 447.6 to 543.9 and 235.0 to 198.7 respectively. Dry mater intake did not differ amongst the rams. However, crude protein intake was significantly higher in rams fed 15% DRD. Whereas DM digestibility coefficient did not differ, a significant difference was recorded in the CP digestibility coefficient of rams with the highest obtained in rams fed 10 and 15% DRD. Final live weight gain was significantly different with rams fed 15% DRD recording twice the gain in rams fed the control diet. The trend was similar for the average daily weight gain with rams on 15% DRD recording a significantly higher gain compared to the control (48.93 vs 28.89 g/day/head). Haematological parameters of rams after the feeding trial were not significantly affected (p<0.05) by the dietary treatments. The serological parameters measured for all the rams fed the DRD concentrate did not differ (p>0.05) among the dietary treatments except albumin and Blood Urea Nitrogen concentration which were significantly influenced (p<0.005) by dietary treatment. Feeding young rams with DRDP improved the final live weight gain and average daily weight gain of Djallonké rams in the Savanna agro ecological zones and could therefore be used as a supplement for small ruminants.

Intake and digestibility of two diets for nine-banded armadillos (Dasypus novemcinctus: Linnaeus, 1758) kept under human care.

The study aimed to evaluate metabolic parameters, nutrient intake, and absorption of two diets formulated for Dasypus novemcinctus armadillos under human care. Were studied two diets: D1-a diet with dry dog food, ground beef, and boiled chicken egg with shells; D2-a diet with the same ingredients as D1, with added banana and papaya. Both are mixed in water. The parameters analyzed were body weight (BW), weight gain (WG), maintenance energy requirement (MER), Lee index, biometrics, body condition score, glucose, triglycerides, total cholesterol, and cholesterol fractions for eight male armadillos. Dietary intake (DI) and efficiency, nutrient intake, metabolizable energy, and digestibility coefficient for the diets were evaluated in six male armadillos. The diet that included fruits showed higher BW, WG, MER, Lee index, and better glucose metabolism. Both diets promoted increases in WG and Lee Index, as well as improvements in glucose metabolism. The diet without fruit improved the lipid profile of the animals. D2 presented the highest DI, better dietary efficiency, and higher energy intake but also a lower crude fiber intake. However, it showed the best utilization of gross fiber and all other nutrients. In conclusion, the diets constituted an adequate nutritional option for captive armadillos and can be used in malnutrition and pathological processes recovery. Although both diets were adequate, the nonfruit diet was preferable due to the improved lipid profile.