Dietary supplementation with canthaxanthin and 25-hydroxycholecalciferol on the incubation performance and fertility of European quail breeders.

This study assessed the effects of combined supplementation with canthaxanthin (Cx) and 25-hydroxycholecalciferol (25-OH-D3) on incubation performance, fertility, and chick quality in European quail breeders. A total of 240 birds were distributed in a completely randomized design with 5 diets and 8 replicates. The animals were fed a basal diet containing 50 µg of vitamin D3 or the basal diet supplemented with 3 ppm Cx and 34.5 µg 25-OH-D3, 6 ppm Cx, and 69 µg 25-OH-D3, 9 ppm Cx and 103.5 µg 25-OH-D3, or 12 ppm Cx and 138 µg 25-OH-D3. Incubation performance was analyzed in 2 periods (32 and 38 wk). Breeders aged 32 wk produced eggs with higher hatchability (P = 0.024), hatchability of fertile eggs (P = 0.026) and lower initial plus mid embryonic mortality (P = 0.021), whereas 38-week-old breeders generated chicks with a higher length at hatching (P < 0.001) and lower final plus pipped embryonic mortality (P = 0.021). In both age groups, Cx + 25-OH-D3 levels had a quadratic effect on egg fertility (P < 0.001), hatchability of total (P < 0.001), and fertile eggs (P < 0.001). The fertility and the number of sperm cells in the perivitelline membrane was analyzed in two periods (26 and 40 wk). A quadratic effect of diet and days after mating on both parameters (P < 0.05) was observed. Eggs from supplementing breeders showed a high fertility (P < 0.001) and sperm cell counts (P < 0.001) for up to 7 and 3 d after mating, respectively, then the control group. Moreover, the supplementation of quail breeder diets with 6 ppm Cx + 69 µg 25-OH-D3 enhances sperm cell longevity in sperm storage tubules, hatchability of total and fertile eggs, fertility, and chick quality, especially in older quail's breeders and reduces embryonic mortality.

High leucine levels affecting valine and isoleucine recommendations in low-protein diets for broiler chickens.

Four experiments were conducted to estimate the optimal standardized ileal digestible (SID) level of branched-chain amino acids in low-protein diets during the starter, grower, and finisher periods, using the response surface methodology, and to study their effects on performance and mRNA expression of genes involved in the mechanistic target of rapamycin (mTOR) pathway of broiler chickens from 8 to 21 D of age. In experiments 1, 2, and 3, a total of 1,500 Cobb male broiler chickens were assigned to 15 diets of a central composite rotatable design (CCD) of response surface methodology containing 5 levels of SID Leu, Val, and Ile with 5 replicate pens of 20 birds each. A 3-factor, 5-level CCD platform was used to fit the second-order polynomial equation of broiler performance. In experiment 4, a total of 540 8-day-old Cobb male broiler chickens were distributed in a completely randomized 2 x 3 x 3 factorial arrangement with 2 SID Leu levels (1.28 or 1.83%), 3 SID Val levels (0.65, 0.90, or 1.20%), and 3 SID Ile levels (0.54, 0.79, or 1.09%) for a total of 18 treatments with 5 replicate cages of 6 birds each. High Leu levels impaired (P < 0.05) gain:feed when birds were fed marginal Val or Ile diets. However, gain:feed was restored when both Val and Ile were supplemented to reach adequate or high levels. High Leu levels increased (P < 0.05) mRNA expression of S6K1 and eEF2 genes only in birds fed high Ile levels. Dietary SID Leu, Val, and Ile levels required for gain:feed optimization in low-protein diets were estimated at 1.37, 0.94, and 0.87% during the starter period; 1.23, 0.82, and 0.75% during the grower period; and 1.15, 0.77, and 0.70% during the finisher phase, respectively. Higher Val and Ile levels are required to optimize the effect of Leu supplementation on mRNA expression of mTOR pathway genes in the pectoralis major muscle of broilers from day 1 to 21 after hatch.

Dietary supplementation with canthaxanthin and 25-hydroxycholecalciferol has beneficial effects on bone and oxidative metabolism in European quail breeders.

This study aimed to investigate the effect of supplementation with canthaxanthin (Cx) and 25-hydroxycholecalciferol (25-OH-D3) on the production performance, egg quality, bone mineral content, blood biochemical parameters, and antioxidant status of European quail breeders. Two hundred and forty quail breeders were distributed in a completely randomized design with 5 diets and 8 replicates of 4 females and 2 males were used. All quail breeders received one of 5 diets: basal diet (containing 2,000 IU vitamin D3) or the same diet supplemented with 3 ppm Cx and 34.5 µg 25-OH-D3, 6 ppm Cx and 69 µg 25-OH-D3, 9 ppm Cx and 103.5 µg 25-OH-D3, or 12 ppm Cx and 138 µg 25-OH-D3. Production performance and internal and external egg quality parameters were not influenced by diet. Eggshell dry weight decreased linearly with increasing supplementation levels, and eggshell ash and calcium content increased quadratically. Plasma phosphorus, calcium, and ionic calcium levels in females and plasma ionic calcium levels in males showed a positive quadratic response to dietary supplementation. Femoral and tibiotarsal dry weight and calcium content were influenced by diet. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity in the liver of males and females and in the serum of females showed a positive quadratic relationship with Cx and 25-OH-D3 levels, whereas the malonaldehyde concentration showed a negative quadratic relationship. DPPH scavenging activity in the serum of male quail increased linearly with supplementation. There was a positive quadratic effect on superoxide dismutase gene expression and a positive linear effect on glutathione peroxidase 7 gene expression, suggesting that dietary enrichment with Cx and 25-OH-D3 might help protect spermatozoa against oxidative damage. The dietary supplement was pro-oxidative at high concentrations (above 9 ppm Cx). The results indicate that diets with adequate levels of Cx and 25-OH-D3 have a beneficial effect on calcium and phosphorus metabolism as well as on the antioxidant defense system. We recommend supplementing European quail breeders in the laying period with 6 ppm Cx and 69 µg 25-OH-D3.

Tibiotarsus bone characteristics and tibial dyschondroplasia incidence of broilers fed diets supplemented with leucine and valine.

Two experiments were conducted to study the effect of standardized ileal digestible (SID) leucine and valine levels on tibiotarsus bone characteristics and the incidence of tibial dyschondroplasia of broilers from day 1 to 21 (Experiment I) and day 21 to 42 post-hatch (Experiment II). Each experimental phase was evaluated independently. In both experiments, a total of 1,500 one-day-old Cobb 500 male broiler chickens were distributed in a completely randomized design 5 × 5 factorial arrangement for a total of 25 treatments. The SID leucine and valine levels were ranged from 10.0 to 19.6 g/kg, and 6.0 to 12.0 g/kg from day 1 to 21 post-hatch, respectively, while day 21 to 42 post-hatch ranged from 10.0 to 18.0 g leucine/kg, and 5.2 to 11.2 g valine/kg. Serum calcium and phosphorus, bone concentrations of calcium, phosphorus and ash, diameter and Seedor index of the tibiotarsus were not affected (p > .05) by the treatments at 21 or 42 days of age. There was an interaction (p ≤.06) between the SID levels of leucine and valine on tibiotarsus breaking strength at 21 days, but not at 42 days of age (p > .05). Tibiotarsus breaking strength was maximized in broilers from day 1 to 21 with the dietary levels of leucine and valine at 14.2 and 9.0 g/kg respectively. Dietary leucine levels reduced linearly (p < .05) the hypertrophic zone of tibiotarsus cartilage at 21 days of age. Therefore, leucine and valine supplementation interact positively on bone strength of broilers from day 1 to 21 post-hatch. Leucine can be a useful amino acid for reducing the hypertrophic cartilage zone in broilers from day 1 to 21, but not from day 21 to 42 post-hatch.

Performance and serum biochemical profile of Japanese quail supplemented with silymarin and contaminated with aflatoxin B1.

The aim of this study was to evaluate the hepatoprotective effect of silymarin in diets contaminated or not with aflatoxin B1 (AFB1) on the productive performance and serum biochemical profile of Japanese quail (Coturnix coturnix japonica) in the laying phase. A total of 240 12-week-old Japanese quail was used in a completely randomized design in a 3 × 2 factorial scheme (additives x contaminated or not with AFB1 - 1,500 µg/kg), totaling 6 treatments and 5 replicates of 8 birds each. The additives used were silymarin (500 g/ton), adsorbent (1 kg/ton), and a control diet (without additive). Of the total aflatoxin content, 84.64% was AFB1; 4.28% was AFB2; 11.07% was AFG1; and AFG2 was not detected. The data were submitted to ANOVA, and means were compared by Tukey's test. There was no interaction (P > 0.05) between the additive and AFB1 on performance parameters. However, the inclusion of AF in diets reduced (P < 0.05) egg weight and feed intake, impairing feed conversion compared to the unchallenged groups. There was an increase (P < 0.05) in blood concentrations of aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), and creatine kinase (CK) in birds challenged with AFB1, regardless of the additive used, characterizing a possible alteration in hepatic metabolism. Serum total protein and globulin levels were reduced (P < 0.05) in birds challenged with toxins. The consumption of diets contaminated with 1,500 µg AFB1/kg altered hepatic function in quail, impairing productive performance and egg weight. The concentrations of silymarin and adsorbent evaluated in this study were not able to mitigate the negative effect of toxins on the metabolism and performance of laying quail.

Supplementation of broiler breeders with fat sources and vitamin e: carry over effect on performance, carcass yield, and meat quality offspring / Suplementação de matrizes de frangos de corte com fontes de gordura e vitamina E: transferência dos efeitos sobre a performance, o rendimento da carcaça e a qualidade da carne da progênie

The aim of this study was to evaluate two sources of oil (soybean and fish) and four additional levels of vitamin E (0, 150, 250 and 350mg/kg diet) in breeder diets between the 42nd and 56th week of age and its effect on performance and meat quality of offspring. The supplementation of fish oil in the maternal diet increased the deposition of DHA and CLA in egg yolk. From 1 to 35 days of age, intermediate levels of vitamin E resulted in lower weight gain and feed intake. To feed conversion, the best result was obtained supplementing the maternal diet with soybean oil, regardless of vitamin inclusion. In addition, the evaluation of meat quality, the fish oil-supplemented-diet resulted in lower moisture loss of the breast fillets. For maternal diet supplemented with fish oil, the inclusion of vitamin E resulted in a linear increase of the pH value of the meat. Greater levels of vitamin E in the maternal diet influenced the functional properties of meat according to the type of oil that was added to the diet. The deposition of different fatty acids in the embryonic egg yolk can directly influence the meat quality of offspring.(AU)

O objetivo deste estudo foi avaliar duas fontes de óleo (soja e peixe) e quatro níveis adicionais de vitamina E (0, 150, 250 e 350mg/kg dieta), em dietas de matrizes entre a 42º e a 56º semana de idade, sobre o desempenho e a qualidade de carne da progênie. A suplementação de óleo de peixe na dieta das matrizes aumentou a deposição de DHA e CLA na gema dos ovos. Entre um e 35 dias de idade, níveis intermediários de vitamina E resultaram em menor ganho de peso e consumo de ração. Para a conversão alimentar, o melhor resultado foi obtido suplementando a dieta materna com óleo de soja, independentemente da inclusão vitamínica. Dietas suplementadas com óleo de peixe resultaram em menor perda de umidade nos filés de peito. Para a dieta materna suplementada com óleo de peixe, a inclusão de vitamina E resultou em um aumento linear do valor de pH da carne. Níveis mais altos de vitamina E na dieta materna influenciaram as propriedades funcionais da carne de acordo com o tipo de óleo adicionado à dieta. A deposição de diferentes ácidos graxos na gema de ovos embrionados pode influenciar diretamente a qualidade da carne da progênie.(AU)

Influence of graded levels of calcium and vitamin K in the diets of laying hens during the growing phase and their effects on the laying phase.

The aim of this study was to evaluate the effect of dietary supplementation of vitamin K (vit K) and Ca in the diets of laying hens on bone and blood parameters and performance during the growing phase and the effects on the laying phase up to 32 weeks. The study utilized 120 Hy-Line W-36 pullets in the growing phase (13-18 weeks), 80 laying hens in the production phase (20-32 weeks), distributed in a completely randomized design in a 2 × 5 factorial arrangement, two levels of Ca (0.8 and 1.4%) and five levels of vit K supplementation (0, 2, 8, 16 and 32 mg/kg) with four experimental units. An experimental diet was fed during the growing phase, and the commercial diet was fed during the production phase and were analysed for biochemistry and bone variables at 18 and 32 weeks. In pullets, a significant interaction of levels of vit K and Ca was observed for total serum calcium (mg/dl), Seedor index, Ca in the bones (%) and medullary bone (%). Pullets at 18 weeks of age, receiving diets with 1.4% Ca, displayed a quadratic effect of vit K with better results for these variables with 17.86, 14.59, 14.48 and 16.80 mg/kg of vit K, respectively. For level 0.8% Ca no effect of vit K was observed. The treatments during the growing phase had no effect on egg production, performance and biochemistry serum until 32 weeks. Medullary bone (%), there was a significant interaction for 1.4% Ca and a quadratic effect for vit K, with greater medullary bone areas observed with 6.09 mg/kg vit K in the diet. Supplementation with vit K in a diet with 1.4% Ca during the growing phase allowed for an increase in the area of medullary bone at 18 weeks, which was maintained until 32 weeks.

Leucine and valine supplementation of low-protein diets for broiler chickens from 21 to 42 days of age.

The objective of this study was to determine the requirements and interactions between the standardized ileal digestible (SID) Leu and Val levels in low-protein diets, and their effects on performance, serum characteristics, carcass yield and diameter of muscle fibers of broiler chickens from d 21 to 42 posthatch. A total of 1,500 21-day-old Cobb 500 male broiler chickens were distributed in a completely randomized design in a 5 × 5 factorial arrangement for a total of 25 treatments with 3 replicates of 20 birds each. Treatments consisted of 5 SID Leu levels (1.0, 1.2, 1.4, 1.6, or 1.8%) and 5 SID Val levels (0.52, 0.67, 0.82, 0.97, or 1.12%). At 42 d of age, there was interaction (P < 0.05) between the SID levels of Leu and Val on feed intake and weight gain. There was a quadratic effect (P < 0.05) of Leu and Val levels on feed conversion, with minimal point estimated at the levels of 1.19 and 0.86%, respectively. Dietary Leu supplementation reduced linearly (P < 0.05) serum concentrations of triglycerides and ß-hydroxybutyrate. Dietary Leu increased (P ≤ 0.05) the fiber diameters of the pectoralis major muscle and breast yield at the levels of 1.24 and 1.13%, respectively, while the thigh yield was improved with the level of 0.71% Val. Abdominal fat decreased linearly (P < 0.05) with increasing levels of dietary Leu and Val. The SID Leu and Val levels needed to optimize weight gain and feed conversion in low-CP diets for broiler chickens from d 21 to 42 posthatch were estimated at 1.15 and 0.86%, and 1.19 and 0.86%, respectively. The supplementation of Leu and Val can reduce the abdominal fat deposition in birds fed low-CP diets during the grower phase. Leu and Val interactions can influence the performance but not the serum characteristics, carcass yield and diameter of muscle fibers of broilers fed low-protein diets. Therefore, it is necessary to consider the dietary Leu content to estimate the ideal level of Val in low-CP diets for optimum broiler performance.

Caecal microbiota of chickens fed diets containing propolis.

The present study aimed to evaluate the effect of different levels of ethanolic extract of propolis (EEP) and raw propolis (RP) on broiler performance and on selected bacterial groups in caecal microbiota using fluorescent in situ hybridization (FISH) measured by fluorescent activated cell sorting. Two experiments were conducted with 120 male chicks from 1 to 21 days of age for each, raised in cages and distributed in a completely randomized experimental design; there were five replicates with four birds per experimental unit and six treatments for each experiment (trial 1 - EEP - 0, 1000, 2000, 3000, 4000 and 5000 ppm and trial 2 - RP - 0, 100, 200, 300, 400 and 500 ppm). Fluorescent probes were used against the bacterial groups in caecal samples collected at 21 days of age. The data were subjected to one-way anova followed by Tukey's and regression analyses were used to assess the relationship between dietary levels of EEP or RP on performance and intestinal microbiota (p < 0.05). In the trial 1, results showed that the EEP did not cause any significant (p > 0.05) modification in the performance and caecal microbiota. In the trial 2, RP inclusion did not affect the performance but changed the bacterial composition (p < 0.05). Clostridiaceae, Gammaproteobacteria excluding Enterobacteriaceae and Lactobacillus spp. showed a quadratic response (p < 0.05), with the lowest value predicted to occur at 240 ppm, 221 ppm and 213 ppm of RP respectively. The proportion of Bacteroidaceae and Gammaproteobacteria did not differ (p > 0.05) among the experimental groups. The inclusion of ethanolic extract of propolis did not affect the performance and intestinal microbiota, whereas the supplementation of raw propolis modulates the caecal microbiota composition without any effects on chicken performance.

Valine, isoleucine, arginine and glycine supplementation of low-protein diets for broiler chickens during the starter and grower phases.

1. Two experiments were performed to study the supplementation of valine, isoleucine, arginine and glycine (Val, Ile, Arg, Gly) in low-protein diets for broiler chickens in the starter (1-21 d; Exp. 1) and grower (22-42 d; Exp. 2) phases. 2. A low-crude protein (CP) diet was formulated to meet the requirements of all amino acids (AA) supplied by the control diet except for Val, Ile, Arg and Gly. The other experimental diets were obtained by the isolated or combined supplementation of the studied AA in the low-CP diet. 3. Growth, serum parameters and litter characteristics were taken in both of the experiments. Carcass measurements were taken in Experiment 2. 4. In the starter and grower phases, low-CP diets without supplementation resulted in birds with a poorer weight gain and feed conversion than those of the birds that received the control diet. 5. In the starter phase, individual supplementation with Val and Gly, but not Ile and Arg, restored the weight gain of the birds, while diets with the addition of Val + Gly, Val + Ile + Arg, Val + Ile + Gly and Val + Ile + Arg + Gly restored their feed conversion. 6. In the grower phase, weight gain was re-established at the same rate as the control diet for the diets supplemented with Val + Ile, Val + Ile + Arg, Val + Ile + Gly and Val + Ile + Arg + Gly. However, the feed conversion was restored only in birds that received the diet supplemented with all studied AA. 7. The supplementation of Val and Gly in low-CP diets was sufficient to avoid adverse effects in the performance and serum parameters of broilers in the starter phase. However, birds in the grower phase required the combined supplementation of Val, Ile, Arg and Gly, to prevent compromised performance.

Effects of dietary supplementation of meat-type quail breeders with guanidinoacetic acid on their reproductive parameters and progeny performance.

This study was conducted to assess the effect of dietary supplementation of meat-type quail breeders with guanidinoacetic acid (GAA) on their reproductive parameters and progeny performance. Two hundred forty meat-type quails at 25 wk of age were distributed in a completely randomized design with 5 treatments and 8 replicates of 6 birds each. The treatments consisted of 5 dietary levels of GAA (0.00, 0.06, 0.12, 0.18, and 0.24%). The progenies from quail breeders were housed according to breeder treatments and fed a conventional diet based on corn and soybean meal without GAA supplementation. Dietary GAA levels did not affect (P > 0.05) the productivity of meat-type quail breeders, although the concentration of guanidinic compounds (creatine, GAA, and creatinine) in the eggs from the breeders increased linearly (P < 0.05) according to the increase in dietary GAA levels. The number of spermatozoa present in the vitelline membrane was not affected (P > 0.05) by the treatments, but there was a quadratic effect (P < 0.05) of the levels of GAA on fertility, embryonic mortality, and egg hatchability, with the best results estimated at 0.13, 0.15, and 0.14% GAA, respectively. The creatine levels of the pectoral muscle in newborn quails showed a quadratic effect (P ≤ 0.07), and the dietary GAA level of 0.11% was estimated to maximize the muscular creatine level in the progeny. There was a quadratic effect (P < 0.05) of GAA levels on weight gain and feed conversion of progeny at 35 d of age with an optimization point of 0.14% GAA for these variables. Dietary GAA supplementation of meat-type quail breeders increases the availability of creatine in eggs and muscle of progeny, which results in better reproductive parameters and better postnatal progeny performance.

Productive performance, eggshell quality, and eggshell ultrastructure of laying hens fed diets supplemented with organic trace minerals.

This study was carried out with the purpose of evaluating the effect of supplementing hens' diets with trace minerals from inorganic or organic sources on the productive performance, eggshell quality, and eggshell ultrastructure of laying hens. Three hundred sixty Hy-Line W36 laying hens between 47 to 62 wk of age were used and distributed in a completely randomized experimental design with 9 treatments, 5 replicates, and 8 birds for each experimental unit. The treatments consisted of a control diet without supplementation of the trace minerals Mn, Zn, and Cu; 4 supplementation levels of these trace minerals from an inorganic source; and the same levels of supplementation from an organic source (proteinates). The supplementation levels in milligrams per kilogram for Mn, Zn, and Cu, were, respectively, 35-30-05, 65-60-10, 95-90-15, and 125-120-20. There was no effect of supplementation of trace minerals on the rate of posture, feed intake, feed conversion, specific weight, and Haugh unit of eggs. However, there was a quadratic effect (P < 0.05) of the levels of trace mineral supplementation on average egg weight and egg mass; the results did not differ regarding the source used. The increase in the levels of supplementation of Mn, Zn, and Cu provided a linear increase (P < 0.05) in the breaking strength and the percentage of eggshell. There was a linear decrease (P < 0.05) in the egg loss and the number of mammillary buttons in the shell. The best results were obtained using diets supplemented with trace minerals from an organic source because these diets provided lower egg loss, higher thickness, and increased strength of the shell. Structurally, organic Mn, Zn, and Cu provided higher thickness of the palisade layer and lower mammillary density. The trace mineral supplementation improved the structural characteristics and the quality of the eggshells.

Effect of dietary supplementation with an ethanolic extract of propolis on broiler intestinal morphology and digestive enzyme activity.

The present study aimed to evaluate the effect of different levels of an ethanolic extract of propolis (EEP) on broiler performance, carcass characteristics, weight of gastrointestinal organs, intestinal morphometry and digestive enzyme activity. 1020 male broiler chicks were assigned in a completely randomised experimental design to six treatments (EEP supplement levels of 0, 1000, 2000, 3000, 4000 and 5000 ppm) and five replications, and 34 birds per experimental unit. The experimental diets were administered from 1 to 21 days of age, and the birds were subsequently provided a ration based on corn and soybean meal. EEP supplementation from 1 to 7 days negatively affected (p < 0.05) the weight gain and feed intake. The proventriculus weight at 7 days exhibited a quadratic response (p < 0.05), which predicted a lower weight at a dose of 2865 ppm of the EEP. For the duodenum at 21 days of age, the response pattern (p < 0.05) predicted that birds that were fed 2943 and 3047 ppm of the EEP would exhibit an improved crypt depth and villus-to-crypt ratio respectively. The villus height, crypt depth and villus-to-crypt ratio in the jejunum and the ileum were not affected (p > 0.05). With increased EEP doses, the duodenal sucrase activity linearly decreased at 7 days of age and linearly increased in the jejunum at 21 days of age (p < 0.05), while pancreatic enzyme activity was unaffected (p > 0.05). Although the carcass and cut yields did not improve, the percentage of abdominal fat decreased (p < 0.05). The supplementation of the broiler pre-starter diet with 1000-5000 ppm of the EEP impaired performance at this stage, most likely due to the decreased sucrase activity. However, the EEP supplementation from 3000 ppm improved intestinal morphophysiology at 21 days of age and did not affect the performance or carcass yield at 42 days of age.

Supplemental glycine and threonine effects on performance, intestinal mucosa development, and nutrient utilization of growing broiler chickens.

A study was conducted to evaluate Gly requirements in low-CP diets with different levels of digestible (dig) Thr, and their effects on performance, intestinal mucosal development, and nutrient utilization of broiler chickens from 21 to 35 d age. A total of 240 twenty-one-day-old Cobb-Vantress male broiler chickens were distributed in a completely randomized 4 × 2 factorial arrangement for a total of 8 treatments with 5 replicates of 6 birds each. The treatments consisted of 4 levels of Gly+Ser (1.47, 1.57, 1.67, or 1.77%) and 2 levels of dig Thr (0.70 or 0.77%, corresponding to 100 or 110% of Thr requirements, respectively). Common diets were fed to broilers until 20 d of age. At d 35, an interaction (P ≤ 0.01) was observed between the Gly+Ser and dig Thr levels for G:F. Glycine supplementation resulted in a linear increase (P < 0.05) in BW gain, G:F, intestinal mucin secretion, apparent digestibility of fat, and AME values of the experimental diets. Threonine levels greater than the levels required (0.77%) improved (P < 0.05) G:F and increased (P < 0.05) intestinal mucin secretion. However, intestinal morphometry and the number of goblet cells in the duodenum, jejunum, and ileum were not affected by the treatments. The dietary Gly+Ser level necessary to optimize G:F in low-CP diets containing 0.77% Thr for broiler chickens during growth was estimated to be 1.54%; however, this requirement may be greater than 1.77% in diets with 0.70% Thr. Supplemental Gly may be essential to support maximum performance for broiler chickens from 21 to 35 d of age when they are fed diets based exclusively on vegetable ingredients and with low protein levels. Glycine can directly or indirectly influence the proper function of the intestinal mucosa and improve dietary energy utilization.

Dietary glycine+serine responses of male broilers given low-protein diets with different concentrations of threonine.

1. The objective of this study was to determine the optimum glycine+serine (Gly+Ser) concentration in low-crude protein (CP) diets that have adequate or high concentrations of dietary threonine (Thr) for broiler chickens in the initial growth phase. 2. Treatments consisted of four concentrations of dietary Gly+Ser (18.4; 19.8; 21.2 and 22.6 g/kg) and two concentrations of dietary Thr (9.3 and 10.7 g/kg, corresponding to 100 and 115% of the required Thr, respectively). 3. At 21d, interactions were observed between dietary Gly+Ser and Thr concentrations for the feed conversion ratio, creatine content in the pectoral muscles and serum concentrations of uric acid. There was a quadratic effect of the concentrations of Gly+Ser in the diets with 9.3 g Thr/kg on the feed conversion ratio and creatine content in the pectoral muscles, with an optimisation concentration of 20.8 and 21.1 g Gly+Ser/kg, respectively. 4. Diets containing 10.7 g Thr/kg negatively affected the feed conversion ratio, relative breast weight, creatine content in the pectoral muscles, serum concentrations of uric acid and ammonia in poultry compared to diets containing 9.3 g Thr/kg. 5. The need for Gly+Ser in diets with low-protein concentration (190 g CP/kg) and adequate concentration of Thr (9.3 g/kg) is 20.8 g/kg for broilers in the 1- to 21-d phase.

Quantidade de metionina+cistina digestível para poedeiras semipesadas de 75 a 91 semanas de idade / Nutritional requirement of digestible methionine + cystine for brown-egg laying hens from 75 to 91weeks of age

Determinaram-se as exigências nutricionais de metionina+cistina digestível para poedeiras de linhagem comercial no segundo ciclo de produção de 75 a 91 semanas de idade, utilizando-se 150 aves semipesadas em delineamento inteiramente ao acaso. Estas foram distribuídas em cinco tratamentos, seis repetições e cinco aves por unidade experimental, alimentadas com uma dieta basal contendo 2.859kcal/kg de energia metabolizável e 16,30% de proteína bruta, suplementada com 0,132; 0,173; 0,215; 0,256 e 0,298% de DL-metionina (98%), de forma a proporcionar 0,588; 0,628; 0,669; 0,709 e 0,750% de metionina+cistina digestível na dieta. A inclusão de metionina+cistina obedeceu, respectivamente, às proporções de 67, 72, 77, 81 e 86% com a lisina fixada em 0,872%. Avaliaram-se os consumos de ração e de metionina+cistina, a conversão alimentar por dúzia e por massa de ovos, a taxa de postura, o peso e a massa de ovos, a porcentagem dos componentes dos ovos e a qualidade interna dos ovos e o ganho de peso. A inclusão de metionina+cistina digestível nas quantidades indicadas não exerceu efeito (P>0,05) sobre as características de produção e qualidade interna e externa dos ovos. A exigência estimada foi de 0,588% de metionina+cistina digestível, correspondendo ao consumo de 654,73mg/ave/dia.

This work determined the nutritional requirements for methionine + cystine for commercial hens in the second production cycle from 75 to 91 weeks of age, using 150 brown-egg layer hens in a completely randomized design, distributed in five treatments, six replicates of five hens each and fed a basal diet containing 2859kcal/kg of metobolizable energy, 16.30% crude protein supplemented with 0.132, 0.173, 0.215, 0.256 and 0.298% DL-methionine (98%), in order to provide 0.588, 0.628, 0.669, 0.709 and 0.750% methionine + cystine in the diet. The inclusion of methionine + cystine followed, respectively, the proportions of 67, 72, 77, 81 and 86% with lysine fixed at 0.872%. The feed intake, methionine + cystine intake, feed conversion per dozen eggs and egg mass, percentage of the eggs, egg weight, egg mass, percentage of egg components and internal quality of eggs and weight gain were evaluated. The inclusion methionine + cystine in the amounts indicated had no effect (P> 0.05) on the production characteristics and internal and external quality of eggs. The requirement was estimated at 0.588% methionine + cystine intake corresponding to 654.73mg/hen/day.

Commercially available amino acid supplementation of low-protein diets for broiler chickens with different ratios of digestible glycine+serine:lysine.

This work studied the effect of supplementing commercially available amino acids in low-protein diets using different ratios of digestible (dig) glycine+serine:lysine (Gly+Ser:Lys) on performance, serum parameters, feathering, and litter characteristics of broiler chickens during the starter period. A total of one thousand fifty 1-d-old Cobb-Vantress male chicks were distributed in a completely randomized experimental design into 6 treatments with 5 replicates of 35 birds each. The treatments were as follows: T1, control diet based on corn and soybean meal formulated with 22% CP (dig Gly+Ser:Lys ratio of 147); T2, diet with a 2% CP reduction, supplemented with Val (dig Gly+Ser:Lys ratio of 137); T3, similar to T2 with the addition of Gly (dig Gly+Ser:Lys ratio of 147); T4, diet with a 3% CP reduction, supplemented with Val, Ile, and Arg (dig Gly+Ser:Lys ratio of 127); and T5 and T6, similar to T4 with the addition of Gly (dig Gly+Ser:Lys ratios of 137 and 147, respectively). At 7 and 21 d, broilers that had received diets with a 3% CP reduction (19% CP) and a Gly+Ser:Lys ratio that was equivalent to 127 had lower G:F (P < 0.05) and lower total protein and albumin serum concentrations (P < 0.05) than those broilers that received the control feed. However, these parameters were restored to the same level as the control diet with an increase in the dig Gly+Ser:Lys ratio from 127 to 137 and 147. Diets with a 3% CP reduction (19% CP) resulted in litter with reduced (P < 0.05) nitrogen content and lower ammonia emission than the litter of broilers receiving the control diet. The treatments did not influence (P > 0.05) the feather length or feathering scores at 21 or 28 d of age. The supplementation of essential amino acids while maintaining dig Gly+Ser:Lys ratios at and above 137 allowed for a reduction in the dietary CP of 3% without undermining the performance, feathering or serum parameters of early stage broilers.

Effect of arginine on the development of the pectoralis muscle and the diameter and the protein:deoxyribonucleic acid rate of its skeletal myofibers in broilers.

This work aimed at evaluating the effects of the supplementation of starter diet with Arg on breast muscle development in broilers and the activation of satellite cells and the aggregation of myofibrillar protein. Male Cobb chicks (n = 990) were randomly assigned to 1 of 5 treatments in a complete random design. Measurements of 33 chicks per treatment were made in 6 repetitions. The treatments consisted of a basal diet with 1.390% digestible Arg (without supplementation) and 4 dietary levels of Arg (1.490, 1.590, 1.690, and 1.790%) with Arg:Lys ratios of 1.103, 1.183, 1.262, 1.341, and 1.421, respectively. Arginine supplementation was used only in the starter phase (1 to 21 d). Dietary supplementation with Arg had a positive effect (P < 0.05) on breast and breast fillet weight on d 7 and 21 and on myofiber diameter on d 14 and 21. However, no effect was observed (P > 0.05) on the protein:DNA ratio, which demonstrates that Arg does not interfere with the mitotic activity of the satellite cells. Independently from mechanism, Arg affected muscle growth in the starter phase positively. Dietary supplementation with Arg in the starter phase had no effect (P > 0.05) on the carcass yield of broilers on d 42. Diet supplementation with Arg at levels above the ones recommended for the starter phase may be necessary for improved muscle development in broilers.

Supplementation of glutamine and vitamin E on the morphometry of the intestinal mucosa in broiler chickens.

The objective of this experiment was to evaluate the influence of Gln and vitamin E (VE) supplementation in the diet of broiler chickens (Cobb-Vantress) on the morphometry of the intestinal mucosa. The design was completely randomized in a 2 x 3 (VE x periods of administering Gln) factorial arrangement. The levels of VE used were 10 and 500 mg/kg of diet and 3 periods of administering (1%) Gln-supplemented starter diet (for the first 7 or 14 d of life or for no added Gln), totaling 6 treatments with 5 replicates of 50 birds per experimental unit. In the growth period (d 22 to 41 posthatch), the treatments consisted only in the respective levels of VE. On d 7, 14, 21, and 41 posthatch, 2 birds per replicate were killed, and samples of the duodenum, jejunum, and ileum were subsequently removed, fixed in Bouin solution, and later embedded in paraffin and stained with hematoxylin-eosin. The parameters analyzed were villus height and crypt depth. An ANOVA was applied to the obtained data, and the means were compared using Tukey's test (5% significance level). Greater development was observed in the duodenum, followed by the jejunum and ileum. On 41 d of life, diets with 10 mg of VE/kg supplemented with Gln (for the first 7 d of life) provided better development of the intestinal mucosa in broiler chickens.

Cellular thiol status-dependent inhibition of tumor cell growth via modulation of p27(kip1) translocation and retinoblastoma protein phosphorylation by 1'-acetoxychavicol acetate.

1'-Acetoxychavicol acetate (ACA) has been shown to inhibit tumor cell growth, but there is limited information on its effects on cell signaling and the cell cycle control pathway. In this study, we sought to determine how ACA alters cell cycle and its related control factors in its growth inhibitory effect in Ehrlich ascites tumor cells (EATC). ACA caused an accumulation of cells in the G1 phase and an inhibition of DNA synthesis, which were reversed by supplementation with N-acetylcysteine (NAC) or glutathione ethyl ester (GEE). Furthermore, ACA decreased hyperphosphorylated Rb levels and increased hypophosphorylated Rb levels. NAC and GEE also abolished the decease in Rb phosphorylation by ACA. As Rb phosphorylation is regulated by G1 cyclin dependent kinase and CDK inhibitor p27(kip1), which is an important regulator of the mammalian cell cycle, we estimated the amount of p27(kip1) levels by western blotting. Treatment with ACA had virtually no effect on the amount of p27(kip1) levels, but caused a decrease in phosphorylated p27(kip1) and an increase in unphosphorylated p27(kip1) as well as an increase in the nuclear localization of p27(kip1). These events were abolished in the presence of NAC or GEE. These results suggest that in EATC, cell growth inhibition elicited by ACA involves decreases in Rb and p27(kip1) phosphorylation and an increase in nuclear localization of p27(kip1), and these events are dependent on the cellular thiol status.