Digestible lysine requirement for growing Japanese quails

A total of 1,000 one-day-old Japanese quails were distributed at random, with 5 digestible lysine levels, in 10 replicates and with 20 birds per experimental unit. The basal diet was formulated based on corn and soybean, with 200.6 g CP/kg, 2900.00 kcal/kg ME, and 8.8 g digestible lysine/kg. This basal diet was supplemented with L-lysine HCl (784 g/kg), replacing glutamic acid, and corresponding to digestible lysine levels of 8.8 g/kg, 9.8 g/kg, 10.8 g/kg, 11.8 g/kg, and 12.8 g/kg. The increase in the levels of digestible lysine produced a greater weight gain in birds with up to 12.2 and 12.1 g of lysine/kg at 40 d of age. Carcass weight increased as levels were increased to up to 11.85 g of lysine/kg, and, similarly, egg production per bird housed increased up to 12.03 g of lysine/kg. A linear increase took place in the growing phase for feathering, fat, and crude protein deposits in the carcass, feed intake, and lysine intake. Egg production and egg mass per bird per d increased linearly in the laying phase with the weight gain of birds decreasing linearly until 100 d of age, and, similarly, the feed conversion per egg mass linearly improved in function of the lysine levels. A level of 11.85 g of digestible lysine/kg in the diet, which corresponded to a lysine intake of 120.5 mg/bird/d, provided better carcass weight at the end of the growing phase and better performance at the beginning of the laying phase for the Japanese quails.     

Marginality and Needs of Dietary Valine for Broilers Fed Certain All-Vegetable Diets

Valine is likely the fourth limiting amino acid in most diets based on corn and soybean meal (C/SBM). However, the exact needs for Val are not well known, and information regarding it is sparse. A series of studies was conducted to validate the limitation of Val in all-vegetable diets fed to broilers, and subsequently to quantify an adequate ratio to Lys in high-yield late-developing broilers (Ross × Ross 708) from 21 to 42 d. A preliminary study was designed to evaluate the supplementation of different amino acids likely to be fourth limiting on a C/SBM-based diet, where Lys, TSAA, and Thr were supplemented but no other critical amino acids were given minimums in the formulation. Results obtained for BW gain, abdominal fat weight, and abdominal fat percentage showed that birds were more responsive (P < 0.05) to l-Val supplementation. A follow-up study using a corn-peanut meal (C/PM)-based diet formulated to be deficient in Val validated (P < 0.05) a Val deficiency based on poor growth performance and resulted in an immediate return to good performance when this amino acid was supplemented. Furthermore, the C/PM diet was compared with a nutritionally similar C/SBM diet, and no difference was observed in the performance of broilers fed these diets, thus validating the ability of the C/PM-based diet to support adequate growth of these broilers. This C/PM-based diet was used to feed gradual concentrations of Val, from levels that would be considered deficient (0.59% digestible) up to adequate (0.84% digestible Val). Results indicate that a ratio of Val to Lys of 78, or a minimum dietary value of 0.74% digestible Val (0.82% total Val), should be adequate for this high-yield broiler grown from 21 to 42 d of age.     

Pre-cecal phosphorus digestibility for corn,wheat, soybean meal,and corn gluten meal in growing Japanese quails from 28 to 32 d of age

The optimization of dietary phosphorus (P) depends on precise details of the P availability in feed ingredients to avoid excess or deficient P in a mixed diet. This study was carried out to measure the apparent ileal digestibility of P for corn, wheat, soybean meal, and corn gluten meal in growing Japanese quails from 28 to 32 d posthatch. A total of 400 quail chicks were randomly distributed across 5 treatments with 4 replicates and 20 birds in each floor pen. The P-free diet (PFD) was formulated based on cornstarch to measure the basal endogenous P losses (EPL). Digestibility coefficients were determined by ileal digesta sampling using TiO₂ as an indigestible marker. The EPL was estimated at 384 mg/kg DMI. The apparent ileal P digestibility (AIPD) for corn, soybean meal, wheat, and corn gluten meal were determined to be 0.38, 0.53, 0.38, and 0.78, respectively. The corresponding values for true ileal P digestibility (TIPD) were 0.48, 0.61, 0.50, and 0.83, respectively. The t-test analysis showed that the difference of AIPD and TIPD values for corn (P = 0.031) and wheat (P = 0.015) were statistically significant, however, no significant differences were observed for corn gluten meal (P = 0.318) and soybean meal (P = 0.104). In conclusion, the correction of AIPD coefficients for EPL in low-P ingredients such as corn and wheat may be much more important than that in high-P feedstuffs such as corn gluten meal and soybean meal in growing quails.     

Effect of dietary digestible lysine level on growth performance,blood metabolites and meat quality of broilers 23–38 days of age

This study was done to evaluate the effects of different dietary digestible lysine (dig Lys) levels on growth performance, blood metabolites, carcass and breast yield, and breast meat quality of broilers 23–38 days of age. Three hundred 23-day-old Cobb-500 male broiler chickens were allocated to a completely randomized design with five treatments (finisher diet containing 0.88%, 0.94%, 1.00%, 1.06% and 1.12% dig Lys) and six replicates of 10 birds each. Feed intake (FI) was not affected by different dietary dig Lys levels. Weight gain (WG) linearly increased and feed conversion ratio (FCR) linearly decreased with an increasing dietary dig Lys levels. With increasing dietary dig Lys levels, carcass and breast yield and breast meat hue angle (h^*) linearly increased, but abdominal fat decreased quadratically, whereas breast meat lightness (L^*) and ether extract composition linearly decreased. Dietary dig Lys levels did not show any significant effect on serum metabolites, breast meat cooking loss and water holding capacity. Based on the linear broken-line regression models, the weight gain, feed conversion ratio and breast yield were optimized when dietary dig Lys levels were 0.95%, 1.01% and 1.02% respectively. It is concluded that Lys requirements vary according to what productive parameter is taken for optimization. A minimum of 1.02% dig Lys concentration in the finisher diet is suggested to optimize breast yield, feed efficiency and performance in broiler chickens.     

P and Ca requirements for Japanese quail

Four experiments were conducted to estimate the phosphorus and calcium requirements for weight maintenance and weight gain in Japanese quails during their growth phase from 16 to 36 days. Japanese quails aged 16 days were used for estimating the phosphorous and calcium requirements for weight maintenance or weight gain, with these quails composing each reference slaughter group and the others distributed in a completely randomized design, housed in cages of galvanized wire (33 × 33 × 16 cm) that were stored in acclimatized chambers with specific environmental temperatures. The light programme used during the 20‐day experimental period was 24 h of artificial light. Analysis of the data showed that the prediction equations for estimating the phosphorus and calcium requirements for weight maintenance and weight gain of Japanese quails between 16 and 36 days of age were P (g/quail/day) = P^0.75*(9.3695 + 7.7397*T) + 9.70*WG, in which P is the phosphorus requirement, and Ca (g/quail/day) = P^0.75*(363.99 – 8.0262*T) + 28.15*WG, in which Ca is the calcium requirement, P is BW (kg), T is temperature (°C) and WG (g/quail/day).     

Estimation of the standardized ileal digestible lysine requirement for primiparous pregnant sows

This experiment was conducted to determine the optimal standardized ileal digestible lysine (SID Lys) level in diets fed to primiparous sows during gestation. A total of 150 (Landrace × Large White) crossbred gilts (weighing 149.9 ± 3.1 kg) were fed gestation diets (12.55 MJ of ME/kg) containing SID Lys levels of 0.43, 0.52, 0.60, 0.70 or 0.80% respectively. Gilts were fed 2.0 kg/day from day 1 to 80 and 3.0 kg/day from day 80 to 110 of gestation respectively. Gilts were allocated to treatments based on their body weight on the day of breeding. Weight gain from day 80 to 110 increased with increasing dietary SID Lys levels (p = 0.044). Fitted broken‐line (p = 0.031) and quadratic plot (p = 0.047) analysis of body weight gain indicated that the optimal SID Lys level for primiparous sows was 0.70 and 0.69% respectively. During gestation, neither backfat thickness nor loin eye area was affected by dietary SID Lys level. Increasing dietary Lys had no effect on the litter size at birth or pigs born alive per litter. Litter weight at birth was not affected by dietary SID Lys level. The litter weight variation at birth quadratically decreased with increasing dietary SID Lys (p = 0.021) and was minimized at 0.70% dietary SID Lys. Gilts fed the 0.70% SID Lys diet had the highest dry matter (p = 0.031) and protein (p = 0.044) content in colostrum. On day 110 of gestation, gilts fed the 0.70% SID Lys diet tended to have the highest serum prolactin (p = 0.085) and serum insulin (p = 0.074) levels. The data demonstrate that the optimal dietary SID Lys was 0.70% for pregnant gilts, which is similar to the recommendation of 0.69% that was estimated by the NRC (2012).     

Individual response of growing pigs to lysine intake

Nitrogen (N) balance experiment was carried out to study the individual and group response of growing pigs to lysine (Lys) intake. A series of 15 purified diets limiting in Lys were fed sequentially to nine pigs (initial body weight, 39 kg) during a 15‐day experiment. Lysine concentration ranged from 50% to 140% of its assumed requirement. N retention in individual pigs was related to Lys intake using linear‐plateau (LP) and quadratic‐plateau (QP) models. No difference in the closeness of fit between the models was found (p = 0.72). There were significant differences between the slopes of individual regression lines in the LP model (p = 0.018) and between the individual plateau values in both models (p < 0.0001). The breakpoint values in the QP model were greater than those of the LP model (p = 0.027), while the plateau values estimated by both models were similar (p = 0.32). In the LP model, no relationship was found between the slopes and plateau values (p = 0.67, r = 0.17) or between the slopes and breakpoint values (p = 0.55, r = ?0.23), thus suggesting that pigs with higher protein deposition rate do not utilize lysine more efficiently. However, there was a close positive correlation between breakpoint and plateau values (p = 0.0005, r = 0.92). Based on LP and QP models, the mean daily requirement of Lys for a 47‐kg gilt was estimated to be 20.8 and 24.2 g (0.79 and 0.92 g/MJ metabolizable energy), respectively, with coefficients of variation of approximately 10%. Marginal efficiency of Lys utilization derived from the LP model was 0.67 and was dependent on the range of input data selected. Lysine disappearance was a curvilinear function of Lys intake, indicating that Lys catabolism is not directly related to Lys intake. The closeness of fit of exponential, saturation kinetics or four‐parameter logistic models applied to data set of all pigs was similar to that of LP or QP models.     

Variation in lysine,threonine, and tryptophan availability in meat and bone meal as estimated by the slope‐ratio growth assay technique in growing rats

Meat and bone meal (MBM) is an important protein source used in animal feeds. However, as the composition and availability of amino acids (AAs) in MBM fluctuate markedly, it is important to verify the magnitude of these parameters in different MBMs. In this study, the AA compositions of 19 MBMs were analyzed to confirm variations in lysine (Lys), threonine (Thr), and tryptophan (Trp), then which were compared with those of soybean meal (SBM) and fish meal (FM). Instability in Lys, Thr, and Trp availabilities in six MBMs were also considered after estimation using the slope‐ratio growth assay technique in rats. Variations in AA composition were evaluated using the coefficient of variance (CV: Standard deviation/Mean). CVs for Lys, Thr, and Trp content were 9.40, 11.83, and 18.12 in MBM, 2.71, 2.48, and 3.19 in SBM, and 10.09, 10.44, and 13.47 in FM. Furthermore, means and SDs for Lys, Thr, and Trp availabilities in MBM were 53.3 ± 10.4% (CV: 19.5), 65.9 ± 17.6% (CV: 26.6), and 83.2 ± 11.2% (CV: 13.5), respectively. These results provide the first evidence that variations in MBM AA compositions were 3.5 to 5.7 times higher than those in SBM, but similar to FM, and that the large variation in availability substantially existed.     

Estimation of dietary lysine requirement using plasma amino acid concentrations in mature thoroughbreds

Four experiments were conducted to estimate dietary lysine (Lys) requirements using plasma amino acid concentrations as a criterion in mature thoroughbreds. In each experiment four adult thoroughbreds were used. The changes in plasma Lys concentration after feeding were observed in Experiment 1. Blood samples were taken from the cervix vein 0.5 h before, and 1, 3, 5.5, and 10 h after feeding. The plasma Lys concentration increased and remained constant until 3 h after feeding, decreased until 5.5 h and remained constant after then. Therefore, the bleed was done at 3 h after feeding in all later experiments. To make sure of the response speed of the plasma Lys to changes of dietary Lys levels, dietary Lys levels were changed from high to low, and low to high levels in Experiment 2. Blood samples were taken just on the changing day and 1, 2 and 3 days after changing diets. The plasma Lys concentration decreased until 2 days after changing the diet, and then remained constant with advancing days after changing the diet from high Lys to low Lys. On the other hand, the plasma Lys increased until one day after changing the diet, and then remained constant with advancing days after changing dietary Lys levels. Thus, blood samples were taken 3 days after feeding in the next experiments. The possibility of estimating the Lys requirement for maintenance using plasma Lys concentration was elucidated by two methods in Experiments 3 and 4. In Experiment 3, the horses were fed a diet containing 0.33 percent Lys for 3 days. After this the diet was changed to diets containing higher levels of Lys to 0.40, 0.47, 0.54, and 0.61 percent every third day. The Lys requirement was estimated to be 0.46 percent of diet from the response of plasma Lys concentration of five Lys levels. In Experiment 4, a 4 × 4 Latin square design was used for four dietary Lys levels. The Lys requirement was estimated to be 0.47 percent of the diet with a plasma Lys concentration of four Lys levels.     

Effects of dietary lysine levels and lighting conditions on intramuscular fat accumulation in growing pigs

This study was conducted to test our hypothesis that intramuscular fat (IMF) accumulation increases in pigs fed on a low lysine diet during the dark period than those fed on the same diet during the light period. Using barrows aged 6 weeks, we monitored whether serum glucose and insulin levels were affected by light conditions. Two diets with different levels of lysine, 0.78% (LL diet) and 1.37% (control diet) were prepared. Eight pigs were fed on the diet during the light period, while the remaining pigs were fed during the dark period. The pigs were fed either the LL diet or the control diet. Although IMF contents of Longissimus dorsi (LD) muscle were higher in the pigs fed on a LL diet (p < .05), the light conditions had no effect. Low dietary lysine caused reduction in serum glucose levels (p < .05) and serum insulin levels (p = .0613). However, they were also unaffected by the lighting conditions. To gain further insights, we determined the messenger RNA levels of insulin receptor, insulin receptor substrate 1, acetyl CoA carboxylase, and fatty acid synthase in LD and Rhomboideus muscles and in the liver.     

基于协方差分析对20～40 kg生长猪真可消化赖氨酸需要量研究

试验选用35头体重为20kg左右的杜×(长×大)三元杂交阉公猪,采用完全随机单因子试验设计,随机分为5个处理,单栏饲喂,自由采食,试验期为35d。分别饲喂真可消化赖氨酸水平(TLys)为1.15%、1.05%、0.95%、0.85%和0.75%的等能(14.23MJ/kg)、等氨基酸模式的玉米-豆粕型日粮。基于协方差分析校正生长猪始重差异,通过测定不同TLys水平对生产性能的影响,确定真可消化赖氨酸需要量。结果表明,当TLys为0.95%时,平均日增重最高(P<0.01),料重比最低(P<0.05);经回归分析,TLys含量为0.95%时,平均日增重达到最大值,而料重比最低。上述结果提示,20～40kg生长猪的TLys需求量为0.95%。     

A simple estimation of ideal profile of essential amino acids and metabolizable energy for growing Japanese quail

An experiment was conducted to determine apparent metabolizable energy (AME) and amino acid requirements of growing Japanese quail based on ideal protein concept using artificial neural network and desirability function (D‐ANN). Seven‐day‐old quail chicks were assigned to nine experimental diets based on central composite design (CCD) containing five levels of AME (2809–3091 kcal/kg) and CP (19–24.8% of diet). The ratio of lysine (Lys) to CP was set at 0.053 among all treatments, and remaining essential amino acids (EAA) were adjusted to Lys. The experimental data of CCD were fitted to D‐ANN model to compute the optimal values for independent variables. The optimal values of inputs including AME, CP, digestible Lys (dLys), methionine (dMet), total sulphur amino acids (dTSAA), threonine (dThr), tryptophan (dTrp), isoleucine (dIle), valine (dVal) and arginine (dArg) for maximizing gain and minimizing feed conversion ratio were estimated at 2865 kcal/kg, 25, 1.32, 0.55, 0.88, 0.84, 0.20, 0.75, 1.04 and 1.45% of diet, respectively, with D (desirability function) = 0.94. The corresponding optimal amounts of amino acids based on total amino acids were 1.42, 0.59, 0.95, 0.90, 0.22, 0.81, 1.12 and 1.56% of diet respectively. The ideal pattern of essential amino acids to Lys was as follows: dMet: dLys = 0.42, dTSAA: dLys = 0.67, dThr: dLys = 0.64, dTrp: dLys = 0.15, dIle: dLys = 0.57, dVal: dLys = 0.79 and dArg: dLys = 1.09. The results of this study showed that amino acid requirements of modern quails might be higher than those reported by NRC.