Modelling Methionine Requirements of Fast- and Slow-Growing Chinese Yellow-Feathered Chickens during the Starter Phase

Standardized ileal digestible methionine requirements for 22 to 29-d-old male broilers based on the growth performance and feather development

The aim of the present experiment was to determine the standardized ileal digestible (SID) methionine (Met) requirement during the grower phase (22 to 29 days). A total of 192 Ross 308 male broilers (745 ± 50.5 g) were assigned to six dietary treatments in a randomized complete block design, with eight replicate cages per treatment. The experimental diets were formulated based on corn, soybean meal, and synthetic amino acids (AA), with different levels of dietary SID Met ranging from 0.40% to 0.65%, in increments of 0.05%. Individual body weight and feed intake per cage were measured at the beginning and end of the experimental period. Weight gain (g/bird), feed intake (g/bird), gain-to-feed ratio (g/kg), feather weight (g), and relative feather percentage (% of body weight) were analyzed for linear or quadratic responses using orthogonal polynomial contrasts. Final body weight, weight gain, and feed intake increased quadratically as dietary SID Met concentration increased (p < 0.05). However, the composition of AA in the feathers showed no quadratic or linear effect based on dietary SID Met concentrations, except for Ile (p = 0.05; quadratic). The SID Met requirements for optimum and maximum weight gain of 22 to 29-days-old male broilers were estimated using the broken-line and quadratic-line models to 0.45% and 0.55%, respectively.

Effects of Aflatoxin B1 on growth performance, carcass traits, organ index, blood biochemistry and oxidative status in Chinese yellow chickens

In this study, the effects of different levels of aflatoxin B1 (AFB1) on the growth performance, carcass traits, organ index, blood biochemistry, and antioxidant capacity of yellow-feathered broilers were investigated to provide a reference for the application of AFB1-containing feed ingredients. In this test, yellow-feathered broilers were chosen as the research objects and divided into five treatment groups, with seven replicates in each group and 75 broilers in each replicate. The AFB1 concentration in the diets of groups 1 to 5 were 1.5 μg/kg, 15 μg/kg, 30 μg/kg, 45 μg/kg, and 60 μg/kg, respectively. The results showed that when dietary AFB1 levels were greater than 45 μg/kg, the feed conversion ratios of broilers of 1-21, 22-42, and 43-63 days of age increased (P<0.05). When dietary AFB1 levels were 30 μg/kg, liver glutathione peroxidase (GPx) activity was decreased (P<0.05), and serum transaminase (AST) activity was increased (P<0.05). Overall, dietary AFB1 levels had negative effects on growth performance, antioxidant capacity, blood biochemistry, and liver metabolism in yellow-feathered broilers. Based on using growth performance as the effect index, AFB1 levels in the diets of yellow-feathered broilers should not exceed 45 μg/kg. Based on using antioxidant capacity, liver function, and blood biochemistry as effect indexes, AFB1 levels in the diets of yellow-feathered broilers should not exceed 30 μg/kg.

Influence of Nano-Methionine supplementation in drinking water on growth performance, lipid metabolism, and related gene expression in broiler chicken

Objectives

The study aimed to determine how Nano-Methionine (Nano-Meth) affected growth, lipid metabolism, and relative gene expression for acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), growth hormone receptor (GHR), insulin-like growth factor receptor-1 (IGFR-1), myostatin (MSTN), and cholecystokinin (CCK) genes in broiler chickens.

Materials and Methods

A total of 100 1-day-old broilers were randomly assigned into 2 groups: 1) the control group received drinking water without any supplements, and 2) the Nano-Meth group received 10 ml/l of 5% Nano-Meth starting from 1 day old until 35 days old (the end of the experiment).

Results

Nano-Meth improved final body weight, weight gains, feed intake, and feed conversion ratio. Compared to the control group, Nano-Meth significantly lowered the serum levels of triglyceride, cholesterol, very low-density lipoprotein, and low-density lipoprotein in chickens. Nano-Meth significantly increased the serum levels of total protein, albumin, high-density lipoprotein, and glucose more than the control group. Nano-Meth lowered the mRNA gene expression of ACC, FAS, MSTN, and CCK but increased that of GHR and IGFR-1.

Conclusions

We concluded that supplementation with Nano-Meth enhances growth performance and decreases lipid accumulation in broiler chickens.

QPCTL Affects the Daily Weight Gain of the F2 Population and Regulates Myogenic Cell Proliferation and Differentiation in Chickens

Molecular breeding can accelerate the process of animal breeding and improve the breeding efficiency. To date, many Indel molecular markers have been identified in livestock and poultry, but how Indels affect economic traits is not well understood. For molecular breeding, it is crucial to reveal the mechanism of action of Indels and to provide more accurate information. The purpose of this study was to investigate how the 52/224-bp multiallelic Indels of the chicken QPCTL promoter area affect the daily weight gain of chickens and the potential regulatory mechanism of the QPCTL gene. The analysis was conducted by association analysis, qPCR, dual-fluorescence assay and Western blotting. The results showed that Indels in the QPCTL promoter region were significantly associated with the daily weight gain in chickens and that QPCTL expression showed a decreasing trend in embryonic breast muscle tissues. Furthermore, QPCTL expression was significantly higher in breast muscle tissues of the AC genotype than in those of the AB and BB genotypes. Based on the transcriptional activity results, the pGL3-C vector produced more luciferase activity than pGL3-A and pGL3-B. In addition, overexpression of QPCTL promoted chicken primary myoblast (CPM) proliferation and inhibited differentiation. The results of this study suggest that Indels in the promoter region of the QPCTL gene may regulate the proliferation and differentiation of CPMs by affecting the expression of QPCTL, which ultimately affects the growth rate of chickens. These Indels have important value for the molecular breeding of chickens, and QPCTL can be used as a candidate gene to regulate and improve chicken growth and development.

A High-Performance Day-Age Classification and Detection Model for Chick Based on Attention Encoder and Convolutional Neural Network

Thanks to the boom of computer vision techniques and artificial intelligence algorithms, it is more available to achieve artificial rearing for animals in real production scenarios. Improving the accuracy of chicken day-age detection is one of the instances, which is of great importance for chicken rearing. To solve this problem, we proposed an attention encoder structure to extract chicken image features, trying to improve the detection accuracy. To cope with the imbalance of the dataset, various data enhancement schemes such as Cutout, CutMix, and MixUp were proposed to verify the effectiveness of the proposed attention encoder. This paper put the structure into various mainstream CNN networks for comparison and multiple ablation experiments. The final experimental results show that by applying the attention encoder structure, ResNet-50 can improve the accuracy of chicken age detection to 95.2%. Finally, this paper also designed a complete image acquisition system for chicken houses and a detection application configured for mobile devices.

Impacts of dietary supplementation with nano-iron and methionine on growth, blood chemistry, liver biomarkers, and tissue histology of heat-stressed broiler chickens

A 28-day study was done to explore the impact of nano-iron alone or combined with methionine on growth, blood chemistry, liver biomarkers, and tissue histology of heat-stressed chicken. One-day-old Ross 308 chicks were randomly allocated to three groups. Each group was divided into three replicates (13 chicks/replicate). The first group was the control one that was fed a basal diet without supplementation (T0). The second group was fed a basal diet with nano-iron 4 mg kg^-1 diet (T1). The third group was fed a basal diet with nano-iron 4 mg kg^-1 diet plus methionine 4 g kg^-1 diet (T2). The results showed that the birds in the control group had significantly (p < 0.05) higher final weights. Also, a partial relief of heat stress adverse effects was observed on growth by T1 compared to T2. The T2 showed a significantly increased (p < 0.05) free iron (Fe) level and transferrin saturation index. Likewise, T2 significantly (p < 0.05) reduced total iron-binding capacity (TIBC) and transferrin level in comparison with T0 and T1. Also, hepatic impairment and inflammatory response were observed in the T2 group when compared to T0 and T1, besides a bad lipid profile. Further, T2 showed raised levels of Fe and ferritin in their hepatic tissues compared to those T1 and T0. A significant increment of thiobarbituric acid reactive and decrement of reduced glutathione levels in the hepatic tissues of T2 and T1 versus T0 levels were recorded. It is concluded that nano-iron at the level of 4 mg kg^-1 in this study is highly absorbed, leading to harmful effects. Further investigations are needed to detect the proper supplemental level.

Effects of maternal and post-weaned rumen-protected folic acid supplementation on slaughter performance and meat quality in offspring lambs

The present study was undertaken to evaluate the influence of rumen-protected folic acid (RPFA) on slaughter performance, visceral organ and gastrointestinal tract coefficients, and meat quality in lambs. Sixty-six lambs from 120 Hu ewes were selected based on body weight and maternal diets and then assigned to six groups using a randomised block experimental design in a 3 × 2 factorial arrangement. The first factor was folic acid (FA) as RPFA in the maternal diet (0 mg/kg (M0F), 16 mg/kg (M16F) or 32 mg/kg (M32F) on DM basis). The second factor was FA in the lambs' diet from weaning until slaughter (0 mg/kg (OC) or 4·0 mg/kg (OF)). The results indicated that the addition of 16 mg/kg FA to the maternal diet increased pre-slaughter weight (PSW), dressing and meat percentage, the reticulum and omasum coefficients, length of the jejunum and ileum, tail fat and perirenal fat coefficient and a* value of the meat colour. The addition of RPFA to the lambs' diet increased PSW, dressing and meat percentage, eye muscle area, abomasum weight, weight and length of the small intestine, but reduced the coefficients of tail fat. An M × O interaction was observed for the weights of heart, lungs, rumen and total stomach, weight and coefficient of omental fat and the girth rib value. Collectively, RPFA in the maternal and lambs' diet improved slaughter performance and meat quality by stimulating the morphological development of the gastrointestinal tract and the distribution of fat in the body.

Hyperhomocysteinemia Induced by Methionine Excess Is Effectively Suppressed by Betaine in Geese

The objective of our study was to investigate the effects of excess Methionine (Met) on the growth performance, serum homocysteine levels, apoptotic rates, and Bax and Bcl-2 protein levels in geese and to study the role of Bet (betaine) in relieving excess Met-induced hyperhomocysteinemia (HHcy). In this study, 150 healthy male 14-day-old Yangzhou geese of similar body weight were randomly distributed into three groups with five replicates per treatment and 10 geese per replicate: the control group (fed a control diet), the Met toxicity group (fed the control diet +1% Met), and the Bet detoxification group (fed the control diet +1% Met +0.2% Bet). At 28, 49, and 70 d of age, the geese in the Met toxicity group had significantly lower body weights than those in the control group (p < 0.05). The serum homocysteine levels in geese at 70 d of age in the detoxification group were significantly lower than those in the Met toxicity group (p < 0.05). Compared with the control, Met significantly increased cardiomyocyte apoptosis rates, while Bet reduced them. In conclusion, our results suggest that excess methionine reduces body weight induced by myocardial apoptosis, and Bet can be used to effectively lower plasma homocysteine levels.