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This experiment was conducted to investigate the effects of dietary hydrolyzed tannins (HT) on production performance and intestinal barrier in weaned meat rabbits, and to determine the application effect of in the diet of weaned meat rabbits. A total of 288 (35-day-old) meat rabbits with similar body weight (half male and half female) were randomly divided into 6 treatments (4 replicates per treatment, 12 rabbits per replicate). The rabbits were fed a basal diet (control group), a diet supplemented with 0.75 kg/t HT in basal diet (0.75 HT), a diet supplemented with 1.5 kg/t HT in basal diet (1.5 HT), a diet supplemented with 3 kg/t HT in basal diet (3 HT), a diet supplemented with 0.20 kg/t enramycin in basal diet (EC group) or a diet supplemented with 0.20 kg/t colistin sulfate in basal diet (CS group) respectively. The trail includes a pre-feeding period of 7 days and a normal feeding period of 30 days. The results were as follows: there were no significant effects on daily feed intake, body gain, feed to gain ratio, diarrhea rate and immune organ index in weaned meat rabbits between control group and HT treated groups (P>0.05). The mortality in rabbits was decreased after dietary supplementation of 3 kg/t HT compared with the control group (P<0.05). Compared with the two antibiotic groups, the mortality of meat rabbits was not significant affected by 3 kg/t HT treatment (P>0.05). The villus height/crypt depth in ileum were increased after dietary supplementation of 3 kg/t HT compared with the control group (P<0.05). The expression of ligand adhesion molecule-2 gene in jejunum was increased after dietary supplementation of 3 kg/t HT compared with the control group (P<0.05). In conclusion, dietary addition of HT has no significant effect on growth performance and diarrhea rate of weaned meat rabbits, and the effect is less than that of antibiotic group. Dietary addition of 3 kg/t HT significantly decreased the mortality in weaned meat rabbits and improved the physical barrier of jejunum. [ABSTRACT FROM AUTHOR]

In order to study the effects of Chinese veterinary medicine compound and probiotic compound in anti-bacterial breeding of poultry, 300 chicks were selected in this experiment, and fed with Chinese veterinary medicine compound and probiotic complex to observe the effects on growth performance, slaughter performance, immune performance, organ index and muscle nutrition quality of Green Leg chicken. The chicken were divided into 5 groups, group 1 (control group) was fed basic diet, group 2 were added 0.083% probiotic complex; groups 3, 4 and 5 were supplemented with 0.3%, 0.6% and 0.9% Chinese veterinary drug compound, respectively. The experimental period was 150 days. The results showed as follows: compared with the control group, the average daily gain in groups 2 and 5 were significantly increased (P<0.01), spleen index in groups 3, 4, 5 were increased, and serum immunoglobulin (IgG, IgM, IgA) and interleukin (IL-1) contents were significantly increased (P<0.01). The full evisceration rate in groups 3, 4, 5 were increased, and the contents of aspartate, glutamic acid, and inosine acid in groups 2, 3, 4 and 5 were increased. In conclusion, the addition of 0.6%, 0.9% Chinese veterinary medicine compound or 0.083% probiotic complex in the feed has a significant effect on the anti-breeding of Green Leg chicken. [ABSTRACT FROM AUTHOR]

Caragana korshinskii is an important legume shrub for windbreak and sand fixation and ecological improvement in northwest China. It has the advantages of large biomass and strong stress resistance. It is rich in lignocellulose, amino acids, polyphenols and flavonoids, and has high nutritional value and potential utilization value. This paper reviews the nutritional characteristics, feed utilization methods and feeding value of Caragana korshinskii, summarizes its feeding effect in ruminants, and analyzes the difficulties and utilization methods of Caragana korshinskii feed utilization. At the same time, the future research and development direction of Caragana korshinskii is prospected, which provides a reference for the in-depth development and utilization of unconventional feed resources of Caragana korshinskii. [ABSTRACT FROM AUTHOR]

In order to explore the influence of the combined breeding mode on the goose breeding industry, the production performance, slaughter performance and meat quality of Sanhua geese were measured by the comparative experiment of cornfield stocking and house feeding, which provided technical basis for the upgrading and transformation of goose industry. A total of 320 geese aged 50 days, half male and half female, were randomly divided into 1 experimental group and 1 control group with 8 replicates in each group and 20 geese in each replicate. The experiment period was 21 days. The geese were fed basic diet in the house and no herbicide was used in the corn field. The results showed that the survival rate, average daily feed consumption and feed to gain ratio of experimental group and control group were significantly different (P<0.01). There were significant differences in slaughter rate, full evisceration rate and half evisceration rate between experimental group and control group (P<0.01). The shear force index of experimental group was significantly different from that of control group (P<0.01). There were significant differences in leg muscle percentage, abdominal fat percentage, drip loss, redness (a*) and yellow (b*) between experimental group and control group (P<0.05). There were no significant differences in other indexes (P>0.05). The results showed that the combined breeding mode had certain advantages in improving the survival rate, slaughtering performance and meat quality, and could significantly reduce the feeding cost. [ABSTRACT FROM AUTHOR]

This research examined the effects of adding slow-release urea to the diet of fattening yaks on their production performance, slaughter performance, and blood biochemical indexes. Twenty-four healthy male Maiwa yaks with similar body weight [(277.9±10.4) kg] were selected and divided into three treatment groups: the control group: fed with the original total mixed ration from the farm (ME 11.03 MJ/kg, CP 10%); 0.5% group: using corn distillers dried grains with solubles (DDGS) to replace part of roughage in the diet, and to decrease the level of roughage, and adding 0.5% slow-release urea (ME 11.35 MJ/kg, CP 12.77%); 1.0% group: using corn DDGS to replace soybean meal and rapeseed meal in the diet, and adding 1.0% slow-release urea (ME 11.42 MJ/kg, CP 12.77%). Yaks were given a 10 d adaptation period and then followed by the 60 d formal feeding experiment. On the 60th day, before the morning feeding, serum samples were collected for biochemical indexes determination. The results showed that: ① the average daily weight gain of the 0.5% group was higher than that of the control group (P<0.05). ② The alanine aminotransferase activity in both the 0.5% and 1.0% groups were higher than those in the control group (P<0.05), and the 1.0% group was higher than the 0.5% group (P< 0.05). The aspartate aminotransferase activity in the 1.0% group was higher than that of the control group (P<0.05). The blood ammonia concentration in 1.0% group was higher than that in control group (P< 0.05), and the plasma urea nitrogen in 1.0% group was higher than that in 0.5% and control group (P< 0.05). ③The slaughter rate and net meat rate of the 0.5% group were 1.1 and 1.4 percentage higher than that of the control group respectively. ④The economic benefits of the 0.5% and 1.0% group were improved by 24.03% and 29.96% respectively compared to the control group. The combined use of 1.0% slow-release urea and corn DDGS can completely replace soybean meal and rapeseed meal in the ration of fattening yaks and increase economic benefits. [ABSTRACT FROM AUTHOR]

This study was to investigate the effects of plant essential oils from different sources on the growth performance of piglets, and to provide scientific basis for the application of plant essential oils in piglet feeding and feed production. In experiment 1, 384 PIC weaned piglets with body weight (7.90±0.46) kg were randomly divided into 4 groups with 4 replicates of 24 piglets each. The control group was fed commercial diet without antibiotic and plant essential oil, and the experimental group was fed essential oil R, essential oil A and essential oil B, respectively. The feeding trial lasted 32 days. In Experiment 2, 320 PIC nursery piglets with body weight (10.92±0.53) kg were randomly divided into 4 treatment groups with 4 replicates of 20 piglets each. The control group was fed commercial diet without antibiotic and plant essential oil, and the experimental group was fed a certain amount of essential oil R, essential oil A and essential oil B, respectively. The feeding trial lasted 23 days. The results of experiment 1 showed that compared with the control group, essential oils R and B could significantly reduce the F/G of weaned piglets (P<0.05), and the F/G of essential oil R was the lowest. In addition, only essential oil R can significantly reduce the diarrhea rate of weaned piglets (P<0.01). The results of experiment 2 showed that the F/G of nursery piglets with essential oil R was significantly lower than that of the control group and other experimental groups (P<0.05). During the experiment, there was no significant difference in diarrhea rate among all treatment groups (P>0.05). In addition, several essential oils had no significant effect on the hair condition and skin color of piglets (P>0.05). In conclusion, adding R essential oil to the diet can significantly improve the production performance of weaned and nursery piglets, and the effect is better than that of A essential oil products and B essential oil products. [ABSTRACT FROM AUTHOR]

This experiment was conducted to study the effects of green tea powder on production performance, serum antioxidant indexes and cecal microflora structure of laying hens. A total of 240 24-weekold Jingfen No.6 commercial laying hens were randomly divided into 4 groups with 5 replicates per group and 12 hens per replicate. The control group was fed a basal diet, and the three experimental groups were fed a basal diet containing 0.50%, 0.75% and 1.00% green tea powder, respectively. The experiment lasted for 8 weeks. The results showed that, the laying rate of 0.50% and 0.75% green tea powder groups were slightly higher than that of the control group (P>0.05), but significantly higher than that of 1.00% green tea powder group (P< 0.05), and the laying rate of 1.00% green tea powder group was slightly lower than that of the control group (P>0.05). Compared with the control group, the addition of 1.00% green tea powder significantly reduced serum superoxide dismutase (SOD) activity (P<0.05), 0.75% and 1.00% green tea powder significantly increased serum glutathione peroxidase (GSHPx) activity (P<0.05), 0.50%, 0.75% and 1.00% green tea powder significantly reduced serum malondialdehyde (MDA) content (P<0.05). Adding 0.50%, 0.75% and 1.00% green tea powder had no significant effect on Chao1 index, Richness index, Shannon index and ACE index of laying hens (P>0.05). The addition of green tea powder had no significant effect on the structure of cecal microbial flora (P>0.05). In summary, dietary green tea powder inclusion could improve the production performance and serum antioxidant indexes, and affected the diversity and structural composition of cecal microbiota in laying hens, the proper supplemental level in diet of green tea powder was 0.50% to 0.75% in the current study [ABSTRACT FROM AUTHOR]

This experiment was conducted to study the effects of dietary Ca/P level on the growth perfor‐ mance and blood indexes of Hu sheep. The single factor design was used, and 48 Hu sheep with similar age and body weight were selected. According to the dietary Ca/P level, it was divided into three treat‐ ments with 4 replicates in each treatment and 3 Hu sheep weaned male lambs in each replicate. They were fed diets of Ca/P level at 2.13, 1.63 and 1.28, respectively, with the concentrate∶ roughage ratio of 33∶ 67. The results showed that: ① dietary Ca/P level had no significant ef‐ fect on feed intake and feed to meat ratio of weaned Hu lambs (P>0.05); the daily gain of low Ca/P level group was significantly higher than that of high Ca/P level group and medium Ca/P level group (P<0.05). ② Serum calcium content increased significantly with dietary phosphorus level (P<0.01); the urea nitrogen of low Ca/P level group was significantly higher than that of high Ca/P level group (P< 0.05); dietary Ca/P level level had no significant effect on serum total protein, albumin, alkaline phospha‐ tase and inorganic phosphorus (P>0.05). Under the experimental conditions, considering the production performance and blood indexes, the suitable dietary Ca/P level of Hu sheep weaned male lambs was 1.28 to 1.63. [ABSTRACT FROM AUTHOR]

The serious shortage of protein feed resources and greenhouse gases emissions from livestock production system have become two major bottlenecks restricting the high-quality and sustainable devel‐ opment of animal husbandry in China. Low-protein diet technology is based on the precise nutrient re‐ quirement of animals to achieve stable or improved production performance by lowering the feed cost. Methane is an inevitable product of ruminant physiological metabolism, representing not only an impor‐ tant energy loss, but also a critical source of greenhouse gas emissions. In recent years, the research on the effect of low-protein diet on production performance, enteric methane emissions of ruminants have increasingly become an important area. Therefore, this paper briefly summarized the definition and characteristics of low-protein diet used for ruminants in recent years, and reviewed the impact of low-protein diet on growth performance, milk pro‐ duction, and enteric methane emissions, and explored the possible mechanism of action behind the low-protein diet to provide theoretical reference for the research and application of this technology in ruminant production regimes [ABSTRACT FROM AUTHOR]

In order to study the hybrid effect between Tibetan chickens and Avian, 1-day-old healthy Ai-Tibetan hybrid chickens and the pure breeding of Tibetan chickens were selected in the experiment, 100 feathers each. In the same feeding environment, the same nutritional standard was provided, and the growth and development, body size index, slaughter performance and meat quality were studied, and the crossbreeding effect of Avian and Tibetan chicken was comprehensively evaluated. The results showed that the growth rate of Ai-Tibetan hybrid chickens was slightly faster than that of Tibetan chick‐ ens on the whole (except 70 days of age), and the body weight at 30 and 60 days of age was significantly higher than that of Tibetan chickens (P<0.05), but there was no significant difference in the other days of age. The breast width of 60-day-old Ai-Tibetan hybrid chickens was significantly higher than that of Ti‐ betan chickens (P<0.05), and the tibia length and oblique body length of 90-day-old Ai-Tibetan hybrid chickens were significantly higher than that of Tibetan chickens (P<0.05). The thigh muscle percentage and liver weight percentage of hens in Ai-Tibetan group were significantly higher than those in other groups, but the other indexes were not significantly different. Muscle color a* of Tibetan chickens was significantly higher than that of Ai-Tibetan hybrid chickens (P<0.05), and the drip loss rate of Ti‐ betan group was much lower than that in AiTibetan hybrid chickens, and there was a signifi‐ cant difference (P<0.05). The cooking loss of the Tibetan chickens was also lower than that of AiTibetan hybrid chickens. The meat quality of Ti‐ betan chickens was better than that of Ai-Tibetan hybrid chickens. Comprehensive analysis showed that the growth rate, slaughter performance and meat quality of the hybrid offspring of Tibetan chickens and Avian had no outstanding advantages in the envi‐ ronment of high altitude, and the hybridization effect was not obvious. [ABSTRACT FROM AUTHOR]

Meta-analysis is used to analyze the effects of sesame meal replacing soybean meal diet on growth performance and meat quality of mutton sheep, so as to provide basis for the feasibility of sesame meal as feed protein source for mutton sheep. Relevant literatures were collected in Chinese and English databases by keywords combination. According to the inclusion and exclusion criteria, eight literatures were included, including 138 lambs fed with sesame meal instead of soybean meal in the experimental group and 66 lambs fed with soybean meal in the control group. Average daily gain and feed conversion ratio were used as growth performance parameters. A total of 204 lambs were collected with pH, shear force and water holding capacity at 24 h after slaughter as the main parameters of mutton quality. Meta-analysis was performed by RevMan software. According to the forest map, the heterogeneity of the included literature was checked. The source of heterogeneity was determined by subgroup analysis. Finally, sensitivity analysis was per‐ formed to evaluate the stability and the publication bias of the literature was evaluated according to the funnel plot. The results showed that the replacement of soybean meal with sesame meal increased the average daily gain of mutton sheep significantly (P≤0.05) and reduced the feed-meat ratio significantly (P≤ 0.05), there was no effect on the pH，shear force (P>0.05), and water holding capacity (P≤0.05). Sub‐group analysis showed that when the replacement ratio of sesame meal was less than 20%, the average daily gain of mutton sheep was significantly increased (P<0.01) and the feed weight ratio was significantly reduced (P≤0.05). Feeding period more than 70 days could significantly increase the average daily gain (P≤0.05) and significantly reduced the feed conversion ratio (P≤0.05). Sensitivity analysis showed that the results of Meta-analysis were stable and reliable, and funnel plot showed that there was no publication bias for the collected literature. In summary, replacing soybean meal with sesame meal can significantly improve the growth performance of mutton sheep. When the proportion of sesame meal replacing soybean meal in the diet is less than 20% and the feeding-period is more than 70 days, the growth performance is the most significant, and there is no negative impact on meat quality. From the perspective of production performance, sesame meal can be used as a new feed protein source for mutton sheep. [ABSTRACT FROM AUTHOR]

This experiment aims to study the effects of grape seed extract on the production performance, serum antioxidant and anti-inflammatory capabilities of laying hens during the late peak period of egg production. Five hundred and fourty 53-week-old Jingfen No.2 laying hens with similar body condition and egg-laying performance were selected and randomly divided into 3 treatment groups, namely the control group (CON group) and the grape seed extract 200 mg/kg group (G2 group), grape seed extract 300 mg/kg group (G3 group), each group has 6 replicates, each replicate has 30 pigeons. The CON group was fed basal diet, the G2 group was fed basal diet + 200 mg/kg grape seed extract, and the G3 group was fed basal diet + 300 mg/kg grape seed extract. The test period is 60 days. The results showed: ①compared with the CON group, the egg production rate, average egg weight and average daily feed intake of the G3 group were signifi‐ cantly increased, and the feed-to-egg ratio was significantly decreased (P<0.05). ② Compared with the CON group, the serum SOD activity of the G3 group was significantly increased and the MDA content was significantly decreased (P<0.05). ③ Compared with the CON group, the serum levels of IL-1β, IL-2, IL-4, IL-6, IL-10, and TNF-α in the G2 group and the G3 group all showed a downward trend, but the difference was not significant (P>0.05). In summary, adding 200 mg/kg grape seed extract and 300 mg/kg grape seed extract to the diet of laying hens during the late peak period of egg production has a positive effect on improving production performance, serum antioxidant and anti-inflammatory capabilities, and 300 mg/kg addition level has the best effect. [ABSTRACT FROM AUTHOR]

This experiment was conducted to study the effects of compound Chinese herbal medicine additives on the production performance, milk quality, and serum immune indicators of lactating cows. Sixty 24-month-old Chinese Holstein dairy cows were randomly divided into 4 groups with 3 replicates in each group and 5 cows in each replicate. Others in the control group were fed a basal diet, and the others in the three experimental groups were fed the basal diet supplemented with 100, 200 g/d and 400 g/d compound Chinese herbal additives, respectively. The experiment lasted for 30 days. The results showed as follows: Compared with the control group, dietary supplementation of 200 g/d and 400 g/d compound Chinese herbal additives significantly increased the average daily milk yield of lactating cows (P<0.05), and significantly decreased the ratio of feed to milk of lactating cows (P<0.05); dietary supplementation of 200 g/d and 400 g/d compound Chinese herbal medicine additive significantly increased the milk protein level of lactating cows (P<0.05), and significantly decreased the somatic cell count of milk (P<0.05). Dietary 200 g/d and 400 g/d compound Chinese herbal medicine additive significantly increased the contents of immunoglobulin A (IgA), immunoglobulin G (IgG) and interleukin-2 (IL-2) in serum of lactating dairy cows (P<0.05). The content of interleukin-1β (IL-1β) in serum of lactating cows was significantly decreased (P<0.05). In conclusion, dietary supplementation of compound Chinese herbal medicine additives can improve the production performance, dairy quality and immune function of lactating dairy cows. Considering the economic cost, the recommended dosage of compound Chinese herbal medicine additives is 200 g/d. [ABSTRACT FROM AUTHOR]

This experiment was conducted to investigate the effects of Antrodia cinnamomea culture on performance, egg quality and serum antioxidant indexes of laying hens in late peak period. A total of 288 Hyline white laying hens (400 days of age) with similar body condition and laying performance in the late peak period of laying were randomly divided into four groups: control group and low, medium and high dose groups. Laying hens in control group were fed a basal diet, and laying hens in low, medium and high dose groups were fed the basal diet supplemented with 50 mg/kg, 100 mg/kg and 200 mg/kg Antrodia cinnamomea culture, respectively. The pre-test lasted for seven days and the experiment lasted for 28 days. The results showed as follows: compared with the control group, the laying rate, daily feed intake and daily egg weight in the Antrodia cinnamomea culture group were slightly increased, and the ratio of feed to egg in the 50 mg/kg and 100 mg/kg Antrodia cinnamomea culture groups were slightly lower than that in the control group, but the difference was not significant (P>0.05); Antrodia cinnamomea culture had no significant effect on egg quality. The proportion of dark red liver in 200 mg/kg Antrodia cinnamomea culture group was 83.33% with the increase of Antrodia cinnamomea culture dosage. With the increase of Antrodia cinnamomea culture, the pathological changes of liver tissue slices of laying hens could be reduced or disappeared; the superoxide dismutase (SOD) content of 200 mg/kg Antrodia cinnamomea culture group was significantly higher than that of 50 mg/kg group and control group (P<0.05), but the contents of malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were not significantly different among all groups (P>0.05). When 50 g and 100 g Antrodia cinnamomea culture were added to the diet per ton, 72 laying hens fed for 28 days could gain an additional profit of 34.4 yuan and 58.4 yuan, respectively. In conclusion, Antrodia cinnamomea culture can improve the production performance of laying hens in the late peak period, reduce the incidence of fatty liver of laying hens, improve serum antioxidant indexes, and increase the breeding income of farmers, among which the 100 mg/kg group of Antrodia cinnamomea has the best profit. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to study the effect of biofermented feed on the performance, egg quality and intestinal microflora of laying hens. A total of 18 000 healthy laying hens at 43 weeks of age with similar egg production rate and average egg weight were selected and randomly divided into 2 groups (6 replicates per group). The control group was fed the basic diet, and the experimental group was fed the basic diet with 5% fermented feed. The experimental period was 60 days. The results were as follows: ① compared with the control group, the egg production rate of the experimental group increased, and the feed to egg ratio, egg breakage rate and dead rate were reduced. ② On the 60th day, the average egg weight, egg white height, yolk color, eggshell weight and yolk weight of the test group were all extremely significantly higher than those of the control group (P<0.01), and the eggshell thickness was significantly higher than that of the control group (P<0.05). ③ Compared with the control group, the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities of the test group were significantly increased (P<0.05); malondialdehyde (MDA) content was significantly decreased (P<0.05); and the immunoglobulin G (IgG) content was highly significantly increased (P<0.01). ④ Compared with the control group, the experimental group of laying hens showed an increase in the abundance of the intestinal thick-walled phylum, a decrease in the abundance of the anaplastic phylum, an increase in the intestinal thick-walled phylum/anaplastic phylum (F/B) ratio, and an increase in the diversity of the community. It can be seen that the addition of biofermented feed to the ration can improve the production performance of laying hens, improve egg quality, enhance the antioxidant capacity and immunity of laying hens, and improve the intestinal microflora of laying hens. Therefore, it is important to use biofermented feeds to improve the performance and intestinal health of laying hens, and this paper can pro‐ vide a reference for the popularization and application of biofermented feeds in laying hens' diets. [ABSTRACT FROM AUTHOR]

In this experiment, 240 one-day-old female ducks were randomly divided into 3 groups with 4 replicates in each group and 20 ducks in each replicate. Ducks in the control group were used a basal diet, and those in the test Ⅰ, Ⅱ group were used the basal diet supplemented with 5×108 CFU/kg and 8×108 CFU/kg 0.1% Bacillus subtilis. The experiment lasted for 60 weeks. The results showed as follows: ① compared with the control group, the growth rate of test Ⅱ group was significantly increased (P<0.01), and the ratio of feed to gain was significantly decreased (P<0.05). ② The body size indexes of meat performance measured at the 10th week showed no significant difference in test group Ⅱ except chest depth and shin circumference (P>0.05), the difference of other indexes was very significant (P<0.01). ③ In terms of reproductive performance, compared with the control group, there were no significant differences in the survival rate, laying rate and the number of eggs laid only in trial Ⅱgroup (P>0.05), but there had significant differences in the soft broken egg rate, the qualified rate of breeding eggs, egg weight, fertilization rate, hatching rate and healthy brood rate (P<0.01). The index of qualified rate, fertilization rate and healthy brood rate had no significant difference (P>0.05), the index of egg weight had significant difference (P<0.05), and the other indexes had extremely significant difference (P<0.01). In conclusion, the diet supplemented with 0.1% Bacillus subtilis preparation 8×108 CFU/kg has the best effect on the performance, body size and reproductive performance of meat-type breeder female ducks. [ABSTRACT FROM AUTHOR]

This experiment was conducted to study the effects of 25-hydroxyvitamin D3 at different doses on production and hatching performance of Hyline brown egg-laying breeders. A total of 400 Hyline brown egg-laying breeders powder parental generation aged 15 weeks were selected and randomly di vided into four groups. The control group was fed a basal diet, and the groups 1, 2 and 3 were fed the basal diet supplemented with 25-hydroxyvitamin D3 20, 40 and 60 µg/kg, respectively. The laying perfor mance and reproductive performance were detected after the beginning of laying. The test period was 81 days. The results showed as follows: the fertilization rate, hatching rate and healthy chick rate of egglaying breeders in groups 1, 2 and 3 were significantly higher than those in control group (P<0.05). The death rate of egg-laying breeders in groups 1, 2 and 3 was significantly lower than that in control group (P<0.05). The bone density and bone hardnessof egg-laying breeders in groups 1,2 and 3 were signifi cantly higher than those in control group (P<0.05). In conclusion, the addition of 25-hydroxyvitamin D3 to the pre-natal and early natal diets can significantly improve the production and reproductive perfor mance of 15-week-old Hyline Brown egg-laying breeders, and the optimal supplemental concentration was 40 µg/kg. [ABSTRACT FROM AUTHOR]

In order to screen excellent gramineous forage crops suitable for planting in high altitude areas, four oat (Avena sativa) varieties, one triticale (Triticale) and one rye (Secale) variety were introduced and planted in the valley farmland of Pamir plateau grazing area in Wuqia County of Kizilsu Kirgiz Autonomous Prefecture in Xinjiang. Through measured the production performance and nutritional quality, and the comprehensive evaluation was carried out by grey relational degree analysis. The results showed the following, The plant height of the rye variety Jieda Dongmu 70 was 167.89 cm, which was significantly higher than that of other varieties (P<0.01), The stem diameter and tiller number of oat variety Ge Laide were the largest, which were 0.48 cm and 5.03. which were significantly higher than that of other varieties (P<0.01). The hay yield of Jeda Dongmu 70 and Ge Laide were 13.68 t/hm² and 13.57 t/hm², which were significantly higher than those of other varieties (P<0.01). There were some differences in nutritional quality among different varieties. The crude protein content of Ge Laide and Sujie was higher than that of other varieties (P<0.01), which was more than 9%. The crude fat and starch contents of Bianfeng were the highest, and the neutral detergent fiber and acid detergent fiber contents were the least. There were significant differences of other trial varieties (P<0.01). By the comprehensive analysis of grey relational degree, the priority order of the varieties was as follows: Ge Laide > Jeda Dongmu 70 > Sujie > Bianfeng > Qinghai No.444 > Kaisu. Therefore, considering the production performance and nutritional quality, it is more suitable to plant the varieties of Ge Laide Oat and Jeda Dongmu 70 rye in the pastoral area of Pamir Plateau. [ABSTRACT FROM AUTHOR]

Saccharomyces cerevisiae cultures improve production performance in ruminants, regulating immune function, regulating rumen microorganisms and promoting digestion, and are increasingly widely used in ruminants. In recent years, scientific and technology workers have conducted a lot of research on the application of S. cerevisiae cultures in livestock production. This paper summarizes the effects of S. cerevisiae cultures on milk yield, milk quality, rumen fermentation and immunity, the effects on feed intake, growth performance, disease resistance, and the effects on feed intake and weight gain and immunity of mutton sheep, so as to provide technical data for the application of S. cerevisiae cultures on ruminants. [ABSTRACT FROM AUTHOR]

In order to study the effects of curcumin combined with thymol on laying performance and antioxi‐ dant capacity of Fengyan black bone hens, a total of 252 healthy Fengyan black bone hens with normal diet and similar weight were randomly divided into three groups, with four replicates for each treatment and 21 chickens for each replicate. The blank group was fed with a basic diet, while the low and high dose groups were supplemented with a mixture of 100 mg/kg and 200 mg/kg curcumin+thymol in the basic diet, respectively. The trial is divided into two stages, seven days of pre trial period and twenty-eight days of trial period. At the beginning of the pre-test period, the normal breeding chickens were fed with full price feed, and then gradually re‐ placed with the test diet for one week. At the end of the fourth week of the formal trial, samples were taken to detect serum, tissue biochemical indicators, organ indicators, egg production rate, egg quality and hatchability, and observe the effects of curcumin and thymol combined application on the production performance and antioxidant level of Fengyan black bone chickens. The results showed that the average egg weight of the three groups had no significant difference (P>0.05), the feed egg ratio of the experimen‐ tal groups were significantly lower than those of the blank group (P<0.05), and the laying rate of the ex‐ perimental groups were significantly higher than those of the blank group (P<0.05); on the 14th day, the eggshell strength, yolk color and Hastelloy units of the low-dose and high-dose groups were significantly higher than those of the blank group (P<0.05), and on the 28th day, the yolk color and Hastelloy units of the low-dose and high-dose groups were significantly higher than those of the blank group (P<0.05). The content of malondialdehyde (MDA) in ileum, fallopian tube and ovary in the high-dose group was signifi‐ cantly lower than that in the blank group (P<0.05), the glutathione (GSH) content in the ileum and ovary of chickens in low and high dose groups increased significantly (P<0.05), while the GSH content in the liver decreased significantly (P<0.05); the activity of superoxide dismutase (T-SOD) novaries of the blank group was significantly higher than that of the test group (P<0.05), and the activity of T-SOD in serum was significantly lower than that of the test group (P<0.05). Therefore, the combination of curcumin and thymol can improve the egg quality, reduce the level of MDA in chickens, increase the activity of T-SOD and GSH, and improve the laying performance and antioxidant capacity of Fengyan black bone chickens. [ABSTRACT FROM AUTHOR]

Capsaicin has various biological functions such as antibacterial, anti-inflammatory, appetite enhancement, digestion promotion, intestinal flora regulation, immunity enhancement, heat stress relief, etc. Moreover, capsaicin has the potential value of replacing antibiotics in poultry farming. This paper reviews the application of capsaicin in livestock and poultry production and its research progress by searching the literature related to capsaicin in livestock and poultry production in recent years, and provides references for further application of capsaicin in ruminant production. [ABSTRACT FROM AUTHOR]

The experiment aimed to investigate the effects of fermented soybean meal on the production performance, egg quality and immune function of Hy-line brown laying hens by replacing soybean meal in the diet of Hy-line brown laying hens. A total of 144 Hy-line brown laying hens of 48 weeks of age with essentially the same body size and egg production rate were selected and randomly divided into two groups with six replicates of 12 hens in each group. The control group was fed the basal diet and the ex‐ perimental group was fed fermented soybean meal instead of 40% of normal soybean meal. The trial pe‐ riod was 8 weeks. The results showed that: ① compared with the control group, fermented soybean meal replacing 40% soybean meal in the diet significantly increased the qualified egg rate of Hy-line brown hens in weeks 1-4 (P<0.05), and had a tendency to improve egg production rate, average daily feed in‐ take and qualified egg rate in weeks 5-8 (0.05≤P< 0.10). ② Compared with the control group, fer‐ mented soybean meal replacing 40% soybean meal in the ration had a tendency to reduce yolk color and Hutchinson units in Hy-line Brown hens at week 4 (0.05≤P<0.10). ③ Compared with the control group, replacing 40% soybean meal in the diet with fermented soybean meal significantly increased immunoglobulin A (IgA) levels at week 4 and week 8 (P<0.05) and decreased serum endotoxin (ET) levels at week 4 (P<0.05) in Hy-line brown hens, while serum interleukin -1β (IL-1β) tended to de‐ crease (0.05≤P<0.10). In conclusion, the replacement of 40% soybean meal in the diet with fermented soybean meal under the conditions of this experiment can improve the qualified egg rate and feed intake, reduce IL-1β factor and ET level, and increase IgA level in Hy-line brown hens thus enhancing the im‐ munity and resistance of the organism. [ABSTRACT FROM AUTHOR]

The objective of this study was to systematically assess the changes of production performance, meat quality, immune and antioxidant properties of Qianbei Ma goat under different feeding method, so as to provide scientific support for high-yield, high-quality and healthy mutton production. Twenty six healthy Qianbei Ma goat rams with similar body weight [(19.68±1.60) kg] were randomly and averagely divided into grazing and stallfeeding groups. The grazing group was fed with traditional grazing, and the stall-feeding group was fed with full price pellet feed. The pre test period was 10 days, and the trial period was 180 days. After the test, three goat in each group were slaughtered to compare the production performance, meat quality, immunity and antioxidant performance of the two groups. The results showed that: ① in terms of production performance, compared with the grazing group, the stall-feeding group had better production performance in terms of final body weight, average daily gain, carcass weight, slaughter rate, net meat weight, meat to bone ratio, shearing force, cooked meat rate, but the skin was thinner, loin eye area was smaller, bone was lighter, pH was higher, with a significant difference in meat to bone ratio (P<0.05). ② In terms of meat nutrient composition, the contents of glycine, tyrosine and proline in the 16 kinds of amino acids in the stall-feeding and grazing groups were significantly different (P<0.05), while the contents of other 13 kinds of amino acids and total amino acids had no significant difference; The contents of protein, fat and cholesterol in the grazing group were higher than those in the stall-feeding group, but there was no difference between the two groups. ③ In terms of immune and antioxidant properties, immune indicators of the stall-feeding group γ interferon was higher than that in grazing group (P<0.05), lysozyme was lower than that in grazing group (P<0.05), and there was no significant difference between MDA and four antioxidant indexes (P>0.05). In conclusion, the meat carrying capacity of Qianbei Ma goat is stronger in stall-feeding than in grazing. The feeding regimens has a small impact on meat quality and antioxidant performance. However, the immune regulation ability of grazing feeding is better, and it is suggested that a suitable indoor (outside) sports field should be equipped in stall-feeding, which can improve the meat production capacity while protecting the immunity and health of the goat. [ABSTRACT FROM AUTHOR]

This experiment was conducted to explore the effects of adding limiting amino acids in low protein diets on growth performance, serum biochemical indexes, nutrient apparent digestibility and nitrogen emissions of growing barrows. Thirty-two Duroc × Landrace × Yorkshire boars with initial body weight [(24.16±2.23) kg] were randomly divided into 4 groups. The control group A was the normal protein level diet group, namely 18% crude protein (CP), the experimental group B, C and D were low protein level diets, which were 15% CP, 14% CP and 13% CP, and supplemented with lysine, methionine, threonine, tryptophan and isoleucine, respectively. The experiment lasted for 35 days. The results showed that: ① reducing dietary protein level to 14% had no significant effect on the growth performance of growing barrows (P>0.05) and decreased to 13% could significantly reduce the final weight, average daily gain and average daily feed intake (P<0.05). ② The nitrogen intake, fecal nitrogen emission, urinary nitrogen emission and total nitrogen emission of growing barrows were decreased with the decrease of dietary protein level. The urinary nitrogen and total nitrogen emissions of each experimental group were significantly lower than those of the control group (P<0.01), the urinary nitrogen emissions in group B, C and D were reduced by 37.86%, 46. 11% and 52. 21%, respectively, and the total nitrogen emissions in group B, C and D were reduced by 22.57%, 28.80% and 32. 48%, respectively. There was no significant difference in nitrogen deposition and nitrogen deposition rate among all groups (P> 0.05). There was no significant difference in nitrogen deposition and nitrogen deposition rate among all group (P>0.05); The apparent biological value of nitrogen in each experimental group was higher than that in the control group, but the difference was not significant (P>0.05). ③ Serum urea nitrogen was mainly affected by dietary CP level. Compared with the control group, the serum urea nitrogen content of each experimental group was significantly decreased (P<0.05). There was no significant difference in serum total protein, albumin, blood glucose, cholesterol and triglyceride levels among all the groups (P> 0.05). ④ Compared with the control group, the weight gain cost of group B was decreased by 1.99% (P> 0.05), and the weight gain cost of group C was decreased by 1.94% (P>0.05). It can be seen that when the CP level was reduced to 14% after the addition of restrictive amino acids to the low-protein diet, it not only had no significant effect on the production performance of growing pigs, but also significantly reduced urinary nitrogen and total nitrogen emissions, and the cost of weight gain was also lower. [ABSTRACT FROM AUTHOR]

To investigate the effects of Gamma-aminobutyric (GABA) acid and IAB on the growth performance of broilers, two broiler experiments were conducted separately. The first batch of broiler experiments was experiment 1, in which 280 broiler chickens were randomly selected and divided into two groups, including the control group and the GABA+IAB experimental group, respectively, with four replicates in each group and 35 chickens in each replicates. The second batch of broiler experiment was experiment 2, in which 192 broiler chickens were randomly selected and divided into four groups, including the control group, GABA experimental group, IAB experimental group, and GABA+IAB experimental group, with four replicates in each group, each replicates had 12 chickens, during the experiment, the daily weight gain, daily feed consumption, feed to meat ratio, immune organ index, and villus length of the broiler chickens in the experimental group were statistically analyzed. The results were as follows: ① the feed meat of GABA+IAB test group was 5.42% lower than that of the control group, and the EPI was 6.28% higher than that of the control group. ② The jejunal villus height and the ratio of villus to crypt of IAB test group and GABA+IAB test group were higher than that of the control group and GABA test group. ③ The spleen index of GABA test group, IAB test group and GABA+IAB test group were significantly higher than that of the control group. The results indicate that adding GABA and IAB to feed can significantly improve the production performance of broilers, while also improving the immune organ index. Among them, IAB has the best promoting effect on intestinal development in broilers, and the combined application of GABA and IAB has a higher effect than single use. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to explore the effects of 1.5%-8% hybrid Broussonetia papyrifera leaves on the production performance, intestinal tissue morphology, digestive enzyme activity, serum antioxidant and biochemical indexes after replacing part of corn and soybean meal in the basic diet of Dawu Golden Phoenix laying hens at the early stage of laying eggs. At the end of 147 day old, tatol of 540 Dawu Golden Phoenix laying hens were selected, which were randomly divided into six groups (each group has six replicates, with 15 hens per replicate): fed them with basic diets containing 0, 1.5%, 2.5%, 3.5%, 4.5%, and 8% hybrid Broussonetia papyrifera leaves replacement ratios, respectively. After the 7-day pre-test period, the daily production performance of the laying hens was counted with the unit of repetition during the formal test period (a total of 56 days). At the end of the for⁃ mal test period, the intestinal tissue morphology, digestive enzyme activity, and serum antioxidant and biochemica indexes of laying hens were measured. The results showed that: compered with the control grouop, all experimental groups were able to significantly reduce the total antioxidant capacity in the serum of laying hens (P<0.01); 1.5% group can significantly increase the total protein in the serum of laying hens (P<0.01); 2.5% group can significantly increase the malonaldehyde, amylase and inorganic phosphorus values in the serum of laying hens (P<0.01); 3.5% group can effectively improve the morphology of duodenum, jejunum and ileum of laying hens, and can significantly increase the activity of amylase in duodenum (P<0.01); the effect of 4.5% group is the best to reduce the mortality rate, feed to egg ratio, abnormal egg rate, and increase the laying rate, average egg weight, and qualified egg rate, and can significantly increase the activities of trypsin, chymotrypsin, and lipase in the duodenum of laying hens (P< 0.01), as well as the glucose value in serum; the total bilirubin value in serum of laying hens was significantly increased by 8% group. The appropriate replacement feeding ratio of hybrid Broussonetia papyrifera leaves can effectively improve the intestinal tissue morphology, production performance, digestive enzyme activity, serum antioxidant and biochemical indexes of laying hens. The replacement feeding ratio of 3.5%-4.5% has the best comprehensive effect and is most suitable for application in production. [ABSTRACT FROM AUTHOR]

This experiment aimed to investigate the effects of substituting Tofu residual after fermentation and enzymolysis for a portion of basal diet on the prodution performance, carcass traits, meat quality, blood indicators, and intestinal health of growing-finishing pigs. A single-factor randomized experimental design was employed, with 800 healthy DLY (Duroc × Landrace × Yorkshire)three-way crossbred pigs selected, with an average initial body weight of (23.5±5.1) kg. The pigs were randomly divided into two groups, with 20 replicates per group and 20 pigs per replicate. The control group was fed a basal diet without Tofu residual, while the experimental group was fed a basal diet with Tofu residual after fermentation and enzymolysis, with an average substitution rate of 3.34% on a dry matter basis throughout the experiment. The pigs were fed a liquid diet throughout the 168-day trial period. At the end of the experiment, seven pigs with similar body weights were selected from each treatment group for slaughter and sampling to measure carcass performance and meat quality. The results showed that: ① Compared to the control group, the experimental group exhibited significantly improved growth performance, with a 6.1% increase in average daily gain (820 g vs 870 g), a 7.3% decrease in average feed conversion ratio (2.75 vs 2.55), a 2.5 percentage point reduction in mortality rate (5.5% vs 3.0%), and a 9.9% decrease in feed cost per kilogram of weight gain (8.51 CNY/kg vs 7.67 CNY/kg); ② compared to the control group, the experimental group showed a significant increase in the abundance of colonic Lactobacillus genus (P<0.05);③ there were no significant differences (P>0.05) in carcass traits, meat quality, serum urea nitrogen and albumin levels, antioxidant and immune parameters, intestinal morphology and goblet cell count, intestinal tight junction protein and mucin expression between the two groups. The results of this study indicate that substituting 3.34% of the basal diet dry matter with Tofu residual after fermentation and enzymolysis and feeding it in liquid form significantly improves growth performance and efficiency, without adverse effects on carcass traits and meat quality, as well as no apparent impact on pig metabolism and overall health. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to study the effects of drinking water feeding of Lactobacillus (Lactobacillus plantarum) preparations on production performance, egg quality, mineral content in eggs, and antioxidant capacity indexes of commercial laying hens in the late laying period. 1 125 healthy laying hens at 81 weeks of age were selected and chivided into 3 groups (5 replicates in each group, 75 hens in each replicate), control group, test group Ⅰ and Ⅱ, fed the same diet conditions under drinking water fed with 0, 3, 5 mL/ (each·d) dose of lactic acid bacteria preparation (live bacteria count ≥ 1.0×109 CFU/mL). The pre-feeding period was one week and the formal trial period was 44 d. The test results were as follows: ① production performance: test groups Ⅰ and Ⅱ significantly increased egg weight (P<0.05), and the egg production rate of test group Ⅱ significantly increased (P<0.05); there was a trend of improvement in the feed-to-egg ratio and egg breakage rate, but there was no significant difference compared with the control group (P>0.05); ② egg quality: the test group Ⅱ could significantly improve eggshell strength (P<0.05) and eggshell thickness (P<0.05) compared with the control group; the differences in eggshell thickness, hastelloy units and protein height were not significant (P>0.05); ③ mineral element content in eggs: test groups Ⅰ and Ⅱ significantly increased magnesium (P< 0.05) and zinc (P<0.05) content in eggs compared with the control group, and test group Ⅱ significantly increased calcium (P<0.05), but no significant differences in other mineral elements (P>0.05); ④ antioxidant capacity: test groups Ⅰ and Ⅱ significantly increased the total antioxidant capacity compared with the control group (P<0.05), but no significant differences in other indicators (P>0.05). In conclusion, drinking water feeding of Lactobacillus plantarum preparation can improve production performance, egg quality and antioxidant capacity of 81-week-old laying hens with the recommended additive amount of 5 mL/(each·d). [ABSTRACT FROM AUTHOR]

The purpose of the experiment was to investigate the effects of Coreopsis lanceolata extract on the production performance, egg quality, serum antioxidant function and reproductive performance of laying egg breeders. A total of 1 200 50-week-old healthy laying egg breeders were randomly divided into 4 groups with 6 replicates in each group and 50 egg breeders in each group. The blank control group was fed with basal diet, and the experimental groups were fed with 300, 500 mg/kg and 1 000 mg/kg extract respectively. The pre-trial period was 7 days and the formal period was 35 days. The results showed that: ① compared with the blank group, with the addition of medium and high dose of Coreopsis lanceolata extract, the laying rate of laying egg breeders increased significantly (P<0.05), and the feedegg ratio decreased significantly (P<0.05). The effect of high dose group on production performance was the most obvious. ② Compared with the blank group, the medium and high dose of Coreopsis lanceolata extract significantly increased the eggshell strength, yolk color and Haugh unit of egg quality in the post-laying period (P<0.05). The high dose group was also the most obvious. ③ Compared with the blank group, the medium and high dose of Coreopsis lanceolata extract significantly improved the antioxidant activity of laying egg breeders in the later stage of laying (P<0.05), especially in the high dose group. ④ Compared with the blank group, the medium and high dose of Coreopsis lanceolata extract significantly improved the reproductive performance of laying egg breeders (P<0.05), especially in the high dose group. It can be seen that adding appropriate level of Coreopsis lanceolata extract to feed can improve the production performance and nutrient utilization efficiency of laying egg breeders, improve egg yolk color and enhance egg quality, and enhance antioxidation and reproductive performance. [ABSTRACT FROM AUTHOR]

To explore the effect of Eucommia ulmoides bark powder on production performance, oxidation resistance and intestinal flora of laying hens, 288 280-day-old Dawu Jinfeng laying hens were randomly divided into four groups, blank control group, 1% respectively eucommia skin eucommia ulmoides powder add group (group 1%), 3% skin eucommia ulmoides powder add group (group 3%) and 5% leather powder add group (group 5%), Feeding for 63 days was a 7-day pre-trial period and an 56-day trial period. At the beginning of the pre-trial period, laying hens were fed the normal full feed and gradually replaced with the experimental diet for the following 7 days. Statistical laying performance of laying hens, after the experiment, eggs, serum, liver, oviduct, ovary and ileum were collected for egg quality detection, antioxidant capacity detection and intestinal flora determination. The results showed that dietary eucommia ulmoides skin powder increased laying rate (P>0.05), increased total antioxidant capacity, decreased the content of malondialdehyde (P<0.05), and decreas`ed the number of v [ABSTRACT FROM AUTHOR]

To improve the feasibility of harvesting more black soldier fly commercial insects per unit breeding area, based on the combined control measures of aeration and filler optimized in the previous test, labotion of combined aeration and packing control measures, the purpose of improving the larval production performance per unit culture area could be achieved by increasing the insect feeding density; ② with the increase of insect density, it has a greater influence on the temperature of aquaculture materials; After the transformation of black soldier fly, the organic matter, total nitrogen, total potassium and total nutrient contents of the residual materials gradually decreased, but the total phosphorus content increased to varying degrees. However, the average length and weight of the larvae of the black soldier fly gradually decreased, and directly led to the gradual decrease of crude fat and total nitrogen content in the worm, but had little effect on the total phosphorus and total potassium of the worm. ③ With the increase in insect density, the survival rate and feeder ratio of black soldier fly larvae gradually decreased, but the insect collection rate and material reduction rate per unit area gradually increased, which could shorten the treatment cycle of food waste and improve the conversion efficiency. The production performance was the best when the insect density was 300 000 Larvae/m², the conversion time of food waste was 9 d, the insect collection per unit area was 23.4 kg/m², the material reduction rate was 84.06%, and the insect ratio was 3.22. The results can lay a foundation for the construction of a standardized production technical parameter system for the transformation of food waste in black soldier fly. [ABSTRACT FROM AUTHOR]

In order to investigate the effects of different concentrations of olive cake (OC) on production performance, immune function and Newcastle disease antibody levels of cyan-shank partridge chicken. A total of 720 1-day-old cyan-shank partridge chickens were randomly divided to control group, 3% OC group, 5% OC group, 7% OC group, 6 replicates for each group and 30 chickens in each replicate. Control group fed normal corn-soybean meal diet, experimental group were fed diet with 3%, 5% and 7% olive cake based on normal corn-soybean meal diets, The experiment is divided into 2 phases, 1-21 d was early period, 22-42 d was late period. The results indicated that, early period, the daily gain, percentage of half eviscerated yield, eviscerated weight, dressed percentage, percentage of breast muscle and percentage of leg muscle can be improved by adding different concentrations of olive cake to the diet, and reduced fead conversion rate. The daily absolute growth of 7% OC group was significantly better than control group (P<0.05), the feed conversion rate of 7% OC group was significantly lower than control group (P<0.05); compared with control group, bursa index was significantly increased in 3% OC group (P<0.05), thymus index was significantly increased in 7% OC group (P<0.05); the levels of NDV antibody in serum of 5% OC group was significantly higher than control group (P<0.05). Late period, the daily absolute growth, percentage of half eviscerated yield, eviscerated weight, dressed percentage, percentage of breast muscle and percentage of leg muscle can be promoted by adding different concentrations of olive cake to the diet, and reduced fead conversion rate. the performance of 7% OC group was significantly better than that of control group (P<0.05); the indexes of immune organs (bursa of Fabricius, thymus and spleen) in 5% OC group were significantly higher than control group (P<0.05); serum NDV antibody levels of 5% OC group was significantly higher than control group (P<0.05). To sum up, under the condition of our experiments, the proper additive dose of OC in the diet could effectively improve the production performance, immune function and Newcastle disease antibody levels of cyan-shank partridge chicken, the advisable additive dose of OC in the diet was 5%. [ABSTRACT FROM AUTHOR]

A single- factor design was used to investigate the effects of dietary casein phosphopeptide (CPP) on calcium metabolism of laying hens during late laying period. A total of 800 Hyline brown laying hens aged 58 weeks were randomly divided into five groups. The hens in the control group were fed a basal diet (T1 group). The experimental groups were fed the basal diets supplemented with 0.5 (T2 group), 1.0 (T3 group), 1.5 (T4 group), and 2.0 (T5 group) g/kg CPP, respectively. The results showed as follows: compared with the control group, the qualified rates of eggs in groups T2, T3, T4 and T5 were significantly increased (P<0.05); the tibia calcium content and tibia strength in T3 group were increased, while the serum alkaline phosphatase activity in T2 and T3 groups was significantly decreased (P<0.05). In duodenum, the carbonic anhydrase activity in T2 group was increased (P<0.05), the gene relative expressions of calcium binding protein and calcium pump in T4 group were significantly up-regulated (P<0.05), and the gene relative expressions of sodium- calcium exchange bodies in T3 and T5 groups were significantly up- regulated (P<0.05). The contents of calcium- binding protein in egg⁃ shell gland of T2 and T3 groups were increased (P<0.05). The relative gene expression level of alkaline phosphatase in experimental (T2, T3, T4, T5) group was up-regulated (P<0.05), while that of carbonic anhydrase was significantly down-regulated (P<0.05). In conclusion, dietary CPP can improve egg qualification rate and related enzyme activities in intestinal tract and eggshell gland of laying hens, and promote the serum calcium content and tibia strength. The T2 and T3 groups supplemented with 0.5 to 1.0 g/kg CPP had the best effect. [ABSTRACT FROM AUTHOR]