With the improvement of human living standards, the demand for meat, eggs and milk has increased significantly, leading to the rapid development of animal husbandry. Antibiotics have been produced largely because they can improve animal functions and prevent diseases. In the context of global antibiotics abuse, livestock and poultry have become important reservoirs for antibiotics and resistance genes. It is urgent to fully understand the distribution and dissemination of antibiotics and resistance genes transmission in the development of animal husbandry in order to provide a reference for the scientific use and rational control of antibiotics in animal husbandry. The article reviews the current status of antibiotic use in animal husbandry. It summarizes the effects of antibiotic resistance gene contamination on livestock, human health, and wildlife. In addition, it emphasizes that future research should focus on the secondary contamination of livestock manure in the surrounding environment and the diffusion mechanism of antibiotic resistance genes in wildlife habitats in animal husbandry. The aim is to provide a reference for the future healthy development of animal husbandry, scientific control of antibiotics, and related research on antibiotic resistance genes.
In this study, the genetic parameters of birth weight (BW), birth litter weight (TLW), weaned litter weight (WW), weaned litter weight (TWW), litter size (LZ) and gestation period (GP) of Alxa cashmere goats were estimated using ASreml software combined with constrained maximum likelihood (REML) method. 6517 breeding traits records of Alxa cashmere goat breeding farms from 2017 to 2022 were collected. Eight different single-trait animal models were fitted, and the best model was selected by LRT test. The variance components and heritability of reproductive traits were estimated by the single-trait model, and the phenotypic and genetic correlations between reproductive traits were analyzed by the two-trait model. The results showed that the estimated heritability values of BW, TLW, WW, TWW, LZ and GP of Alashan white cashmere goats were 0.15±0.04, 0.16±0.02, 0.20±0.06, 0.12±0.03, 0.14±0.03 and 0.32±0.05, respectively. The genetic correlation coefficient ranged from -0.49 to 0.73. The highest genetic correlation coefficient between LZ and TLW was 0.73, and the lowest genetic correlation coefficient between LZ and BW was -0.49. The phenotypic correlation ranged from -0.50 to 0.65, among which TWW and TLW had the highest phenotypic correlation coefficient of 0.65, followed by LZ and TLW with the phenotypic correlation coefficient of 0.61, and LZ and BW had the lowest phenotypic correlation coefficient of -0.50. The results showed that the reproductive traits of Alxa cashmere goats were low heritability traits and were not only affected by non-genetic factors such as year and group, but also all the traits were affected by maternal effects. The high correlation between LZ and other reproductive traits indicates that selection based on LZ is effective and can improve the overall reproductive performance of ewes. In the actual production process, the breeding performance of Alxa cashmere goats can be improved by improving the feeding management and nutrition level.
To investigate the polymorphisms of the promoter region 23 bp and the first intron region 12 bp insertion/deletion of Wenshan cattle prion protein gene (PRNP), the polymorphism data of PRNP gene 23 bp and 12 bp of Wenshan cattle were genotyped by polymerase chain reaction and agarose gel electrophoresis. Through comparative analysis with the PRNP data of cattle reported in the literature, the resistance of Wenshan cattle to mad cow disease was obtained. Results showed the frequency of the 23 bp allele in the promoter region of the PRNP gene of Wenshan cattle is predominantly represented by the deletion type (0.654). The frequencies of the 12 bp insertion and deletion alleles in the first intron region are 0.913 and 0.087, respectively, and the frequency of the deletion haplotype is very low (0.082). A significant difference (P<0.05) was observed when comparing the frequencies of the 12 bp insertion/deletion alleles in Wenshan cattle with those reported in cases of BSE-affected and healthy cattle from Germany, the United Kingdom, and Switzerland. However, no significant difference (P>0.05) was found in the insertion/deletion allele frequencies between Wenshan cattle and water buffalo. Therefore, it is concluded that the relatively high frequency of the 12 bp insertion allele and the extremely low frequency of the deletion type haplotype (23 bp insertion-12 bp deletion) in Wenshan cattle confer a higher resistance to BSE disease, making them a valuable resource for disease-resistant breeding programs. Analysis of disease resistance in local cattle breeds in China is beneficial for providing data support for molecular breeding of disease resistance in cattle breeds.
F2 individuals of 462 Texel sheep × Altay sheep were selected in this study, including 229 male lambs and 233 female lambs. All the experimental sheep were reared under uniform conditions until 8 months of age and then slaughtered. After slaughter, the tenderness was measured by C-LM4 tenderness meter. Illumina sheep high density (600K) SNP chip was used for genotyping, and the MLM model of GEMMA software was used for genome-wide association analysis of tenderness traits. After quality control, the remaining 613178 SNPs were used for genome-wide association analysis, and a total of 9 potential SNPs were found to be related to tenderness on chromosomes 2, 6, 23, and 24, respectively. Based on the biological functions of genes and related literature, EREG, AREG and PDE1A genes were speculated to be involved in the biological processes of muscle regeneration and muscle fiber formation, and could be used as important candidate genes affecting tenderness. The aim of this study was to locate SNP sites related to sheep tenderness and their important candidate genes by genome-wide association analysis, so as to provide a scientific basis for improving sheep muscle tenderness by molecular biological methods.
In order to study the differences in phenotypic traits of Altay wool quality among different age groups and provide reference data for the breeding of Altay sheep, a total of 439 Altay ewes aged 1.5 to 5 years were sampled for wool analysis. The results showed that age significantly influenced the fiber diameter and staple length of Altay wool (P<0.01), and had a significant effect on fiber strength (P<0.05). Ewes at 1.5 years old had the finest fiber diameter, while those at 2 years old had the highest staple length. Ewes at 5 years old had significantly higher fiber diameter and staple length compared to other age groups (P<0.01), and ewes at 1.5 years old had significantly higher fiber strength compared to other ages (P<0.01). The fiber diameter of Altay wool was highly positively correlated with staple length and fiber strength (P<0.01). The fiber content was highly positively correlated with coarse wool whiteness, coarse wool luster, and elongation at break (P<0.01), and wool whiteness was highly positively correlated with wool luster (R=0.998), coarse wool whiteness, and coarse wool luster (P<0.01). These research findings provide a reliable basis for the evaluation of Altay wool quality and the breeding of superior livestock.
YOU Junyi, DU Zhaohui, KANG Yahao, DUAN Yu, LIU Xiaowei, YANG Biquan, LU Yongshou, WANG Yuan, LIANG Guodong , MA Yunhui, HU Jianhong, PANG Weijun, SUN Shiduo, LI Xiao
To introduce and select terminal father for pig farms, and select commercial pig combinations that meet the market demand, different lines and breeds, including Danish Duroc, French Duroc, American Duroc and PIC boars were selected and crossed with 2~4 parities of Canadian line binary sows to determine the reproductive performance of sows, daily weight gain of fattening pigs, feed intake, feed-to-meat ratio, death and culling rate, and economic efficiency and other indexes. The results showed in terms of reproductive performance, the total litter size and healthy litter size of Danish Duroc group (DC) were significantly higher than those of American Duroc group (P<0.05). The litter weight of healthy newborns in French Duroc group (FC) was significantly higher than that in American Duroc group (MC) (P<0.05). Average birth weight in MC group was significantly higher than that in PIC group (P<0.05). In terms of growth performance of commercial pigs,DC group had the shortest age of 100kg of correction. The ratio of feed to meat in MC group at 170 days of age was significantly higher than that in PC group (P<0.05). The daily gain at 170 days of age in DC group was significantly higher than that in PC group (P<0.05). The slaughtering weight of DC group was significantly higher than that of the other three groups (P<0.05). The average daily gain in DC group was significantly higher than that in PC group (P<0.05). The ratio of feed to meat in MC group was significantly higher than that in PC group (P<0.05). FC group had the lowest death and culling rate of 2%.Under the same conditions of growth and fattening, Danish Duroc group line has the highest number of litters and has obvious advantage in growth rate and the best economic benefit.
Poultry is one of the animals that needs long time light exposure. Scientific and correct light program has a significant impact on the growth and development, sexual maturity, first birth age, and egg production peak of laying hens. It is of great production significance to set the corresponding light program during the different stages of induced molting in fasting and feeding recovery. In this study, 529-day-old Guifei chickens with similar body weight and about 60% egg production rate were used as experimental material. According to the different periods of fasting induced moult, the changes of light regime were divided into four stages, and samples were collected at five different periods: the last day of the first stage (16 h L/8 h D, Before fasting), stage Ⅱ (8 h L/16 h D for 3 days), and stage Ⅲ (10 h L/14 h D for 13 days) (F0, F3, F16), and 6 d and 32 d of stage Ⅳ (gradually increasing light exposure by 0.5 h/d to 16 h L/8 h D). The number of follicles, ovarian antioxidant indicators, KIT-PI3K-PTEN-AKT signaling pathway and GDF9 gene expression were measured to explore the role of light program in the process of fasting induced molt. Results showed that the levels of FSH, LH, E2 and P4 in serum decreased when light exposure was shortened（P<0.001）, and the activities of superoxide dismutase (SOD)(P<0.05) and glutathione peroxidase (GSH-PO) (P<0.001) increased. In particular, primordial follicles were likely to be activated, leading to the increase of numbers of small yellow follicles(P<0.01), primary follicles and secondary follicles(P>0.05). When the light was gradually restored, the expression of KIT and PI3K was continuously high(P<0.001), the expression of PTEN decreased(P<0.01), and the expression of AKT was basically unchanged(P>0.05). The serum levels of reproductive hormones and ovarian antioxidant levels returned to the pre-test state, but the overall number of follicles increased. The results suggest that scientific and reasonable light program during fasting and molting has an auxiliary effect on the remodeling of ovarian function.
Black soldier fly larvae have good application prospects in the resource utilization of kitchen waste. To investigate the effect of spiciness on the growth of black soldier fly larvae, seven different spiciness gradient diets (capsaicin concentration of 0, 0.2, 0.4, 0.6, 0.8, 1.0 and 1.2%) were fed to 7-day-old black soldier fly larvae in this study. The results showed that the feed to gain ratio of the 0.8% capsaicin group was significantly lower than that of the 0.6% capsaicin group (P<0.05), but there was no significant difference with other groups. The larvae in the 0.8% capsaicin group had the lowest dry matter content and were significantly lower than those in the 0.6% and 1.2% capsaicin groups (P<0.05). There were no significant differences in other indicators such as growth performance, survival rate, conversion rate and waste reduction index of black soldier fly larvae (P>0.05). The results showed that the 0.8% capsaicin group had the least nutrients converted from feed, and the 0.6% capsaicin group had the lowest conversion efficiency. Therefore, the larvae of black soldier fly show great tolerance to spiciness, and the results of this study will provide basic data for black soldier fly larvae in the resource utilization of kitchen waste.
Regional optimization and rational distribution of animal husbandry is an inevitable requirement of agricultural supply-side reform and high-quality development. In this paper, the spatial autocorrelation method is used to analyze the geographical agglomeration characteristics of animal husbandry by using the panel data of provincial animal production in China, and the causes of its formation are analyzed. The results show that the animal husbandry in China presents obvious agglomeration characteristics, and the development of animal husbandry in each province is significantly affected by its neighboring provinces. The spatial agglomeration of industry is unbalanced, with “high-high” agglomeration in eastern and central China and “low-low” agglomeration in western China. Livestock husbandry layout is relatively stable, and it will continue to maintain the status in the future. Based on this, this paper puts forward some policy suggestions, such as promoting moderate scale operation, developing professional, market-oriented and integrated industry chain, and improving supporting system of animal husbandry.
Subclinical mastitis (SCM) in dairy cows is an asymptomatic type of mastitis, usually manifested by the increased somatic cell count (SCC), decreased milk fat content and lactose content. This research explored the factors affecting the incidence of SCM in dairy farms in Jiangsu under the influence of SCC change patterns, 853 936 records of dairy herd improvement (DHI) records were collected from 2010 to 2020 in 14 dairy farms in Jiangsu. Based on the division of 4 SCC change patterns (continuously healthy, newly infected, cured and persistently infected), the Chi-square test was used to explore the effects of different farm sizes, parities, calving seasons, calving intervals and 305-days milk production on SCC change pattern. The results showed that the percentages of the four patterns in the records were: 83.52% (continuously healthy) > 6.02% (newly infected) > 5.89% (persistently infected) > 4.57% (cured). There were extremely significant differences in the distribution of SCC patterns between different levels of each factor (P<0.01). Among them, cattle in small and medium-sized farms and with high parity, spring calving, calving interval greater than 441 d and 305 d milk yield of 13 001~15 000 kg had a higher SCC in the next lactation month, which increased the risk of SCM in dairy cows. Cattle in farms with a size of more than 5 000 cattle, of parity 1, autumn calving, and with a milk yield of 9 001~11 000 kg in 305 days were continuously healthy in high proportion. The results indicate that farm size, parity, calving season, calving interval, and 305-day milk production have extremely significant effects on the SCC change patterns in Holstein cows, which provides reference for the prevention of SCM in Jiangsu large-scale farms.
The experiment aimed to investigate the effect of plant extracts replacing anti-coccidian drugs on growth performance and fecal coccidian count in broilers. A total of 234 1-day-old healthy yellow-feathered broilers were selected and randomly divided into 3 groups, with six replicates in each group and 13 broiler chickens in each replicate. The test period was 55 days. The control group was fed the basic diet, the anticoccodidian group was fed the basic diet + 500 g/t dinitolmide, and the plant extract group was fed basic diet + 500 g/t plant extract. The results showed that the average daily gain of the anti-coccidian essential oil group from 1 to 21-day-old chicks was significantly higher than that of the anti-coccidian drug group (P＜0.05), and the feed to gain ratio was significantly lower than the drug group (P＜0.05). In the overall period, there was no significant difference in daily weight gain and feed intake between plant extract group and anti-coccidian drug group, and the feed to gain ratio decreased by 6.30%, so did the mortality rate by 10.26% . The number of fecal coccidia at 33 days in the plant extracts was significantly lower than that in the anticoccidia group and control group (P＜0.05). In conclusion, plant extracts can be used as alternatives for anti-coccidian drugs and have promising applicable prospect in animal husbandry.
The pollutant characteristic parameters of a pig farm are the important basis for the evaluation of harmlessness and resource utilization of pig manure. In order to understand the variation of pollutant characteristic parameters after multistage treatment of manure, especially for sewage, in Jiangxi large-scale pig farms, a large-scale pig farm with USR+A/O+MBR wastewater treatment model in Jiangxi was selected to conduct annually seasonal monitoring on pollutant characteristics in each stage. The results showed that the parameters of Manure OM, NH3-N, TN and TP were 50.84%, 0.41%, 2.47% and 5.94%, respectively, and the contents of OM and TP increased, but the contents of NH3-N and TN decreased. The characteristic parameters of COD, NH3-N, TN and TP in the final effluent were 386.06 mg/L, 70.89 mg/L, 493.53 mg/L and 7.61mg/L respectively, the total removal rates of pollutants were 95.40%, 72.73%, 91.41% and 95.89%, respectively. The results indicate that the combined processing mode of“USR+A/O+MBR”can remove the pollutant well, and the effluent water quality meets the requirements of pollutant discharge standards of livestock and poultry industry.
The objective of this study was to evaluate the thermal environment quality of closed rabbit houses during winter through a three-dimensional stable state simulation analysis of the thermal environment (wind speed, temperature, and humidity) in the rabbit house based on computational fluid dynamics (CFD) simulation technology. The results showed that the closed rabbit house environment was controlled by a low-efficient exhaust system, with a dead angle of airflow in the middle area. The wind speed was unevenly distributed, which did not meet the favorable wind speed range of the rabbit house. The temperature showed an upward trend from the air inlet on the west side to the air outlet on the east side, ranging from 15.56 ℃ to 22.40 ℃, which was in line with the most suitable temperature range of the rabbit house. However, the distribution of relative humidity showed an opposite trend to temperature variation, from 54.39% to 81.78%, which was slightly beyond the optimum relative humidity range of the rabbit house. The relative error range between the measured and simulated values of temperature and relative humidity was less than 5%, indicating that it is feasible to use this model to evaluate environmental factors. This study provides a reference for optimizing the regulation scheme of the commercial rabbit house in winter.
Cryopreservation of honeybee semen is of great significance to the conservation and improvement of honeybee germplasm resources and varieties, which is conducive to progeny determination and genome selection in honey bee breeding, and accelerates the breeding process. Honeybee sperm has special structure, and cryopreservation has a great influence on its viability and fertilization rate, which has not been widely used. This article reviews the research status of bee semen cryopreservation, the structure of bee sperm, the mechanism of cryotrauma and the research progress of bee semen freezing technology. It provides reference for further optimization and improvement of honeybee semen cryopreservation technology.
With the rapid development of intensified dairy livestock industry, how to avoid the huge impact of heat stress on dairy livestock even on livestock industry has become a challenge requiring urgent attention in intensified farms. Heat stress may lead to a series of changes including decreaced performance, immunity and reproductive performance. It is reported that trace element Chromium (Cr) can inhibit the adverse effects caused by heat stress and mitigate the harm to animals. This paper reviews the regulatory effects and research progress of chromium on heat-stressed dairy animals, based on the research findings of domestic and international scholars.
Journal of Domestic Animal Ecology
Monthly ,Founded in 1980
Superintendent: Ministry of Education of the People's Republic of China
Sponsored by: Northwest A&F University
Chief Editor: CHEN Yulin
website: jcst.magtech.com.cn
ISSN 1673-1182
CN 61-1433/S
Mailing code: 52-112
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