Quantitative trait loci for milk production and functional traits in two Danish Cattle breeds

Quantitative trait loci (QTL) in Danish Jersey and Danish Red cattle were independently mapped by least squares regression analysis. For Jersey breed, five grandsire families were genotyped for 186 markers on 16 chromosomes (BTAs). Eight traits analysed were milk yield (MY), fat percentage (FP), protein percentage (PP), clinical mastitis (CM), somatic cell score (SCS), maternal stillbirth, maternal calf size (MCS) and maternal calving difficulty. For Red breed, nine grandsire families were genotyped for 166 markers on 18 BTAs. Six traits analysed were MY, FP, PP, CM, SCS and female fertility. Nine and five QTL were detected in Jersey and Red breed, respectively, in across family tests. In Jersey breed, the results indicate QTL for CM and MCS on BTA 3. Additionally, there is an indication of QTL for MCS and FP on BTA 1 and a tentative evidence for a QTL for MY on BTA 26. There is a high risk of detected QTL being false positives. The detected QTL in Jersey breed indicate interesting results from a breeding perspective, but a practical application should await genome-wide association studies.     

Achievements and Prospects of Aquaculture and Aquafeed Industry in China

This article presents a comprehensive review on the achievements obtained in the past a few decades and the prospects in aquaculture and aquafeed industry in China. The total production of aquaculture in China increased from 2.38 million tons in 1978 to 36 million tons in 2008, growing 15 times in 30 years.     

Effects of duration and combination of drought and flood conditions on leaf photosynthesis,growth and sugar content in sugarcane

Global climate change will result in extreme environments, such as droughts and floods. We investigated the individual and combined effects of droughts and floods of varying duration on sugarcane (Saccharum spp.) growth using a pot experiment under glasshouse conditions with the following six treatments: drought for 15 d, prolonged drought for 30 d, flood for 15 d, prolonged flood for 30 d, short flood followed by prolonged drought, and prolonged flood followed by prolonged drought. Plants that were subjected to drought conditions, including drought after a flood, had reduced CO₂ assimilation (through stomatal closure) and leaf areas, whereas flood conditions showed no effect. During flooding, some roots died, and adventitious roots with well-developed aerenchyma appeared from the submerged nodes. At the time of harvest, there were no significant differences in stem fresh weight, sucrose content, or sugar yield between the treatments. However, ion content analysis revealed that flood conditions caused an accumulation of sodium in the bottom of stems and adventitious roots. Therefore, under flood conditions, plants may develop adventitious roots, which may offset the negative effects of root death, helping them to maintain their growth and yield.     

Effect of waterborne zinc exposure on lipid deposition and metabolism in hepatopancreas and muscle of grass carp <Emphasis Type="Italic">Ctenopharyngodon idella</Emphasis>

The aim of the present study was to explore the effect of waterborne zinc (control, 0.85, 2.20, 3.10 mg/l, respectively) exposure on lipid deposition and metabolism in the hepatopancreas and muscle of grass carp Ctenopharyngodon idella. The lipid content, Zn accumulation, and the activities and expression levels of several enzymes involved in lipid metabolism were determined in hepatopancreas and muscle. Waterborne Zn exposure reduced growth performance and increased Zn accumulation in both tested tissues. In hepatopancreas, Zn exposure increased lipid content, the activities of lipogenic enzymes, such as 6PGD, G6PD, ME, ICDH and FAS, as well as the mRNA expression level of G6PD, 6PGD, ICDH, FAS and SREBP-1. But the activity of CPT I and the mRNA expression of HSL, CPT Iα1a, CPT Iα2a and PPARα were down-regulated by Zn exposure. In contrast, in muscle, waterborne Zn exposure decreased lipid deposition, activities of 6GPD, ICDH and ME, as well as the mRNA expression level of G6PD, ICDH, ME, FAS and SREBP-1. However, the activity of CPT I as well as the mRNA expression level of PPARα, HSL, CPT Iα2a, CPT Iα1b and CPT Iβ were up-regulated by Zn exposure. Our results indicate that waterborne Zn increases lipid content by up-regulating lipogenesis and down-regulating lipolysis in hepatopancreas. But, in muscle, waterborne Zn reduces lipid accumulation by up-regulating lipolysis and down-regulating lipogenesis. Differential patterns of lipid deposition, enzymatic activities and genes’ expression indicate the tissue-specific regulatory mechanism in fish.     

库尔勒香梨龟背状果实性状浅析

本文对香梨龟背果的单果重、种子数、偏歪程度、硬度、可溶性固形物等进行了测定分析。结果表明,龟背果多发生于宿萼果实和萼端未突起的果实;龟背状主要是由于果实纵向不均衡生长造成的;扁平面硬度大、可溶性固形物含量低;果实的饱满种子数少,且分布不均匀,扁平面无饱满种子或饱满种子少于膨大面的;龟背果是一类劣质畸形果。     

Partial cDNA sequence of a relaxin‐like factor (RLF) receptor,LGR8 and possible existence of the RLF ligand‐receptor system in goat testes

Relaxin‐like factor (RLF), also known as insulin‐like factor 3 (INSL3), is produced by testicular Leydig cells, but its specific receptor LGR8 (leucine‐rich repeat family of G‐protein‐coupled receptor 8) has not been identified in goats. This study aimed to identify complementary DNA (cDNA) sequences of goat LGR8, and characterize the expression of both RLF and LGR8 in goat testes by RT‐PCR and immunohistochemistry. Testes were collected from immature (3‐month‐old) and mature (24‐month‐old) Saanen goats, and partial cDNA sequences of the goat homologue of human LGR8 were identified. The sequence encoded a reduced peptide sequence of 167 amino acids, which corresponded to transmembrane regions 2 through 5, followed by the beginning of intracellular loop 3 of human LGR8. Expression of both LGR8 and RLF genes was drastically increased in mature testes compared with immature ones. Although RLF protein was restricted to Leydig cells, LGR8 protein was detected in both Leydig cells and seminiferous epithelial cells (possibly germ cells and Sertoli cells). These results reveal a possible existence of the RLF‐LGR8 ligand‐receptor system within the goat testis, suggesting that RLF may play a role in testicular function through LGR8 on Leydig cells and seminiferous epithelial cells in an autocrine and/or paracrine manner.     

呼伦贝尔草原矿生态受损预测与修复对策

以伊敏五牧场煤矿为例,通过图形叠加法、调查法和类比法,探讨了呼伦贝尔草原矿生态受损预测与修复方法.根据煤矿开采后土地沉陷以及土地利用情况,将项目区划分为沉陷区和土地占用影响区.项目区总面积为5638.24hm2,受到影响的区域面积为4244.67hm2.其中有75.3%的土地将发生沉陷,由陆地生态系统演化为水域生态系统,另一部分也产生不同程度的裂缝和塌陷等.主要是通过土地整治和植被恢复等方法进行修复.不受采煤沉陷影响的区域面积是1393.58hm2,包括工业场地、排矸场、运输工程和场外线性工程等,工程建设的实施将破坏地表植被,加剧水土流失.除采取围栏封育的保护措施外,还要制定相应土地复垦和水土保持措施.     

儿菜生物学特性研究

本文在儿菜栽培及其生长发育与温度观测的基础上, 描述了儿菜的生物学特性, 提出了儿菜通过春化作用的条件,为儿菜的推广工作提供了科学的依据。     

Co-feeding of live feed and inert diet from first-feeding affects Artemia lipid digestibility and retention in Senegalese sole (Solea senegalensis) larvae

The present study intended to evaluate the effects of early introduction of inert diet in lipid digestibility and metabolism of sole, while larval feed intake, growth and survival were also monitored. Solea senegalensis larvae were reared on a standard live feed regime (ST) and co-feeding regime with inert diet (Art R). Trials using sole larvae fed with Artemia enriched with two different lipid emulsions, containing glycerol tri [1-¹⁴C] oleate (TAG) and L-3-phosphatidylcholine-1,2-di-[1-¹⁴C] oleoyl (PL), were performed at 9 and 17 days after hatching (DAH) to study lipid utilization. Co-feeding did not affect sole survival rates (ST 59.1 ± 15.9%; Art R 69.56 ± 9.3%), but was reflected in significantly smaller final weight at 16 DAH (ST 0.71 ± 0.20; Art R 0.48 ± 0.14 mg). Higher feed intake was observed in sole larvae fed on Artemia enriched with labeled PL at 9 DAH but not at 17 DAH. At 17 DAH, the smaller larvae (Art R treatment) ingested proportionally more Artemia in weight percentage, independently of enrichment. At 9 DAH lipid digestibility was equal among treatments and higher than 90%, while at 17 DAH it was higher in ST treatment (around 73%) compared to the Art R group (around 66%). Lipid retention efficiency at 9 DAH was higher in the Art R treatment, reaching values of 50%, while these values almost duplicated at 17 DAH, ranging up to 80% in both treatments without significant differences. These results show that co-feeding of live feed and inert diet from first-feeding in Senegalese sole has a toll in terms of growth and lipid digestibility but does not seem to compromise lipid metabolic utilization.     

Effects of dietary cholesterol on growth, survival and body composition of juvenile abalone Haliotis discus hannai Ino

An experiment was conducted to determine the dietary cholesterol requirement of juvenile abalone Haliotis discus hannai. Eight isoenergetic (18.15–18.61 kJ/g) and isonitrogenous (29.00–29.78% protein) diets, supplemented with 0.00, 0.15, 0.30, 0.45, 0.60, 0.75, 0.90 and 1.05% cholesterol were evaluated. Juvenile abalone (initial weight: 0.67–0.72 g) were reared in a flow-through water system for 24 weeks. During the feeding trial, water temperature was maintained at 14–17 °C, salinity 31–33, pH 7.4–7.9. Abalone fed diet without cholesterol supplementation had the lowest weight gain ratio (WGR, 356.70%). Survival ranged from 98.52 to 100.00% and was not significantly different among treatments. There were no significant effects of dietary cholesterol on composition and cholesterol concentration in the muscle and viscera of abalone. Based on data of WGR using broken-line analysis, the optimal dietary cholesterol requirement of juvenile abalone was found to be 0.23%.