Whole-genome re-sequencing association study on yearling wool traits in Chinese fine-wool sheep

To investigate single nucleotide polymorphism (SNP) loci associated with yearling wool traits of fine-wool sheep for optimizing marker-assisted selection and dissection of the genetic architecture of wool traits, we conducted a genome-wide association study (GWAS) based on the fixed and random model circulating probability unification (FarmCPU) for yearling staple length (YSL), yearling mean fiber diameter (YFD), yearling greasy fleece weight (YGFW), and yearling clean fleece rate (YCFR) by using the whole-genome re-sequenced data (totaling 577 sheep) from the following four fine-wool sheep breeds in China: Alpine Merino sheep (AMS), Chinese Merino sheep (CMS), Qinghai fine-wool sheep (QHS), and Aohan fine-wool sheep (AHS). A total of 16 SNPs were detected above the genome-wise significant threshold (P = 5.45E-09), and 79 SNPs were located above the suggestive significance threshold (P = 5.00E-07) from the GWAS results. For YFD and YGFW traits, 7 and 9 SNPs reached the genome-wise significance thresholds, whereas 10 and 12 SNPs reached the suggestive significance threshold, respectively. For YSL and YCFR traits, none of the SNPs reached the genome-wise significance thresholds, whereas 57 SNPs exceeded the suggestive significance threshold. We recorded 14 genes located at the region of ±50-kb near the genome-wise significant SNPs and 59 genes located at the region of ±50-kb near the suggestive significant SNPs. Meanwhile, we used the Average Information Restricted Maximum likelihood algorithm (AI-REML) in the “HIBLUP” package to estimate the heritability and variance components of the four desired yearling wool traits. The estimated heritability values (h²) of YSL, YFD, YGFW, and YCFR were 0.6208, 0.7460, 0.6758, and 0.5559, respectively. We noted that the genetic parameters in this study can be used for fine-wool sheep breeding. The newly detected significant SNPs and the newly identified candidate genes in this study would enhance our understanding of yearling wool formation, and significant SNPs can be applied to genome selection in fine-wool sheep breeding.     

Flight Distance and Avoidance Score in Thoroughbred Foals and Yearlings and the Relationship with Handling Frequency in the Young Ages

Flight and avoidance reactions from human were examined using 168 postweaning Thoroughbred foals in 22 breeding farms. Further 114 yearlings of 168 foals were tested in the following summer. The foal handlings by the stabler were asked in questionnaire. The relationship between the behavioural reactions and the foal handling frequencies was analyzed. The flight reaction was estimated as the distance from the animal to a stranger when the animal began to flight away from his approach. The avoidance scores were set up from (1) (not resistant) to (5) (touch rejection) from human touching. In the stabler questionnaire, handling frequencies of “body brushing”, “rectal temperature measurement”, “hoof cleaning”, and “stall cleaning” in the early nursing period were asked. The handling frequencies were scored from (1) (not done) to (5) (every day). In the preliminary test, a measurement reliability of the flight distance and the avoidance score was confirmed. The mean flight distances were 0.56 m and 0.27 m in the postweaning foals and the yearlings, respectively. Touch-avoidance scores of the highest frequency were (3) and (2) in the postweaning foals and the yearlings, respectively. As the results of Spearman’s rank-correlation analysis, “body brushing” showed highly negative relationships with “flight distance” (ρ=–0.31, P<0.001) and “avoidance score” (ρ=–0.37, P<0.001) in the postweaning foals. In the yearlings, “hoof cleaning” also showed significantly negative relationships with these behavioural indices (ρ=–0.24, P<0.01; ρ=–0.22, P<0.01, respectively).     

不同杂交组合周岁羔羊肉用性能分析

为了探讨高原放牧条件下不同杂交后代的肉用品质,以白萨福克、特克塞尔、邦德、澳洲美利奴为父本,以甘肃高山细毛羊为母本杂交生产羔羊肉(分别设为Ⅰ、Ⅱ、Ⅲ和Ⅳ组)。选择4个杂交组合周岁羔羊各5只,开展屠宰测定和肉质分析。结果表明,引入品种可以明显提高甘肃高山细毛羊的产肉力,4个组合中萨×甘组、澳×甘组改良效果最为显著,白萨甘细的肌肉分级标准判定其为TM级,脂肪含量略高,澳甘细和特甘细均为PME级,邦甘细为PL级。     

Botanical Composition of Yearling-Steer and Mature-Ewe Diets in the Kansas Flint Hills

Awareness of herbivore diet composition is an essential element of rangeland stewardship. Objectives of our experiment were to characterize diet selection by yearling steers and mature ewes grazing native tallgrass prairie, changes in dietary preferences that occurred with advancing season, and overlap in selection patterns between ewes and steers. Eight contiguous native tallgrass pastures (31 ± 3.3 ha) were grazed by yearling beef steers (n = 279 per yr) from 15 April to 15 July for two grazing seasons. Mature ewes (n = 813 per yr) subsequently grazed four of the eight pastures (0.15 ha per ewe) from 1 August to 1 October each year. Beginning 1 May, five fresh fecal pats were collected along four permanent transects per pasture at 2-wk intervals until steers were removed on 15 July. Subsequently, fecal grab samples were collected from 25 designated ewes per pasture on 15 August and 15 September. Microhistological analyses were conducted on fecal samples to estimate dietary botanical composition, using 17 grass, forb, and browse species from the experimental site as reference standards. Botanical composition of pastures was estimated annually in October. Diet selection was evaluated using Kulcyznski’s Similarity Index. The proportions of total graminoids and total forbs in steer diets were not different (P = 0.37) among sampling periods. Steer diets were dominated by graminoids (≥ 88.4% of diets) throughout the experiment. Steers and ewes exhibited strong preference for Bouteloua gracilis, Buchloe dactyloides, Dalea purpurea, and Liatris punctata. Ewes also demonstrated strong preferences for Vernonia baldwinii and Ambrosia artemisiifolia. Steers avoided Lespedeza cuneata and Symphyotrichum ericoides, whereas ewes did not avoid any of the reference standards. Ewes selected approximately equal proportions of graminoids and forbs (58% and 42% of diets, respectively), and proportions did not differ (P = 0.67) between sampling periods. Diet selection by mature ewes and yearling steers overlapped by 65% under the conditions of our experiment.     

阔叶树播种苗的苗期水分生理特性研究

对皂角、合欢、灯台树、黄杨4种阔叶树种一年生播种苗的苗期水分生理特性进行研究,结果表明,4个树种的叶片鲜重含水量在73%～81%之间,各树种的抗旱能力依次为黄杨>合欢>皂角>灯台树;对各树种蒸腾强度的测定结果表明,皂角、灯台树蒸腾强度日变化为双峰曲线,黄杨、合欢为单峰曲线;通过测定皂角、合欢裸根苗的叶和根的水势,进一步证明了合欢的抗旱性强于皂角。     

The effects of feeding a low level of distiller's dried grains with solubles (DDGS) to yearling Holstein steers

We examined the effects of feeding a low percentage of distiller's dried grains with solubles (DDGS) to yearling Holstein beef steers during the late stage of the fattening period on growth performance and carcass quality. Fifteen animals were fed a total mixed ration (TMR) feed plus a DDGS supplement equal to 10% of the total feed weight for 3 months (DDGS group). The other 15 animals were fed TMR with no DDGS (Control group). The vitamin E (VE) levels in the blood from the DDGS group showed a tendency to be higher in the DDGS group (P = 0.056). Blood urea nitrogen levels in the DDGS group were also higher (P < 0.05). The Beef Color Standard (BCS) number for the DDGS group was also higher than that for the Control group (P < 0.05). Forty‐eight hours after cutting, the yellowness (b*) value for Longissimus muscle in the DDGS group was significantly higher (P < 0.05) and the redness (a*) value in the DDGS group tended to be higher than that in the Control group (P = 0.05). The study results show a potential for adding value to yearling beef by improving the ability to maintain meat color with an increase in VE content.     

Exercise in Thoroughbred yearlings during sales preparation: a cohort study

Reasons for performing study: There is increasing evidence suggesting that early exercise in Thoroughbred racehorses may be beneficial to the development of the musculoskeletal system. At present, information on the exercise programmes and health problems of individual yearlings during a sales preparation is scant. Objectives: To describe the exercise and health problems of Thoroughbred yearlings during preparation for sales, and to identify variations in exercise between and within farms. Methods: A prospective cohort study was used to collect exercise and health information from 18 farms across New Zealand. Daily exercise records for individual horses were recorded during the studfarms' preparation for the annual national yearling sales in January 2009. Results: Data were collected from 319 yearlings, of which 283 (88.7%) were exercised (hand walking, mechanical walker and lungeing) during their preparations. Sales preparation lasted a median of 69 days (interquartile range 61–78) and differed significantly between farms (P<0.001). The median exercise time performed differed significantly by gender (P<0.001), farm (P<0.001) and month of the preparation (P<0.001), but not by type of sale (P = 0.14) or category of sales price (P = 0.12). Within certain farms, daily exercise differed between horses as did total exercise by gender and the number of days spent in the sales preparation. Lameness was the most common condition affecting yearlings and the overall incidence rate of lameness was 0.08 per 100 horse days (95% confidence interval 0.05–0.13). Incidence rates of lameness varied significantly between farms (P = 0.02), but not by age (P = 0.77), sales type (P = 0.58) or month of the preparation (P = 0.53). Conclusions and potential relevance: Yearling exercise programmes varied between and within farms. Since exercise is already being tailored for each individual horse, there may be an opportunity to allow for modifications to sales preparation with the future career in mind.     

一龄鳜鱼种培育试验

为满足规模化养鳜对大规格鱼种的需求，进行了一龄鳜培育试验。在２个１．２亩的池塘里放养夏花鳜鱼种８４００尾，培育９２天，结果育成平均规格６８．５ｇ／尾的一龄鳜鱼种４９３．２ｋｇ，成活率９０％。