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The Murchison Widefield Array (MWA) is an electronically steered low-frequency (<300 MHz) radio interferometer, with a ‘slew’ time less than 8 s. Low-frequency (∼100 MHz) radio telescopes are ideally suited for rapid response follow-up of transients due to their large field of view, the inverted spectrum of coherent emission, and the fact that the dispersion delay between a 1 GHz and 100 MHz pulse is on the order of 1–10 min for dispersion measures of 100–2000 pc/cm3. The MWA has previously been used to provide fast follow-up for transient events including gamma-ray bursts (GRBs), fast radio bursts (FRBs), and gravitational waves, using systems that respond to gamma-ray coordinates network packet-based notifications. We describe a system for automatically triggering MWA observations of such events, based on Virtual Observatory Event standard triggers, which is more flexible, capable, and accurate than previous systems. The system can respond to external multi-messenger triggers, which makes it well-suited to searching for prompt coherent radio emission from GRBs, the study of FRBs and gravitational waves, single pulse studies of pulsars, and rapid follow-up of high-energy superflares from flare stars. The new triggering system has the capability to trigger observations in both the regular correlator mode (limited to ≥0.5 s integrations) and using the Voltage Capture System (VCS, 0.1 ms integration) of the MWA and represents a new mode of operation for the MWA. The upgraded standard correlator triggering capability has been in use since MWA observing semester 2018B (July–Dec 2018), and the VCS and buffered mode triggers will become available for observing in a future semester.
In this paper, some contributions are made to the theory of algebraic equations over the rational field with conditions imposed on the Galois group. In § 1, for a given abstract group G all faithful permutation representations Ḡ are obtained, and it is shown that if one of them is the group of some equation with splitting field K, then any of them is the group of some equation, also with splitting field K. The method of proof enables us to construct an equation having as group a given faithful permutation representation Ḡ of a prescribed group G if we are given an equation having as group some faithful representation of G. In § 2, equations having nilpotent group are considered, non-normal extension fields are discussed, and a canonical form is obtained for the roots of non-normal irreducible equations; this form is used to characterize fields and equations with nilpotent groups.
Coinfection with human immunodeficiency virus (HIV) and viral hepatitis is associated with high morbidity and mortality in the absence of clinical management, making identification of these cases crucial. We examined characteristics of HIV and viral hepatitis coinfections by using surveillance data from 15 US states and two cities. Each jurisdiction used an automated deterministic matching method to link surveillance data for persons with reported acute and chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections, to persons reported with HIV infection. Of the 504 398 persons living with diagnosed HIV infection at the end of 2014, 2.0% were coinfected with HBV and 6.7% were coinfected with HCV. Of the 269 884 persons ever reported with HBV, 5.2% were reported with HIV. Of the 1 093 050 persons ever reported with HCV, 4.3% were reported with HIV. A greater proportion of persons coinfected with HIV and HBV were males and blacks/African Americans, compared with those with HIV monoinfection. Persons who inject drugs represented a greater proportion of those coinfected with HIV and HCV, compared with those with HIV monoinfection. Matching HIV and viral hepatitis surveillance data highlights epidemiological characteristics of persons coinfected and can be used to routinely monitor health status and guide state and national public health interventions.
During early lactation, when requirements for energy and protein are high, tissue protein requirements cannot be fulfilled by microbial protein alone and the opportunity arises to feed protected protein as a supplement to provide UDP which will compensate for the deficit between tissue protein requirements and microbial protein supplied by RDP.
The recent increased use of out-of-parlour feeders for dairy cows has occurred for two main reasons: (1) convenience, including ease of rationing and saving labour; and (2) claims made for beneficial responses in milk yield and/or milk composition. The suggestions concerning improvements in milk composition arise from the effects of the increased frequency of concentrate feeding on certain rumen parameters. There is a reduced fluctuation in those parameters, with a maintenance of ruminai acetate production, which gives beneficial effects on milk fat production. Evidence from the literature indicates that an increased frequency of concentrate feeding does not increase the proportion of milk fat (on a weight basis) but merely rectifies a decrease in milk fat caused by a high concentrate to forage ratio. In trials conducted over 2 years, two groups of cows were offered equal amounts of concentrates from either a controlled out-of-parlour concentrate feeder to provide frequent feeding (O), or twice daily in the parlour (P). Group O out-yielded group P (25.1 v. 23.9, s.e. of difference 0.32** and 27.1 v. 25.4, s.e. of difference 0.56** kg milk/day) in years 1 and 2, respectively. The milk fat content (g/kg) for group O was consistently lower than for group P (36.5 v. 38.1, s.e. of difference 0.91, P = 0.10; 39.8 v. 42.6, s.e. of difference 1.47, P = 0.15) but the difference was not significant. The solids-not-fat content (g/kg) was significantly higher for group O in year 1 (89.9 v. 89.1, s.e. of difference 0.18***) but similar for the two groups in year 2 (90.9 v. 90.9, s.e. of difference 0.60, NS). Overall, the yields of milk fat on the two treatments were similar but the yields of all other milk constituents were increased significantly with out-of-parlour feeding.
This study compared the effect of feeding AmyPlus, a moist feed, as opposed to rolled wheat on the yield and composition of milk from dairy cows consuming grass silage based total mixed ration (TMR). Seventy-two Holstein-Friesian cows were distributed into AmyPlus (Treatment) and Wheat (Control) groups and loose housed on straw in an open shed. Each kg Wheat based concentrate contained 345g rolled wheat, 230g rapeseed meal, 115g sugarbeet pulp, 115g Molaferm 20, 115g soybean meal, 56g barley straw and 24g vitamin-minerals. In contrast, each kg AmyPlus based concentrate contained 501g AmyPlus (480g DM /kg), 105g rapeseed meal, 126g sugarbeet pulp, 126g Molaferm 20, 84g soybean meal, 41g barley straw and 17g vitamin-minerals. Here, AmyPlus was loaded directly into the mixer wagon to prepare fresh AmyPlus based TMR with a silage to concentrate ratio of 68:32. Each TMR was fed once daily to the corresponding group of cows also receiving 2kg of Distillers’ grains per cow in the parlour during milking. Daily milk yield and composition was recorded from November 1999 to February 2000. The overall daily Dry matter intake (DMI) of each TMR per cow remained uniform (20.19 vs 20.15 kg for Treatment and Control group respectively) across both groups. Daily milk yield and total cell counts per cow did not vary significantly (P>0.05) between groups during various months. While, milk fat and protein contents were greater in Treatment than Control group during each month, the differences were significant (P<0.05) only during November and December for fat and in January for protein. On average, the Treatment group tended to show a non-significant increase (P>0.05) in daily milk yield per cow by 0.144 kg than the Control group. The fat (46.2 vs 43.7) and protein (34.5 vs 33.5) contents in g /kg milk were also increased significantly (P<0.001) in Treatment compared with Control group. Total cell counts did not vary significantly (P>0.05) and remained within the acceptable limits. The cows consuming AmyPlus maintained their health as indicated by their intake, production, cell counts and general appearance. It would appear that AmyPlus can replace rolled wheat in TMR. However, it may be necessary to evaluate the storage, economic and environmental implications of using such moist co-products in silage based dairy rations.
Optimising heifer growth rates is an essential component of dairy replacement management in order to ensure sustainable heifer replacement stocks. Continuous evaluation of the growth pattern of heifers in a herd may be used to identify particular effects of nutritional management and the environment. Body weight is considered the most useful indicator of a heifer’s growth rate, both in practice and experiment work, along with body measurements reflecting the skeletal growth of heifer. The aims of this research are to investigate: 1) body trait : age relationships, 2) ratio of body measurements to body weight, and 3) to predict body weight based on body measurements of Holstein heifers in Indonesia.
Mastitis has been one of the major diseases in dairy herds inducing economic costs associated with decreasing milk yield and its quality as well as increasing health care practices. In response to bacterial infection, the concentration of somatic cells increases in the milk of dairy cows (Boettcher et al., 2007). Somatic cell count has been widely utilised as an indicator trait for mastitis. Somatic cell count, like milk yield, varies with stage of lactation and more accurate genetic evaluation of dairy cows could be obtained when a test day model is used (Haile-Mariam et al., 2001). The main aim of this research was to compare fixed and random regression test day models in genetic evaluation of Iranian Holstein first lactation cows based on their predicted breeding value for somatic cell score.
A number of feed additives including antibiotics have been widely used in the poultry industry for several decades. The manipulation of gut function and microbial habitat of domestic animals with feed additives has been recognized as an important tool for improving growth performance and feed efficiency (Collington et al, 1990). Recently, the concerns about possible antibiotic residues and disease resistance have aroused great caution in the usage of antibiotic in the animal industry (Ricke et al, 2005). The ban on the use of antibiotic as feed additives has accelerated and led to investigations of alternative feed additives in animal production. The primary alternatives to enhance gut function and growth performance to date include acidification of feed, feeding probiotic organisms, and prebiotic compounds (Patterson and Burkholder, 2003). The main aim of the present research was to evaluate the efficiency of alternative antibiotic growth promoters on growth performance in Iranian Ross broiler performance.
The main aim of animal breeding programmes is to increase productivity and profitability of farm livestock through genetically improving the economic merit of farm livestock (Smith, 1998). This can be achieved by increasing the mean value of a population for one or several economically important traits by the genetic improvement of the animals in this population. In dairy cow husbandry, many traits of economic importance such as lactation milk yield and reproductive traits have long been of interests for breeders to increase profitability of dairy farms. Age at first calving is economically important because it determines when an animal begins its productive life and therefore could influence the lifetime productivity of an animal. Also, age at first calving can be considered as a measure of heifer fertility performance associated with reproductive efficiency. The main objective of the present research is to analyse genetic aspects of lactation milk yield and age at first calving for Holstein heifers in Khorasan province of Iran.
The Taiwanese government assists their dairy industry by supporting domestic prices through a combination of import restrictions, price support, government purchasing and subsidised disposal of surpluses. As a result, dairy production in Taiwan is insulated from international price trends. However, these dairy assistance policies can not protect the domestic price after Taiwan joins the World Trade Organisation (WTO) at the end of 2001. To access the impact of an open market, linear programming (LP) is applied to model the influence of changing feed price and milk value on dairy farm profitability.
The palm grows well in wet, humid parts of tropical Asia (mainly South-east Asia), Africa, and Central and South America Palm oil is a greatest oils the entire world. The palm oil has a greatest saturated fatty acid. The main aim of this study was to determine the best level of palm olein oil on production performance (gain body weight, egg production, egg weight, egg mass, FCR and feed intake), egg quality (Haugh unit, yolk index, yolk colour index, shell thickness and specific gravity), egg cholesterol and blood factors of laying hens of Leghorn W36.
Reproductive performance has a large influence on production and profitability. In Taiwan, survey data shows an average number of lactations of 2.87 with 67% being culled before their third lactation and a first calving age (CA) of 30 months (Chang, 1988). In order to indicate the impact of reproductive performance and calving pattern on revenue, linear programming (LP) is applied to model the effect of both replacement rate (RR) and CA.
The minimum amount of dietary NDF needed by a cow is largely based on ruminal and animal health (NRC, 2001). On average, NDF is less digestible than non-fibre carbohydrates (NFC, NRC, 2001). Therefore, NDF concentration is negatively correlated with energy concentration. The NDF is related to ruminal pH, fat percentage, and chewing activity (NRC, 2001). Fat is commonly added to diets of high yielding dairy cows to increase energy density. However, the addition of fat can interfere with rumen fermentation which can result in decreased fibre digestion. Fibre characteristics of the diet may influence the extent to which fats interfere with rumen fermentation. Therefore, the type of fibre influenced the degree of negative effects caused by ruminally active fats (Tackett et al, 1996). The main aim of the present research was to evaluate the effect of supplemental fat and NDF on fibre digestibility, rumen pH and chewing activity in lactating dairy cows.
Genetic parameters, which are based upon (co) variance components, are necessary elements in dairy cattle genetic evaluation programmes for either productive or reproductive traits that are of economic importance. Recently, there has been an increasingly interest in applying Bayesian-based methods as an alternative over classical linear models such as REML to estimate more accurate genetic parameters of the traits under consideration in animal breeding data (Gianola, 2000). However, as compared to classical methods such as REML, Bayesian estimation of genetic parameters is theoretically more complex and also needs much more computational time that could be a potential a limiting factor in practical application of the Bayesian methods. In this study the main objective is to estimate of heritability of complete lactation milk yield of Iranian Holstein heifers with the use of Bayesian (based on Gibbs Sampling that is a Monte Carlo method) and REML (based on Analytical Gradients technique) approaches.
Thawed rumen contents have been used to obtain strained rumen fluid (SRF) to estimate in vitro dry matter degradation (DMD) of feeds (Mohamed et al., 2002). However, thawed SRF (TSRF) gave lower DMD than fresh SRF (FSRF) which was partly attributed to reduced microbial activity in TRSF following storage at -20°C. This study examined the addition of glycerol (G) as cryopreservative and washing from particle associated microbes to SRF before its storage for later use as TSRF to estimate in vitro degradation of rapeseed meal (Rsd) and grass nut (Gnt).
Feed intake in the days immediately following weaning is both low and variable. This period is critical as low food intakes can lead to reduced digestive efficiency and suboptimal animal welfare. This is of commercial importance as performance around weaning has been shown to impact on the number of days an animal takes to reach a given slaughter weight (Mahan and Lepine 1991). If the variation in an individual’s performance could be characterised in terms of feeding behaviour and/or social status then production systems could be designed to optimise growth. In this trial liveweight gain during the late suckling period and liveweight gain, familiarity with penmates and social status (as determined by weight) after weaning were analysed to assess their impact on the performance of the post weaned pig.
Fresh rumen contents are the most common source of inoculum for use to estimate in vitro degradation of ruminant feeds. However, the need to routinely access fistulated or slaughtered cattle to obtain rumen contents limits the availability of such inoculum and hence the applicability of in vitro methods by the commercial laboratories. Therefore, it would be advantageous, if rumen contents are preserved in sufficient quantity and used as a source for inoculum for use when there is a need to do so to estimate degradability of ruminat feeds. This study compared the suitability of frozen rumen contents as a source of inoculum to estimate in vitro rumen degradation of rapeseed meal (rapeseed) and grass nuts at various times.
Considerable variation has been observed between studies investigating the milk yield (MY) response (MYR) to exogenous growth hormone (GH) in dairy cows. Daily injections of 25 mg/day of the recombinant product caused a MYR of over 10 kg/d (Bauman et al. 1985), a level of response rarely repeated since. Other studies using apparently similar doses and management regimes have reported no substantial effect of the hormone on MYR (e.g. Hof et al. 1991). While these studies are extreme examples, it is clear that variability in MYR has occurred between trials. In contrast, relatively little information has been published concerning variation in the MYR between treated cows. Indeed, the notion of individual variation in the MYR to GH remains contentious: Bauman (1992) suggested that the variation in the MY of GH treated cows was similar to that of control cows, and that variation in the MYR between individuals does not exist. The object of this experiment was to investigate the extent of the individual variation of the MYR to GH in dairy cows, and to relate this to changes in plasma concentrations of hormones and metabolites.