RT-PCR Test Reagent Kit Of COVID-19 The novel coronavirus belongs to the β genus. COVID-19 is an acute respiratory infectious disease. People are generally susceptible. Currently, the patients infected by the novel coronavirus are the main source of infection; asymptomatic infected people can also be an infectious source. Based on the current epidemiological investigation, the incubation period is 1 to 14 days, mostly 3 to 7 days. The main manifestations include fever, fatigue and dry cough. Nasal congestion, runny nose, sore throat, myalgia and diarrhea are found in a few cases. rt pcr kit,pcr test reagent,rt pcr test kit,pcr test reagent kit,pcr reagent kit Shenzhen Uni-medica Technology Co.,Ltd , https://www.unimed-global.com
1. Colostrum It is important that 4 liters of colostrum be fed rapidly within 4 hours of the calf's first birth. Absorption of protein antibodies is time-dependent, decreasing by 25% in the first 4 hours after birth, 50% in 12 hours after birth, and 85% to 95% in 24 hours after birth. Calves after birth do not have any levels of blood antibodies because they cannot absorb proteins from their mothers in the uterus. The goal is to feed calves with at least 100 grams or as high as 200 grams of immunoglobulin (IgG) via colostrum. If colostrum has an average of 50 g of IgG/litre of immunoglobulin, then each calf fed 2 liters of colostrum can have 100 g of IgG. Since most colostrum samples do not contain up to 50 g/l of immunoglobulin, and in production practice, the level of antibody protein in colostrum is rarely monitored, so that calves are fed in the first colostrum At least 100 grams of IgG is obtained, preferably 4 liters of colostrum in the initial colostrum feeding. The dirty colostrum of E. coli greater than 100,000 colony-forming units is a significant problem. In the field surveys in the United States, 33 to 99% of the samples were more than these recommended levels. In this way, the yak has inadvertently inoculated this “bacterial soupâ€. Even if 4 liters of colostrum was fed within 4 hours of birth, the value of colostrum is greatly reduced due to excessive contamination of the colostrum. Research has indicated that the main source of these contaminations is due to milking, transporting and feeding of colostrum (Gordden, 2007). All these utensils must be almost sterilized, because the number of bacteria from the colostrum to the feeding, every 20 to 30 minutes, the number can be doubled, but depends on the surrounding temperature. Dirty colostrum is equivalent to causing illness or death within the first 2 to 3 weeks after the calf has emerged, because it is the time when calves are most likely to occur and are most likely to cause death. The benefit of feeding 2 liters or 4 liters of colostrum at birth was found in a field study. The study has been feeding yaks to their first two lactation periods and found differences among them (Faber et al., 2005). Broilers fed 5 liters or 4 liters of colostrum on the first feeding have a 50% lower veterinary cost at 14 months of age, 0.23 kg more daily gain, and prolific during the first lactation period 11% of the 305-day adult equivalent milk quantity (9907 kg vs. 8952 kg), and 17% of the 305-day adult equivalent milk quantity (11294 kg vs. 9642 kg) during the second lactation period. This shows that colostrum has more benefits than simply providing absorbable antibody proteins and other nutrients. Some of the more than 200 biologically active substances that are likely to be found in colostrum have an important impact on very early breast development and subsequent milk production increase.
Second, liquid feeding Because calves do not have ruminal function at birth, they must initially be fed a liquid diet to provide most of the nutrients in the first few weeks. These fluids pass through the rumen sulcus over the rumen, and enter the abomasum or stomach. Where the digestion process begins, the contents of the atrophy are then drained into the small intestine for nutrient absorption. The concentration of protein/fat/solids is the main variable that provides fluid nutrition. Since milk contains about 13% solids, traditional milk replacer (MR) is mixed with similar levels of solids. The protein and fat levels of U.S. milk replacers are usually 20% each, and are commonly referred to as 20/20 milk powder. The amount fed is a key factor. Traditionally, a milk replacer with a feed level of 0.227 kg was mixed in 2 liters of water and fed twice daily. However, this only provides the protein and energy required for a sufficient weight gain of 0.227 kg of daily weight (NRC2001, abbreviated). Since then, the current level of feeding has increased to 0.284 kg, mixed in 2 liters of water and fed twice daily. However, in order to achieve most of the nutrition provided by the genetic potential for growth, more protein and higher feed levels are needed. The most practical and cost-effective feeding levels are fed with 28/15 powdered milk powder in an average of about 0.386 kg mixed in 3 liters of water and fed twice daily. This is often referred to as accelerated or intensive feeding. Comparison of feeding regimens for 20/20 and 28/15 milk powders (Stamey et al., 2011) resulted in higher daily gain and heavier calves. It also causes calves to convert nutrition into body weight during the period when their lives are most fragile and in their most effective growth. This method allows the yak to achieve a goal that is twice the birth weight from calving to the end of two months.
Third, water is often limited and lacking in the feeding of calves. Yaks like ready-made, clean and warm water. Calves and cows prefer warm water because it does not interfere much with the temperature of rumen or rumen bacteria (Dracy et al., 1968; Bewley et al., 2008). This is even more important in cold weather. Cold water can cause cold shock to the ruminal bacteria and increase the caloric needs of the calves after they drink cold water. Calves and cows need about 4 times the amount of water used to feed dry matter (Ketrtz et al., 1984; Quigley et al., 2006; Kramer et al. 2009). If there is no ready-to-use clean drinking water, the dry matter intake (DMI) will cut back. Second, fresh and clean drinking water must be available daily for calves fed colostrum and transitional milk. This also prompted calves to eat yaks earlier. Keep in mind the key 4:1 ratio of water to dry matter in production practice.
Fourth, the rumen of calves before forage weaning development, it is best to avoid marginal acidosis but also to promote the development of volatile fatty acids in the rumen papillae fermentation promoter. The order of volatile fatty acids that contribute to the development of the rumen papilla is butyrate, propionate, and acetic acid. Feeding forage before weaning, while avoiding marginal acidosis, does not provide the best mixture of volatile fatty acids, but also causes gastrointestinal filling and affects body weight gain. In fact, forages impede the development of the rumen papillae (Warner, 1999). The physical shape of the dietary material is a key factor affecting rumen development and function.
Fifth, yaks start food calves do not like yaks in the starter food powder, and this will reduce their intake of calf starter intake. The physical shape of yak starter diet is very important for the development and function of its rumen. The form of granulation has become more common due to cost and operational reasons, but it does not lead to early functional rumen development. In one study, yaks were fed the same formula, but one was granulated and the other was a mouth-watering starter (grained and mixed with whole grain corn or oats) (Porter et al., 2007). . In this trial, the yak ruminating time observed for the first time was 6.0 weeks and 3.7 weeks of age, respectively, and the percentage of time for rumination was 8.7% and 21%, respectively. The calves that are fed the mouth-warming foodstuffs also feed more of the starter diets after weaning (P dietary materials should be kept fresh, dry, and fed in proportions. Therefore, the storage time of starter diets on dairy farms is generally not to exceed 1 Months: The initial feeding of yak starter should begin in the first week and can be as little as 50 to 100 grams per head per day, and the remaining material should be changed every day.Then the amount of feedstuffs to be fed, along with calves intake As the volume increases, it gradually increases.
A ubiquitous problem is that there is often no clear separation between the drinking water and the starter containers. This separate interval must be large enough so that the yaks cannot drop water into the diet or bring the diet material into drinking water. Followed by dirty water and wet starter diet will reduce the intake of both. VI. Weaning Conversions and Changes Weaning conversions or transitions of calves are as important as the perinatal period before and after calving, but are often not considered. For yak, it is two weeks before weaning and two weeks after weaning. In order to reduce the stress after weaning and avoid the decrease of production performance, calves need to gradually enter and steadily go out of this period. This means that yaks should eat an average of 0.5kg of starter food per day. Then during the next week, subtract one of the two times from whole milk or milk replacer. This will allow yak starter to have approximately double the feed intake to 1 kg per day (partly weaned). Finally, in the third week, another whole milk or milk replacer feed was subtracted. This also increased the yak compound approximately double to 2kg per day (completely weaned). Continuing to feed yaks with starter foods and providing fresh and clean drinking water will increase the intake of starting foods to 2.3~3.7kg per day. With this progressive and well-managed, yaks will experience weight gain during the week of partial weaning. The minimum reduction, and reduce stress due to a complete weaning transition or transition period.
A one-off excess of calves at weaning can lead to health problems, especially respiratory problems. When calves are weaned, they too experience other significant changes. These changes may include immunization in addition to weaning. If they have not been dehorned, they may deviate and transfer calves into their first social or social changes. The population, from yak material to yak growth material, and start feeding forage or roughage - may add 50% or more of forage to the whole mixed diet. All these one-time changes will produce stress and reduce immunity. Field data from a dairy herd in New York State showed that once yak suffers from respiratory problems, it will damage life (Warnik et al., 1995). Heifers suffering from respiratory problems have a slow growth and are 6 months older than their cohorts at the time of first calving. They have more calving difficulties and are eliminated faster than those calves who were once of similar age.
Feed intake and feeding for heifers For heifers, there is often a variation in dry matter intake (DMI) and it is difficult to predict. In the 1989 Cow Nutrient Demand (NRC), feed intake predictions were based primarily on estimated energy needs, and then the required DMI was calculated in reverse to meet these needs. Except for heifers weighing more than 450 kg, this led to a similar curve for the 2001 NRC dry matter forecast. This turning point in the 1989 dry matter intake estimate was based on the assumption that lower quality/energy forage could be used for these larger heifers. This amount of dry matter intake is then needed to meet the energy needs of these heifers. In fact, lower quality forage or forage will reduce dry matter intake because of its lower digestibility and digestibility while also increasing gastrointestinal filling. In the NRC 2001, the actual dry matter intake of dairy heifers was mainly collected from the experiments conducted by the Purina Feed Company Dairy Research Center for 20 years, and compared with the beef heifers used in the 1996 NRC beef cattle. The equations are marked. The observed dry matter intake (data points) was initially lower than the predicted DMI (line), and then a higher increase was seen above the forecast line when the DMI was at 5 kg/day and above. This turn is consistent with heifers older than 6 months of age. Milk heifers have higher DMIs than females with a smaller maternal year, which may simply reflect the larger size, especially body height, of dairy cows that are genetically directional. Another key point is that as the heifers eat more, the exact DMI distribution (variation) also increases. In fact, the DMI variation of this heifer is likely to be greater than that of the lactating cow. This may be due to the genetic diversity of heifers, but it is more likely due to the large differences in the nature of feeding schemes that are used with the heifers' different environmental conditions.
Dry food intake increased with body size and decreased by the percentage of body weight. The ratio of protein to metabolic energy (ME) can be used as a reference point for evaluating heifer diets (Vande Haar, 1998). Simply multiply the crude protein (% of DM) by 10 and divide by megacaloric energy/kg. At 66 g/million calories, about 66% of dietary calories are derived from protein. As heifers grow bigger, there is a corresponding increase in maintenance and energy. If protein is higher than needed, the waste of nitrogen will occur. If energy is higher than needed, obesity may occur even if the protein is suitable. If forage or roughage quality is poor, increasing protein levels will only benefit digestibility and feed intake to one point. Above that point, the additional protein concentration is useless (Jahn et al., 1976). The quality of forage or roughage is a major limiting factor in heifer dry matter intake, digestibility, and daily gain.
Eight, the growth target body height builds the growth body frame. The armpit/shoulder height at birth is 76 cm. An additional 53 cm can be expected at the first calving of 24 months of age. These exact values ​​vary with the genetic cloth (Kertz et al., 1997), but the pattern of highly increased is different. The increase in height is curvilinear, and the following situation occurs: 50% occurred in the first 6 months, and only 25% occurred in the last 12 months before 24 months of calving (Kertz et al., 1998). The increase in heifer height is not compensatory. The target for weight gain is 0.8 to 0.9 kg/day, and it is relatively linear after weaning. The increase in adipose tissue/adipocytes is initially proliferative and later hypertrophic.
It is important to avoid premature excess obesity because this can lead to problems with perinatal cows.
Nine, the most economically efficient nutrient conversion occurs at the youngest age, partly because of its smaller weight. Although kilograms are more expensive to feed per kilogram of feed, they may actually have higher feed costs per kilogram of weight gain due to increased maintenance requirements as body weight increases. Field data from Wisconsin (Zwald et al., 2007), the individual components and total costs of juvenile growth for milk by weight. During the collection of these data, the cost of raising heifers to first calving was $1,649. 20% of this total cost occurred during the calf period, and nearly 50% of this cost is labor. Unfortunately, many dairy farms are able to reduce the cost of yak during the yak period by 25 to 50 US dollars, but this is a small part of the total cost of heifers, and this is not conducive to the most vulnerable dairy farms and the highest nutritional efficiency Growing animals.
10. How does the feeding and management of yak affect subsequent milk production reactions?
A major study of the Northeastern United States with more than 300,000 cows (Keown et al., 1986) found that between the weight of 550 kg after the first calf heifers gave birth and the amount of milk produced during the first lactation D. More recently, Cornell University studied 1244 first-lactation data summarized by dairy herds (Soberon et al., 2011) and found that pre-weaning daily gain (ranging from 0.1 to 1.59 kg) was directly related to the first lactation period. And later milk production during lactation. A difference of 1 kg in weight gain on the day prior to weaning resulted in more milk of approximately 1872 kg in the first lactation period and more milk production of approximately 5021 kg in the first three lactations. This response far exceeds the genetic progression of approximately 90 kg of milk per year found in the United States dairy herds. Other studies have found similar correlations, but compared to what was found in the Cornell Institute, a smaller number of animals limit the difference in sex. However, except for one study, they all showed similar trends.
For future growth yak for dairy herd renewal, further improvements in feeding and management are needed to better enable calves to achieve the genetic potential of milk production. Table 1 Tested to 8-week-old yaks starting with different physical shapes (granulated or mouthfeel), calf performance, rumen parameters and digestibility.
This PCR Test Kit is used for in vitro qualitative detection of novel coronavirus 2019-nCoV in respiratory specimens including oropharyngeal swab, sputum, bronchoalveolar lavage fluid and nasopharyngeal swab. Primer sets and FAM labeled probe are designed for specific detection of ORFlab gene of 2019-nCoV, VIC labeled probe for N gene of 2019-nCoV. Human RNase P gene extracted concurrently with the test sample provides an internal
control to validate nucleic extraction procedure and reagent integrity. Probe targeting human RNase P gene is labeled with CY5.
Feed management for yak and heifers
Dairy yaks for dairy cow herd renewal, such as in the United States, have considerable room for improvement. In the nationwide survey that began in the United States in 1991, the loss of calves before weaning was approximately 8% to 11%. The latest National Animal Health Surveillance Survey (NAHMS) found that the number of stillbirths was 6.5%, and the mortality after weaning was about 2%. This 6.5% of the number of stillbirths is somewhat sceptical, as few dairy farms in the region maintain a good record. Other studies have found that the number of stillbirths ranges from 10% to 20% (Meyer et al. 2011; Etteina et al. 2004). Therefore, at least 20% of calves cannot be renewed as future herds due to these types of deaths. Most of these yak deaths occur due to diarrhea before weaning and respiratory problems after weaning (NAHMS, 2007). The most common cause of respiratory problems after weaning is due to too many changes in one time, leading to severe stress and reduced immunity. Field data shows that once a yak has a respiratory problem, it will damage his life (Warnik et al., 1995). Slower growth rates, later first calving and subsequent early eviction during the first lactation, it is necessary to avoid the yak's respiratory problems. Yak has three crucial periods, both before and after calving (including cow, environment, colostrum management), two weeks after the death of most calves, and weaning conversions. The focus of this article is to explore all aspects of raising calves and heifers.