조사논문 : 육우문제의 본질과 정책대응

조석진 ( Suk Jin Cho ),이용건 ( Yong Geon Lee ) 한국축산경영학회,농업정책학회(구 한국축산경영학회) 2013 농업경영정책연구 Vol.40 No.3

Dairy beef mainly produced by fattening male calf is precious domestic beef resource explaining more or less than 15% of total beef production as of 2011. But the price of newly born 7~10 days old male calf is almost negligible and even cannot find outlet. This phenomenon is not new and has been repeated depending upon the situation in Hanwoo, the Korean native cattle sector. Regrettably, however, no fundamental measure to stabilize the price has been taken up to now. As a result, recently the unsold newly-born male calf began to render significant negative impacts to the dairy farm management mainly due to soaring feed price and environmental problems within the limited space. Consequently, proper systematic not temporary measures to stabilize the price of dairy calf are badly needed. For this, it is desirable to support the price of dairy calf within the framework of Calf Production Stabilization System together with Hanwoo calf. In addition,both independent marketing channels for dairy beef and large scale public ranch for dairy calf are necessary. Also enhancement of beef quality and cost reduction are prerequisite in the era of FTA for dairy beef to compete with imported beef, the strong substitute.

Detection and molecular characteristics of bovine rotavirus A in dairy calves in China

Xiaoying Liu,Nan Yan,Hua Yue,Yuanwei Wang,Bin Zhang,Cheng Tang 대한수의학회 2021 Journal of Veterinary Science Vol.22 No.5

Background: Bovine group A rotavirus (BoRVA) is a major cause of severe gastroenteritis in newborn dairy calves. Only one study has investigated the G and P genotypes among dairy calves in a few regions of China, which were G6 and P[5]. Therefore, data on the prevalence and molecular characteristics of BoRVA in dairy calves in China remains limited. Objectives: The purpose of this study was to investigate the prevalence and molecular characteristics of BoRVA in dairy calves in China. Methods: 269 dairy calves diarrheic samples from 23 farms in six provinces in China were collected to detect BoRVA using reverse transcription polymerase chain reaction. Results: 71% of samples were determined to be BoRVA-positive. Two G genotypes (G6, G10) and two P genotypes (P[1], P[5]) were identified, and G6P[1] BoRVA was the predominant strain. Moreover, the VP7 and VP4 gene sequences of these dairy calf BoRVA strains revealed abundant genetic diversity. Interestingly, eight out of 17 complete G6 VP7 sequences were clustered into G6 lineage VI and analysis showed the strains were closely related to Chinese yak BoRVA strains. Conclusions: The results of this study show that BoRVA circulates widely among dairy calves in China, and the dominant genotype in circulation is G6P[1], first report on molecular characteristics of complete P[5] VP4 genes in chinese dairy calves. These results will help us to further understand the prevalence and genetic evolution of BoRVA among dairy calves in China and, thus, prevent the disease more effectively.

A Note on Risk Factors for Calf Mortality in Large-Scale Dairy Farms in the Tropics : A Case Study on Rift Valley Area of Kenya

Bebe, B.O.,Abdulrazak, S.A.,Ogore, P.O.,Ondiek, J.O.,Fujihara, T. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.6

The aim of this study was to assess the associations of some potential risk factors and occurrence of calf mortality in large-scale dairy farms. Njoro area of the Rift valley, Kenya was selected due to its potential of large-scale dairy farms, since the time of the Europeans settlers. The study was retrospective and focused on the calves dying from January 1996 through October 1998. Sample of studied population consisted of 105 calves extracted from the farm records. Data was collected using a questionnaire and were grouped into farm-level and animal-level factors. Calf mortality was 15.6% and important risk factors for calf mortality were sex of calf, season of birth, pneumonia disease, age of dam when calf was born and house type for calves. Female calve born during colder wet seasons and born to dams of 2-4.5 years of age were equally at higher risk. Calves raised in movable pens compared to those raised in permanent pens were at higher risk of mortality from pneumonia. Animal level factors were major causes of calf mortality in commercial farms used in this study and therefore details study is needed in these factors in controlling the calf mortality rates.

Factors Affecting High Mortality Rates of Dairy Replacement Calves and Heifers in the Tropics and Strategies for Their Reduction

Moran, John B. Asian Australasian Association of Animal Productio 2011 Animal Bioscience Vol.24 No.9

The tropics is not an ideal location for calf rearing as the high temperatures and humidities introduce many potential disease problems to milk fed calves. In addition, the type of dairy farming (generally poorly resourced small holder farming) and the general lack of awareness of the long term implications of poorly reared stock do not encourage farmers to pay close attention to their calf and heifer rearing systems. Surveys of calf rearing systems in Asia, tropical Africa and South America highlight the high calf and heifer mortalities. A range of 15 to 25% pre-weaning calf mortality is typical on many tropical dairy farms. It is often as high as 50%, indicating very poor calf management. This contrasts with US findings of less than 8% mortality from birth to 6 months while surveys of Australian farmers report only 3% losses. Simple extension programs on farms in Sri Lanka and Kenya have drastically reduced calf mortalities and improved pre-weaning growth rates. Improved management strategies leading to lower calving intervals, higher calving rates, reduced still born and pre-weaned calf mortalities and fewer non pregnant heifers can supply many more dairy herd replacements than currently occurs. Such strategies can increase the number of replacement heifer calves in the herd from 15 to over 35%, thus allowing farmers to increase their herd sizes through natural increases. Simple management procedures such as ensuring adequate intake of good quality colostrum within the first 12 hours of life, housing and good hygiene to minimise disease transfer, providing clean drinking water, developing appropriate feeding protocols to encourage early rumen development and paying closer attention to climate control and animal health can all lead to improved calf vigour and performance. Good record keeping is also important so farmers can more easily identify susceptible calves and quickly treat potential problems.

젖소 송아지와 한우 송아지의 설사병 발생률 비교

Taemook Park,Gil Jae Cho,Young JIn Yang,Il-Sun Ryu 한국동물위생학회 2024 한국동물위생학회지 (KOJVS) Vol.47 No.2

From July to December 2022, we investigated the incidence of enteric pathogens causing diarrhea in calves under 100 days old at 22 farms across Korea. A total of 354 calves (including 247 dairy calves and 107 Korean native calves) were included. We used commercially available rapid diagnostic kits to identify five enteric pathogens, including bovine rotavirus (BRV), bovine coronavirus (BCoV), Cryptosporidium. Escherichia coli (E. coli ), and Giardia . This study investigated how factors such as age, season, and birth month, which can influence the incidence of intestinal pathogens, affect the incidence of these pathogens in diarrheic dairy calves and Korean native calves. Our study found that the incidence of diarrhea-causing pathogens differed between dairy and Korean native calves. In diarrheic dairy calves, bovine rotavirus (BRV) incidence rates, correlated with season and birth month. Similarly, Cryptosporidium incidence C were associated with age and season, while Giardia incidence rates varied by season and birth month. Korean native calves, on the other hand, exhibited seasonal and birth month-related variations in BRV incidence rates, with Cryptosporidium incidence rates influenced by birth month.

Effects of an odor or taste stimulus applied to an artificial teat on the suckling behavior of newborn dairy calves

Maria Malidaki,Matthias Laska 한국축산학회 2018 한국축산학회지 Vol.60 No.4

Background: In their first days of life, dairy calves in artificial rearing systems often have difficulty using an artificial teat for feeding. Methods: We examined the age at which calves are able to stand up voluntarily and suckle as well as their suckling behavior when presented with a plain dry teat versus a dry teat modified with a presumably attractive odor or taste substance. Single-housed newborn dairy calves (n = 51) were presented for ten consecutive days with a two-minute two-choice test, in which suckling time was recorded for 1) a plain (control) teat versus a glucose-coated teat (taste test) and 2) a plain teat versus a teat with a "Freshly Cut Grass" odor (odor test). Results: On average, the calves were able to stand up voluntarily and suckle from the second or third day of age on. The "Freshly Cut Grass" odor had no significant effect on their suckling behavior. In contrast, the calves showed a significant preference for suckling the glucose-coated teat and displayed a significantly longer total suckling time in the taste test compared to the odor test. There were no significant differences between sexes regarding suckling behavior. Conclusion: The results of the present study show that glucose had a significant effect on the calves’ teat preference and significantly increased total suckling time with a dry artificial teat. As such, glucose may increase suckling motivation in non-efficient drinkers or ill calves with low motivation to suckle.

Effects of an odor or taste stimulus applied to an artificial teat on the suckling behavior of newborn dairy calves

Malidaki, Maria,Laska, Matthias Korean Society of Animal Sciences and Technology 2018 한국축산학회지 Vol.60 No.1

Background: In their first days of life, dairy calves in artificial rearing systems often have difficulty using an artificial teat for feeding. Methods: We examined the age at which calves are able to stand up voluntarily and suckle as well as their suckling behavior when presented with a plain dry teat versus a dry teat modified with a presumably attractive odor or taste substance. Single-housed newborn dairy calves (n = 51) were presented for ten consecutive days with a two-minute two-choice test, in which suckling time was recorded for 1) a plain (control) teat versus a glucose-coated teat (taste test) and 2) a plain teat versus a teat with a "Freshly Cut Grass" odor (odor test). Results: On average, the calves were able to stand up voluntarily and suckle from the second or third day of age on. The "Freshly Cut Grass" odor had no significant effect on their suckling behavior. In contrast, the calves showed a significant preference for suckling the glucose-coated teat and displayed a significantly longer total suckling time in the taste test compared to the odor test. There were no significant differences between sexes regarding suckling behavior. Conclusion: The results of the present study show that glucose had a significant effect on the calves' teat preference and significantly increased total suckling time with a dry artificial teat. As such, glucose may increase suckling motivation in non-efficient drinkers or ill calves with low motivation to suckle.

Effects of feeding different levels of dietary corn silage on growth performance, rumen fermentation and bacterial community of post-weaning dairy calves

Li Lingyan,Qu Jiachen,Zhu Huan,Liu Yuqin,Wu Jianhao,Shao Guang,Guan Xianchao,Qu Yongli 아세아·태평양축산학회 2024 Animal Bioscience Vol.37 No.2

Objective: The objective of this study was to evaluate the growth performance, rumen fermentation parameters and bacterial community of post-weaning dairy calves in response to five diets varying in corn silage (CS) inclusion.Methods: A total of forty Holstein weaned bull calves (80±3 days of age;128.2±5.03 kg at study initiation) were randomized into five groups (8 calves/group) with each receiving one of five dietary treatments offered as total mixed ration in a 123-d feeding study. Dietary treatments were control diet (CON; 0% CS dry matter [DM]); Treatment 1 (T1; 27.2% CS DM); Treatment 2 (T2; 46.5% CS DM); Treatment 3 (T3; 54.8% CS DM); and Treatment 4 (T4; 67.2% CS DM) with all diets balanced for similar protein and energy concentration.Results: Results showed that calves offered CS had greater average daily gain, body length and chest depth growth, meanwhile altered rumen fermentation indicated by decreased rumen acetate concentrations. Principal coordinate analysis showed the rumen bacterial community structure was affected by varying CS inclusion diets. <i>Bacteroidetes</i> and <i>Firmicutes</i> were the predominant bacterial phyla in the calf rumens across all treatments. At the genus level, the abundance of <i>Bacteroidales_RF16_group</i> was increased, whereas <i>Unclassified_ Lachnospiraceae</i> was decreased for calves fed CS. Furthermore, Spearman’s correlation test between the rumen bacteria and rumen fermentation parameters indicated that <i>Bacteroidales_RF16_group</i> and <i>Unclassified Lachnospiraceae</i> were positively correlated with propionate and acetate, respectively.Conclusion: The results of the current study suggested that diet CS inclusion was beneficial for post-weaning dairy calf growth, with 27.2% to 46.5% CS of diet DM recommended to achieve improved growth performance. <i>Bacteroidales_RF16_group</i> and <i>Unclassified Lachnospiraceae</i> play an important role in the rumen fermentation pattern for post-weaning calves fed CS.

Effect of Calf Birth Weight on the Subsequent Fertility of Holstein Heifers

임현주,손준규,윤호백,백광수,권응기 사단법인 한국동물생명공학회 2012 한국동물생명공학회지 Vol.27 No.2

This study investigated the effect of birth weight on the fertility of Holstein heifers. Growth parameter (body weight) was measured at birth. Calves were analyzed as three subgroups: low (L), average (A) and high (H) birth weight (BW) calves. LBW calves were born 10 kg lighter than HBW calves. Fertility data collected included age at first breeding (AFB), number of services per conception, pregnancy rate to first artificial insemination (AI), and age at first calving (AFC). Primiparous calves in HBW are smaller compared to multiparous cows (18.3% versus 48%). Although not significantly different, LBW offspring appeared to breed faster over the service period compared with the ABW offspring that bred three weeks later on the average. The mean pregnancy rate to first AI for LBW heifers was higher (60%) than ABW (48%) and HBW (45%). HBW cows required more services per conception (2.1) than the LBW (1.7) and ABW (1.9). There were significant differences (p<0.05) in age at first calving among the different calving birth weights. Smaller birth size did not have any subsequent adverse effects on fertility. HBW offspring were more likely or tend to have worse fertility parameters.

대규모 젖소 목장의 10년간 송아지 폐사 원인 분석

허태영,정영훈,최창용,조용일,강석진,이현준,기광석,백광수,서국현,Hur, Tai-Young,Jung, Young-Hun,Choe, Chang-Yong,Cho, Yong-Il,Kang, Seog-Jin,Lee, Hyun-June,Ki, Kwang-Seok,Baek, Kwang-Soo,Suh, Guk-Hyun 대한수의학회 2013 大韓獸醫學會誌 Vol.53 No.2

The objective of this study was to investigate the calf death and analyse the causes of the mortality by based on medical records and autopsy findings during 10 years in a large dairy farm. Total of 1,361 calf born and 146 calf dead during the invested period. Mortality rate was 10.7% and showed the big difference by year-specific mortality from 2.8% (4 calves) to 19.2% (28 calves). The highest rate of mortality was 1 week age (18.5%, 27 calves) and followed by 2 week age (11.6%, 17 calves) and mortality of more old calf tended to be reduced. The death less than 4 weeks and 8 weeks of age of the entire mortality accounted for 41.1% (60/146 calves) and 70.0% (102/146 calves), respectively. Causes of calf death were digestive diseases (53.4%), respiratory diseases (17.1%), musculoskeletal disease (8.2%), and systemic disease (8.2%) in order. Specific causes of calf death was highest in enteritis (43.2%), followed by pneumonia (14.4%), sepsis (8.2%) and fractures (3.4%). Seasonally, most of calf death happened in winter (48.6%) and then fall (21.2%). This results showed that enteritis and pneumonia are the main reason of calf death but other reasons were involved in calf death on the based on autopsy finding. On going research relating factors of calf mortality is needed.