• Asian-Australasian Journal of Animal Sciences
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• 제24권9호
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• pp.1318-1328
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• 2011

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.

• Asian-Australasian Journal of Animal Sciences
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• 제16권6호
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• pp.789-793
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• 2003

An investigation was conducted on 729 Hariana cows maintained at Government Livestock Farm, Hisar, from 1973 to 1999, with an objective to compare the efficiency of various selection indices for attaining desired genetic gains in the index traits. The various traits included were age at first calving (AFC), service period (SP), calving interval (CI), days to first service (DFS), number of services per conception (NSPC), lactation milk yield (LY), peak yield (PY), dry period (DP). Except for LY, PY and AFC the heritabilities of all other traits were low. Desirable associations among reproductive traits are supportive of the fact that any one of these traits incorporated in simultaneous selection is expected to cause correlated response in other traits. Production traits (LY and PY) were positively correlated, while DP had low negative genetic correlation with LY, and high genetic correlation with PY. Thus, DP can be taken as additional criteria in selection index for better over all improvement. Almost all production traits except DP had low negative correlation with AFC, SP, DFS and CI meaning that reduction in reproduction traits up to certain level may increase production performance. While, the correlation of NSPC with LY and PY was moderate positive. Among four trait indices I23: incorporating PY, AFC, SP and NSPC and among three trait indices I1: incorporating LY, AFC and SP were the best as these required least number of generations (4.87 and 1.35, respectively) to attain desired goals. Next in order of preference were PY or LY along with DP and SP as the best indices (I20 and I16) of which, index with PY may be preferred instead of LY as it produced considerably high correlated response in LY and reduction in NSPC as well.

• 한국임상수의학회지
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• 제20권3호
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• pp.369-375
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• 2003

The ultrasonography was performed in 77,924 subestrous dairy cows from 680 dairy farms at 57 districts. The cows were examined for confirmation of resumption of ovaries and uterus after 30 days postpartum, for early pregnancy diagnosis after 30 days post-insemination, confirmation of pregnancy at 8 month post-insemination, and for diagnosis of reproductive dysfunctions, respectively. The results of reproductive examination by ultrasonography in 77,924 dairy cows were ovarian disorders 35,452 (46.8%), uterine disorders 10,721 (13.8%), pregnancy and pregnant failure 24,044 (30.8%), adhesion of reproductive tracts 167 (0.2%), freematins 13 (0.01%) and others 6,527 (8.4%) cows, respectively. The 13,732 (49.6%) cows out of 27,694 cows were treated for silent heat or error of estrus detection, 3,473 (12.5%) cows for follicular cysts, 815 (3.0%) cows for luteal cysts, 606 (2.2%) cows for inactive ovaries, 4 (0.01%) cows for granulosa cell tumors, and 6,455 (23.3%) cows for endometritis, respectively. The indices of reproductive efficiencies before (2001-08-10) and after (2003-07-20) periodical examination of reproductive status were as follows; the mean intercalving interval were shortened from 471 days to 383 days, the mean interval calving to conception were shortened from 187 days to 99 days, the mean interval calving to first service were shortened from 105 days to 67 days, the mean cows showing heat by 60 days postpartum were increased from 33% to 89%, the mean conception rate to first service were increased from 43% to 68%, and the mean service per conception were shortened from 2.6 times to 1.8 times, respectively. These results suggest that periodical examination of reproductive status would be useful for the improvement of the reproductive performance in dairy cows.

• Reproductive and Developmental Biology
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• 제38권3호
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• pp.123-127
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• 2014

This study was conducted for SNPs in the 5'-regions of estrogen receptor-${\alpha}$ (ESR-${\alpha}$), and association with calving interval (CI), service per conception (SPC) and 305 days milk yield in Hanwoo and Holstein dairy cattle. The genetic improvement was incurred low reproduction performance. The objective of this study was to investigate connections between single nucleotide polymorphisms (SNP) of Estrogen receptor-${\alpha}$ (ESR-${\alpha}$) with reproduction performance (calving interval, service per conception, and 305 d milk yield) in Hanwoo and Holstein dairy cattle. Hanwoo and Holstein blood samples were collected from 183 and 124 dam of breeding farms and DNA was extracted. Primer design was based on NCBI GenBank (Accession No. AY340579). The PCR-RFLP method with Bgl I was used to genotype the cattle. The result showed two variants of the ESR-${\alpha}$ gene. The Bgl I cut the 492 bp amplification product into 322 bp and 170 bp fragments for allele G, while allele A remained uncut, resulting in two restriction fragments for homozygote G/G and three fragments for heterozygote A/G. We found two of different genotypes in these breeds, A/G and G/G. In Hanwoo, the A/G genotype frequency was 0.13, and G/G was 0.87. The CI of A/G was $382.18{\pm}10.03$ days, and G/G was $381.69{\pm}5.22$ days. The SPC of A/G was $1.62{\pm}0.16$, and G/G was $1.32{\pm}0.04$. While CI showed no significance difference, SPC exhibited significant difference (p<0.05). In Holstein cattle, the frequency of genotype A/G was 0.02 and G/G was 0.98. The 305 days milk yield of A/G was $7,253.00{\pm}936.00kg$ and of G/G was $8,747.51{\pm}204.88kg$, showing no significant difference.

• 한국임상수의학회지
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• 제33권2호
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• pp.87-92
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• 2016

This field study investigated the effects of dystocia on the postpartum complications, milk production, and reproductive performance in Holstein dairy cows. Calving difficulty was scored on a rank scale of 1 to 5. Cows with a calving score of three or higher were judged to have dystocia. The cows (n = 565) were categorized based on the presence (n = 61) or absence (n = 504, control) of dystocia. The incidence of retained placenta (45.9% vs. 16.3%), metritis (39.3% vs. 17.1%), endometritis (47.5% vs. 16.3%) and pyometra (9.8% vs. 1.2%) were greater in cows from the dystocia group than those from the control group (p < 0.0001); however, there was no difference in the incidence of metabolic disorders (32.8% vs. 31.0%) between the two groups (p > 0.05). The prevalence of culling was higher in cows from the dystocia group (26.2%) than in those from the control group (14.5%, p < 0.05). During the 5-month postpartum period, milk production was lower (p < 0.05) in cows from the dystocia group than in those from the control group. Furthermore, the hazard of insemination by 150 days in milk (DIM) was lower in cows from the dystocia group (hazard ratio [HR] = 0.64, p < 0.005) than in those from the control group. Logistic regression analysis revealed that the odds ratio for the probability of pregnancy after the first artificial insemination was 0.36 times (p < 0.05) higher in cows from the dystocia group than in those from the control group. The hazard of pregnancy by 360 DIM was lower in cows from the dystocia group (HR = 0.45, p = 0.0001) than in those from the control group. In conclusion, dystocia resulted in increased postpartum complications, and decreased milk production and reproductive performance in Holstein dairy cows, leading to increased culling.

• Asian-Australasian Journal of Animal Sciences
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• 제13권2호
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• pp.182-187
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• 2000

Forty-two Holstein cows (21 multiparous) were assigned by calving date and parity to three dietary sequences to evaluate the effect of time of initiating fat supplementation to diets on lactation and reproductive performance. The dietary sequences were: 1) control, no supplemental fat from 1 to 98 days in milk (DIM) ; 2) control diet from 1 to 28 DIM then 3% supplemental fat (calcium salts of long-chain fatty acids) from 29 to 98 DIM; or 3) 3% supplemental fat from 1 to 98 DIM. Feeding supplemental fat did not enhance mean milk and 4% fat corrected milk (FCM) yields, but efficiency of FCM production was higher for cows fed supplemental fat. Milk fat percentage was unchanged whereas milk protein percentage was depressed with fat supplementation. Feeding supplemental fat reduced DMI and energy balance but there were no differences among treatments on time to resumption of ovarian cyclicity or conception rate to first service. Concentrations of progesterone during the first two ovulatory cycles tended to be greater in the fat-supplemented groups. Feeding supplemental fat starting at either parturition or 29 DIM increased efficiency of FCM production, but did not greatly enhance reproductive performance.

• Journal of Animal Science and Technology
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• 제49권2호
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• pp.239-244
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• 2007

본 연구는 한우 송아지의 이유시기별 발육, 사료섭취량, 질병발생 및 어미소의 번식효율에 미치는 영향을 조사하기 위하여 수행되었다. 시험축은 축산연구소에서 자체 생산된 한우 송아지 60두를 공시하여 이유시기별로 조기이유(EW, 생후 3개월령)와 관행이유(NW, 생후 4개월령)에 각각 29 및 31두씩 배치하여 두 개의 시험구를 두었다. 송아지의 포유기 및 이유후 체중과 일당증체량은 이유시기에 따른 차이는 없었다(p>0.05). 또한 인공유, 목건초, 건물, 조단백질 및 TDN 섭취량도 이유시기에 의한 영향은 없었다(p>0.05). 어미소의 분만간격은 관행이유 시험구에 비해 조기이유 시험구에서 23일 정도 단축되는 경향을 보였다(p>0.05). 한편 이유시기에 따른 발생 질병의 종류와 발병율은 시험구간 차이가 없는 것으로 조사되었다. 따라서 이유시기 단축이 한우 송아지의 성장, 사료섭취량 및 질병 발생에 미치는 부의 영향은 없었을 뿐만 아니라 어미소의 분만간격을 단축시키는데 효과가 있는 것으로 사료된다.

• 한국임상수의학회지
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• 제30권6호
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• pp.435-441
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• 2013

본 연구는 젖소에서 분만 후 첫 수정 간격 및 임신 간격이 이후의 번식능력에 미치는 영향에 대하여 조사하였다. 첫 번째 분석에서는, 705두의 젖소 자료를 첫 수정 간격에 따라 짧은 간격(30-60일, n=217), 중간 간격(61-90일, n=309) 및 긴 간격(91-150일, n=179) 군으로 구분하였다. 자궁내막염의 발생은 짧은 간격 및 중간 간격 군에 비해 긴 간격 군에서 증가되었다(p<0.05). 첫 수정 간격이 증가함에 난소낭종의 발생은 증가한(p<0.05) 반면, 분만 후 5 개월 간의 BCS는 반대로 낮았다(p<0.01). 분만 후 365일까지의 임신율은 중간 간격 군에 비하여 긴 간격 군에서는 낮았으나(hazard ratio[HR]=0.70, p<0.0001), 짧은 간격 군에서는 높았다(HR=1.41, p<0.0001). 두 번째 분석에서는, 436두의 젖소 자료를 임신 간격(공태 기간)에 따라 짧은 간격(30-90일, n=154), 중간 간격(91-180일, n=183) 및 긴 간격(181-360일, n=99) 군으로 구분하였다. 후산정체 발생율은 중간 간격 군에 비해 긴 간격 군에서 높았으나 (p<0.05), 난소낭종의 발생은 짧은 간격 군에 비해 중간 간격 및 긴 간격 군에서 증가하는 경향이 있었다(p=0.08). BCS는 분만 후 1개월에 중간 간격 및 긴 간격 군에 비해 짧은 간격 군에서 낮았다(p<0.05). 산유량은 분만 후 2개월에서 5개월까지 짧은 간격 군에 비해 중간 간격 군에서 증가하였다(p<0.05). 분만 후 150일까지 첫 수정율은 짧은 간격 군에 비해 긴 간격 군이 낮았다(HR=0.73, p<0.02). 분만 후 365일까지의 임신율은 중간 간격 군에 비하여 긴 간격 군에서는 낮았으나(HR=0.64, p<0.0001), 짧은 간격 군과 중간 간격 군에서는 차이가 없었다(p > 0.05). 더욱이, 도태율은 짧은 간격 군에 비해 긴 간격 군에서 증가하였다(p<0.05). 결론적으로, 젖소에서 첫 수정 간격 및 임신 간격의 연장은 이후 번식능력의 감소를 초래하였으며, 이것은 산후 질병의 증가, BCS 감소 및 많은 산유량에 기인하였다.

• 한국가축번식학회지
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• 제17권1호
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• pp.27-34
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• 1993

The present study was conducted to examine the reproductive performance of dairy cow at alpine area. 1,515 dairy cows were managemented at above 800m of sea level around the Dea-Gwan Ryeong in Kangweon-Do. The results at this study were as follows ; 1. The average first estrus was 105.0 days after pastruation. 2. The highest percentage ofpregnancy(26.4%) and parturation(27.6%) were obtained at September to November and June to August, respectively. 3. The rate of pregnancy was 61.0%. Pregnancy rates according to insemination times of 1, 2 and 3 were 60.8, 23.5 and 9.8%, respectively and insemination time per pregnancy was 1.64. 4. Ages of first inseminatin, pregnancy and parturition of heifer were 17.9, 18.6 and 27.7 months, respectively. 5. Time of postpartum pregnancy was 133.0 days after parturition, and pregnancy period and calving interval were 279.6 and 410.3 days, respectively. 6. Six ratio of offspring was 52.1% of female versus 47.9% of male, and the proportion of twins was 0.65%. 7. The proportions of normal parturition, stillbirth and abortion were 91.9, 2.2 and 5.9%, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제22권7호
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• pp.1060-1068
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• 2009

The buffalo (Bubalus bubalis) is an important contributor to milk, meat, power, fuel and leather production in many developing countries. Buffaloes can be categorized into Asian and Mediterranean buffaloes. Asian buffalo includes two subspecies known as Riverine and Swamp types. Riverine (water buffalo) and Swamp buffaloes possess different genetics (50 vs. 48 chromosomes, respectively), morphology (body frame, body weight, horn shape and skin color) and behavior (wallowing in mud or water) and thus, are reared and used for different purposes. Low per head milk yield, poor reproductive performance (seasonal breeding behavior, anestrous, and longer calving interval) and low growth rate in buffaloes have been attributed to insufficient supply of nutrients. In many parts of Asia, where the buffalo is an integral part of the food chain and rural economy, irregular and inadequate availability of quality feedstuffs and their utilization are hampering the performance of this unique animal. Balanced nutrition and better management can enhance buffalo productivity. Many efforts have been made in the last few decades to improve nutrient supply and utilization in buffaloes. Recent research on locally available feed resources such as crop residues, and industrial by-products, dietary addition of micronutrients, use of performance modifiers and use of ruminally protected fat and protein sources have shown significant potential to improve growth, milk yield and reproductive performance of buffaloes. However, a number of issues, including establishment of nutrient requirements for dairy and beef, development of buffalo calf feeding systems, nutritional management of metabolic and reproductive anomalies, and understanding and exploitation of the buffalo gut ecosystem, need to be addressed. Extensive coordinated research and extension efforts are required for improved buffalo nutrition in developing countries.