• Korean Journal of Animal Reproduction
• /
• v.22 no.4
• /
• pp.359-366
• /
• 1998

A survey was carried out to investigate the effect of the parity on reproductive traits of Hanwoo(Korean native cows). Data on the reproductive traits of 670 Korean native cows were collected from January, 1996 to December, 1997 and analyzed by the parity. The results obtained were summarized as follows; 1. The average ages at first breeding, first conception and first calving were 443.0, 457.0 and 746.6 days, respectively. 2. The average days to first estrus after calving was 70.1 days and it was shortest in the cows with more than 5 parities (60.4 days) and longest in the cows at 4th parity (79.7 days). 3. The average number of services per conception was 1.53 and it was fewer in the cows at 2nd paity (1.43), but more in the cows with more than 5 parities (1.73). 4. The average days to first conception after calving was 91.2 days and there was a trend that it was longer as the parity of cows increased(p＞0.05). 5. The average length of calving interval was 375.3 days and it was shortest in the cows at 2nd cows (370.8 days) and longest in the cows at 4th parity (395.2 days).

• Journal of Embryo Transfer
• /
• v.1 no.1
• /
• pp.35-49
• /
• 1986

Recipients are an integral part of embryo transfer and they are expensive to maintain as a good recipient. Recipient management is one of the most important components in a successful embryo transfer program. Management includes selection and subsequent care of the animals. A good recipient is basically on "open" cows or heffers whose reproductive tract is capable of receiving one or two embryos and incubating it to term. Potential recipients should be always be healthy and cycling normally ranging from 18 to 23 days. A thorough veterinary examination is recommended for candidate of recipients and cattle for questionable health should be eliminated from the recipient herd. Age and size of recipients are particularly important considerations when heifers are used, because of most embryos available for transfer are from large dams and sires. Body condition can influence a recipient's production, reproduction and health. Obese and underconditioned cattle should be avoided for use. Transfer of fresh embryos especially requires precise synchronization of donors and recipients. For estrus synchronization, PGF$_2$$\alpha$ is injected twice 10 to 12 days apart and short4erm progestagen treatment is applied to potential recipient cattle by coil into vagina (PRID) or ear implant (Synchro-Mate-B). The highest pregnancy results are achieved in recipients at exact synchrony with donors or 12 to 24 hr earlier than donors. Estrus detection is a major factor in breeding efficiency. High accuracy can be achieved by use of heat mount detection alds or by obserbing cattle for 30-minute peroids 3 times daily. Assay progesterone in milk can be used to discrIminate between pregnant and nonprenant recipients. Rectal palpation on day 35 to 70 after is an accurate and safe method of pregnancy diagnosis. Embryonic mortality in recipients may be associated with factors such as high environmental temperature and nutritional or lactational stress in early lactation period. Achievement of short calving interval requires concentrated management activity during the first 90 days following calving. Acceptable candidate for a recipient should be routinely vaccinated for infectious diseases. Proper nutritional programs according to NRC requirements and body condition scoring system for recipient cattles are vital to the ultimate success of an embryo transfer program.r program.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.3
• /
• pp.330-339
• /
• 2002

Fifty one Nili-Ravi dairy buffaloes in their last two months of gestation were selected. After parturition, rectal examination of reproductive organs was carried out until the occurrence of the first oestrus (PEI). Milk samples were analyzed for milk progesterone levels (MPL). Ovulation (POI) was confirmed by rectal palpation and MPL. Feed and blood samples were collected fortnightly and analyzed. Body condition score (BCS) was recorded on a scale of 0 to 5. Crude protein (CP) intake varied among different seasons and correlated positively with serum urea levels, POI (p<0.01) and PEI (p<0.05). Excess CPI was lower in the group showing oestrus as compared to those remaining as anoestrus (p<0.05). The dietary ratio of crude protein - metabolizable energy (CP:ME) in the oestrus animals was narrow and constant, while the anoestrus animals had a widely fluctuating one. In normal breeding season (NBS) calvers, mean serum urea level (SUL) was lower than the low breeding season (LBS) calvers. SUL was positively correlated with PEI and POI (p<0.01). Up to six months postpartum, SUL were constantly higher in anoestrus than oestrus buffaloes. Mean metabolizable energy (ME) intake was lower in the NBS calvers than the LBS calvers (p<0.01). BCS and postpartum ovulation interval were correlated with ME intake (p<0.01). Prepartum ME intake was higher in oestrous as compared to anoestrous animals (p<0.05). Higher and lower ME intakes were associated with anoestrus, while a moderate energy intake was associated with a PEI of less than 75 days. Buffaloes with poor BCS belonged to the LBS calving group and most of the NBS calving buffaloes had good BCS. BCS was negatively correlated with PEI (p<0.01) and was higher in oestrous buffaloes than anestrus. It was concluded that excess intake of crude protein, associated with higher serum urea levels and low energy intake, associated with poor body condition, are the key factors for low reproductive efficiency. It may be corrected by adopting a proper feeding strategy.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.6
• /
• pp.789-793
• /
• 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.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.10
• /
• pp.1406-1415
• /
• 2013

The study was conducted to correlate the periparturient immune status in terms of neutrophil functions and cytokine expression in peripheral blood mononuclear cell culture with impending postpartum reproductive disorders in buffaloes. Forty pregnant buffaloes were observed for occurrence of postpartum reproductive disorders (PRD), i.e., metritis, endometritis and delayed uterine involution etc., during one week prepartum to four weeks postpartum period. A representative number (n = 6) of buffaloes that did not develop any PRD were included in group I (healthy, control), while the animals which experienced PRD were assigned into group II (PRD, n = 8). The blood samples were collected at weekly interval from one week prepartum to four weeks postpartum period considering the day of calving as 'd 0'. Differential leucocytes counts, superoxide and hydrogen peroxide production activity in isolated neutrophils and the mRNA expression profile of cytokines i.e., IL-2, IL-4 and IFN-${\gamma}$ in PBMC culture were studied in all the samples. A higher total leucocytes, neutrophil and band cells count along with impaired neutrophil functions i.e., lowered level of production of superoxide and hydrogen peroxide before parturition and during early postpartum period were observed in buffaloes developing PRD. Further, a lower expression of IL-2, IFN-${\gamma}$ and IL-4 mRNA in PBMC culture was observed at calving in buffaloes that subsequently developed PRD at later postpartum. Thus, suppression in neutrophil function and cytokine expression at prepartum to early postpartum period predisposes the buffaloes to develop postpartum reproductive disorders. Hence, monitoring of neutrophils function and cytokine expression profile would be effective to predict certain reproductive disorders at late pregnancy or immediately after parturition in buffaloes. In future, this may be a novel approach for determining suitable management and therapeutic decisions for prevention of commonly occurring reproductive disorders in farm animals.

• Reproductive and Developmental Biology
• /
• v.30 no.3
• /
• pp.213-218
• /
• 2006

This study was conducted to investigate the effect of abnormal ovarian cycle postpartum on subsequent reproductive performance of Holstein cows. The cows were considered to have resumed ovarian cyclicity on the day of ovulation if followed by regular ovarian cycles. Total 58.8 percentage of the cows(l14/194) had normal resumption of ovarian cyclicity(resumption within 40 days after calving), and 41.2%(80/194) had delayed resumption(resumption did not occur until >40 days after calving). Delayed resumption Type I(one or more ovarian cycles with luteal phase >20 days, i.e. prolonged luteal phase; 17.5%) and delayed resumption Type II(first ovulation did net occur until $\geq$40 days after calving, i.e. anovulation 22.7%) were the most common types of delayed resumptions. When compared with cows with a normal ovarian cycle, the cows of delayed resumption Type I had a lower 100 days AI submission conception and pregnancy rates(84.2% vs 40.0%; p<0.01, 24.0% vs 21.4% and 20.2% vs 11.1%, respectively), and longer intervals to first AI and to conception($64.7{\pm}2.79$ days vs $105.7{\pm}7.48$ days and $105.1{\pm}7.16$ days vs $133.7{\pm}11.17$ days, respectively; p<0.01). Similarly, when compared with cows with normal ovarian cycles, the cows of delayed resumption Type II had lower 100 days conception and pregnancy rates(24.0% vs 20.0% and 20.2% vs 16.3%, respectively), and longer intervals to first AI and to conception($64.7{\pm}2.79$ days vs $72.6{\pm}4.45$ days and $105.1{\pm}7.16$ days vs $120.8{\pm}12.33$ days, respectively). In conclusion, abnormal ovarian cycles postpartum adversely affected reproductive performance, including AI submission rate, pregnancy rate, interval to first AI, and calving to conception interval in Holstein cows.

• Korean Journal of Veterinary Research
• /
• v.14 no.2
• /
• pp.253-268
• /
• 1974

A total of 331 dairy cattle in Jeonnam area were examined for the breeding status and hematological values during the period from June to August. 1971 and 1974. The data obtained were analysed according to the status of breeding and the type of farm management. The results obtained in this work were summarized as follows: 1. 331 dairy cows were grouped as pregnant (63.81%) anestrus after parturition (12.45%), pregnancy unknown (11.48%), repeat breeder (10.32%), and others (1.94%). 2. The summery of reproductive histories and clinical examination were as follows. Average of calving interval was 16.5 months, interval from parturition to first breeding 97 days and postpartum interval to first estrus 72 days. Services per conception was 1.6 rate of postpartum estrus (60 days) 12.0%, and the rate of repent breeder 10.3%. 3. Generally, the blood values of RBC, Hb, serum total protein and A/G ratio were lower than those normal values, especially, the cows which showed abnormal values belonged to the repeat breeder and the unknown to conception group. The mean value for serum inorganic phosphorus was the normal value or hyperphosphatemia, on the other hand, the mean value for serum calcium of the repeat breeder group was the lowest than the other group. 4. Follow-up evaluations on the results of the laboratory tests strongly suggest that the problems of repeat breeder had a tendency to occur more frequently in the large herd (A and B type farm), and the Ca/P ratio of almost all the cows showed abnormal values.

• Journal of Veterinary Clinics
• /
• v.30 no.6
• /
• pp.435-441
• /
• 2013

This retrospective study evaluated the effects of the interval from calving to first insemination (ICFI) and days open (DO) on the reproductive performance in dairy cows. In the first analysis, data from 705 cows were grouped based on the ICFI: short (30-60 days, n=217), medium (61-90 days, n=309), and long (91-150 days, n=179). The occurrence of endometritis was greater in the long group than in short and medium groups (p<0.05). The occurrence of ovarian cysts increased with increasing ICFI (p<0.05), while body condition score (BCS) during the 5 month postpartum period was lower with increasing ICFI (p<0.01). The hazard of pregnancy by 365 days in milk (DIM) was lower (hazard ratio [HR]=0.70, p<0.0001) in the long group, but higher (HR=1.41, p<0.0001) in the short group compared with the medium group. In the second analysis, data from 436 cows were grouped based on the DO: short (30-90 days, n=154), medium (91-180 days, n=183), and long (181-360 days, n=99). The occurrence of a retained placenta was greater in the long group than in the medium group (p < 0.05). Ovarian cysts occurred more frequently in medium and long groups than in the short group (p=0.08). BCS was lower in the short group compared with medium and long groups at month 1 postpartum (p<0.05). Milk yield (kg/day) was greater in the medium group compared with the short group at months 2 to 5 postpartum (p<0.05). The hazard of first insemination by 150 DIM was lower in the long group than in the short group (HR=0.73; p<0.02). The hazard of pregnancy by 365 DIM was lower (HR=0.64, p<0.0001) in the long group than in the medium group, while the hazard did not differ between short and medium groups (p>0.05). Moreover, the culling rate was greater in the long group than in the short group (p<0.05). In conclusion, a longer ICFI and DO resulted in reduced reproductive performance in dairy cows, which was attributable to an increase in postpartum diseases, a lower BCS and a greater milk yield.

• Reproductive and Developmental Biology
• /
• v.38 no.3
• /
• pp.123-127
• /
• 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.

• Journal of Animal Science and Technology
• /
• v.49 no.2
• /
• pp.239-244
• /
• 2007

This study was conducted to investigate effects of weaning age on growth perforance, feed intake, disease occurrence and maternal reproductive efficiency in Hanwoo. Sixty experimental calves were allocated into two groups, early weaned (n=29, calf age 90 d, EW) and normally weaned (n=31, calf age 120 d, NW). Body weights and average daily gains during nursing and post-weaning periods were similar between two groups (p>0.05). Weaning age had no effect on calf starter, grass hay, dry matter, crude protein and TDN intakes of calves (p>0.05). Maternal calving interval in EW was shortened by 23 days compared to NW (p>0.05). Any difference in occurrence of disease was not observed between groups. Present results indicate that early weaning age has no negative effects on growth performance, feed intake or on disease occurrence in Hanwoo calves. And it has positive influence on maternal calving interval.