• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.511-514
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• 1999

Data pertaining to 1111 first lactation performance record of Karan Fries (Holstein-Friesian $\times$ Zebu) cows spread over a period of 21 years and sired by 72 bulls were used to examine the efficiency of sire indices for lactation milk production using auxiliary traits. First lactation length, first service period, first calving interval, first dry period and age at first calving were considered as auxiliary traits. The efficiency of this method was compared with simple daughter average index (D), contemporary comparison method (CC), least-square method (LSQ), simplified regressed least-squares method (SRLS) and best linear unbiased prediction (BLUP) for lactation milk production. The relative efficiency of sire evaluation methods using one auxiliary trait was lower (24.2-32.8%) in comparison to CC method, the most efficient method observed in this study. Use of two auxiliary traits at a time did not further improve the efficiency. The auxiliary sire indices discriminate better among bulls as the range of breeding values were higher in these methods in comparison to conventional sire evaluation methods. The rank correlation between breeding values estimated using auxiliary traits were high (0.77-0.78) with CC method. The rank correlation among auxiliary sire indices ranged from 0.98 to 0.99, indicating similar ranking of sire for breeding values of milk production in all the auxiliary sire indices.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.2
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• pp.229-232
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• 1997

Effects of short-term treatment with somidobove (recombinantly produced bovine somatotropin, BST) on estrous cyclicity and fertility were studied in dairy buffaloes. Twenty buffaloes of Nili-Ravi breed calving during the same season were assigned to either control (n=8) or treated group (n=12). The buffaloes of treated group received single infection (prolonged release) of 320 mg of somidobove on day-60 postpartum. The mean values for interval to first postpartum estrus, first service conception rate, services per conception, service period and calving interval for the treated group were 96.4 days, 66.7%, 1.70, 164 days and 473 days, respectively. The corresponding values for the control group were 92.5 days, 62.5%, 1.87, 135 days and 439 days. Means of all variables did not differ between control and treated group (p > 0.05). Three buffaloes of the control and four buffaloes of the treated group did not conceive at first service. Out of these, two buffaloes of control and one buffalo of treated group exhibited normal estrous cycles. It is concluded from these data that short term BST-treatment has no adverse effect on reproductive functions of dairy buffaloes.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.3
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• pp.219-221
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• 1995

Data on productive and reporductive performance of native cows maintained at Savar Dairy Farm, Central Cattle Breeding Station (CCBS), Savar, Dhaka, were collected from the periods of 1980-1988. The mean calving to first breeding during the second parity was longer (p < 0.01) than the fourth and fifth parities (152 vs 105 and 96 days respectively). There was no difference on the parameters like first breeding to conception, service period, gestation length, number of services per conception and total milk yield over the parities. The mean calving interval during the second parity was longer (p < 0.05) than the fourth and fifth parities. The mean lactation length during the first parity was longer (p < 0.01) than those of second, third, fourth and fifth lactations (317 vs 237, 266, 250 and 247 days respectively). The mean per day milk yield during the first lactation was lower (p < 0.01) than those of second, third, fourth and fifth lactations (1.88 vs 2.55, 2.75, 2.54 and 2.57 kg respectively). The mean dry period was longer in first lactation (p < 0.05) compared to third and fifth lactations (209 vs 141 and 129 days respectively).

• Korean Journal of Veterinary Research
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• v.59 no.4
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• pp.181-185
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• 2019

The traditional calculation of gestation length (GL) in Holstein cows relies solely on the insemination day and has a high error rate for actual calving dates. The present study was conducted to develop a more accurate method of estimating GL. Among 3,578 Holstein cows, the number of fetuses had a significant (p < 0.05) effect, with GLs of 282.4 ± 2.5 days for singletons and 276.0 ± 1.6 days for twins. Within the singleton group, the GLs were 284.6 ± 1.9 days for males and 280.3 ± 1.5 days for females, a significant difference (p < 0.05). However, within the twin group, there was no difference in GLs among twin males, twin females, or twins of both sexes. Gestation was significantly shorter for singleton males born from June to August but significantly longer for twin males born in the May to June period (p < 0.05). Neither parity nor housing type was associated with any significant difference in GL. In order to predict the calving dates of Holstein cows accurately and improve their management, calculations should consider the number and sex of fetuses as well as the insemination season.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1192-1198
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• 2011

Peri-partum metabolic profile was evaluated in winter and summer calving, with 15 Murrah buffaloes in each seasonal group. In summer calvers, significantly lower values were observed for blood plasma urea nitrogen (BUN) at day 30 pre-partum (p<0.05), on calving day (p<0.05) and at all other stages (p<0.01); plasma non-esterified fatty acids (NEFA) values were significantly lower on day 30 pre-partum (p<0.01) and on day 60 post-partum (p<0.05). This was associated with significant reduction in days to first service (DFS) and service per conception (SPC) and an overall better reproductive performance in terms of service period, risk to first service on days 60, 90 and >90, and pregnancy risk to first service up to days 60 and 90. This may be attributed to better pre-partum nutritional status. Cervical and uterine involution were completed in fewer days, involutional changes took place at a faster pace and there were a lower number of abnormal involutional changes in winter compared to summer season. This may be attributed to better post-partum nutrition and less environmental stress. However, validation requires further targeted cohort investigation with a large sample size.

• Korean Journal of Animal Reproduction
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• v.13 no.1
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• pp.1-6
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• 1989

A field survey was conducted to obtain the data on reproductive performation of Korean native cattle. The data for this study were taken from 6,461 breeding records of cows raising at general farms in 8 Hanwoo(native cattle) pure breeding areas from June, 1984 through November, 1985. The recycling rate within 30 days, 31 to 60 days, and 61 to 90 days postpartum was 7.5%, 40.0%, and 32.8%, and it amounted to 80.3%, while the non-recyling rate up to 120days postcalving was 8.4%. Conception rate according to insemination(AI) frequencies was 65.7% at 1st AI, 21.3% at 2nd AI, and 8.4% at 3rd AI, respectively. It amounted to 95.4% up to 3rd AI. Clving rate during the spring time was the highest, 39.6%, and tended to be reduced according to summer(31.6%), autumn (16.3%), and winter (12.5%). Spring and summer were the highest seasons for pregnancy and their gestation rates are 33.7% in spring and 39.2% in winter, respectively. The days from calving to estrus and conception, and calving interval of the cows, which calved two or three times, tended to be reduced. However, the more parities, the more they are extended. According to parities, gestation length and services per conception showed irregular tendencies.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.575-579
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• 2000

First lactation records of 683 Murrah buffaloes maintained at NDRI, Karnal which were progeny of 84 sires used for comparing the heritability estimates of age at first calving, first lactation milk yield and first service period under single and multiple trait models using restricted maximum likelihood (REML) method of estimation under an individual animal model. The results indicated that the heritability estimates may vary under single and multiple trait models depending upon the magnitude of genetic and environmental correlation among the traits being considered. Therefore, a single or multiple trait model is recommended for estimation of variance components depending upon the goal of breeding programme. However, there may not be any advantage of considering a trait with zero or near zero heritability and having no or very low genetic correlation with other traits in the model. Lower heritability estimates of part lactation yield (120-day milk yield) implied that there may not be any advantage of considering this trait in place of actual 305-day milk yield, whereas, comparable heritability estimates of predicted 305-day milk yield suggested that it could be used for sire evaluation to reduce the cost of milk recording under field conditions.

• Asian-Australasian Journal of Animal Sciences
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• v.1 no.1
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• pp.47-53
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• 1988

Daily milk yield estimates were obtained on 74 lactations of 35 Japanese Black cows on weeks 1 to 9, 11, 13, 17, 21 and 26 postpartum using the weigh-suckle-weigh method. The data obtained were analyzed by least-squares procedures according to the models including the following effects; dam, lactation number, season of calving, week of experiment and partial regressions on the lactation number. The overall mean and standard error for daily milk yield was $4.55{\pm}0.04\;kg$. The milk yield declined essentially linearly throughout the experimental period. The main effects of lactation number, season of calving and week of experiment were highly significant. Differences in daily milk yield among cows were significant, and the repeatability was estimated as $0.60{\pm}0.06$. The overall means(kg) and repeat-abilities of cumulative milk yield for 1, 4, 9, 13, 17, 21 and 26 weeks postpartum were 41, 0.08; 166, 0.40; 361, 0.61; 503, 0.66; 632, 0.67; 749, 0.65 and 884, 0.58; respectively. The means of calf weight at birth and 26 weeks weight for different lactations ranged from 25.5 to 33.6 kg and 145.6 to 185.4 kg, respectively. Calf daily gains between experiment weeks were low in earlier stages of lactation.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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• pp.331-334
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• 2003

The assessment of reproductive potentials of female gayal under semi-intensive management was conducted with 18 animals in Bandarban hilly area of Bangladesh. Age at first estrous (days), age at first conception (days), length of estrous cycle (days), number of service per conception (natural), gestation period (days), age at first calving (days), and calving interval (natural service) (days) of gayal were $598.2{\pm}168.44$, $723{\pm}169.94$, $21.86{\pm}2.93$, 1.41, $296.05{\pm}3.87$, $1014.42{\pm}260.32$ and $465{\pm}80.48$ respectively. Daily milk yield and lactation length of gayal were $304.98{\pm}30.46ml/day$ and $116.67{\pm}8.08days$. Gayal male calves had higher birth weight (19.67 kg) than female calves (15.58 kg) in first lactation. Birth weight increases in second and third lactation than first lactation in both male and female calves. Highest conception rate observed in winter season and 70.60% successful conception occur when service was given within 21-30 h of estrous. Maximum number of female gayal use to come in estrous in winter and calved in monsoon and autumn. Cervicitis and irregular heat were the most reproductive problems followed by metritis, case of abortion, anestrous and repeat breeding. From this study it was observed that the reproductive performance of gayal is very close with the domestic cattle. It may use as beef cattle for the hilly regions of Bangladesh.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.4
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• pp.580-585
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• 2016

The objective of this study was to determine cow characteristics and farm management factors during the dry period associated with early postparturient intramammary infection (IMI) and subsequent clinical mastitis (CM). Data were collected three times: before drying off (P1), during the dry period (P2), and 5 to 14 days after calving (P3), using questionnaires and farm investigation. Milk samples were aseptically collected for bacterial identification at P1 and P3. Factors associated with IMI and CM were analyzed using multiple logistic regression models. The final model showed that IMI in early postpartum was significantly associated with full insertion of dry cow antibiotic, dry cows in barns with a combination of tie and free stalls, body condition score (BCS) in dry period and after calving, and milk yield before drying off. For IMI cows, factors significantly associated with clinical expression of mastitis were having daily barn cleaning, teat disinfected with alcohol before administration of dry cow therapy, BCS before drying off, milk yield before drying off, and days in milk at drying off. In conclusion, both cow and farm management factors are associated with the IMI rate and subsequent expression of clinical signs of mastitis in early postpartum cows.