• Asian-Australasian Journal of Animal Sciences
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• v.16 no.2
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• pp.185-188
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• 2003

Data on the use of breeding records of dairy cattle farm of Fenghuang-shan in Chengdu areas during a period of six years is systematically analyzed. The results show that Holstein heifers have their 1st estrus at an average age of $513.6{\pm}46.7$ d which is not related to the calving season. Estrus mostly occurs in the months with mild ambient temperature (March, April, May, November and December). There is a very poor rate of estrus detection; only 30.0% successive estrus is observed within 24 d, 29.3% within 25-48 d, 40.6% over 48 d. The average number of insemination per conception is 1.50 for heifers and 1.74 for cows, but conception rate (CR) is lower in the relatively warm months (July, August and September) ranged from 48.1% to 51.9% compared with 58.1% to 68.5% in other months. High temperature is the most important factor affecting fertilization in warm months, but neither did CR decline immediately with the increased air temperature in June, nor did it increase immediately with the declined air temperature in September. Post partum anestrous period is $119.5{\pm}60.5$ d. The average interval from calving to conception is $159.4{\pm}85.6$ d with only 19.8% of the cows conceived within 85 d of calving. Cows with high milk yield have longer acyclic periods and lower conception rates. Improvement of efficient managements must be a precedent condition in Chengdu areas.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.435-438
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• 1992

Data were collected on productive and reproductive performance of different $F_1$ crossbred cows (Deshi cows joined by A.I. to Sindhi, Sahiwal, Jersey or Holstein-Friesian Bull semen) reared by farmers in and around the Bangladesh Agricultural University campus at Mymensingh. The traits considered were birth weight, age at first heat, age at first calving, gestation length, post-partum heat period, milk yield, lactation length, dry period and calving interval. Data were analyzed statistically using a completely randomized design and Duncan's Multiple Range Test to compare and determine the significance of between individual group means. It was observed that the Holstein $\times$ Deshi had the highest birth weight (21.4 kg) followed by Sahiwal (17.6 kg), Jersey (16.7 kg) and Sindhi (16.1 kg). Shortest age at first heat (854 and 920 days) and age at first calving (1002 and 1201 days) were found for the Jersey $\times$ Deshi and Holstein $\times$ Deshi crosses respectively. The post-partum heat period were significantly different between breeds with Jersey and Holstein sired calves having the shortest intervals. There was no difference in the gestation length of the four crosses. Holstein $\times$ Deshi and Jersey $\times$ Deshi cows gave the highest milk yields due to longer lactation periods and higher daily milk production. Similarly, Holstein $\times$ Deshi and Jersey $\times$ Deshi crosses had significantly shorter dry periods and Jersey $\times$ Deshi had a shorter calving interval. From this study it may be concluded that exotic genotypes such as Holstein-Friesian and Jersey can perform very well under rural conditions in Bangladesh.

• Korean Journal of Animal Reproduction
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• v.21 no.4
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• pp.411-421
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• 1997

A survey was carried out to investigate the symptoms and occurance of reproductive disorder in Hanwoo(Korean native cattle). Data of the reproductive disorder of 561 heads from 28 farm households have been collected from Dec. '95 to Nov. '96 and analyzed calving no, nutritional body condition and housing forms. The results obtained are summarized as follows: 1. The incidence of reproductive disorder was 20.1% and the major common symptoms were repeat breeding(39.8%), anestrous(31.0%), nymphomania(10.6%) and subestrous(8.9%). 2. The incidence of reproductive disorder according to the calving no., that of heifer, calved one to two calving no. and over three calving no. were 20.6%, 13.9% and 34.5%, respectively. 3. Reproductive disorder incidence according to the nutritional body condition was 18.3%, 14.6% and 48.7% at body condition score(BCS) less than 2.0, 2.5 to 3.0 and over than 3.5, respectively. At BCS over 3.0, the symptoms of common reproductive disorder were repeat breeding(17.6%), anestrous(12.2%), nymphomania(10.8%) and subestrous(2.7%). 4. The incidence of reproductive disorder according to the housing form 15.8% and 34.6% for group feeding in open house and individual stanchion feeding in stall, respectively. In group feeding, reproductive disorder incidence of cows raised in space of more than 9.9$m^2$ per head was 14.1%, while that of cows raised less than 9.9$m^2$ per head was 18.2%. And incidence of repeat breeding, aneestrous and subestrous was more frequent in individual stanchion feeding than group feeding.

• Korean Journal of Veterinary Research
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• v.52 no.1
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• pp.57-59
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• 2012

In this study, we investigate the status of calcium (Ca) homeostasis at parturition in three dairy farms (I, II, and III), Heilongjiang, China. Twenty multiparous Holstein cows from each farm were randomly assigned to this experiment. The dietary cation-anion difference (DCAD) was 91 mEq/kg of DM for farm I, 152 mEq/kg of DM for farm II, and 85 mEq/kg of DM for farm III. Incidence of hypocalcemia was above 75% and urine pH was above 7.25 at calving in each farm. Compared to other farms, cows in farm II that fed the greatest positive DCAD had the lowest concentration of serum Ca, the highest concentration of serum PTH, and the greatest urine pH at calving (p < 0.05). However, there was not significant difference in serum 1,25-dihydroxy-vitamin D and hydroxyproline concentration of the cows among three farms. This is the first study to confirm that hypocalcemia is very prevalent at calving in Chinese dairy farms, and the high positive DCAD is a major risk factor that results in hypocalcemia at calving, which may reduce ability of the cow to maintain Ca homeostasis.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.8
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• pp.1133-1139
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• 2015

This study aimed to determine the effects of parenteral selenium (Se) and vitamin E supplementation on economic impact, milk yield, and some reproductive parameters in high-yield dairy cows in the dry period and in those at the beginning of lactation. At the beginning of the dry period, cows (n = 323) were randomly divided into three groups as follows: Treatment 1 (T1), Treatment 2 (T2), and Control (C). Cows in group T1 received this preparation 21 days before calving and on calving day, and cows in group T2 received it only on calving day. The cows in the control group did not receive this preparation. Supplementation with Se increased Se serum levels of cows treated at calving day (p<0.05). Differences in milk yield at all weeks and the electrical conductivity values at the 8th and 12th weeks were significant (p<0.05). Supplementation with Se and Vitamin E decreased the incidence of metritis, the number of services per conception and the service period, but had no effects on the incidence of retained fetal membrane. A partial budgeting analysis indicated that Se supplementation was economically profitable; cows in group T1 averaged 240.6$ per cow, those in group T2 averaged 224.6$ per cow. Supplementation with Se and Vitamin E has been found to increase serum Se levels, milk yield, and has positive effects on udder health by decreasing milk conductivity values and incidence of sub-clinical mastitis.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1513-1520
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• 2009

Forty-six Holstein heifers were used in a completely randomized design and assigned to 1 of 2 treatments to evaluate the effects of 2 diets varying in ruminal fermentable carbohydrate sources, namely ground corn (GC) and rolled wheat (RW), on metabolism and performance of primiparous cows in the periparturient period. The heifers were fed diets as a total mixed ration (TMR) with similar energy and crude protein content including i) 18.57% GC, or ii) 18.57% RW from -24.13${\pm}$7.73 d relative to expected calving until calving. After calving, all animals received the same lactation diet until 28 d. Animals were group fed from the beginning of the study to -7 d relative to expected calving, fed individually from d -7 to 7 days in milk (DIM), and again group fed to 28 DIM. The pre-partum diets affected (p<0.05) dry matter intake (DMI), energy intake, energy balance (EB) and urinary pH during the last week pre-partum. There was no effect of pre-partum carbohydrate source on overall plasma concentration of glucose, nonesterified fatty acid (NEFA), $\beta$-hydroxybutyrate (BHBA), albumin, triglyceride (TG), cholesterol, aspartate aminotransferase (AST), insulin, and cortisol during the periparturient period. Cows fed the RW diet during the pre-partum period had greater calcium for the first week (p<0.05) and during 28 d (p = 0.08) of lactation compared with heifers fed the GC diet. Primiparous cows fed the RW diet produced greater milk protein content and yield (p<0.05). Primiparous cows fed the RW diet had lower milk urea nitrogen (MUN) and somatic cell count (SCC) than cows fed the GC diet (p<0.05). The results of this study show that feeding pre-partum diets with a rapidly fermentable source of starch but low energy content can improve animal metabolism and performance and smooth the transition of primiparous Holstein cows from gestation to lactation.

• Food Science of Animal Resources
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• v.21 no.4
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• pp.358-366
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• 2001

To investigate the compositions of Holstein colostrums, samples were collected at 12 hour-interval after 12hrs postpartum. Milk protein, milk fat, SNF and total solid content of the colostum rapidly decreased from 12 hours to 48 hours after calving whereas lactose was the lowest at 12 hours after calving. Ash content was not shown to changes during lactation periods. Immunoglobulin G(IgG) concentration was also significantly(p<0.05) high in both primiparous and multiparous colostrum collected at 12 and 24 hours after calving. IgG concentration of primiparous and multiparous colostrums at 12 hours after calving was 44mg/ml and 44.27mg/ml, respectively. There was no apparent difference in IgG level between primipara and multipara. Fatty acid composition of colostral lipid was not shown to changes during lactation period. However, lauric acid, myristic acid and total saturated, fatty acid were slightly decreased in multiparous colostral lipid. Capric acid, myristic acid and palmitoleic acid composition in primiparous colostral lipid were slightly higher than those of multiparous colostral lipid throughout all lactation periods.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.2
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• pp.159-163
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• 2004

Data pertaining to first lactation records of 316 Murrah buffaloes, progeny of 47 sires, maintained at NDRI Farm for a period of 18 years were analysed to construct selection indices and to examine their robustness by changing the relative economic values of different economic traits. A total of 120 selection indices were constructed for three sets of relative economic values ( 40 for each set) considering different combinations of seven first lactation traits viz. age at first calving (AFC), first lactation 305 day or less milk yield (FLMY), first lactation length (FLL), first calving interval (FCI), milk yield per day of first lactation length (MY/FLL), milk yield per day of first calving interval (MY/FCI) and milk yield per day age at second calving (MY/ASC). The three sets of relative economic values were based on economic values of different traits, 1% standard deviation of different traits and regression of different traits on FLMY. The 'optimum' indices for the first two sets had five traits each namely AFC, FLMY, FLL, FCI and MY/ASC giving improvement in aggregate genotype of Rupees 269.11 and Rs. 174.88, respectively. The accuracy of selection from both indices was 70.79 and 69.39%, respectively. The 'best' selection index from the third set of data again had five traits (AFC, FLMY, FLL, FCI and MY/FLL) giving genetic gain of Rs. 124.16 and accuracy of selection of 71.81%. The critcal levels or break-even points for FLMY for varying levels of AFC and FCI estimated from the "optimum index" suggested the need of enhancement of present production level of the herd or reduction of AFC or FCI. It was concluded that economic values of various first lactation traits were the most appropriate to construct selection indices as compared to other criteria of assigning relative economic weights in Murrah buffaloes.

• Korean Journal of Animal Reproduction
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• v.10 no.1
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• pp.58-65
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• 1986

The results from a survery on the reproduction of a, pp.oximately 500 dairy cows raised in four different farming areas including Cheju city, Jochun, Hallim and Sung-up are summarized as follows; 1. At the occurrence of first estrus, the average age of the heifers was 15.1 months (330 Kg/B.W.), and at first conception 18.0 months (354Kg/B.W.). There was no regional differences. 2. The average interval of the estrous cycle was 20.4 days. And the repetition of esturs after unsuccessful insemination occurred on an average of 1.6 times, especially 2.0 times in the herds of the Jochun district. 3. The ages at the first calving were similar to the data recorded for the domestic mainland's herds at 27.1 months. But some regional differences were recognized within the four districts: i.e. 28.6 (Cheju city), 27.4(Jochun), 27.1(Hallim) and 25.3 months (Sung-up). There was no significant differences in sex ratio of newborns at 50.4%(♂) and 49.6%(♀). 4. The intervals of esturs recurrence and the following conception after calving were 80.0 and 95.8 days respectively. In the followsing conception intervals after cavling, 90.6-97.4 days were average for the herds of Cheju city and Jochun districts, 62.4-69.7 days for those of Hallim and Sung-up districts. 5. The average gestation period was 279.8 days, and was almost identical in the four districts. 6. The calving intervals was 377.7 days in average, and it was shorter than the data recorded for the domestic mainland's herds. Also it was reduce gradually according to the calving frequency.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.230-238
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• 2021

This study attempted to determine the characteristic features of postpartum dairy cows during their return to estrus. Moreover, it investigated the effects of abnormal ovarian cycles (AOC) on subsequent reproductive performance and the relationship between normal ovarian cycles (NOC) and the blood urea nitrogen (BUN) level postpartum. Incidentally, 56.3% of the Holstein cows and 66.7% of the Jersey cows had NOC, whereas the 43.7% and 33.3% of the Holstein and Jersey, respectively, had AOC. Within 100 days of calving, the cows with AOC had significantly lower rates of artificial insemination (AI) submission as well as pregnancy and a significantly longer interval to first AI, as compared to that in the cows with NOC. Additionally, the cows with NOC had a significantly higher first AI conception rate than that in the cows with AOC. In this study, of the 32 Holstein cows, 8 resumed their ovarian cycle within 20 days of calving, 10 resumed the cycle with 21-40 days of calving, 8 within 41-60 days of calving, while the remaining 6 did not resume their ovarian cycles until 60 days postpartum. Furthermore, the likelihood ratios of incidence of NOC are 0.93, 1.94, and 0.38, respectively, in the groups with BUN levels < 15, 15-19.9, and ≥ 20 mg/dl. In conclusion, AOC postpartum adversely affects reproductive performance such as AI submission rate, pregnancy rate, interval to first AI and first AI conception rate; moreover, an increase or decrease in the BUN levels beyond 15-19.9 mg/dL leads to the AOC postpartum.