• Asian-Australasian Journal of Animal Sciences
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• 제26권2호
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• pp.189-194
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• 2013

The goal of this study was to evaluate the effects of lactation stage and individual performance on milk cis-9, trans-11 conjugated linoleic acid (CLA) content in dairy cows. In experiment 1, the milk cis-9, trans-11 CLA content from dairy cows in early ($0.33{\pm}0.014%$), middle ($0.37{\pm}0.010%$), and late stages ($0.44{\pm}0.020%$) showed significant differences (p<0.05); and the individual contents of the major fatty acids, especially cis-9, trans-11 CLA in cows of the same lactation were also variable. In the second experiment design as a validation test, our results once again showed that the individual contents of cis-9, trans-11 CLA were various, and a difference of about 2-fold (0.55% vs 0.95%) was observed, although the animals were offered same diet. These data demonstrated that lactation stage and individual performance have considerable effects on milk cis-9, trans-11 CLA contents.

• Asian-Australasian Journal of Animal Sciences
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• 제15권5호
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• pp.627-632
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• 2002

Genetic parameters for dairy performance traits were estimated, breeding values for the traits of all breeding sires and cows were predicted and the genetic trends were estimated using the breeding values in the Central Cattle Breeding Station (CCBS). A total of 3,801 records for Bangladeshi Local, 756 records for Red Sindhi and 959 records for Sahiwal covering the period from 1961 to 1997 were used in this analysis. Traits considered were total milk production per lactation (TLP), lactation length (LL) and daily milk yield (DMY). The genetic parameters were estimated by the REML using MTDFREML program. The breeding values were predicted by a best linear unbiased prediction (BLUP). In all sets of data, the genetic trends for the dairy performance traits were computed as averages of breeding values for cows born in the particular year. The estimates of heritability for TLP (0.26 and 0.27) and DMY (0.28 and 0.27) were moderate in Bangladeshi local and Red Sindhi breed, respectively. Furthermore, the heritability estimate for LL (0.24) was moderate in Red Sindhi. The estimates of heritabilities for all traits were low in Sahiwal. The repeatability estimate was high for TLP, moderate for LL and moderate to high for DMY. All variances estimated in Bangladeshi Local were low, comparing the respective values estimated in both Red Sindhi and Sahiwal. On the other hand, additive genetic variances for the three traits were estimated very low in Sahiwal. The genetic trends for the three dairy production traits have not been positive except for the recent trend in Bangladeshi Local.

• Asian-Australasian Journal of Animal Sciences
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• 제27권4호
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• pp.587-591
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• 2014

Automatic milking systems (AMS) rely upon voluntary cow traffic (the voluntary movement of cattle around a farm) for milk harvesting and feed consumption. Previous research on conventional milking systems has shown differences between dairy cow breeds for intake and milk production, however, the ability to manipulate voluntary cow traffic and milking frequency on AMS farms through breed selection is unknown. This study investigated the effect of breed (Holstein Friesian versus Illawarra) on voluntary cow traffic as determined by gate passes at the Camden AMS research farm dairy facility. Daily data on days in milk, milk yield, gate passes and milking frequency for 158 Holstein Friesian cows and 24 Illawarra cows were collated by month for the 2007 and 2008 years. Illawarra cows had 9% more gate passes/day than Holstein cows over the duration of the study; however, the milking frequency and milk yield of both breeds were similar. Gate passes were greatest for both breeds in early lactation and in the winter (June to August) and summer (December to February) seasons. These findings highlight an opportunity to translate increased voluntary cow movement associated with breed selection into increased milking frequencies, milk production and overall pasture-based AMS performance.

• Asian-Australasian Journal of Animal Sciences
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• 제6권4호
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• pp.549-553
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• 1993

In 1985, fifty Jersey cows were imported to Pakistan from United States of America (USA). This paper compares milk production and reproduction performance of imported cows and their daughters under USA and Pakistan conditions. The imported cows which had yielded 5,858 kg, of milk (305 d lactation) in the USA produced only 3,192 kg, at NARC. The milk production of their daughters averaged 2,617 kg, being 22% lower than their mothers under the same environment at NARC. Year and season of calving had no significant effects on milk production. Average milk production of the first lactation was 10% lower than the mean of the second, third and fourth lactations, but, the differences between lactation means were non-significant. Mean calving interval in the USA was 385 days, whereas the same cows had a longer (p<.01) calving interval of 490 days at NARC. The calving interval of the daughters was longer (452 d; p<.01) than their mothers calving interval in the USA, and shorter (p<.01) than their mothers calving interval in Pakistan. The low age at first calving suggests that locally born Jersey cows were not reproductively disadvantaged by the local environment and nutrition, suggesting the adaptability of this breed in the new environment.

• Asian-Australasian Journal of Animal Sciences
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• 제12권7호
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• pp.1025-1030
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• 1999

Fifth one Nili-Ravi dairy buffaloes in their last two months of gestation, were selected in NWFP Pakistan. Rectal palpation was carried out fortnightly, until the occurrence of first estrus. Ovulation was confirmed per rectum and milk progesterone levels (MPL). Body condition score (BCS)was recorded weekly. Milk samples were collected weekly for MPL and blood samples fortnightly for metabolites analysis. Milk yield was recorded and samples were collected for milk fat. The buffaloes calving during the normal breeding season (NBS, August to January)had short (p<0.01) postpartum estrus interval of $55.95{\pm}4.90$ days versus $91.15{\pm}11.61 $ days in the buffaloes calving during the low breeding season (LBS, February to July). MPL in the LBS calvers remained lower than NBS calves (p<0.01). The incidence of silent ovulation was higher during LBS as compared to NBS (70.6% versus 29.4%). MPL showed a pattern opposite to atmospheric temperature. In NBS calvers serum glucose levels were higher (p<0.01) and magnesium levels were lower (p<0.01) than LBS calvers. Higher serum urea was found in summer and spring than that autumn and winter (p<0.05). The reproductive performance in buffaloes calving in the LBS coincided with a low BCS (p<0.01). Fat corrected milk production (FCM) was higher in NBS than LBS (p<0.01) calvers.

• 한국동물위생학회지
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• 제19권1호
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• pp.39-45
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• 1996

Sulfonamides are widely used to treat mastitis of cattle in field. The study was carried out to analyze sulfonamid residues In raw milk from south Kyeonggi area. The milk sample was deproteinated with acetone and defatted with hexane. The residual sulfonamides were extracted with ethylacetate, concentrated under vaccum, reconstituted with the acetate buffer-methanol mixture, reacted with fluorescamine, and then analyzed by HPLC-fluorescence detector(EX. 39nm, Em. 495nm) with methanol : acetate buffer system(3/2, v /v) as a mobile phase. The results analyzed by Thin layer chromatography and High performance liquid chromatography were summarized as follows. 1. A total of 24 cases out of 478 raw milk samples(5.0%) collected during April and May showed positive reaction to sulfonamide residues. Among 24 positive reactors, 9 cases were positive to sulfanilamides(32.1%), 8 cases were positive to sulfathiazoles(28.6%) and 5 cases were positive to sulfamonomthoxines (7.9%) , respectively. 2. During July and August, 31 cases out of 464 raw milk samples(6.7%) showed positive re action to sulfonamide residues. Among them S cases were positive to sulfanilamides, 5 cases sulfathiazoles and 5 cases sulfamonomethoxines(16.1%), respectively.

• Food Science and Biotechnology
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• 제16권1호
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• pp.18-22
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• 2007

The objective of this study was to develop and assess the performance of an aseptic system for liquid milk contained in plastic bottles, from a small-scale production standpoint. Commercial sterility tests conducted on the bottled milk were utilized in our assessments of the system, via the identification and monitoring of the principal points of the process. Four 150 L batches of milk with pH values of approximately 6.7 were heat-processed at between 137 and $143^{\circ}C$ for 10 see in a plate heat exchanger, and then aseptically transferred to 500 mL high-density polyethylene (HOPE) bottles, in an ISO class 7 clean room. The aseptic condition of the bottles was achieved via 10 see of rinsing with a mixture containing 0.5% peracetic acid and 0.8% hydrogen peroxide at $30^{\circ}C$, followed by another rinse with sterile water. Of the 4 batches processed, 2 were determined to exhibit commercial sterility, on the basis of the physical-chemical and microbiological criteria adopted. It was concluded that some adjustment of the processing line was required in order to achieve full commercial sterility for all processes. The aseptic system developed and assessed in this study was demonstrated to have great potential for the processing and transferring of milk into plastic bottles, from a small-scale production standpoint.

• Animal Bioscience
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• 제37권6호
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• pp.1121-1129
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• 2024

Objective: Objective of the study was to reduce heat stress in Murrah buffaloes and maintain their milk production and other vital functions during heat stress. Methods: A total of 21 dyads of calf-mother Murrah buffalo were selected for the study and equally divided in 3 treatment groups. First treatment group was restricted calf contact (RCC), second treatment group was fence line calf contact (FCC) and third treatment groups fence line calf contact and heat stress protection (FCC-HSP [time-controlled fan-fogger system] in the shed). Present study was conducted from April to mid-September 2021. Results: Maximum temperature and temperature humidity index in FCC-HSP shed were significantly (p<0.05) lower than that in FCC and RCC shed. Higher (p<0.05) mean daily milk yield in both the treatment groups FCC (10.36±0.30) and FCC-HSP (10.97±0.31) than RCC (8.29±0.41) was recorded. Though no significant difference between FCC and FCC-HSP in daily milk yield but FCC-HSP yielded 600 gm more milk than FCC. Pulse rate (PR) and respiration rate (RR) were lowest in FCC-HSP followed by FCC and RCC, respectively. Cortisol and prolactin levels were lower (p<0.05) in FCC-HSP followed by FCC and RCC, respectively. Conclusion: Hence, FCC along with heat stress ameliorative measures helped the buffaloes to be free of stress and maintain milk yield during heat stress period of the year in tropical conditions.

• 대한수의학회지
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• 제44권2호
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• pp.293-301
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• 2004

We investigated the effect of reproductive herd health program (RHHP) on the reproductive performance in high yielding dairy herds. Data collected from 205 lactations at Boeun County, Chungbuk from April 2001 to Dec. 2003 included postpartum reproductive and metabolic diseases, body condition score (BCS), reproductive performance and milking records. First we compared the reproductive performance of cows without RHHP (pre-RHHP group) and cows with RHHP (RHHP group). Intervals from calving to first service (99.6 vs. 81.8 days) and to conception (160.3 vs. 131.8 days) were shorter in the RHHP group than in the pre-RHHP group. Secondly, we determined the effect of milk yield (305 days) on the occurrence of postpartum diseases, BCS changes, and reproductive performance in cows under RHHP. The occurrence of metritis and metabolic diseases were greater in the over-10,000 kg group than in the under-10,000 kg group. The over-10,000 kg group lost more body condition than the under-10,000 kg group from calving to month 3 postpartum. Nevertheless, reproductive performance did not differ between the two groups. These results indicate that reproductive performance can be improved by the application of RHHP in high yielding dairy herds and that reproductive performance in the cows under RHHP are not affected by high milk yielding.

• Asian-Australasian Journal of Animal Sciences
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• 제21권8호
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• pp.1088-1096
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• 2008

Data from milk performance testing were used to analyze genetic and environmental trends for purebred Tsigai, Improved Valachian and Lacaune sheep. 103,715 (Tsigai), 212,962 (Improved Valachian) and 2,196 (Lacaune) test-day records gathered by the State Breeding Institute of the Slovak Republic entered the analyses. The respective pedigree data comprised 23,724 (Tsigai), 51,401 (Improved Valachian) and 438 (Lacaune) records. The multiple-trait, mixed model methodology was used to predict the breeding values for daily milk yield, fat and protein content and to estimate the fixed and remaining random effects assumed to affect the above mentioned traits, separately for each breed. The breeding values for daily milk yield were adjusted for 150-day standardized lactation length by multiplying with the constant 150, as the breeding goal of the selection scheme in Slovakian sheep is to increase 150-day milk production and constant heritability throughout the whole lactation is assumed. The genetic trends were expressed as changes in averages of breeding values across birth years of animals. For Tsigai and Lacaune breeds, cumulative genetic changes over the analyzed period were 3.8 and 5.1 kg for 150-day milk, 0 and -0.16% for fat content and 0 and -0.12% for protein content. For Improved Valachian breed, either a low (1.6 kg for 150-day milk yield) or zero (fat and protein content) cumulative genetic change was found. The environmental trends were calculated as averages of solutions for flock-test day effect across years and months in which measurements were taken. A distinctive cyclical pattern which reflected short-time variation in milk production traits was found. Possible explanations for this phenomenon are given and discussed.