• Biomolecules & Therapeutics
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• v.25 no.5
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• pp.545-552
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• 2017

Increasing concern is being given to the association between risk of cancer and exposure to low-dose bisphenol A (BPA), especially in young-aged population. In this study, we investigated the effects of repeated oral treatment of low to high dose BPA in juvenile Sprague-Dawley rats. Exposing juvenile rats to BPA (0, 0.5, 5, 50, and 250 mg/kg oral gavage) from post-natal day 9 for 90 days resulted in higher food intakes and increased body weights in biphasic dose-effect relationship. Male mammary glands were atrophied at high dose, which coincided with sexual pre-maturation of females. Notably, proliferative changes with altered cell foci and focal inflammation were observed around bile ducts in the liver of all BPA-dosed groups in males, which achieved statistical significance from 0.5 mg/kg (ANOVA, Dunnett's test, p<0.05). Toxicokinetic analysis revealed that systemic exposure to BPA was greater at early age (e.g., 210-fold in $C_{max}$, and 26-fold in AUC at 50 mg/kg in male on day 1 over day 90) and in females (e.g., 4-fold in $C_{max}$ and 1.6-fold in AUC at 50 mg/kg vs. male on day 1), which might have stemmed from either age- or gender-dependent differences in metabolic capacity. These results may serve as evidence for the association between risk of cancer and exposure to low-dose BPA, especially in young children, as well as for varying toxicity of xenobiotics in different age and gender groups.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.335-356
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• 1997

Injection of bovine growth hormone (bGH) to lactating dairy cows increases milk yield and yields of milk components including fat. It is generally believed that most of the anabolic effects derived from bGH in animal tissues are primarily mediated by IGF-1. IGF-1 is a strong anabolic peptide in the plasma of animals and exerts mitogenic and metabolic effects on target cells. Contrary to most protein hormones, the majority of IGF-1 in circulation is bound to the binding proteins (IGFBPs) which are known to be responsible for modifying the biological actions of IGF-1, thus making determinations of IGF-1 actions more difficult. On the other hand, fat is a major milk component and the greatest energy source in milk. Currently, the fat content of milk is one of the major criteria used in determining milk prices. It has been known that flavor and texture of dairy products are mainly affected by milk fat and its composition. Acetyl-CoA carboxylase (ACC) is the rate limiting enzyme which catalyzes the conversion of acetyl-CoA to malonyl-CoA for fatty acid synthesis in 1ipogenic tissues of animals including bovine lactating mammary glands. In addition to the short-tenn hormonal regulation of ACC by changes in the catalytic efficiency per enzyme molecule brought about by phosphorylation and dephosphorylation of the enzyme, the long-term hormonal regulation of ACC by changes in the number of enzyme molecules plays an essential role in control of ACC and lipogenesis. Insulin, at supraphysiological concentrations, binds to IGF-1 receptors, thereby mimicking the biological effects of IGF-1. The receptors for insulin and IGF-1 share structural and functional homology. Furthermore, epidermal growth factor increased ACC activity in rat hepatocytes and adipocytes. Therefore, it can be assumed that IGF-1 mediating bGH action may increase milk fat production by stimulation ACC with phosphorylation (short term) and/or increasing amounts of the enzyme proteins (long term). Consequently, the main purpose of this paper is to give the readers not only the galactopoietic effects of bGH, but also the insight of bGH action with regard to stimulating milk fat synthesis from the whole body to the molecular levels.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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• pp.348-352
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• 2003

An investigation was made into the protein profile of colostrum/milk of ten Murrah buffaloes and of their ten buffalo calves during their first week of neonatal life to study the materno-neonatal transfer of immunoglobulins (Ig). Calves were pail fed 3.5 liter of colostrum and/or milk per calf/day exclusively from their dam. First blood sample from newborn calves was collected before colostrum feeding on the day of birth (day zero) and the sampling continued daily for seven days after colostrum/milk feeding. Colostrum/milk Ig and IgG values were $4.82{\pm}2.60$, $2.19{\pm}1.90$, $1.12{\pm}0.82$, $0.69{\pm}0.44$, $0.59{\pm}0.31$, $0.47{\pm}0.20$, $0.40{\pm}0.22$, $0.40{\pm}0.25$ and $3.58{\pm}1.90$, $1.08{\pm}0.92$, $0.52{\pm}0.40$, $0.31{\pm}0.20$, $0.27{\pm}0.14$, $0.22{\pm}0.08$, $0.18{\pm}0.09$, $0.14{\pm}0.08$ respectively during 0-7 days post partum. The concentration of total colostrum/milk proteins, Ig, IgG and albumin were highest within 12 h post-partum. Thereafter, the concentrations followed a declining trend which may be attributed to the reduced transfer of proteins from the maternal blood, declining synthesis by the mammary glands and/or depletion of stored proteins. The concentrations of plasma Ig and IgG before colostrum feeding on day zero were $0.42{\pm}0.09$ and $0.08{\pm}0.03$ respectively. The levels of plasma Ig were $1.90{\pm}0.37$, $1.80{\pm}0.31$, $1.80{\pm}0.26$, $1.81{\pm}0.28$, $1.78{\pm}0.31$, $1.79{\pm}0.21$, $1.80{\pm}0.32$ and of IgG were $1.57{\pm}0.41$, $1.30{\pm}0.29$, $1.31{\pm}0.21$, $1.27{\pm}0.18$, $1.23{\pm}0.21$, $1.23{\pm}0.16$, $1.26{\pm}0.21$ on days 1-7 after birth after colostrum/milk feeding. The concentrations of total plasma proteins, Ig, IgG were lowest before colostrum feeding and increased significantly (p<0.05) after colostrum feeding in buffalo neonates. The results suggest that the highest amounts of colostral Ig and IgG were available on the day of parturition and thus the calves should receive colostrum as early after birth as possible. Colostrum Ig and IgG concentrations were not correlated to plasma Ig and IgG concentrations in the post-suckle buffalo calves and therefore, colostrum Ig and IgG concentrations were probably not the principle determinants of calf post-suckle plasma Ig and IgG concentrations.

• Korean Journal of Veterinary Research
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• v.29 no.1
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• pp.69-73
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• 1989

In vitro antifungal susceptibility test was carried out on 53 strains of Candida spp isolated from milk of dairy cows with subclinical mastitis and teat cups of milking machines, Nystatin, clotrimazole, miconazole, econazole, 5-fluorocytosine, cycloheximide, haloprogin and griseofulvin were tested by the agar dilution method. The 84.8% to 98.2% of Candida strains were inhibited by clotrimazole, econazole and miconazole at $${\leq_-}25{\mu}g/ml$$, and clotrimazole was most active. Interspecies differences of antifungal susceptibility were recognized and these were as follows. C albicans was most sensitive to clotrimazole (GM-MIC, $5.49{\mu}g/ml$) followed by 5-fluorocytosine, econazole and miconazole. C pseudotropicalis and C guilliermondii were notably sensitive to haloprogin, clotrimazole, miconazole, cconazole, 5-fluorocytosine, and haloprogin (GM-MIC, $0.17{\sim}0.19{\mu}g/ml$) was most active. C krusei was most sensitive to cycloheximide (GM-MIC, $0.54{\mu}g/ml$) followed by clotrimazole, haloprogin, miconazole and econazole. C parapsilosis was somewhat sensitive to econazole, cycloheximide, clotrimazole, and econazole (GM-MIC, $7.26{\mu}g/ml$) was most active. C tropicalis showed very low sensitivity to all tested drugs (GM-MIC, $${\geq_-}20.32{\mu}g/ml$$).

• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.244-257
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• 2023

The study aimed to investigate the effect of low-frequency oscillations on the cow udder, milk parameters, and animal welfare during the automated milking process. The study's objective was to investigate the impact of low-frequency oscillations on the udder and teats' blood circulation by creating a mathematical model of mammary glands, using milkers and vibrators to analyze the theoretical dynamics of oscillations. The mechanical vibration device developed and tested in the study was mounted on a DeLaval automatic milking machine, which excited the udder with low-frequency oscillations, allowing the analysis of input parameters (temperature, oscillation amplitude) and using feedback data, changing the device parameters such as vibration frequency and duration. The experimental study was performed using an artificial cow's udder model with and without milk and a DeLaval milking machine, exciting the model with low-frequency harmonic oscillations (frequency range 15-60 Hz, vibration amplitude 2-5 mm). The investigation in vitro applying low-frequency of the vibration system's first-order frequencies in lateral (X) direction showed the low-frequency values of 23.5-26.5 Hz (effective frequency of the simulation analysis was 25.0 Hz). The tested values of the first-order frequency of the vibration system in the vertical (Y) direction were 37.5-41.5 Hz (effective frequency of the simulation analysis was 41.0 Hz), with higher amplitude and lower vibration damping. During in vivo experiments, while milking, the vibrator was inducing mechanical milking-similar vibrations in the udder. The vibrations were spreading to the entire udder and caused physiotherapeutic effects such as activated physiological processes and increased udder base temperature by 0.57℃ (p < 0.001), thus increasing blood flow in the udder. Used low-frequency vibrations did not significantly affect milk yield, milk composition, milk quality indicators, and animal welfare. The investigation results showed that applying low-frequency vibration on a cow udder during automatic milking is a non-invasive, efficient method to stimulate blood circulation in the udder and improve teat and udder health without changing milk quality and production. Further studies will be carried out in the following research phase on clinical and subclinical mastitis cows.