ObjectiveThe aim of the current study was to describe the relationship between milk yield and lactation number, stage, length and milking frequency in Korean Holstein dairy cows using an automatic milking system (AMS).MethodsThe original data set consisted of observations from April to October 2016 of 780 Holstein cows, with a total of 10,751 milkings. Each time a cow was milked by an AMS during the 24 h, the AMS management system recorded identification numbers of the AMS unit, the cow being milking, date and time of the milking, and milk yield (kg) as measured by the milk meters installed on each AMS unit, date and time of the lactation, lactation stage, milking frequency (NoM). Lactation stage is defined as the number of days milking per cows per lactation. Milk yield was calculated per udder quarter in the AMS and was added to 1 record per cow and trait for each milking. Milking frequency was measured the number of milkings per cow per 24 hour.ResultsFrom the study results, a significant relationship was found between the milk yield and lactation number (p<0.001), with the maximum milk yield occurring in the third lactation cows. We recorded the highest milk yield, in a greater lactation length period of early stage (55 to 90 days) at a 4× milking frequency/d, and the lowest milk yield was observed in the later stage (>201 days) of cows. Also, milking frequency had a significant influence on milk yield (p<0.001) in Korean Holstein cows using AMS.ConclusionDetailed knowledge of these factors such as lactation number, stage, length, and milking frequency associated with increasing milk yield using AMS will help guide future recommendations to producers for maximizing milk yield in Korean Dairy industries.

Abstract. The present study investigated an ethanol extract of the aerial part of Aralia cordata Thunb. (Araliaceae) for possible neuroprotective effects on neurotoxicity induced by amyloid β (Aβ) protein (25 -35) in cultured rat cortical neurons and antidementia activity in mice. Exposure of cultured cortical neurons to 10 μM Aβ(25 -35) for 36 h induced neuronal apoptotic death. At 1 -10 μg/ml, A. cordata inhibited neuronal death, elevation of intracellular calcium ([Ca 2+ ] i ), glutamate release into the medium, and generation of reactive oxygen species (ROS) induced by in primary cultures of rat cortical neurons. Memory loss induced by intracerebroventricular injection of ICR mice with 15 nmol Aβ(25-35) was inhibited by chronic treatment with A. cordata (50 and 100 mg/kg, p.o. for 7 days) as measured by a passive avoidance test, and corresponding reductions were observed in brain cholinesterase activity and neuronal death measured histologically in the hippocampal region. Oleanolic acid isolated from A. cordata also inhibited neuronal death, elevation of [Ca 2+ ] i , glutamate release, and generation of ROS induced by Aβ(25-35) in cultured rat cortical neurons, suggesting that the neuroprotective effect of A. cordata may be, at least in part, attributable to this compound. From these results, we suggest that the antidementia effect of A. cordata is due to its neuroprotective effect against Aβ(25-35)-induced neurotoxicity and that A. cordata may have a therapeutic role in preventing the progression of Alzheimer's disease.

This study was performed to discover bifidobacteria isolated from human intestines that optimally convert linoleic acid (LA) to conjugated linoleic acid (CLA) and to optimize the culture conditions of milk fermentation. One hundred and fifty neonatal bifidobacteria were screened for CLA-producing ability, and Bifidobacterium breve LMC 017 was selected as it showed about 90% conversion of free LA in MRS broth. The selected strain showed resistance at 0.5% LA in microaerophillic conditions. When monolinolein (LA 90%) was used as a substrate for CLA production, the conversion rate was lower compared to free LA, but the growth rate was unaffected during the milk fermentation. There was no significant difference in CLA production between aerobic and anaerobic conditions, and little decline in CLA was shown after the maximal CLA level had been reached. CLA production increased by 80% with 24 h of incubation in milk containing additional skim milk (5%), where the proteins may have facilitated the production of CLA by enhancing the interaction of substrate with the bacteria. CLA production did not decline after 9 h of fermentation and an additional 12 weeks of storage with other commercial starters. This demonstrates the possibility of using this strain as a costarter in the production of CLA-enriched yogurt.