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We investigated the shape of the lactation curves of milk fatty-acid compositions and determined the optimal lactation curve function for each fatty-acid profile. The Hokkaido Dairy Milk Recording and Testing Association provided us with test-day records. We analyzed the proportion of de novo fatty acids per 100 g of raw milk, represented as DnM (%), the proportion of de novo fatty acids to total fatty acids, DnF (%), and the proportion of preformed fatty acids to total fatty acids, PrF (%). For DnM, we fitted polynomials ranging from the first to the fourth order, whereas the first to second-order Wilmink models were considered for DnF and PrF. The goodness of fit was assessed based on the mean error and mean squared error for each days in milk (DIM). DnM exhibited a slight increase as days in milk progressed. DnF increased up to DIM 126 and then decreased slightly. PrF declined until DIM 145 and then increased slightly. The optimal lactation curve function was determined to be the second-order polynomial for DnM and the first-order Wilmink model for DnF and PrF. The lactation curves for each calving age and month were similar to the single lactation curve estimated using the full data set, which included all individuals, for each trait. [ABSTRACT FROM AUTHOR]

This study evaluated the risk of using genomically-tested, young Holstein sires (GYS) to produce progeny with a low Nippon Total Profit index (NTP). The risk was defined as the probability that the progeny had a true NTP lower than the dam's estimated NTP. The service sires available as of August 2023 in Japan were divided into three classes : daughter-proven sires with 60 or more daughters with milk records (BULL-OLD), daughter-proven sires with fewer than 60 recorded daughters (BULL-NEW), and GYS with no daughters (BULL-GYS). Two classes of dams were considered : cows born in 2020 (COW-2020) and genomically-tested heifers born in 2022 (HEI-2022). For each class, we assumed a hypothetical animal with the average published NTP. We then used these animals as parents for mating. The true NTP of progeny was assumed to follow a normal distribution, with the mean as the parent average of estimated NTP and the variance as the sum of the prediction error variance of the parent average of estimated NTP and the Mendelian sampling variance. For COW-2020 (or HEI-2022), the risk for BULL-OLD was 14.4% (23.2%), for BULL-NEW, 10.2% (17.1%), and for BULL-GYS, 2.1% (4.1%). The result suggests that the genomically-tested young sires are more effective than daughter-proven sires in improving the average of the true NTP in dairy herds. [ABSTRACT FROM AUTHOR]

This paper illustrates the recent trends of academic publishers, who are responsible for disseminating trusted research results in scholarly communication, by watching the activities of the International Association of STM Publishers, which has a strong presence in the scholarly publishing industry. "STM Trends" published annually by the association, will be taken up as material for an overview of the current situation, and initiatives such as SeamlessAccess, GetFTR, and AI will be outlined. [ABSTRACT FROM AUTHOR]