Hokkaido Journal of Livestock and Grassland Science
Online ISSN : 2434-138X
Print ISSN : 2187-5391
Volume 6 , Issue 1
Showing 1-3 articles out of 3 articles from the selected issue
Original Articles
  • Haruna SATO, Miki YOSHIDA, Masahiro WATANABE, Hiroshi SHIMIZU, Koichi ...
    2018 Volume 6 Issue 1 Pages 9-15
    Published: March 23, 2018
    Released: October 17, 2019
    JOURNALS FREE ACCESS

    The majority of Japanese Black beef cattle farms product calves in Hokkaido, Japan. It is very important to produce calves that are sold at a high price in markets. The genetic characteristics for the market price of calves were examined by the construction of a statistical model and estimation of genetic parameters. This study used 2,570 records on calves of Japanese Black beef cattle that were sold at auctions in Hokuren Tokachi market between 2007 and 2009. Age in days, sex, reproductive method and inbreeding coefficient for the calves were included in the analysis. Also, live weight, daily gain (live weight/age in days), withers height, chest girth and hip height were considered. Best model for market price included year, month, herd, sex, reproductive method, age in days, live weight, hip height, inbreeding coefficient and breeding value of the animals (calves). The market price had the highest genetic and phenotypic correlation coefficient (0.51 and 0.52) with live weight. Heritability of the market price was 0.64, which meant that a part of the variation was at least attributed to genetic difference among animals.

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  • Michi YAMADA, Tomohito IWASAKI, Koji YAMADA, Kentaro KOITO, Hiroki NA ...
    Type: Original Articles
    2018 Volume 6 Issue 1 Pages 17-22
    Published: March 23, 2018
    Released: October 17, 2019
    JOURNALS FREE ACCESS

    Changes in the fatty acid composition and free amino acid content in commercial sliced pork containing high concentrations of α-linolenic acid from perilla seeds (Egoma pork) and pork fed with common ingredients (control) were examined. No significant differences in the storage time were observed in the fatty acid composition in Egoma pork and control. We observed an increase in many amino acids in the control during the storage time with the free amino acid content being significantly higher after six or eleven-day storage compared with that of day zero (P<0.05). In contrast, the free amino acid content of glutamic acid, methionine, leucine and phenylalanine increased and that of asparagine, glutamine and arginine decreased in the Egoma pork during the storage time. The levels of carnosine and anserine were consistent between the two pigs during the storage.

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  • Yasuhiro AOKI, Miyuki KATAOKA, Yasuko UEDA, Toshihiro SATO, Tsuyoshi K ...
    Type: Original Articles
    2018 Volume 6 Issue 1 Pages 23-27
    Published: March 23, 2018
    Released: October 17, 2019
    JOURNALS FREE ACCESS

    On a dairy farm that employed an automatic milking system (AMS), milk wastage occurred due to an unusual rancid flavor. Therefore, we investigated the relationship between milking frequency and free fatty acid (FFA) levels in milk, which could relate to the rancid flavor, on dairy farms that used AMS. The 946 data sets obtained in April 2017

    from lactating cows of 8 commercial dairy herds in Kenebetsu (Nakashibetsu, Hokkaido) were analyzed. The cows were classified into 7 groups based on the milking frequency per day (< 2.0, 2.0-2.5, 2.5-3.0, 3.0-3.5, 3.5-4.0, 4.0-4.5, and ≧ 4.5) and the average FFA levels in individual milk samples were compared among the classes. The FFA levels were observed to rise obviously with the increase in milking frequency (P<0.001). The following linear relationship was observed between FFA levels in individual milk samples and milking frequency: Y = 0.486X – 0.077 (r = 0.313, n = 946, P < 0.001), where Y is the FFA level (mmol/100 g fat) and X is the milking frequency (times per day). From this regression equation, the FFA level is calculated to be more than 2.0 mmol/100 g fat when the milking frequency was over 4.3 times per day, which may be a threshold in recognizing the rancid flavor. These results suggest that milking too many times per day is undesirable if the increase in milk FFA levels is to be avoided.

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