Effect of milk production season on the period between tow calving, percentage of fat and the daily milk yield of Friesian cows in south of Yemen

تأثير الموسم الإنتاجي اللبن على فترة بين الولادتين ونسبة الدهن وإنتاج اللبن اليومي لأبقار الفريزيان في جنوب اليمن

Abstract

This study included 28 Friesian cows, randomly selected from the herd of Al-Wali dairy cows farm of Al-Wali Group for Development and Investment in Lahj Aden Yemen, according to the available records, Breeding 64 records for the year 2020 to 2023 to study the period between the two births and we chose a period from the  2023 year, with the aim of estimating the daily production of milk and fat (by recording the daily production and taking 12 samples of milk in the other third of June and analyzed in the Laboratory of Food Science and Technology at Nasser's Faculty of Agricultural Sciences, University of Aden) to study some factors affecting these characteristics as we the studied traits. The SAS 2004 and 2022 XL.STAT program with the adoption of a complete random design (CRD) were used to analyze the trial data as well as using the (LSD) test to determine the significant differences between the means, and the following are the most important results obtained: calving interval, fat percentage and daily milk production were, 391 days, 3.3% and 10 kg, respectively. The effect of seasons of milk production on the percentage of fat and daily milk production was highly significant (P<0.01) and not significant on the  calving interval. We conclude from this study the effects of the milk production Parity on the percentage of fat and daily milk production.