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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/9037

Title: The objective of this study was to determine the effects of chelated chromium supplementation on lactation performance and blood components of Holstein cows under heat stress. One hundred and sixty multiparous lactating Holstein cows (120-130 days post-partum), were used in this study. Animals were divided equally (80 cows/treatment) and were randomly allocated to one of two treat¬ment diets. Diet I, was total mixed rations (TMR) without chromium (Cr) added and served as a control. Diet 2, basal diet, with chromium yeast (chelated chromium) added at manufacturer's rec¬ommended level (4 g/head per day). The average maximum and minimum air temperatures were 29.0 and 24.80° C respectively. The averaged temperature-humidity index (THI) was 78.6 units. Adding
Authors: A. K. A. Ali*, A. A. ALEssa
M. A. Alshaikh
R. S. Aljumaah, A. A. AI-Haidary
Keywords: Conception, Odd Ratio, Holstein Cattle, Logistic Regression
تاريخ النشر: 2005
Abstract: Logistic Regression Analysis was used to compute the odds ratio (OR) and probability of conception of Holstein dairy cows of AL-MARAIE company. Data consisted of 103,778 reproductive records collected from three farms in the central region in the Kingdom of Saudi Arabia. Records were classified according to lactation number, season of calving and milk level. At first lactation, OR of first service was 0.63 of other services and probability of pregnancy from first services was 0.39. Odds ratio increased to 1.72 at fourth lactation or probability of conception reached 0.63. The probability of conception increased from 0.39 for cows inseminated at first services to 0.75 at fifth service insemination. Odds ratio of cows calving in winter were higher than those calving in summer. Odds ratio of conception of low producing cows is about twice as likely to occur from first service as from other services. However, OR of conception of high producing cows was higher than one (probability=0.56) from first service and increased to 1.63 (probability=0.65) from third service. Odds ratio was in favor of the right uterus horn where probability of conception from first service was slightly greater than 50% in first and second lactations and less than 50% in favor of left horn in later lactations. (Aslan-Aust: J. Anim. Sci. 2005. Vol 18, No.3: 308-313)
URI: http://hdl.handle.net/123456789/9037
يظهر في المجموعات:College of Foods And Agricultural Science

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