Sadegh Mayahi; Morteza Mamouei; Saleh Tabatabaei; Khalil Mirzadeh
Volume 5, Issue 3 , July 2014, , Pages 201-205
Abstract
High ambient temperature is the major constraint on Buffalo productivity. The aim of this study was to evaluate the reproductive performance and thyroid gland function in winter and summer seasons in Khuzestan buffalo bulls. Six male indigenous buffaloes of Khuzestan with nearly the same age (2-3 years ...
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High ambient temperature is the major constraint on Buffalo productivity. The aim of this study was to evaluate the reproductive performance and thyroid gland function in winter and summer seasons in Khuzestan buffalo bulls. Six male indigenous buffaloes of Khuzestan with nearly the same age (2-3 years old) and weight were used. Semen and blood samples through jugular vein were collected, every two weeks throughout the summer and winter seasons. The thyroid hormones and thyrotropin stimulating hormone (TSH) concentration in blood serum were measured by radioimmunoassay method. Semen quality was determined, using computer assisted sperm analyzer (CASA) and routine methods. The concentration of thyroxin (T4) was lower in winter than summer (p ≤ 0.05). The level of T3 uptake was higher in cold season than that of in hot season (p ≤ 0.05). The differences of tri-iodotyronine (T3) and TSH concentrations, as well as free thyroxin index were not significant between seasons. The semen volume and spermatozoa parameters including concentration, progressive motility, linear velocity, mean velocity, beat cross frequency, linear coefficient and straightness coefficient were higher in winter than summer (p ≤ 0.05). Semen pH and amplitude of lateral head displacement of spermatozoa were higher in summer than winter (p ≤ 0.05). In winter, there was positive correlation between spermatozoa concentration and T3 value of blood serum (p ≤ 0.05). There were positive correlations between values of semen volume and T4, progressive spermatozoa motility percent and TSH, as well as, total motility of spermatozoa and TSH in summer (p ≤ 0.05). In general, thyroid function and semen quality of Khuzestan buffaloes may be affected by seasons.
Maede Moosavi; Abdolah Mirzaei; Mohsen Ghavami; Amin Tamadon
Volume 5, Issue 1 , March 2014, , Pages 13-19
Abstract
The aim of the present study was to compare the occurrence and duration of clinical mastitis in different seasons, stages of lactation period and parities in a Holstein dairy farm in Iran. A retrospective epidemiological survey from April 2005 to March 2008 was conducted on 884 clinical mastitis cases ...
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The aim of the present study was to compare the occurrence and duration of clinical mastitis in different seasons, stages of lactation period and parities in a Holstein dairy farm in Iran. A retrospective epidemiological survey from April 2005 to March 2008 was conducted on 884 clinical mastitis cases of 7437 lactations. Data of each case including calendar-date of mastitis onset, days in milk (DIM) of mastitis onset (early: 0-74 DIM; middle: 75-150 DIM, and late ≥ 150 DIM), duration of mastitis, and parity (1, 2, and ≥ 3) were recorded. Based on date of mastitis onset, cases were classified into stages of lactation. Moreover, beginning of mastitis was seasonally categorized. Duration of clinical mastitis after treatment in early lactation was less than late lactation in the first-parity cows (p = 0.005). In early lactation period, the first-parity cows suffered clinical mastitis in days earlier than two other parity groups (p < 0.001). Moreover, in late lactation period, the first-parity cows had clinical mastitis in days later than cows in the third and more parities (p = 0.002). Occurrence of clinical mastitis in summer increased in late lactation period but in winter increased in early lactation period (p = 0.001). In addition, occurrence time of clinical mastitis in summer were in days later than in spring (p = 0.02) and winter (p = 0.03) in early lactation period. In conclusion, occurrence of mastitis in winter and spring during early lactation and in summer during late lactation period were more prevalent especially in lower parities.
