Farhad Kamali Dehkordi; Hamid Amanlou; Nima Sadeghi Broujeni
Abstract
The objective of this experiment was to determine the effects of fish meal supplementation on productive and reproduction performance in repeat breeder Holstein cows. Two hundred and sixty-one multiparous Holstein cows with at least three consecutive unsuccessful inseminations, without clinically detectable ...
Read More
The objective of this experiment was to determine the effects of fish meal supplementation on productive and reproduction performance in repeat breeder Holstein cows. Two hundred and sixty-one multiparous Holstein cows with at least three consecutive unsuccessful inseminations, without clinically detectable reproductive disorders, were randomly allocated to 1 of 3 dietary treatments. Dietary treatments were control, 2.5 or 5% fish meal, that replaced soybean meal. Cows were timed inseminated following the Double-Ovsynch protocol. Milk yield was (38.49, 39.92, and 41.42 kg/d, for cows fed the control, 2.5 and 5% FM diets respectively) of which the difference (P<0.01) between the control and 5% FM diets was significant. Likewise, 4% FCM was higher for treatment 5% FM relative to control (P<0.05). Milk fat, protein and lactose content (%) were not different among treatment (P>0.05) but milk protein yield was higher (P<0.05) for cows fed the 5% FM than control and 2.5% FM diets was significant. Plasma and milk urea nitrogen concentrations decreased significantly (P<0.05) affected fish meal by consumption. Plasma cholesterol concentration was higher for cows fed 5% FM compared to the control diet (P<0.01). Plasma progesterone concentration at 16 d post artificial insemination was greater for treatment 5% FM relative to control treatment (P<0.05). Pregnancy at the first service and cumulative (1st and 2nd service) for cows fed 5% FM content higher than control diet (P<0.05). These results indicated that supplementation the diet with 5% fish meal improved fertility and productive performance in repeat breeding cows.
Vahid Gholami; Hamid Amanlou; Davood Zahmatkesh; Nima Sadeghi
Abstract
We used 263 Holstein repeat breeder dairy cows (193±58 DIM) based on randomized complete design. Animals in control group (no supplementation), groups 2 and 3 supplemented with 2,244 mg of zinc, 295.5 mg copper and 480 mg manganese either inorganic trace minerals (ITM) and chelated (glycinates) ...
Read More
We used 263 Holstein repeat breeder dairy cows (193±58 DIM) based on randomized complete design. Animals in control group (no supplementation), groups 2 and 3 supplemented with 2,244 mg of zinc, 295.5 mg copper and 480 mg manganese either inorganic trace minerals (ITM) and chelated (glycinates) trace minerals (CTM) sources, respectively. Supplemental minerals were fed daily as a top dress. All cows were inseminated according to Double-Ovsynch protocol. Super oxide dismutase concentration tended to have higher in CTM and ITM treatments than in control group (P=0.09). Progesterone concentration at day 11 after artificial insemination was higher in CTM and ITM treatments than in control group (P<0.05). Cows in CTM and ITM treatments tended to have greater odds of becoming pregnant at first and cumulative (first and second service) than cows in control group (P=0.1 and P=0.13 respectively). According to the results of this study, diets supplemented above National Research Council (NRC, 2001) requirments for zinc, copper and manganese in repeat breeding cows, improved fertility.
Hadi Dashti; Ahmad Riasi; Mohammad Ali Edris; Golam-Reza Gohrbani; Hossein Omidi-Mirzaei
Abstract
The aim of this study was to consider reproductive performance parameters and blood progesterone concentration changes in high-producing dairy cows (39±2 kg per day) after artificial insemination, in summer and winter. 270 heads of Holstein dairy cattle were choose in three big dairy farms, and ...
Read More
The aim of this study was to consider reproductive performance parameters and blood progesterone concentration changes in high-producing dairy cows (39±2 kg per day) after artificial insemination, in summer and winter. 270 heads of Holstein dairy cattle were choose in three big dairy farms, and blood samples were collected at days seven, ten and fourteen after artificial insemination. Temperature-humidity index was calculated according to one proposed formula (Dikmen and Hansen, 2009). The results showed that the maximum temperature–humidity index(THI) was 77.35 and 57.47 in summer and winter respectively. Pregnancy rates in cows inseminated during the winter months was significantly higher (p<0.01) than cows inseminated during the summer, and the effects of lactation on conception rate was significant in both seasons (p<0.01). Open days (101.18 vs. 165.07) and number of services per conception (2.05 vs. 3/48) in the winter were significantly lower than cows inseminated during the summer (p<0.01). In day 14 after insemination, blood serum progesterone concentration in cows inseminated in the winter was significantly higher (p<0.01) than summer. Results of this study showed that summer heat stress has significantly affects reproductive performance of dairy cows in central of Iran.
