HamidReza Dadkhah; GholmReza Ghorbani; Farzad Hashemzadeh; Abbas Rajaeerad
Volume 25, Issue 1 , April 2023, , Pages 13-24
Abstract
The objective of this study was to evaluate the effect of feeding two oral Ca boluses at calving and 12 h later on feed intake, milk yield, body weight (BW) changes, blood calcium and some reproductive parameters of high producing dairy cows during summer season. Twenty-four Holstein cows with average ...
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The objective of this study was to evaluate the effect of feeding two oral Ca boluses at calving and 12 h later on feed intake, milk yield, body weight (BW) changes, blood calcium and some reproductive parameters of high producing dairy cows during summer season. Twenty-four Holstein cows with average parity of 2.8 ± 0.8 were selected and randomly assigned to one of two treatments including control or the group receiving slow-release oral Ca bolus at calving and 12 h post-calving. Row milk yield was greater in cows receiving Ca boluses compared to control treatments during 21 days of lactation (P = 0.02). The milk fat (P = 0.01) and solid non-fat percentage (P = 0.05) were greater in cows that received calcium bolus compared to control treatment. In addition, energy-corrected and fat-corrected milk yields increased in cows received Ca bolus (P = 0.03). Plasma glucose and serum calcium concentration as well as BW change were not affected by experimental treatments. The pregnancy per artificial insemination, days to first insemination and open days were not significantly different between the experimental treatments (P >0.05). The results showed that using oral calcium bolus at calving and 12 hours after calving improved milk production and composition, but had no effect on serum Ca, BW change during first 21 days of lactation, and reproduction parameters.
Ali Nargeskhani; Ali Moharrery; Hossein Mehraban; Mohammad Javad Zamiri
Volume 23, Issue 3 , September 2021, , Pages 337-349
Abstract
This study was conducted to compare the effect of a cellulosic (wheat straw; WS) and non-cellulosic (beet pulp; BP) forage source on high producing dairy cows during the transition period (three weeks before to six weeks after calving). Multiparous Holstein cows (n=36) with mean body weight of 697±59.6 ...
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This study was conducted to compare the effect of a cellulosic (wheat straw; WS) and non-cellulosic (beet pulp; BP) forage source on high producing dairy cows during the transition period (three weeks before to six weeks after calving). Multiparous Holstein cows (n=36) with mean body weight of 697±59.6 kg and body condition score of 3.3±0.22 were used in the experiment. Before calving, the cows received diets containing 7.17% WS (n=18) or BP (n=18). After calving, the cows in each group were divided into two subgroups (n=9), and received the diets containing 5% BP or WS. Prepartum dry matter intake (DMI) was similar between dietary treatments but prepartum digestibility of DM (P=0.05) and neutral detergent fiber (P= 0.06) was lower in cows feeding on the WS diet. The yield of energy-corrected milk, 4% fat-corrected milk and milk fat percentage tended to be higher in the cows fed with the BP diet during the prepartum period (P = 0.09). In conclusion, the results showed that feeding non-cellulosic forages during the transition period may improve the performance in dairy cows.
Mir Hossein Najafi; saeed zeinoaldini; Abolfazl Zali; mahdi Ganjkhanlou; Hossein Mohammadi
Volume 23, Issue 1 , March 2021, , Pages 73-82
Abstract
This study was conducted to investigate the effect of reducing dietary ratio of omega-6/omega-3 essential fatty acid (EFA) on dry matter intake, yield and milk composition, ovarian performance and blood concentrations of estradiol and progesterone using 24 multiparous Holstein cows. Experimental treatments ...
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This study was conducted to investigate the effect of reducing dietary ratio of omega-6/omega-3 essential fatty acid (EFA) on dry matter intake, yield and milk composition, ovarian performance and blood concentrations of estradiol and progesterone using 24 multiparous Holstein cows. Experimental treatments including different n-6 to n-3 EFA ratio; namely, 2.5, 4.5, or 6.5 parts of n-6 to 1 part of n-3 EFA. Dry matter intake and milk yield of cows were recorded daily. Also, body condition score and milk composition were recorded and ovarian activity was monitored by transrectal ultrasound scanning. Dry matter intake and milk composition were not affected by treatments. Daily milk yield was significantly higher in low and medium n- 6/n-3 FA ratio diets in comparison to high diet (P<0.05). Cows assigned to high n-6/n-3 FA ratio diet had greater plasma Haptoglobin concentrations compared to other diets (P<0.05). Results indicated that number of large follicles was greater in medium diet than high diet (P<0.05). Progestrone concentration was significantly decrease in high diet treatment (P<0.05). Results of this study indicate that modulating dietary n-6/n-3 FA ratio could lead to a higher milk yield and improve ovarian performance in fresh cows.
mahdi dehghani-sanij; Mohammad Ali Norouzian; Ahmad Afzalzadeh; ali assadi-alamouti
Volume 22, Issue 2 , June 2020, , Pages 211-221
Abstract
To study the effects of feeding rumen-protected ascorbic acid and salicylic acid on performance of dairy cows under heat stress conditions, forty four lactating dairy cows in early lactation were allocated in a completely randomized design with 4 treatments and 11 animals in each treatment for 30 days. ...
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To study the effects of feeding rumen-protected ascorbic acid and salicylic acid on performance of dairy cows under heat stress conditions, forty four lactating dairy cows in early lactation were allocated in a completely randomized design with 4 treatments and 11 animals in each treatment for 30 days. Experimental treatments were: 1) control (diet without coated ascorbic acid and salicylic acid), 2) diet contained 30 g/d coated ascorbic acid, 3) diet contained 10 g/d coated salicylic acid and 4) diet contained 30 g/d coated ascorbic acid + 10 g/d coated salicylic acid. Cows were fed with salicylic acid supplement had a higher daily milk yield (51.47 kg/day) compared to other experimental groups (P<0.05). Feeding of coated ascorbic acid increased milk fat percent, glucose, BHBA, NEFA concentration and decreased somatic cell count compared to other treatments (P<0.05). Total milk's solids, energy and fat corrected milk and milk urea nitrogen were increased in coated ascorbic acid group compared to control (P<0.05). Blood urea concentration in coated ascorbic acid and salicylic acid group were less than control group (P<0.05). The results showed that feeding coated ascorbic acid and salicylic acid could improve performance of Holstein dairy cows in early lactating phase under heat stress conditions.
Maryam Arianfar; Mohammad Rokouei; Gholamreza Dashab; Hadi Faraji- Arough
Volume 20, Issue 3 , November 2018, , Pages 351-363
Abstract
The objective of this study was to compare some nonlinear functions (Wood, Dhanoa, Wilmink, Ali-Schaeffer, Cappio Borlino, Cobby – Le Du, Dijkstra, Rook, Gous and Nelder) to describe the milk production curve of Iranian Holstein cattle. A dataset consisted of 6079976, 4879486 and 3312416 test-day ...
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The objective of this study was to compare some nonlinear functions (Wood, Dhanoa, Wilmink, Ali-Schaeffer, Cappio Borlino, Cobby – Le Du, Dijkstra, Rook, Gous and Nelder) to describe the milk production curve of Iranian Holstein cattle. A dataset consisted of 6079976, 4879486 and 3312416 test-day milk yield records related to first, second and third three lactation periods, respectively, from 3550 herds collecting by the Animal Breeding Center of Iran from 1983 to 2017, were used. The average of test day milk records for three lactation was 31.17, 34.08 and 33.83 kg, respectively. The nlme package of R software (version 3.4.3) was used for fitting nonlinear functions. The nonlinear functions were compared using four goodness of fit criteria, including Akaike’s information criterion (AIC), Bayesian information criterion (BIC), Root mean square error (RMSE) and Durbin-Watson index (DW). The Rook function showed the best fit for the milk production curve shape for three lactations in Iranian Holstein cattle when compared to other functions. The Gous and Rook functions showed the highest accuracy in predicting peak time, peak yield and persistency of milk production parameters in different lactations, but in general, the Rook function has a high predictive value in estimating the milk curve parameter descriptors.Therefore, Rook function is recommended for describing the milk production curve of Iranian Holstein cattle.
masood didarkhah; hadi sarir
Volume 20, Issue 2 , August 2018, , Pages 293-304
Abstract
The purpose of this experiment was to evaluate the effect of probiotic and peribiotic supplements on performance of Holstein dairy cows. For this purpose, 40 Holstein dairy cows with daily milk production of 33 ± 0/8 kg and initial weight 700 ± 40 kg were divided into four groups in a completely ...
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The purpose of this experiment was to evaluate the effect of probiotic and peribiotic supplements on performance of Holstein dairy cows. For this purpose, 40 Holstein dairy cows with daily milk production of 33 ± 0/8 kg and initial weight 700 ± 40 kg were divided into four groups in a completely randomized design. The experimental treatments consisted: 1- control group (basic diet) 2- probiotic group (base diet + 4 gr probiotic per head per day) 3- prebiotic group (base diet + 14 gr perbiotypes per Ross per day) 4- Synbiotic group (base diet + 4 gr probiotic + 14 gr perbiotic per head per day). The results of this experiment showed that there was a significant difference between the average duration of chewing, rumination and eating among different diets (P <0.05). The most duration of chewing, rumination and eating belonged to the group that consumed probiotics and had a significant difference with other groups (P <0.05). Probiotics consumption increased the amount of daily milk production, milk production with 3.5% fat and milk production with 4% fat, and a significant difference (P <0.05) with the control group (basal diet without additive). Feed efficiency increased in supplementary rations and resulted in a better performance of probiotic diets. Health indicators, consistency and fluidity of stool in supplementary diets have also improved.
Ayoub Laki; Mehdi Dehghan-Banadaky; Abolfazle Zali; Mehdi Ghanjkhanlou; Kamran Rezayadi
Volume 18, Issue 2 , June 2016, , Pages 249-260
Abstract
The aim of this study was to investigate the effect of feeding of steeped barley grain with lactic acid (LA) and citric acid (CA) on dry matter intake, feeding behavior, apparent nutrients digestibility, rumen pH and milk production. Eight early lactating Holstein cows in the second parities were ...
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The aim of this study was to investigate the effect of feeding of steeped barley grain with lactic acid (LA) and citric acid (CA) on dry matter intake, feeding behavior, apparent nutrients digestibility, rumen pH and milk production. Eight early lactating Holstein cows in the second parities were used in 4×4 Latin square change- over design. Treatments consisted of basis diet containing 1) dry rolled barley grain (DR), 2) dry rolled barley grain steeped in an equal quantity of tape water alone (W), 3) or in 0.75% LA, or 4) 1% CA for 24 h. The result of this study showed that dry matter intake, feeding behavior and apparent nutrients digestibility did not significantly different among treatments. Rumen pH was greater at 6 h after feeding in LA and CA diets (P<0.05). Treatments had no effect on fecal score and pH. Milk and Fat corrected milk production unaffected by treated barley. While milk protein and none- solids fat were significantly greater in CA diet in compared to others (P<0.05). Others milk composition had not influenced by type of processing. In conclusion, treated barley grain with LA and CA had increased rumen pH 6 h after feeding but other characters including milk production and composition, apparent nutrient digestibility and feeding behavior unaffected by barley grain processing method.