The study objective was to evaluate the effects of reducing dietary starch content in fresh cow diets while maintaining NDF levels by substituting barley grain (BG), corn silage (CS), or both with beet pulp (BP) on DMI, lactation performance, serum mineral and metabolites concentrations, liver enzymes and liver functionality index (LFI), serum insulin and revised quantitative insulin sensitivity check index (RQUICKI). Thirty-six multiparous cows were randomly assigned to 1 of 4 experimental diets from calving to 21 days in lactation. Experimental diets were a high-starch diet with ground BG (CO; 24.9% starch; 0% BP) and 3 low-starch diets where BP substituted for either BG (BB; 19.6% starch; 7% BP), CS (BC; 20.6% starch; 12% BP) or CS and BG (BCB; 20.3% starch; 12% BP). Relative to CO cows (16.50 kg/d), DMI was greater for BC (17.70 kg/d) and BCB (17.50 kg/d) cows, but it was lesser in BB (15.60 kg/d) cows. Similar to DMI results, milk yields tended to be greater for BC (37.89 kg/d) and BCB cows (37.81 kg/d) compared to CO cows (35.41 kg/d), but BB cows (33.05 kg/d) tended to produce less milk than CO cows. Relative to CO, cows fed BB had lower serum glucose concentrations, whereas cows fed BC and BCB had higher serum glucose. Serum insulin concentrations were lower for BB cows than for other exprimental groups. Relative to CO, serum NEFA and BHB concentrations were lower for BC and BCB, but was similar between BB and CO. The RQUICKI was lower for CO, BC cows than BB cows, and cows in BCB tended to have less RQUICKI compared to BB during postpartum. The concentrations of gamma glutamyl transferase were lower in BC and BCB cows relative to CO and BB cows. The cows fed CO and BB had higher serum bilirubin relative to cows fed BC and BCB diets. Although, LFI for CO cows was similar to cows on BB, BC and BCB, BC cows had higher LFI than BB cows and tended to have greater LFI than CO cows. Overall, reducing dietary starch by replacing CS (BC) or a mix of CS and BG (BCB) with BP positively affected DMI and milk yield and indicated improved energy metabolism and liver function during the first 21 d of lactation compared to when BP was fed instead of BG to reduce starch (BB).

Background and objectives: Recently the European Simental and Montbeliard dual-purpose breeds have been imported into Iran. Crossbred lactating cows were hypothesized to outperform Holsteins under environmental stresses. The objective of this study was, therefore, to compare production, reproduction, metabolism, and health of purebred Holstein cows vs. crossbred Holstein × Montbeliarde and Holstein×Simmental cows under hot and humid conditions of the north of Iran (Sari, Mazandaran). Material and methods: Dairy crosses were produced by crossing Holstein (H) cows with Montbeliarde (M) and Simmental (S) bulls’ semen. The performance and health of 70 primiparous cows from each breed (210 cows in total) were compared during their first lactation. Blood samples were taken from 15 primiparous cows from each breed at stages of close-up, calving, and 21 days after calving. Samples were analyzed for glucose, BHBA, NEFA, calcium and, magnesium. Statistical analyses were performed using SAS programs (GLM and MIXED procedures). Results: Results showed that Montbeliarde×Holstein and Simmental×Holstein crossbred cows were not different (P> 0. 05) from pure Holsteins in rectal temperature, fertility, and other reproductive indices, 305-d milk yield, milk fat and protein yield, stillbirth, mastitis, and laminitis rates, and close-up blood metabolites. However, Montbeliarde×Holstein cows had greater calving difficulty than did Simmental×Holstein cows (P < 0. 05). Moreover, both crossbred groups had a higher incidence of metritis compared to purebred Holstein cows (P < 0. 05). The purebred Holsteins exhibited more desirable udder traits than did crossbred cows (P < 0. 05). The crossbred cows had a higher body condition score (BCS) during the transition period than did the pure Holsteins (P<0. 05). However, the stature of Simmental×Holstein crossbred cows was shorter than pure Holstein. Foot angle was steeper for Holstein×Simmental and Holstein×Montbeliarde crossbred cows, but Holstein×Montbeliarde crossbred cows were similar to pure Holstein cows for hoof measurements. Conclusions: The findings of this study suggest that Holstein×Simmental and Holstein×Montbeliarde crossbred cows did not outperform the first-lactation of purebred Holstein cows. In adition, the crossbred cows experienced higher rates of dystocia and metritis under stressful hot and humid conditions.

The study was carried out at Agarfa ATVET College dairy farm to evaluate the reproductive performance of Holstein Friesian×Arsi and Holstein Friesian×Boran cattle. For the study, records compiled from 1983 to 2012 at the Agarfa dairy farm were used as original data. The effects of breed, bloodlines, season and parity on the reproductive traits were evaluated. Data were analyzed using the general model of the SAS program. The overall mean±SE of age at first service (AFS), age at first calving (AFC), days open (DO), calving interval (CI), number of service per conception (NSPC), breeding efficiency (BE) and longevity were 32.05±0.57 months, 41.16±0.56 months, 194.62±3.42 days, 475.92±3.44 days, 1.35±0.03 service, 68.67±0.01% and 7.77±0.25 years, respectively. Breed had significant effect (P<0.05) on AFS and AFC. Bloodlines, season and parity had significant effect (P<0.01) on DO and CI. Breed, bloodlines, season and parity had significant effect (P<0.01) on breeding efficiency. Season of insemination significantly affect NSPC (P<0.01). Longevity was only affected by bloodlines. Generally reproductive performances found in this study were lower than the performance reported in many tropical regions. Therefore, due consideration should be given in calf and heifer management, heat detection, accuracy of artificial insemination, feeding and health care.

The objective of this study was to evaluate the effect of supplementing close-up diets with rumen undegradable protein on serum metabolites and the incidence of health disorders of Holstein dairy cows, during the hot season. Eighty-eight multiparous Holstein dairy cows were randomly assigned to 1 of 2 treatment groups: low crude protein (14.3% CP; 14CP) and high crude protein (17.1% CP; 17CP) diets. Blood samples were collected weekly from d -30 up to calving and then at 0, 5, 14, and 21 days after calving, for serum metabolites determination.  Cows fed the 17CP diet had higher serum concentrations of albumin, blood urea nitogen, and Mg than 14CP cows during the close-up period. In postpartum, the 17CP cows had higher serum albumin and creatinine and lower free fatty acid, BHB, and glucose concentrations than the 14CP cows. The risk to developing subclinical ketosis (SCK), metritis and endometritis were higher for the 14CP cows than the 17CP cows. Overall, feeding high rumen undegradable protein diet to close-up cows during the hot season increased serum creatinine concentrations and lowered the incidence of SCK and metritis and endometritis postpartum.

Extended Abstract Background: A reason for crossbreeding is to combine desirable traits from two or more different breeds, and a specific beef breed may transfer superior genes of growth, feed efficiency, and dressing percentage to crossbred animals, leading to the superiority of the resulting hybrid animals over purebred animals due to heterosis. Some other beneficial results of crossbreeding include selecting beneficial genes from other breeds and eliminating the undesirable effects of inbreeding. This study aimed to compare feedlot performance between the male Montbiliard × Holstein (M × H) crossbred and purebred Holstein (H) calves over 6 months in hot and humid conditions of Iran. Methods: The experiment was carried out at the national research and development cattle station of Gawdasht in the suburbs of Babol, Mazandaran Province. For this purpose, 23 male calves (165.3 ± 35.33 kg BW), including 10 H and 13 M × H males, were assigned to one of the two treatments in a completely randomized design. The calves were kept individually in 3 × 3 m pens with free access to feed and water. The diets of experimental calves were formulated based on the nutritional needs of fattening calves during two subsequent experimental periods using common feeds. The calves were fed two times daily in equal portions at 8:00 and 16:00 with a total mixed ration. The animals were weighed at the beginning of the experiment after fasting for 8 h, and recording was repeated at 30-day intervals thereafter. Dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber digestibility were measured during the first 5 days of the 6th month of the fattening period using the difference in the concentration of AIA in feed and feces. In the last experimental day, blood samples were collected from the tail veins of calves to measure some serum parameters, including urea, urea nitrogen, triglyceride, total protein, and albumin. All variables were statistically analyzed using the mixed-model procedure of the statistical analysis systems in a completely randomized design. Animals were expected as the random effect in the experimental model. The means were compared using Tukey’s multiple comparisons procedure with an error level of 5%. Results: In the 6-month fattening period, there was no difference in the average dry matter intake in kg/day and also as a percentage of body weight between M × H calves and H calves (8.356 vs. 7.967 kg/d and 3.23 vs. 3.50 % of BW in M × H and H calves, respectively). However, the average daily gain of M × H calves (1.357 kg/d) tended to be higher (P = 0.08) than H calves (1.190 kg/d). Feed conversion ratio (FCR) was better in M×H calves (6.41) (P=0.04) than in H calves (7.73), and significant changes in FCR were observed during the fattening period in both groups, with an increase as the calves aged (P < 0.01). There was no significant difference in the digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber between the two experimental groups. The addition, the concentrations of urea nitrogen, triglyceride, total protein, and blood serum albumin of M × H calves were similar to H calves and within the normal range of reported parameters for healthy cattle. However, the glucose concentration in the blood serum of M × H calves tended to be higher than in H calves (P = 0.06). Conclusion: In a fattening period of 6 months, M × H calves showed 14.0 % more weight gain and 17.1 % better FCR than H calves, while they had similar feed consumption. Therefore, cross-breeding between Montbiliard and Holstein cows can be a successful strategy to improve beef production by producing commercial calves for slaughter.

Background and objectives: Red meat is one of the strategic foods to meet the increasing requirements of human populations to high quality protein. Therefore, this study aimed to compare growth performance, carcass characteristics, and economic profits between Holstein-Belgian Blue cross and pure Holstein calves. Material and methods: This study was carried out in the Mahdasht Milk and Meat farm, Dasht-e Naz Agriculture Company near Sari (Mazandaran, Iran). The performance of 24 calves of each breed (48 calves in total) was compared in a fattening period of 7 months. The average weight and age of calves at the start of the experiment were 258. 21 and 274. 95 kg; 321 and 313 d, respectively. Feed intake was measured daily for each group. A total mixed ration was delivered to the experimental animals twice a day at 0800 and 1600 h. Animals weighted monthly to obtain average daily gain. Statistical analyses were performed using SAS software (GLM and MIXED procedures). Results: The results indicated that average daily gain was significantly higher in crossbred calves than in pure-bred Holstein calves (1. 43 vs 1. 33 kg). The pure-bred Holstein calves had significantly lower dry matter intake than Belgian Blue crossbred calves. However, feed conversion ratio was no significant in Belgian Blue crossbred calves when compared to the Holstein group (6. 74 vs 7. 04). the dressing percentage for BB×H crossbred was higher than for pure Holstein. The effect of genetic groups was not significant on the thickness of the fat covering the back, through the front, and back hindquarters. However, the thickness of the fat covering loin was significantly different between genetic groups (P<0. 05). Weights of internal organs (i. e., kidneys, liver, and heart) were significantly higher in pure Holstein calves than those in crossbred cattle. Also, fat depots weight (subcutaneous and visceral) was significantly highest in pure Holstein and lowest in Belgian Blue crossbred calves (P<0. 05). Conclusions: Economic calculations demonstrated that the respective highest profit for the whole fattening period belonged to crossbreds of BB×H (38543843 Rials), and pure Holsteins (24826300 Rials). Therefore, the hypothesis that the calves from Holstein-beef crosses have higher economic productivity than pure Holstein calves was substantiated.

Abstract:The purpose of this research was to determine the population structure and effective population size of Najdi, Holstein and their hybrids in the herds of Khuzestan province. For this purpose, the genomic information of 329 cattle samples including 141, 60 and 128 samples from Holstein, mixed and Najdi breeds were used. The samples were genotyped with Illumina SNP30K genomic arrays. Population analysis was done using PCA and plotNJ, and in both methods the populations were somewhat separated. The range of r2 is from 0.150 ± 0.359 in chromosome 26 to 0.244 ± 0.450 in chromosome 20 for the Holstein breed and 0.130 ± 0.319 in chromosome 28 to 0.271 ± 0.462 in chromosome 20 in were mixed livestock, while the highest value of r2 was observed in the Najdi breed from the range of 0.120 ± 0.311 in chromosome 28 to 0.271 ± 0.483 in chromosome 20. The effective size of the populations in the fifth generation for the populations of this study was 45 Najdi heads, 101 mixed heads and 110 Holstein heads. These numbers for Najdi cattle are far from the recommended values for the protection of populations, and this indicates a serious risk of eliminating native Najdi cattle in the near future. Reducing the effective size will increase the sensitivity of this population to the upcoming environmental changes.

Epithelial inclusions were detected in myocardium of a 2-month-old male Holstein calf. Microscopically, nonpurulent myocarditis along with focal tubular and acinar structures covered with cuboidal epithelial cells was seen in the myocardium. Most tubular and acinar structures stained with Masson’s trichrome were found to be surrounded with a dense collagen. Tubular and acinar structures had PAS positive basement membrane. Immunohistochemical staining revealed that tubular and acinar structures were both vimentin and pancytokeratin positive, while the connective tissue was only vimentin positive.

Introduction: Secondary sex ratio (SSR) is the proportion of males to females at birth. It has been shown in many different mammalian species, many factors are associated with SSR. Changes in secondary sex ratio in dairy cows is considered economically important and the ability to change it could affect the revenues and profitability of a dairy farm. Thus, sperm or embryo sexing techniques in recent years has attracted more attention. Most breed of dairy cattle are more likely to have female calf is born to use them as replacement heifers and in order to maintain their productive herd number. On the contrary, when the goal is the production of meat, bull calves due to higher growth rates and production efficiency, are more convenient and more economically efficient. The aim of present study was to investigate some key factors affecting SSR in Iranian Holstein cows.According to Fisher, the sex ratio in the population under the control of natural selection is not always the same. There is overwhelming evidence to support the theory that shows Fisher Primary and secondary sex ratio sex ratio can deviate from this balance and natural selection caused a change in this ratio can be in certain circumstances. For example, the secondary sex ratio of 52: 48 has been reported in dairy cows. Studies on mammalian species suggest that several factors, including latitude of the location, the dominant regional climate model, time and frequency of mating to ovulation, diet, age of parents, physical score, breed and produced eggs from ovarian left or right can have a significant effect on the secondary sex ratio. Weather conditions may modify the internal environment and the effect on physiological mechanisms or through the impact on the frequency and type of foods available to parents, the secondary sex ratio is impressive. The impact on the quantity and quality of parent's access to food sources in many species of mammals, the sex ratio has been fixed.Previous reports have shown that high environmental temperature and higher rates of evaporation from a week to a month before conception secondary sex ratio was increased.Materials and method: The demographic, production and reproduction data of six large dairy farms between years 1375 and 1389 were used. The rolling average of 305 d fat corrected milk yield was 8145 kg with a range of 7578 to 8670 Kg. Breeding Center of Iran and the herds covered by the registration and recording them on a regular basis carried out by experts dairy cooperatives. The flocks were in the area northeast of the country.Production data (date corrected milk production and the cumulative production by 60 and 305 days of lactation), reproductive data (such as calving year, calving season, type of birth, sex of calf, the latest information on AI, days open), and details the possible removal of the flock or death were recorded. Data were collected from flocks before the analysis was re-verification. Used by sperm, sperm into four groups: Iranian, Canadian, American and other countries (including sperm taken from European countries) groups. The data were analyzed using multivariate logistic regression model.Statistics 0/05 was used to ensure meaningful results.Results and discussion: Results showed that the ratio of males to females was 53 to 47. Origin of the sires (including Iranian, American, or Canadian) had no impact on secondary sex ratio. Type of calving (eutocia vs.non-eutocia calving including dystocia and still birth) had significant impact on SSR (P<0.05). SSR was not effected by calving year. Season of calving, days open, parity, and the corrected 305 d milk yield also had no impact on SSR while the interaction of parity and type of calving was significant (P<0.05).Conclusion: In conclusion, the results of this study shows that type of calving only had a significant effect of SSR.