seyyed homayoun farhangfar

The shape of lactation curve is unique for each cow and is affected by various genetic and non-genetic factors. Hence, its study in each cow and herd separately is important for making managerial decisions.

In order to study the factors affecting lactation curve in Holstein dairy cows, 271509 test day milk records (milking three times a day) of 30997 primiparous cows which calved in 79 herds in Mashhad city, from years 1993 to 2015 were used. The incomplete Gama function fitted to records, using NLIN procedure of SAS. Effect of herd, year, month and age at first calving, percent of Holstein gene, average mean of daily humidity, average mean of daily temperature, minimum and maximum temperature on lactation curve parameters were studied using GLM procedure of SAS. Also, correlations of lactation curve parameters with each other and with climatic parameters were calculated using CORR procedure of SAS.

In studied herds lactation period began with producing 16.76 Kg milk daily and on day 88th reached the peak with 34.44 Kg yield and persistency was 7.43. Herd, year, month and age of calving and percent of Holstein gene had significantly affected the lactation curve (P<0.01). The trend of changing the level of initial milk yield, days to peak milk yield and the lactation persistency, was increasing through the studied years. Among the climatic parameters only average mean of daily temperature had significant effect on some lactation curve parameters.

As genetic evaluation of dairy cattle moves toward the use of test day models, therefore investigating the factors affecting the shape of lactation curve in order to include them in the model and increase the accuracy of genetic parameters estimation is necessary.

Olive leaf extract (OLE) can be used as a rich source of antioxidants due to its polyphenol compounds. The purpose of this research was to measure the antioxidant activity and the effect of aqueous (AOLE) and alcoholic (HOLE) extracts of olive leaves on performance, quality characteristics of eggs, biochemical blood serum, hematology, and immune response of laying hens. This experiment was conducted with 440 high-line laying hens (25 weeks old) in the form of 11 experimental treatments, with 5 replications and each replication including 8 hens for three periods of 28 days in a completely randomized design with five levels of AOLE (200, 400, 600, 800 and 1000 mg/kg) and five levels of HOLE (200, 400, 600, 800 and 1000 mg/kg). The DPPH method was used to measure the antioxidant activity of the extract. Functional traits were measured periodically. Blood was taken from the wing vein for serum biochemical and hematological analysis. Injection of the Newcastle vaccine was performed on the 40th day of the experiment, and blood was taken from the wing vein seven days later. The results showed that birds receiving 1000 levels of AOLE and HOLE had the highest percentage of production compared to the control treatment. The highest number of white blood cells and heterophils and antibody titers against Newcastle virus were observed in birds treated with 1000 HOLE levels. In general, the use of 1000 mg/kg of aqueous and alcoholic extract of olive leaves improves the performance and quality of laying eggs.

Pedigree and weight trait records belonging to 13633 Baluchi lambs descendent from 308 ram and 3747 dam which were collected in North-east animal breeding center from years 1989 to 2021 were used. Six univariate animal models with fixed (birth year, month, type, sex of lamb and age of dam) and different random effects were fitted to data. Effects of non-genetic factors on weight traits were investigated by Proc GLM of SAS software, and to estimate the variance components the Wombat software was used. All fixed effects had significant effect on the studied traits (P<0.001). Model with additive autosomal, sex linked, and additive maternal random with covariance between direct additive genetic and maternal genetic effect had the lowest AIC and was used for genetic analysis. For birth, weaning, 6, 9 month and yearling weight respectively additive autosomal heritability were 0.16, 0.34, 0.41, 0.49 and 0.56, additive sex-linked heritability were 0.004, 0, 0, 0.007 and 0.005 and maternal heritability were 0.34, 0.38, 0.32, 0.32 and 0.36. Results showed that sex-linked genes possibly have negligible and close to zero additive genetic effects on body weights at initial ages and in comparison, more noticeable effects on body weights at higher ages. In general, it is recommended to use an animal model for genetic analysis of growth traits in sheep, which is able to separate the total genetic variance into three autosomal, sex-dependent and maternal components in order to be more effective in genetic selection.

The worldwide population growth leads to an increase in livestock production that along with the challenges caused by climate change and water scarcity highlights the importance of raising resistance livestock such as camels. The present study aimed to investigate the effect of partial and total replacement of dietary alfalfa with camelthorn. Total 18 fattening Sandi growing dromedary camels (9 to 10 months old with an average initial weight of 115±7.7 kg) were randomly assigned to one of three experimental treatments in a completely randomized design, with 6 replicates for each treatment. Experimental diets included: 1- control diet (without camelthorn), 2- diets containing 25% camelthorn, and 3- diets containing 50% camelthorn (dry matter basis). The feed intake was recorded daily and the animals were weighed monthly (on days 0, 30, 60, 90, and 150 of the experiment). The results showed that dry matter intake was increased with increasing camelthorn inclusion in the diet (P ≤ 0.05). Although, the average daily gain was reduced in the diet containing 50% DM camelthorn (P ≤ 0.05), but no significant difference was observed between the treatment containing 25% DM camelthorn and control. Feed cost per kilogram weight gain and profit per kilogram of weight gain tended to increase (P = 0.01) with increasing the inclusion of camelthorn in the diet. Overall, the findings of this study showed that feeding camels with camelthorn up to 50% of dietary DM, not only did not have severe deleterious effects on growth performance, but also reduced the production costs.

The present study was aimed to evaluate temporal changes in milk fatty acids and antioxidants of Saanen goat in response to berberine (BBR) supplementation during the transition period. Twenty-four primiparous Saanen dairy goats were used from 21 days before predicted parturition to 21 days after kidding. Experimental treatments were included: 1) control (without BBR supplement), 2) control + 1 g/d BBR, 3) control + 2 g/d BBR and 4) control + 4 g/d BBR. Body condition score (BCS) and body weight (BW) of individual goats were measured on days -21, -14, -7, 0, 7, 14 and 21 relative to parturition. Also, milk samples were harvested at days 0, 7, 14 and 21 following parturition. The results showed that dry matter intake (DMI), BCS and milk yield were increased with supplementation of 2 and 4 g/d BBR (P≤0.05). Milk lactose was also enhanced with increased BBR ingestion (P≤0.05). BBR consumption caused changes in milk fatty acids (FAs) profile in accordance with the energy balance. By supplementing 2 and 4 g/d BBR in transition goats, the level of de novo FAs were increased and free fatty acids (FFAs) were decreased (P≤0.05). BBR supplementation was also associated with a decrease in C18:1n9 fatty acid. The level of milk malondialdehyde (MDA) in goats supplemented with 2 and 4 g/d BBR was also decreased (P≤0.05). The total antioxidant capacity (TAC) as well as the level of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) enzymes in the milk of goats fed 2 and 4 g/d BBR was higher than the control (P≤0.05). In summary, these results showed that BBR supplementation as a new therapeutic strategy in transition period could improve lactation performance, energy balance, and milk antioxidant indicators.

The effect of using different levels of olive cake on production, milk composition and antioxidant atatus of dromedary camels, an experiment using 9 Turkmen dromedary camels with milk production of 5 ± 0.7 kg/day and average weight of 500 ± 30 kg a 3 three-week periods (14 days of adaptation and 7 days of sampling) was investigated in the form of a change over design with 3 treatments and 9 replications. The experimental treatments were included: 1- control group, 2- treatment containing 15 percent olive cake and 3- treatment containing 30 percent olive cake. Feed intake and milk production were not affected by experimental treatments. Milk fat percent a nd yield and milk protein percent (2.5, 0.11 kg and 2.66, respectively) decreased due to use of olive cake in the diet (P<0.05). There was no difference in the concentration of most of fatty acids and the ratio of omega-6 to omega-3 fatty acids in the milk of camels fed experimental diets, but concentration of palmitic acid in camels that consumed 30 percent olive cake was lower than control group (P<0.05). According to the results of this research, the use of olive cake (in the level of 30 percent of ration DM) in camel feeding, may have positive effects on increasing the nutritional value of dairy products especially in arid and semi-arid areas.