Iranian Journal of Animal Science
Year:2019 | Volume:49 | Issue:4|Papers Count:10

Genetic evaluations are computed to assess the genetic merit of animals based on mixed model equations. An important assumption for setting up these equations is that all genetic relationships among animals are available and correct. The objectives of the present study were to estimate the effects of incomplete pedigree and paternity errors on genetic evaluation. Data and pedigree of 100 dairy herds were obtained from Animal Breeding Center of Iran. Final data edited included milk yield records from 302860 first lactation Holstein cows. DMU Trace program was used for tracing ancestors and creating the full pedigree of animals. To simulate incomplete and wrong pedigrees, different scenarios including 8, 12, 16, 20, 24 percent of paternal identifi cation numbers were removed or replaced using R program. Breeding values for milk yield was predicted by animal model using DMU program. Spearman's rank correlation was estimated for superior animals in different scenarios using SAS software. Estimates of heritability for full, incomplete and wrong pedigrees were 0. 29, 0. 26 and 0. 27, respectively. The results showed a high variation in ranking of animals and determination of superior animals (P<0. 01). As an example, at 12% level scenario, Spearman's rank correlation of BVs predicted from full pedigree with incomplete and wrong pedigrees were 0. 65 and 0. 60, respectively. Selection effectiveness, defined as the ratio of common superior animals in alternative scenarios, was decreased by increasing the rate of misidentification and errors (P<0. 01). Incorrect pedigree and misidentification of animals could reduce accuracy of breeding values and consequently bias in animals ranking.

This study was carried out to evaluate the effects of supplementing corn steep liquor (CSL), as a nitrogen source, with different dietary carbohydrate sources on in vitro gas production, fermentation parameters, digestibility and activity of rumen microbial enzymes of male lamb's diets. The 8 experimental diets contained different energy sources (including different levels of barley, corn and molasses), in which a constant level of CSL was used (13% of diet dry matter (DM)), incubated in vitro. Experimental diets were 1) corn, 2) barley, 3) mixture of corn/barley and replacing the former with4) 5, 5) 10, 6) 15, 7) 20 and 8) 25% molasses. The maximum and minimum gas production at 72 and 96 (h) of incubation, and potential of gas production (b) were obtained by incubation of diet containing15% molasses and corn diets, respectively (P<0. 05). However, the greatest and lowest values for fractional rate of gas production (c) and microbial protein synthesiswere observed in the diets containing 10 and 25% molasses, respectively (P<0. 05). The concentration of NH3-N was greatest by supplementing CSL with 25% molasses, while it was lowest in the diet containing 10% molasses (P<0. 05). The addition 10% molasses along with CSL increased the activity of carboxymethyle cellulase and microcrystalline cellulase compared with the other treatments (P<0. 05). The highest activity of filter paper-degrading (FDP) was obsereved with the diet in which CLS was supplemented with 5% molasses, while supplementing CSL conating diet with 25% molasses led to the lowest FPD activity (P<0. 05). In conclusion, the results of present study showed that supplementing CSL containing diet with 10% of molasses improved nutrient digestion, rumen fermentation and nitrogen metabolism in vitro.

The aim of the study was to compare two strategies in Mazandaran native fowls using computer simulation. Simulated traits included body weight at birth (BW1), at eight weeks of age (BW8), at twelve weeks of age (BW12), at maturation (BWM), age at sexual maturity (AFE), weight of first egg (EWM), mean egg weight from 28 to 32 weeks of age (EW28-32) and egg number (EN). The first strategy was to select cockerels based on breeding value of BW12 and hens based on a selection index with 4-traits including BW12, AFE, EW28-32 and EN. The second strategy was to select cockerels and hens using a selection index based on a 4-traits including BW12, AFE, EW28-32 and EN. After 10 generations, the first strategy improved BW1, BW12, BWM, EW28-32 and EWM to 1. 49, 573. 81, 397. 58, 3. 96, and 3. 75 grams and AFE and EN to-3. 51 days and 2. 09 eggs, respectively. After 10 generations, the gain for traits in the second strategy for BW12, BWM, AFE and EN was 415. 78, 218. 74 grams and-9. 77 days and 9. 45 eggs, respectively. At the end of the tenth generation increase of inbreeding in the first and second strategies was 0. 048 and 0. 070, respectively. The results showed that the first strategy was suitable for a breeder flocks with the aim of chickens suitable for broiler production and the second strategy was suitable for a dual-purpose flocks with the aim of producing egg and meat.

Polyphenols content in the grape seed are considered as potent aromatase inhibitors. In this study, the grape seed extract was injected into the egg as an anti-aromatase and its effects on sex differentiation and gonadal structure in broiler chicks were investigated. A total of seven hundred eggs from Ross 308 were divided into 7 experiment groups. Treatments including: injection of 3(GSE3) and 4(GSE4) milligrams of grape seed extract and zinc, 3 (NGSE3) and 4(NGSE4) milligrams of nanoparticle of grape seed extract and zinc, 0. 05 mg tamoxifen and zinc (TOM+Zn), 0. 5 ml normal saline (PC) and control with no injection (NC). Injection was performed on day 5 of incubation from the narrow side of egg. After hatch, chickens were reared for 5 weeks. Results showed that compared to controls, injection of grape seed extract caused significant increase in percentage of male chick(P<0. 05). No significant differences were found in day old chick weights (P>0. 05). Feed intake, body weight, body weight gain and feed conversion ratio appeared with no significant differences (P>0. 05). The study of gonadal structure in chicks indicated a high degree of sexual reversal in chicken treated with 3(NGSE3) and 4(NGSE4) mg of nanoparticles of grape seed extract and zinc. Conclusion is that the grape seed extract has the potential to act as an anti-aromatase compound to produce higher percentage of male broiler chicks.

The aim of this research was to determine effects of different toxin adsorbents on the amount of Diazinon residues and effectiveness of these additives on ruminal parameters and some blood metabolites in Mohabadi lactating goats fed with high white grape pomace-based diets (27. 71%). In this study, 20 lactating goats with 50± 5 kg body weight were used in a completely randomized design with 4 treatments and 5 replications. Experimental treatments included diets containing: 1-White grape pomace without toxin adsorbent or control group 2-Grape pomace processed with Mycofix-Plus toxin adsorbent 3-Grape pomace processed with Bio-Tox toxin adsorbent 4-Grape pomace processed with Bio-Acid toxin adsorbent. Adding adsorbent compounds of toxins to diets with high levels of grape pomace reduced the amount of Diazinon in the diet (P˂ 0. 05), so the highest amount of Diazinon in control treatment (4. 08 mg/kg) and the lowest amount of toxin was observed in treatment group treated with Bio-Tox supplement (0. 67 mg/kg). As a result of adding different toxin adsorbents there was an increase in the amount of dry matter intake (DMI), rumen N-NH3, total VFA, propionic acid, glucose and urea concentration (P˂ 0. 05). Adsorbents did not have a significant effect on the Rumen protozoa population (p>0. 05). Adding different adsorbents reduced Non-esterified fatty acids (p<0. 05). There was not any significant difference among the investigated groups in terms of the concentration of β-hydroxybutyrate (BHBA), total protein and albumin as a result of adsorbent use (p>0. 05). As a conclusion, the amount of the adsorbent and deactivating compounds of toxins in diets with high levels of grape pomace reduced the amount of Diazinon and improved feed intake, rumenal and blood parameters in Mahabadi's lactating goats.

This study was conducted to investigate the effects of supplementing dairy cows diet with various levels of commercial chestnut condensed tannins (CT) supplement (Silvafeed), on in vitro gas production (GP) and fermentation parameters, nutrients digestibility and activity of rumen microbial enzymes in vitro using rumen liquor of cow. Dietary treatments were control diet (without CT) and supplementing control diet with CT at the levels of 0. 45, 0. 90 and 1. 35 g per kg dietary dry matter (DM). Inclusion levels of dietary tannins were based on recommendation of manufacturer. Results showed that GP at all of incubation times, potential (b) and rate (c) of GP were not affected by experimental treatments (P>0. 05). Except for ammonia nitrogen concentration and microbial protein production which were decreased and increased with increasing rate of CT in the diet respectively (P<0. 05), while the other fermentation parameters were unchanged by incubation of experimental diets (P>0. 05). Activity of fibrolytic enzymes such a carboxymethyl cellulase, microcrystalline cellulase and filter paper-degrading activity were not affected by supplementing diet with CT (P>0. 05), while rumen protease activity was decreased linearly with enhancing level of CT in the diet (P<0. 05). In conclusion, the results of present study revealed that adding condensed tannins to dairy cows diet up to 1. 35 g/kg dietary DM improved nitrogen metabolism in the rumen, and this could reduce the requirements for dietary rumen undegradable protein.

In order to investigate the effects of in ovo injection of different sources of manganese on performance and tibia characteristics of broilers, a total of 480 fertile eggs from ROSS 308 were assigned to 6 treatments, 4 replicates of 20 eggs per replicate in a completely randomized design. The experimental treatments included non-injected (negative control, NC), injection of1 ml serum physiology(positive control, PC), 1 ml of manganese sulfate (MnS), 1 ml of manganese-methionine (MnM), 1 ml of nano manganese (NMn) and 1 ml of nano manganese methionine (NMnM). The results showed that the in ovo injection of different sources of manganese lead to improvement in broilers growth. The highest and lowest body weight gain in entire production period were recorded for NMn and PC group, respectively (P<0. 05). NMn and NMnM groups showed the best feed conversion ratio in whole experimental period (P<0. 05). The tibia length at 21 day of age was significantly higher in treatment containing MnS and fresh and dry weights of tibia at 21 and 42 days of age were significantly increased with NMn (P<0. 05). The tibia breaking strength at 21 and 42 days of age was significantly increased in treatments containing NMnM and NMn (P<0. 05). The tibia volume, density and ash percentage were not affected by experimental treatments on 21 and 42 days of age (P>0. 05). According to these results, it seems that the in ovo injection of manganese nanoparticles as a feed additive has positive effects on performance and tibia characteristics of broilers.

The present study was evaluated the effects of acetic acid treating and autoclaving the bitter vetch (Vicia ervilia) on nutrients degradability, protozoa counts, some ruminal parameters, and metabolisable protein. Three Farahani permanent rumencanulated sheep were used in a 3×3 Latin square design with 21-d periods. Three experimental treatments were; 1) raw bitter vetch, 2) chemical processed bitter vetch, and 3) physical processed bitter vetch. Treating bitter vetch with 8% acid acetic and its autoclaving (121 ˚ C, 117 Kpa, 20 min) were considered as chemical, and physical processing, respectively. The incubation times for in situ experiment were 2, 4, 8, 16, 24 and 48 h. Metabolisable protein was estimated based on in situ data as well. The results cleared that both processing methods (i. e. chemical and physical) reduced the degradation of dry matter and protein in the rumen which physical treating was more effective in this reduction. However the processing methods did not change metabolisable protein content of treatments. The results of protein fractionation showed that autoclaving caused to reduce the A and B1 fractions and increased the slow degradable fractions (P<0. 05). Ruminal ammonia nitrogen concentration was tended to be significant (P=0. 06). The protozoa count increased in rumen fluid of sheep fed autoclaved bitter vetch. The results of the current study showed that both chemical (treating with acetic acid) and physical processing (autoclaving) transferred the protein degradation from the rumen into small intestine and the effect of physical treating (autoclave) was more relevant.

In order to investigate the different times of GnRH injection on the reproductive activities of Lake-Ghashghaei ewes supperovulated with eCG in autumn season, 60 ewes (2-3 ages and average body weight 49± 1. 8 Kg) were chosen. Estrus cycle of ewes were synchronized by progesterone sponges during a 14 days period. One day before removing the sponges, 400 IU of eCG were injected intramuscularly. Then the ewes were divided into 4 groups according to receiving GnRH on different days (one, seven and 12 days) or not receiving GnRH (control) after estrus observation and reproductive indexes such as the rate of return to estrus and pregnancy rate, were measured and compared among different groups in two continuous estrus cycle. The result indicated that there were not any significant differences (P>0. 05) in the rate of return to estrus, pregnancy rate, parturation rate, fecundity and prolificacy among treatment groups, but the rate of twin birth was significantly (P<0. 05) lesser in the groups, receiving GnRH in 7 and 12 days compared with the group that recieved GnRH in the first day. Serum progesterone concentration in pregnant, delivered, single and twin births ewes that received GnRH were significantly (P<0. 05) more than control ewes. In conclusion, GnRH administration during different days after mating increased serum progesterone concentration in Lake-Ghashghaei ewes. Moreover, the rate of twining birth in ewes which received GnRH on the first day, was significantly more compared with using GnRH on 7 th th and 12 days after estrus.