Journal of Animal Production
Year:2019 | Volume:20 | Issue:4 |Papers Count:11

The objective of the present study was the genetic evaluation of retained placenta (RP), metritis (MET), number of inseminations to conception (INS), and days open (DO) in Holstein cows using standard (SMMs) and recursive (RMMs) mixed models. Data on 50230 first-lactation Holstein dairy cattle, collected during 2008 to 2017 in 17 large dairy herds were used. The data were analyzed using four-variate animal Threshold-Gaussian models under SMMs and RMMs. The existence of causal effects from RP on MET, INS and DO, from MET on INS and DO and from INS to DO were considered in RMMs. The causal effects of RP and MET on INS were 0. 19 and 0. 09 services, respectively; and those on DO were 4. 74 and 5. 38 days, respectively. Also, causal effect of INS on DO was obtained as 33 days. The considered causal relationships except that of RP on MET, phenotypic and residual correlations among the disorders and fertility traits were statistically significant and different under two models. Posterior means of heritability for RP, MET, INS and DO were 0. 15, 0. 17, 0. 07 and 0. 09 under SMMs, respectively; and 0. 16, 0. 17, 0. 07 and 0. 1 under RMMs, respectively. The difference between the corresponding heritability estimates under SMMs and RMMs were not statistically significant. Therefore; RMMs may be an alternative for SMMs in genetic evaluation of studied traits in first-lactation Holstein cows.

In this study, effects of the in ovo injection of Khazak egg yolk into the yolk of the Ross 308 eggs on some of offspring's inflammatory and immune indices as well as on the relative expression of intestinal and hepatic TNF-α and/or Zo-1 genes, were investigated. For this purpose, 250 fertile Ross 308 eggs were randomly assigned into two equal experimental groups including test (In ovo injection of Khazak yolk) and control (In ovo injection of Ross yolk) group. After hatching, chickens were reared for six weeks under the same standard environmental conditions with exposure to some certain inflammatory stimuli between 21-28 days of age. Chicken’ s blood and/or tissues samples were collected on days 10 and 42, and the samples were analyzed for the target traits. Results showed that Khazak yolk component caused a reduction in the levels of pro-inflammatory TNF-α cytokine in both offspring's liver and intestinal tissue (P<0. 05). Compared to the control group, khazak yolk injection was found to enhance the titer of IgA natural antibody as well as primary and secondary antibody titer response against sheep red blood cells (SRBC) and reduces both serum levels of offspring's CRP protein and liver ALT enzyme (P<0. 05). According to the results of the present study, injection of Khazak native hen egg-yolk into the yolk of eggs from Ross 308 commercial broiler breeder can effectively suppress the expression of TNF-α inflammatory cytokine in the offspring's liver and intestinal tissue.

In this study, the effect of different levels of ZnO, nano-ZnO and Zn-methionine, in pre-and post-partum diets, on feed intake, Zn absorption, microbial protein, as well as metabolites and IgG, IgM and IgA in the blood and colostrum of ewes and suckling lambs were investigated. Experiment was conducted from 50 days before to 30 days after lambing. Sixty pregnant Khorasan-Kurdish ewes were divided into six experimental groups (10 replicates) in a randomized complete block design. Experimental diets contained ZnO, nano-ZnO and Zn-methionine to meet NRC recommendation, or higher than NRC-recommended level. Replacing ZnO with nano-ZnO or Zn-methionine had no effect on different variables in ewes, but increasing Zn level in the diet of ewes resulted in an increment of daily Zn intake, a decline of Zn absorption coefficient and an increase of fecal Zn excretion (P<0. 05). Feeding mother ewes with different Zn sources had no effect on blood metabolites and immunoglobulins of the suckling lambs. Overall, nano-ZnO had no positive or negative effects on ewes and suckling lambs and using Zn-methionine instead of ZnO did not improve the metabolic condition of the animals. On the other hand, the increasing dietary Zn concentration increased zinc excretion in the environment. In practice, using the conventional ZnO at the NRC recommendation level is sufficient to provide the requirement, and to maintain the immunity of pre-and post-partum ewes and there is no need for additional Zn from other sources.

Two experiments were conducted to assess the addition of pistachio by-product biochar (PBB) to lactating ewes’ diet. In first experiment, the effects of the addition of different levels (0, 0. 5, 1 and 1. 5% diet on dry matter basis, DM) of PBB on rumen fermentation parameters after 24h of incubation were investigated in a completely randomized design with four treatments and three replications. Second experiment was designed to evaluate effect of feeding selected level of PBB on performance and nutrient digestibility of 8 lactating Kermanian ewes in a Latin square change-over design with two 21-day periods. Methane production and ammonia-N concentrations decreased linearly (P<0. 01), and pH increased linearly (P<0. 01) as the dietary level of PBB raised. With the addition of 1% PBB to the lactating ewes’ diet, milk yield, blood glucose, digestibility of DM increased (P<0. 05) and blood urea nitrogen (BUN) decreased (P<0. 05) compared to control group. In general, adding 1% of PBB to lactating ewes’ diet can improve milk yield and digestibility of DM.

This study was conducted to evaluate the effects of garlic and thyme’ s medicinal plants essential oils blend as a feed additive following feed restriction on growth performance, relative growth rate and ileal microbial population of broiler chickens. This study was conducted using 336 one-day old chickens (Ross 308) as a factorial experiment (2×3) in a completely randomized design in six treatments with four replications and 14 birds per each replicate. The factors included two levels of feed restriction (without feed restriction and %10 feed restrictions) and three types of growth promoter additives (none-additive, blend of essential oils and antibiotic). The results showed that the body weight in 18 days of age was significantly affected by feed restriction (P <0. 05). Feed restriction, feed additive and interaction between them did not affect the performance parameters. The addition of EO resulted in significant reduction in mortality rate (P <0. 05). Feed costs for one kg of body weight were not affected by experimental treatments. Under the feed restriction, the population of E. coli and the total aerobic bacteria in ileum significantly reduced at 18 days of age (P <0. 05). At 42 days of age, the addition of EO resulted in a significant reduction in E. coli, total aerobic bacteria count and increasing Lactobacillus counts (P <0. 05). As a general conclusion, use of EO in feeding chicks faced with feed restriction could significantly increase the compensatory growth and might reduce the mortality and improve the ileal microbial population as well.

The present study was conducted to determine the zinc (Zn) requirement in broiler chickens fed wheat-soy based diet. Two hundred fifty day-old broiler chicks (Ross 308), were randomly assigned to a completely randomised design (CRD) experiment with 5 treatments, and 5 replicates of 10b each. The experimental treatments included five dietary Zn levels (30, 70, 110, 150, and 190 mg/kg) provided by the addition of reagent grade “ ZnSO4. 7H2O” . The experiment lasted from 1-42d of age. Increasing dietary Zn level to 70mg/kg significantly increased 10, 24 and 42d live body weight (LBW), feed intake (FI) and weight gain (WG) during 1-10, 25-42 and 1-42d of age and feed efficiency (FE) during 1-10d of age. The linear broken-line (LBL), quadratic-broken line (QBL) and the quadratic polynomial (QP) regression models were used to estimate the Zn requirement. The Zn requirement for optimal final LBW and FI, WG, and FE during 1-42d of ages by LBL model were 68. 77, 83. 12, 66. 99 and 62. 75 mg/kg of diet, and by QBL model 70. 00, 79. 93, 69. 63 and 58. 01 mg/kg of diet, respectively. In conclusion, Zn requirement varied between 58-83 mg/kg, which is higher than NRC and is lower than strain recommendation in the broiler chickens fed wheat-based diet.

This study was conducted to determine the regression equations based on chemical analyses for predicting apparent metabolizable energy corrected for nitrogen retention (AMEn) with nine soybean oil samples available in Iran’ s market. Soybean meal AMEn was measured by replacement method with broilers in starter (seven to d 10), grower (21 to d 24) and finisher (31 to d 34) periods through acid insoluble ash marker. The results of current study demonstrated that there are significant difference between chemical analyses data and also biologically determined AMEn of soybean samples available in Iran’ s market. The mean of soybean meal AMEn measured in the starter, grower and finisher periods were 1463, 1871 and 2025 kcal/Kg based on dry matter, respectively. Moreover, the difference between estimated value using NRC equation and biologically determined AMEn, in the starter, grower, finisher and whole periods was 34. 2, 15. 8, 8. 9 and 19. 7 percent, respectively. Finally, these equations based on coefficient of determination and standard error of prediction criteria are suggested for the starter: AMEn=47. 873×NFE, grower: AMEn=60. 203×NFE, finisher: AMEn=65. 612×NFE and the whole of periods: AMEn=57. 923×NFE. As a result, it seems that the equations of current study with accurate AMEn estimation of soybean meals will cause optimum broiler performance.

This experiment was conducted to assess the effect of safflower meal (SFM) containing microbial and enzyme supplementations on performance, meat quality and humoral immunity of Japanese quail. A total of 300 seven-daysold Japanese quails were assigned in a completely randomized design to five treatments, four replications and 15 chicks in each replication. The experimental treatments included 1) a corn and soybean meal based diet (control) 2) diet containing 20% SFM 3) diet containing 20% Fermented SFM 4) diet containing 20% SFM + Calsporin® probiotic at a rate of 50 mg/kg feed and 5) diet containing 20% SFM+ Endo-Power® enzyme to the amount of 125 mg/kg feed. The results of this study showed that the use of fermented SFM, Calsporin® probiotic and enzyme treatments improved weight gain and feed intake of chicks when compared to control group (P<0. 05). The feed conversion ratio for the chicks in control group and quails receiving diets containing fermented SFM and SFM+ Endo-Power® enzyme was lower than that of other experimental groups (P<0. 05). Birds fed with SFM had lower meat cooking loss (P<0. 05). The meat water holding capacity and also antibody titer against sheep red blood cell (SRBC) were higher in treatment receiving fermented SFM when compared to control group (P<0. 05). According to the positive effects of nutrition with fermented SFM and containing probiotic and enzyme supplements on performance, meat quality and immunity system of Japanese quail, this accessible and inexpensive source of protein could be used in quail diet.

The aim of this study was to examine the effects of Artemisia annua L. essential oil (AAEO) and probiotic (Lactobacillus acidophilus) on egg and carcass quality of laying Japanese quails. A total of 180 46-d-old female Japanese quail were randomly allocated to 4 dietary treatments in a completely randomized design with five replicates and nine birds per each. The experimental diets were: 1) basal diet as control group (without additive), 2) basal diet plus oxytetracycline (200 mg/kg), 3) basal diet plus AAEO (250 mg/kg) and 4) basal diet plus probiotic (4. 02 × 1011 CFU Lactobacillus acidophilus per kg diet). Results showed that the use of probiotic caused to an increase in the cumulative egg weight and daily egg mass, when compared with control and AAEO treatments (P<0. 05). In comparison to control group, supplementing the basal diet with AAEO resulted in decreases on MDA level of egg yolk (P<0. 05) and liver weight (P=0. 06). In addition, the F3 and F2 follicles weights were increased when the basal diet supplemented with each of the feed additives (P <0. 05). It can be concluded that, Lactobacillus acidophilus can be used as an alternative to antibiotics for increasing the egg production, and AAEO can be used to produce healthy products in feeding laying Japanese quails.

To evaluate the effect of type (Rice Hull (RH) and Oat Hull (OH)), level (3 and 6 percent) and particle size (0. 5 and 2 mm) of insoluble fiber on performance, carcass characteristics and intestinal morphology of chickens, 360 day-old male broilers (Ross 308), were use in a completely randomized design with 9 treatment and 4 replicate with 10 birds each, for 42 days. In the 29-42 days, broilers fed 6 percent with 0. 5 mm RH had higher (P≤ 0. 05) average daily gain, daily feed intake and lower feed: gain than control group. In fact, the 6 percent with 0. 5 mm OH inclusion reduced (P≤ 0. 01) abdominal fat and carcass performance as compared to control (P≤ 0. 0`5). Results showed that broilers fed OH and RH had higher relative weight of gizzard and gallbladder than broilers fed the control diet (P≤ 0. 05). Broilers fed RH had higher villus length than other treatment in the jejnum at 21 and 42 days of age and duodenum at 21 days of age (P≤ 0. 01). In this experiment, the broiler fed 3 percent RH with 2 mm particle size had the highest epithelium width (P≤ 0. 01) in the ileum section at 21 day of age. Therefore the results showed inclusion of 3 percent RH with 0. 5 mm particle size to broiler diets may improve the growth performance and intestine morphology.

This study was carried out in order to evaluate the relationship between some productive and reproductive factors with calf sex (CS), in Shahryar city from 2017 to 2018. Synchronization and pregnancy detection were performed by a veterinarian. Heat detected cows were inseminated by artificial insemination (AI) or mated by bull cow based on their reproductive history. Implantation of fetus in left-side or right-side of uterine horn was determined by sonography. The CS of newborn calves was also registered immediately after calving in order to analyze the sex ratio. Results showed that the intervals between calving and first insemination service had no significant effect on CS. In addition, CS was not affected by age of cow and type of insemination. However, implantation of fetus in the rightside compared to the left-side uterine horn resulted in a greater ratio of female than the male calves(P>0. 05). The ratio of female calves in the dairy cows with high milk production (45%) was higher than those with low milk production (25%, P<0. 05). The primiparous cows significantly produced (P<0. 05) higher ratios of female calves (60%) rather than multiparous cows (47%, 46% and 47% in the second, third and fourth parturition, respectively). It can be concluded that, the uterine horn side implantation, level of milk production and primiparous or multiparous cows’ statement are effective factors on CS. Therefore, it is possible to convey the sex ratio of new born calves to a desired ratio by manipulating some parameters in dairy cows before the birth.