مجله علوم دامی ایران
سال پنجاهم شماره 4 (زمستان 1398)

Abdominal fat deposition and several other unique features in the metabolism of birds such as interaction between genetic and endocrine factors, fasting hyperglycemia and insulin resistance are signs of obesity and metabolic disorders in poultry, similar to humans. The main purpose of this study was to use transcript profile of fat tissue in two groups of broiler chickens with high and low abdominal fat deposition, to identify the genes involved in storage and metabolism of fat, as well as the signaling pathways associated with the endocrine glands. Based on the analysis of microarray and RNA-seq data, 2914 and 1867 genes were detected as differentially expressed genes, respectively. In total, 1835 genes were identified by comparing the genes with a significant difference in expression (P<0.000001). Then, by comparing the number of relevant genes among the transcript profiles, the most important related genes were THBS1, COLEC12, ANXA7, RGS19, TMEM258 and HTR7L, which in the main process of pathways controlling synthesis, fat metabolism and storage and the endocrine signaling pathways activated by adipokines, are involved. The analysis of the relevant tissue may indicate the role of ventricular fat as a metabolic and endocrine organ in broiler chickens.

This study was conducted to investigate the effects of replacement of soybean meal with canola meal and corn processing on productive performance of Holstein dairy cows. Twelve Holstein cows (milk yield= 46±3 kg/d) were assigned to a replicated 4×4 Latin square design with a 2×2 factorial arrangement of treatments. Factor 1 was corn processing method, ground corn or steam flaked corn, and factor 2 was two ratio canola meal to soybean meal (50:50 or 100:0). No significant interactions of main treatment effects occurred for lactation performance data. Dry matter intake and milk production was not affected by replacement of soybean meal with canola meal. Milk compounds concentration was not affected by this replacement. Substitution of hundred percent of soybean meal with canola meal in the diet decreased the apparent digestibility of the dry matter. Feed intake was decrease when the cows received steam flaked corn compared with those receiving ground corn. Milk fat content decreased but milk protein content increased in cows fed steam flaked compared with those fed ground corn. Although these results showed no interaction effects of replacement of soybean meal with canola meal and corn processing method on performance, higher canola meal ratio and steam flaked corn improved feed efficiency and has a positive effect on the metabolism of nitrogen and energy, so recommended to fed in high-yielding cows under the conditions of this experiment.

This study was conducted to investigate the performance of growth and carcass traits of Lori-Bakhtiari (L), Romanov×Lori-Bakhtiari (F1RL), Pakistani×Lori-Bakhtiari (F1PL), (Pakistani×Lori-Bakhtiari)×(Romanov×Lori-Bakhtiari) (¼P¼R½L) and (Romanov×Lori-Bakhtiari)×(Romanov×Lori-Bakhtiari) (F2RL) crossbred lambs. Carcass characteristics of Lori-Bakhtiari (n=50), F1RL (n=41) and F2RL (n=20) crossbred lambs. Lambs were weaned at the age of 90 ± 5 days. Lambs were slaughtered at six month of age. Birth weight in Lori-Bakhtiari (5.12 kg) was significantly (P<0.05) higher than in Romanov (4.81 kg) and Pakistani (4.57 kg) crossbred. Weaning weight and body weight in six months were significantly higher (P<0.05) in Romanov × Lori-Bakhtiari crossbred lambs (30.96 and 42.75, respectively) than in Lori-Bakhtiari (28.81 and 41.69, respectively) and others genetic compositions. F1RL and F2RL crossbred lambs for lean percentage were significantly (P<0.05) higher than in Lori-Bakhtiari lambs in constant age (59.57, 60.57 and 50.03, repectively) and in constant weight (60.99, 59.24 and 49.56, repectively). Weight and percentage of total fat of carcass in Lori-Bakhtiari lambs (7.56 kg, 31.57% in constant age 6.65 kg, 30.46% in constant weight, repectively) were significantly (P<0.05) higher than of F1RL (4.25 kg, 20.91% and 4.30 kg, 20.08%, repectively) and F2RL (2.95 kg, 17.97% and 5.12 kg, 22.46%, repectively) lambs. In conclusion, crossbreeding between Romanov and Lori-Bakhtiari (F1) improves body weight at weaning and at six months of age, and carcass composition.

The aim of this study was to investigate the effect of curcumin on post-thawed sperm quality parameters and fertility of male broiler breeders. Twenty 49-week-old Ross 308 broiler roosters were randomly divided into four experimental groups (n=5). Different levels of curcumin including: 0 (T1), 10 (T2), 20 (T3) and 30 (T4) mg of curcumin/bird/day were supplemented to basal diet and fed to the birds from 49-61 weeks of age. After a 5-week of feeding curcumin (49-53 weeks), sperm quality was assessed for 6 weeks (54 to 59 weeks of age) following cryopreservation of semen samples. In order to evaluate fertility rate, the semen samples from weeks 60 and 61 were thawed and artificially inseminated into 68 broiler hens (n=17). Curcumin supplementation increased total motility in the T3 and T4 groups, and progressive motility in the T2, T3, and T4 groups compared to the T1 group (P<0.05). Feeding curcumin increased the viability of sperm in T3 and T4 groups compared to the T1 group (P<0.05). Plasma membrane functionality (HOS) was increased in all curcumin-treated birds compared to the control group (P<0.05); however, the highest performance was observed in T3 and T4 groups. Curcumin supplementation increased fertility rate in T3 and T4 groups compared to the T1 group. In general, the results of this study indicated positive effects of curcumin on sperm quality and fertility of broiler breeder roosters after thawing, and the best results were obtained when 20 or 30 mg of curcumin were fed daily for 13 weeks.

In this experiment, effects of injection of vitamin E (VE) and selenium (Se) solution and vitamin B12 (VB12) and iron (Fe) solution to transition dairy cows on colostrum quality and calves’ antioxidant capacity, concentrations of VE and VB12, Fe and Se, serum metabolites and blood cells were studied. Twentyprimiparous (607.09±60.26 kg of body weight) and twentymultiparous (712±55.54 kg of body weight) Holstein dairy cows were divided to 4 based on parity and body weight in a randomized completely block design. Experimental treatments consisted of 1) injection of 7 ml of NaCl % 0.9 (Control), 2) injection of 60 ml of VE and Se solution, 3) injection of 7 ml of VB12 and Fe solution and 4) injection of 60 ml of VE and Se solution with 7 ml VB12 and Fe solution. Solutions injected on 21 and 7 day prepartum and calves blood samples collected before and 24h after cholestrum feeding. Results indicated that treatments had no effect on calves’birth weight and colostrum concentrations of fat, protein, lactose and solid not fat, and immunoglobulinG. Serum concentrations of VE and B12, Se and Fe, serum activities of glutathione peroxidase, catalase, total antioxidant capacity and serum metabolites did not affected by the experimental treatments. Altogether, it can be concluded that injection of VE and Se solution and VB12 and Fe solution to transition dairy cows on days 21 and 7 prepartum had no effect on calves’immune system at first 24h of life.

Supplementing anionic salts to make negative DCAD in close-up heifers’ diets is still a challenging topic in formulation of dairy cattle rations. Twelve close-up Holstein heifers (21 ± 7 d expected to calving date) were fed individually and allocated to two treatments of 6 animals each. Experimental treatments were; 1) positive DCAD with level of +165 meq/kg basis on dry matter; and 2) negative DCAD with the level of -85 meq/kg basis on dry matter. Dry matter intake (DMI), milk yield and composition, colostrum yield and its immunoglobulins content and some blood metabolites (pre- and post-partum) were evaluated. The results show that DMI was similar between treatments. The blood pH was lesser in negative-DCAD fed heifers. Among blood metabolites, only Ca was increased in negative-DCAD fed heifers. Colostrum and milk yield and milk composition, colostrum concentrations of IgM and IgA were similar between treatments. However, serum and colostrum concentrations of IgG were slightly increased in negative-DCAD fed heifers; a further research should be carried out to elaborate on the effects of using negative-DCAD rations in close-up heifers exposed to stressful conditions.

The experiment was carried out to investigate the effect of aluminum silicate (AS), humic acid (HA), Saccharomyces cerevisiae cell wall (SC), herbal powder (HP) and a commercial toxin binder to alleviate the effects of aflatoxin B1 (AFB1) in broiler diet.  In this experiment we used 320 day old chicks in a completely randomized design with 8 treatments and 4 replications, and 10 birds in each replicate, from 7 to 28 days of age. Experimental treatments were: 1) negative control (NC; without AFB1), 2) positive control (PC; contaminated by 0.3 mg AFB1 / kg diet), 3) PC + AS, 4) PC + AS + HA, 5) PC + AS + SC, 6) PC + AS + HA + SC, 7) PC + Magnotox as a commercial binder and 8) PC + HP. Feeding AFB1 contaminated diet reduced broiler performance, increased relative weights of liver, heart, pancreas and reduced serum albumin, total protein and glucose concentrations (P <0.05). Inclusion of AS in PC diet individually improved the negative effects of AFB1. However, supplementation of SC boosted AS effects, HA supplementation was rarely effective. Finally, it can be concluded that the combination of AS + SC has the highest adsorbing ability of AFB1.

The aim of the present study was to investigate the effect of single nutritional grouping (TMR1) compared to multinutritional grouping (TMR4) on productive performance and milk composition during a complete lactation period. Four hundred and eighty-four lactating Holstein cows were blocked based on parity (158 first, 134 second, and 192 third lactation or higher) and were randomly assigned one of two TMR1 and TMR4. Cows in 1TMR produced 4.04 kg more milk than those in 4TMR group (P<0.01). Likewise, 4% FCM yield was higher for 1TMR relative to 4TMR (37.46 vs. 33.1 kg, respectively). The content of milk compositions were not affected by experimental treatments (P> 0.05). According to the results of milk production, fat (P<0.01) and protein milk yields (P<0.01) were higher for TMR1 compared to TMR4. Cows in 4TMR were culled 1.58 times compared to those in 1TMR during lactating period. (CI95%= 1.01-2.46; P= 0.04).