Lactation performance and serum biochemistry of dairy cows fed supplemental chromium in the transition period

This study was conducted to evaluate the effect of supplemental chromium on performance and blood serum biochemistry of dairy cows. Thus, 20 multiparous Holstein cows (parity 3) were equally divided into two groups, group one (control), which received no chromium supplementation and group two (treatment) which received 5 g/day chromium methionine from week 5 prior to parturition until 12 weeks thereafter. Milk production and milk composition were evaluated on 4, 8 and 12 weeks after parturition. Serum biochemistry concentrations (serum glucose, cholesterol, triglyceride, total protein, and cortisol and insulin concentration) and blood hematology (red blood cell, hematocrit, hemoglobin concentration and percentage neutrophils, lymphocytes, monocytes, basophiles, eosinophils and ratio of neutrophils to lymphocytes) were measured on 2 and 5 weeks prior to parturition and 1 and 4 weeks thereafter. Results indicate that milk production was significantly affected by chromium-methionine supplementation during the entire period (P<0.01) but no significant effect on milk composition was found. Supplemental chromium had no significant effect on serum glucose, cholesterol, triglycerides and insulin concentration and blood hematology parameters (P<0.05). However, chromium supplementation tended to increase significantly, serum total protein concentration and decrease cortisol concentration (P<0.05). The results of this experiment showed that chromium methionine supplementation in multiparous dairy cows diet may improve their milk yield in transition period.Key words: Dairy cow, transition period, chromium-methionine, milk yield, serum biochemistry

Effects of supplemental microbial phytase enzyme on performance and phytate phosphorus digestibility of a corn-wheat-soybean meal diet in broiler chicks

This experiment was conducted to investigate the effects of supplemental phytase in a corn-wheatsoybean meal basal diet on phosphorus (P) digestibility and performance of broiler chicks. 378 one-day old broiler chicks (Ross 308) were allocated to 3×3 factorial arrangements with three levels of phytase enzyme (0, 500 and 1000 FTU/kg) and three levels of non-phytate P (100, 80 and 60% of NRC requirements). Broiler chicks received experimental diets from 7 to 49 days of age. Phytase significantly (P < 0.05) improved body weight gain and feed intake. Tibial ash and P contents increased significantly by phytase supplementation. Ileal P digestibility increased and P excretion reduced by added phytase. The greatest response due to supplemental phytase regarding P digestibility and utilization was obtained at the lowest dietary non-phytate P (NPP) level (60% of NRC requirements). Difference between various levels of added phytase (500 and 1000 FTU/kg) regarding P excretion and utilization was not significant. The interactions between supplemental phytase and dietary NPP for P utilization, tibial ash and P contents were significant (P < 0.05). The results indicate that, supplemental microbial phytase (500 FTU/kg of diet) added to diet containing NPP lower than NRC requirements (60%) can improve growth performance, tibial ash and phytate P utilization in broiler chickens.Key words: Broiler, phytase, phosphorus digestibility, growth performance, tibia

Performance, immunity, serum biochemical and hematological parameters in broiler chicks fed dietary thyme as alternative for an antibiotic growth promoter

A research study was conducted to investigate the effect of dietary inclusion of thyme powder as an antibiotic growth promoter substitution on performance, immune responses, hematological and biochemical parameters in broiler chicks. In this study, 192 day old chicks (Ross 308) were allocated to four treatments with four replicates based on a completely randomized design. Dietary treatments included control, antibiotic (flavophospholipol), and 5 and 10 g/kg thyme powder. Supplementing the diet with antibiotic and 5 g/kg thyme resulted in a significant increase in body weight (P<0.05). Feed intake of broilers was not markedly influenced by treatments but birds fed diets containing antibiotic had the lowest FCR (P<0.05). None of the immune related parameters tested differed significantly among experimental treatments (P>0.05). Thyme powder at 10 g/kg level significantly (P<0.05) increased HDL-cholesterol concentration but protein, albumin, triglyceride, total and LDL cholesterol concentrations were not influenced. Treatments also failed to induce any statistical impacts on hematological parameters of broilers including red and white blood cell count, hemoglobin and hematocrit values. The obtained results suggest that supplementing broilers’ diet with 5 g/kg thyme can indicate favorable influences of antibiotic growth promoter on performance without any detrimental impacts on immune responses and blood parameters.Key words: Broiler, thyme, growth performance, immunity, serum biochemistry, hematology

Reproductive performance by dairy cows fed supplemental chromium-methionine (Cr-Met) in transition period

This study was conducted to study the effect of supplemental chromium on reproductive performance of dairy cows. Thus, forty multiparous Holstein cows (parity 3) were allocated to two treatments and 20 replicates in a completely randomized design. In this study, treatments consisted of: control group, which received no chromium supplementation and treatment group, which received 6 g/day chromium from chromium  methionine. The cows allocated to this experiment from week 3 prior to parturition until 9 weeks thereafter.  Reproduction parameters consisted of: insemination index and numbers of open days, clinical metabolic  disorders which include acidosis, milk fever, retained placenta and displaced abomasums, and also clinical  puerperal complications consisting of: mastitis, endometritis and ovarian cysts were determined. Results  indicate that Cr supplementation significantly causes decrease in the numbers of open days (p < 0.05). Clinical metabolic disorders and clinical puerperal complications were not affected by chromium methionine  supplementation. The results of this experiment showed that chromium methionine supplementation in  multiparous dairy cows diet may improve their reproductive performance in transition period.Key words: Dairy cow, Chromium methionine, reproductive performance

Efficiency of different levels of Satureja hortensis L. (Savory) in comparison with an antibiotic growth promoter on performance, carcass traits, immune responses and serum biochemical parameters in broiler chickens

This study was conducted to examine the effects of different levels of Satureja hortensis L. (Savory) in comparison with an antibiotic growth promoter (flavophospholipol) on performance, carcass characteristics, immune responses and serum biochemical parameters of broiler chicks. In this study, 240 one-day-old mixed sex broiler chicks (Ross 308) were weighed and randomly allocated to the 4 treatment groups, each with 4 replicates and with 15 broilers in each replicate. The dietary treatments consisted of the basal diet (control), antibiotic group receiving 4.5 mg/kg flavophospholipol, and 5 and 10 g/kg savory powder added to the basal diet. Performance parameters were measured in the growth periods. At day 42, two birds per replicate were slaughtered for the determination of carcass traits. Antibody titers against newcastle, influenza viruses and sheep red blood cell (SRBC) were determined. At day 42, biochemical parameters such as albumin, protein, triglyceride, total cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) of cholesterol were determined. The results show that supplementing 5 g/kg savory improved body weight of broilers at days 14, 28 and 42 but differences did not show statistical significance. Feed intake and feed conversion ratio (FCR) index were not markedly affected by dietary treatments. Internal organ weights and carcass characteristics were not significantly influenced by the dietary treatments at day 42. The use of 5 g/kg savory powder led to the highest antibody titers against SRBC as compared to other groups (P<0.05). The serum biochemical parameters were not affected by dietary treatments. The results suggest that dietary inclusion of 5 g/kg savory can be applied as alternatives to in-feed antibiotics for broiler diets.Key words: Broiler, growth performance, immunity, Satureja hortensis L., biochemical parameters

Possible role of available phosphorus in potentiating the use of low-protein diets for broiler chicken production

A total of 945 male Ross 308 broiler chicks were used in a growth study to explore the interaction between dietary crude protein concentration and available phosphorus. Nine experimental treatments were constructed factorially by offering low, medium, or standard protein concentrations without or with low, standard, or high available phosphorus. Diets were based on corn, wheat, and soybean meal and all nutrients other than protein/amino acids and available phosphorus were maintained at or above breeder guidelines. Additional synthetic amino acids were used in the diets with low protein concentration in attempt to maintain digestible amino acid supply. Diets were offered to 7 replicate pens of 15 chicks per pen from day 8 to 35. Growth performance was measured during the grower (day 8–24) and finisher (day 25–35) periods. On day 35 carcass composition was determined, blood was drawn for various biochemical measurements and the tibia was excised for mechanical and compositional analyses. Birds that received the low-protein diet had lower terminal body weight and higher feed conversion ratio compared with those that received diets with adequate crude protein content. However, addition of available phosphorus to the low-protein diet resulted in significant reductions in weight-corrected feed conversion that were not evident in the diet with adequate protein content. Bone architecture was only moderately influenced by dietary treatment but birds that ingested the diets containing low and medium protein concentrations had relatively heavier abdominal fat pad weight. Blood biochemistry, especially ammonia, uric acid, and phosphorus, was influenced by both dietary protein and available phosphorus and trends suggested that both axes are involved in protein accretion and catabolism. It can be concluded that performance losses associated with feeding low protein diets to broiler chickens may be partially restored by additional available phosphorus. The implications for use of exogenous enzymes such as protease and phytase and protein nutrition per se warrants further examination

Copper hydroxychloride is more efficacious than copper sulfate in improving broiler chicken's growth performance, both at nutritional and growth-promoting levels

This study was designed to compare the effects of nutritional and growth-promoting levels of copper hydroxychloride (CH) with copper sulfate (CuSO4) on growth, carcass characteristics, tibia traits and mineral concentration in broilers fed a conventional wheat-soybean meal-based diet. Day-old Ross 308 male chicks (n = 864) were randomly assigned into 8 dietary treatments with 6 replicates of 18 chicks per treatment. The dietary treatments included a basal diet containing no supplemental copper (Cu) serving as the negative control (NC); basal diet supplemented with 15 or 200 mg/kg Cu as CuSO4; basal diet supplemented with either 15, 50, 100, 150, or 200 mg/kg Cu from CH. Diets were fed over the starter (day 1–14) and grower (day 14–35) phases. Birds in the NC group gained the same body weight and had similar feed conversion ratio (FCR) to birds receiving 15 mg/kg Cu as CuSO4, but birds receiving 15 mg/kg Cu as CH had a lower FCR than the NC birds (day 0-35; P 4 (P P P > 0.05). The highest and lowest tibia ash content were observed in birds fed diet with 150 mg/kg Cu as CH and 200 mg/kg Cu as CuSO 0.05). The highest and lowest tibia ash content were observed in birds fed diet with 150 mg/kg Cu as CH and 200 mg/kg Cu as CuSO4, respectively (P 4 (P 4 in promoting growth performance, both at nutritional and pharmacological levels

A mono-component microbial protease improves performance, net energy, and digestibility of amino acids and starch, and upregulates jejunal expression of genes responsible for peptide transport in broilers fed corn/wheat-based diets supplemented with xylanase and phytase

A total of 90 male Ross 308 broiler chicks were used in a digestibility and performance bioassay to explore the effect of reduction in dietary protein and digestible amino acids and inclusion of an exogenous mono-component protease on amino acid digestibility, net energy, jejunal gene expression, and bird performance. Four dietary treatments were created by the supplementation, or not, of 2 control diets with a mono-component exogenous protease. The control diets were corn/wheat/soybean meal-based and were formulated to be either nutritionally adequate or reduced in protein and amino acids (around 3%). The 2 control diets were supplemented with xylanase and phytase (2000 FYT). Treatments were therefore arranged as a 2 × 2 factorial design. The reduction in diet nutrient density had no significant effect on various experimental outcomes (including bird performance, amino acid digestibility, and net energy [NE]) that were measured with the exception of a reduction in the expression of aminopeptidase N and glucose transporter 2. However, the addition of exogenous protease resulted in an increase in weight gain and a reduction in feed conversion ratio (around 4%; PPP= 0.06). Protease addition also resulted in an increase in both apparent metabolizable energy (AME) (+73 kcal/kg; PPP= 0.06). These results confirm the efficacy of exogenous protease in broiler diets that contain both xylanase and phytase and suggest substantial beneficial effects that extend beyond protein and amino acid nutrition. The effect of exogenous protease on energy partitioning, starch digestibility and the efficiency of nitrogen cycling is an area for further study