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The influence of dietary oxidized oil was studied on laying hen performance, egg quality and blood metabolites. Experiment was conducted on 160 laying hens (Hy-Line W-36, 54-61 wk of age) in a completely randomized design with five treatments and four replicated cages containing eight birds per cage. Dietary treatments replaced fresh soybean oil in the control diet (3% fresh soybean oil, 15.25% crude protein, and 2858 Kcal/kg metabolizable energy) with 0, 25, 50, 75 and 100% oxidized oil. Egg production and egg weight were recorded daily and feed intake, feed conversion ratio, and egg mass were calculated weekly. Egg quality traits were recorded on a biweekly basis. Hen’s body weight was measured individually at the beginning and end of the experiment. Serum metabolites were determined at the end of the experiment. There was a significant difference between diets with different oxidized oil levels in egg weight, egg mass, Egg production, and feed conversion ratio (P < 0.05). Feed intake was not affected by dietary treatments. There was no significant difference between oxidized oil levels on blood serum triglyceride, total cholesterol, high-density lipoprotein, low-density lipoprotein and very low-density lipoprotein. Malondialdehyde of the liver was not affected by oxidized oils. The results of this study have clearly demonstrated that maximum 25% oxidized oil could be replaced by fresh oil in the diets without any adverse effect on the performance of laying hens.

The aim of the current study was to evaluate the replacement effect of soybean meal (SBM) at different levels (0 as D1, 33 as D2, 67 as D3 and 100% as D4 based on crude protein (CP) content) by guar meal (GM) on ruminal gas production kinetics, ruminal digestibility and fermentation characteristics of a fattening diet for lambs. Three experiments were conducted. The first experiment of 144-h incubations was aimed to determine comparatively the gas production kinetics of SBM and GM. The gas production kinetics and the ruminal digestibility and fermentation of the fattening diet, containing different proportions of SBM and GM, were also studied by the incubations of 144-h and 24-h in the second and last experiments, respectively. The results of the first kinetic experiment indicated a higher asymptote of gas production (a), half time to asymptote of gas production (T1/2) and metabolizable energy (ME) and a lower fractional rate of gas production (µ) for SBM than GM (P <0.001). Replacing SBM with GM had no effect on gas production kinetics of the fattening diet at any substitution levels in the second kinetic experiment (P>0.05). However, the gas produced after 24-h of incubation (GP24), in vitro true dry mater degradability (IVTDMD), in vitro true organic matter degradability (IVTOMD), partitioning factor (PF), microbial biomass production (MBP) and total volatile fatty acids (TVFA) concentration increased with D2 compared to D1 and D3 in the last experiment. The ammonia concentration decreased with D2 and D3 compared to D4 (P<0.05), nevertheless, the ruminal volatile fatty acids (VFA) pattern was not affected by the treatments (P>0.05). These results demonstrated that the protein from SBM might been replaced by that from GM in fattening diets for lambs at the levels up to 67%, but the 33% substitution is recommended because of its beneficial effects on ruminal digestibility and fermentation. [ABSTRACT FROM AUTHOR]

The article discusses a study to determine the effect of protein and methionine levels on jejunal and magnum molecular aspects, blood parameters, bone mechanical properties and performance of laying hens. Topics discussed include increase in egg production, egg weight, and egg mass with methionine level, effects on jejunal deoxyribonucleic acid concentration, blood parameters thyroxine, and low density lipoprotein by different levels of methionine and protein, and RNA:DNA ratio in jejunum.

Serum level of zinc, copper, β-carotene, vitamin A, and concentrations of Zn and Cu in hoof of 97 multiparous Holstein dairy cows with different locomotion scores (LSs) were evaluated. Simultaneously, Zn and Cu concentrations of close up, fresh and high yielding cattle rations were 77, 94, 75 and 31, 28, 22 ppm, respectively. Based on LSs, despite normal serum copper levels in all three groups, with increasing degree of lameness serum and hoof Cu concentrations of the severe lame group were significantly lower than healthy and moderate lame groups (P=0.0178) and (P=0.0002), respectively. Serum β-carotene and vitamin A level of the three groups were sub-optimal. Significant negative correlations were observed between LSs with serum vitamin A level (r=-0.246, P=0.0145), LSs with hoof Cu concentration (r=-0.323, P=0.0150) and serum Zn concentration and Cu (r=-0.281, P=0.032). The results suggest that the deterioration of hoof tissue may be associated with reduced copper hoof content. Our findings demonstrated that lame group was at risk of subclinical vitamin A deficiency, which could be established from the healthy stages. Possibly, excess consumption of Zn could conflict with Cu absorption and utilization. Furthermore, vitamin A supplementation may have assisted in reduction of lameness in experimental animals. In conclusion, the serum and hoof concentrations and dietary intake of copper, zinc and vitamin A can have an impact on degrees of lameness and their interactions should be considered. [ABSTRACT FROM AUTHOR]

Some factors affecting crude protein balance (CPB), as a measure of efficiency, were studied using 2824 records of 501 lactating Holstein cows. The CPB (kg d-1) was calculated as crude protein (CP) intake (kg) minus CP yield (kg). Two different statistical methods including principal components (PCs) and general linear model analyses were used to study the effects of different factors. Crude protein balance had a moderate correlation with PCs 1 (-0.206), 2 (0.318) and 3 (-0.281), which accounted for 65.6% of total variations. Age, parity, lactation stage, pregnancy stage, dry matter intake (DMI), milk yield (MY), fat corrected milk yield (FCM), milk fat percentage (F%), milk lactose percentage (L%), milk fat yield (FY), milk protein yield (PY), milk lactose yield (LY), dietary levels of net energy for lactation (NEL), CP, ruminally undegradable protein (RUP), neutral detergent fiber (NDF) and ether extract (EE) and income over feed cost (IOFC) were correlated to CPB, at least, in one of PCs 1, 2 or 3. In general, linear model analysis CPB was significantly affected by parity and lactation stage and had significant partial linear regression coefficients on DMI (kg d-1), F%, FY (kg d-1), PY (kg d-1), NEL (Mcal kg-1) and dietary levels of CP (%), RUP (%), NDF (%) and EE (%). The quadratic partial regression coefficients of CPB on NEL, CP, RUP and NDF were also significant. The estimates for optimum dietary levels of NEL, CP and RUP for minimizing CPB in the studied population were 1.49 Mcal/kg, 11.29% and 7.58%, respectively. In comparison to NRC's estimates, it seems that, more NEL, RUP and NDF and less CP are needed to minimize protein balance in lactating dairy cows. [ABSTRACT FROM AUTHOR]

The article presents an abstract of the research paper "Performance and egg quality of laying hen fed different sources of zinc," by A.A. Saki and colleagues.

Background: Aflatoxins are fungal secondary metabolites negatively affecting ruminant performance; however, little information is available on their impact on rumen fermentation., Aims: This study aimed at determining the effects of different concentrations of aflatoxin B1 (AFB1) from Aspergillus flavus on in vitro gas production and ruminal fermentation parameters using two experiments (Exp.)., Methods: In Exp. 1, two concentration ranges (0, 0.5, 1, and 1.5 µg/ml of rumen inoculum as low and 0, 5, and 10 µg/ml as high concentration ranges) were used to evaluate AFB1 effect on gas production kinetics using 96-h incubations. In Exp. 2, only the high concentration range was used to investigate AFB1 effects on ruminal fermentation parameters using 24-h incubations., Results: In the low concentration range, the half-time of asymptotic gas production (T 1/2 ) increased and the fractional rate of gas production (µ) decreased linearly with AFB1 dosage (P<0.05). However, in the high concentration range, the asymptotic gas production (A) and T 1/2 decreased; and the lag time (L) and "µ" increased linearly (P<0.001) by increasing the concentrations of AFB1. In Exp. 2, dry matter (DM) and organic matter (OM) disappearance, microbial biomass (MB) and total volatile fatty acids (TVFA) concentrations were depressed, but pH and ammonia-N concentration increased (P<0.01) by increasing the concentrations of AFB1. The pattern of rumen volatile fatty acids (VFAs) was also modified by AFB1, as the propionate proportion increased at the expense of acetate., Conclusion: Aflatoxin B1 had an adverse effect on in vitro ruminal fermentation parameters in high concentration ranges (5 and 10 µg/ml).

Zinc (Zn) is an essential element in the growth of all animals and plays structural and catalytic roles in many enzymes and functional proteins. Two completely randomized trials were conducted to evaluate the effects of different sources of zinc on performance, nutrient digestibility, blood mineral profile, and antioxidant enzyme activities in male growing lambs on a barley-based diet. The first trial was conducted for 70 days and consisted of 30 lambs (30.8 ± 2.8 kg mean body weight, 4-5 months of age) which were randomly allocated to five treatments consisting of a basal diet (19.72 mg Zn/kg DM), or the basal diet supplemented with 30 mg Zn/kg DM, added as either zinc-sulfate (ZnSulf; inorganic), zinc-methionine (ZnMet), zinc-proteinate (ZnProt) or zinc-glycinate (ZnGly). For the second trial, to measure the effects of dietary Zn on nutrient digestibility, four lambs from each group of the first experiment were randomly allocated to individual digestibility cages for 12 days (first 7 days as an adaptation period followed by 5 days of sample collection). Among the groups, dietary Zn supplementation above basal level significantly improved average daily gain, average daily feed intake, feed/gain ratio, and superoxide dismutase activity of red blood cells (P < 0.05). Glutathione peroxidase activity of lambs supplemented with organic Zn was significantly (P < 0.05) higher than inorganic and control groups. At the end of the trial, the concentration of plasma Zn, tri-iodothyronine (T3), thyroxine (T4), and the activity of alkaline phosphatase was increased (P < 0.05) in all groups receiving Zn as compared with controls (P < 0.05). In addition, thyroxine level in animals supplemented with Zn-methionine and Zn-proteinate was greater than in animals receiving Zn-glycine and Zn-sulfate. The results of the second trial revealed that the supplementation with Zn-methionine and Zn-proteinate increased the digestibility of crude protein (CP) and acid detergent fiber (ADF) compared to groups supplemented with Zn sulfate and control (P < 0.05). All organic sources of Zn improved organic matter (OM) digestibility compared to inorganic and control (P < 0.05). Results indicated that, regardless of source, supplementation of Zn in growing lambs improved growth performance, blood antioxidants, and thyroid hormone levels. Furthermore, Zn-methionine and Zn-proteinate supplementation appeared to improve the digestibility of CP, OM, and ADF more effectively than Zn-sulfate.

The aim of this study was to determine the effect of the supplementation of a slow-release bolus of zinc (Zn), selenium (Se), and cobalt (Co) at late gestation (6 week prepartum) on performance and some blood metabolites of Mehraban ewes and their lambs until weaning. Seventy pregnant ewes, 6 weeks prior to expected lambing, were randomly divided into two groups (35 heads each) including (1) control group and (2) slow-release bolus group. Blood samples of ewes were obtained on day 10 prepartum and 45 and 90 days postpartum, and milk samples were collected on day 45. Blood samples of lambs were collected on days 10, 45, and 90. Body weight at birth and weaning and average daily gain were higher and percentage of mortality and white muscle disease rate were lower in lambs whose mothers were given a bolus (P < 0.05). Slow-release bolus administration increased serum alkaline phosphatase and whole blood glutathione peroxidase activity, plasma concentrations of Zn, Se, and vitamin B 12 in ewes and their lambs (P < 0.05). In addition, serum creatine phosphokinase activity of lambs whose mothers were given bolus was lower (P < 0.05). Serum concentration of T 3 in bolus given ewes and their lambs was higher (P < 0.05) and serum T 4 concentration was lower (P < 0.05). Zinc, Se, and vitamin B 12 concentrations in milk were significantly higher in treated ewes (P < 0.05). Obtained results showed that maternal supplementation of zinc, selenium, and cobalt as slow-release ruminal bolus in late pregnancy improved some mineral status of ewes and their lambs until weaning and led to higher body weights of lambs at weaning.

The objective of this experiment was to follow the time-course changes of the milk fatty acids (FA) and particularly conjugated linoleic acid (CLA), n-3, and n-6 FA in response to feeding whole rolled safflower seed (SS). Eighteen cows were blocked by milk production, days in milk, and parity, and randomly assigned to 1 of 3 diets by replacing whole cottonseed with SS. The control diet contained no SS (SS0), whereas the other diets contained 3% of dry matter as SS (SS3) or 6% SS (SS6). The study was conducted for 8 wk. Cows fed SS produced more milk than SS0, with SS3 producing more milk than SS6, but without a change in milk fat yield or milk fat %. Except for C8:0 FA, changes in milk FA were not observed until the third week of SS feeding. The C8:0 began decreasing during wk 1 of SS feeding and continued to decline to wk 8. Short-chain FA (C6:0 to C11:0) and medium-chain FA (C12:0 to C16:1) concentrations decreased in milk when cows were fed SS, whereas long-chain FA (C18:0 and higher) increased after wk 3. The milk long-chain FA increased from wk 3 until wk 5 and then reached a plateau with little difference between SS3 and SS6, whereas the short-chain FA decreased more in milk from cows fed SS6 than SS3. Total CLA increased slightly less than 5× in milk from cows fed SS compared with SS0. Over the same time frame, n-3 FA declined and n-6 FA increased in the milk from cows fed SS, with no difference between SS3 and SS6. This study indicated that SS fed at 3 and 6% of DM had the potential to increase milk production and the CLA in milk, but with a corresponding increase in n-6 FA., (Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

This experiment was conducted to study the effects of different sources of zinc (Zn) on blood metabolites and balances of some minerals in lambs. In the first part, 20 6-7-month-old lambs were randomly allotted to four treatments including (1) basal diet containing 22.47 mg Zn/kg DM without supplementary Zn (control), (2) basal diet + 40 mg Zn/kg DM as ZnSO4 (ZnSO4 40), (3) basal diet + 20 mg Zn/kg DM as Zn-proteinate (Zn-Pro 20), and (4) basal diet + 40 mg Zn/kg DM as Zn-proteinate (Zn-Pro 40). Blood samples were taken on days 0, 28, and 65 before morning feeding. In the second part, four lambs from each treatment were randomly transferred to metabolic cages to evaluate the effects of different sources of Zn on N, Zn, Fe, and Cu retentions. This trial consisted of 18 days, with the first 12 days as the adaptation period followed by 6 days of sample collection. The results of this study showed that the source of Zinc had no significant effect on the analyzed parameters. Average daily gain and feed efficiency were improved by Zn supplementation (P < 0.05). Daily feed intake, plasma glucose, Fe and Cu concentrations, serum total antioxidant capacity, red blood cell count, packed cell volume, and hemoglobin concentration did not differ significantly between treatments (P > 0.05). Plasma Zn concentration, alkaline phosphatase (ALP) and bone-specific alkaline phosphatase (BALP) activity, and white blood cell and lymphocyte count differed significantly between control and Zn-supplemented groups (P < 0.05) as Zn supplementation improved these parameters. Nitrogen, Fe, and Cu retentions did not differ between treatments (P > 0.05). Zinc retention showed a significant difference between control and Zn-supplemented groups (P < 0.05), but there were no significant differences among the Zn-supplemented groups. The results of this study show that Zn supplementation improved performance and zinc retention in lambs. However, there were no significant differences between zinc sources used in this study.

This present study was conducted to evaluate the effects of dietary inclusion of 4, 8 and 12 g kg(-1) phytogenic feed additives mixture on performance, egg quality, ovary parameters, serum biochemical parameters and yolk trimethylamine level in laying hens. The results of experiment have shown that egg weight was increased by supplementation of 12 g kg(-1) feed additive whereas egg production, feed intake and feed conversion ratio (FCR) were not significantly affected. There were no significant differences in egg quality parameters by supplementation of phytogenic feed additive, whereas yolk trimethylamine level was decreased as the feed additive level increased. The sensory evaluation parameters did not differ significantly. No significant differences were found in serum cholesterol and triglyceride levels between the treatments but low- and high-density lipoprotein were significantly increased. Number of small follicles and ovary weight were significantly increased by supplementation of 12 g kg(-1) feed additive. Overall, dietary supplementation of polyherbal additive increased egg weigh, improved ovary characteristics and declined yolk trimethylamine level.

Two trials were conducted in a 2 × 2 + 1 factorial arrangement based on a completely randomized design to evaluate the effects of different sources of selenium (Se) on performance, blood metabolites, and nutrient digestibility in male lambs on a barley-based diet. The first trial lasted for 70 days and consisted of 30 lambs (35.6 ± 2.6 kg mean body weight, about 4-5 months of age) which were randomly allotted to five treatments including: (1) basal diet (containing 0.06 mg Se/kg DM; control) without supplementary Se, (2) basal diet + 0.20 mg/kg Se as sodium selenite (SeS 0.20), (3) basal diet + 0.40 mg/kg Se as sodium selenite (SeS 0.40), (4) basal diet + 0.20 mg/kg Se as selenium yeast (SeY 0.20), and (5) basal diet + 0.40 mg/kg Se as selenium yeast (SeY 0.40). For the second trial, four lambs from each group of experiment 1 were randomly allocated to individual metabolic cages for 14 days to measure the effects of dietary Se on nutrient digestibility. The results revealed that there were no significant differences for average daily gain, average daily feed intake, feed/gain ratio, hematological parameters (packed cell volume, red blood cell, white blood cell, and hemoglobin values), serum total protein, albumin, globulin, aspartate amino transferase, alkaline phosphatase, and creatine phosphokinase due to supplementation of different amounts and sources of Se in lambs. Dietary Se supplementation significantly improved (P < 0.001) glutathione peroxidase activity in blood. Furthermore, at the end of the trial, serum tri-iodothyronine (T3) amount also increased (P < 0.05), while serum thyroxine (T4) amount decreased (P < 0.05). Digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber increased (P < 0.05) by Se yeast supplementation. It may be concluded that supplementation of Se in lambs had no significant effect on performance and blood hematology, but increased blood glutathione peroxidase activity and serum T3 amount and decreased serum T4 amount as compared to non-supplemented control lambs. Furthermore, Se yeast improved nutrient digestibility in lambs.