Forty-eight 19-wk-old Bovan White laying hens were fed 1 of 5 diets containing either hemp seed (HS) or hemp seed oil (HO). The level of HO was 4, 8, or 12%, whereas the level was 10 or 20% for the HS. A set of 8 birds fed wheat-, barley-, and corn oil-based diets served as the control. Performance was monitored over 12 wk. Average hen-day egg production was not affected upon feeding of either HS or HO diets. Egg weight was higher than that of the controls for hens consuming the 20% HS diet (P < 0.05). Feed intake was lower than that of the controls for birds consuming the 4% HO diet but similar across other treatments. Final BW were not affected by diet, with the exception of being lower than that of the controls (P < 0.05) in hens consuming the 12% HO diet. The total egg yolk n-3 fatty acid content increased linearly (P < 0.05) with increasing dietary α-linolenic acid provision with the HS- or HO-based diets. A quadratic response (P < 0.05) was observed for docosahexaenoic acid levels in egg yolk in response to increasing dietary α-linolenic acid supply. The expression of hepatic fatty acid desaturase 1 and 2, key genes for the desaturation of long-chain polyunsaturated fatty acids, was significantly decreased (50-60% of controls; P < 0.05) as a result of feeding HS or HO diets. Based on the results from the current study, the inclusion of the hemp products HS or HO in the diets of laying hens up to a maximum level of 20 and 12%, respectively, does not adversely effect the performance of laying hens and leads to the enrichment of the n-3 fatty acid content of eggs.

This study was conducted to determine the effects of hemp oil (HO) and HempOmega (HΩ), an equivalent product to HO, on performance and tissue fatty acid profile of layers and broiler chickens in two separate experiments. In the first experiment, forty 19-wk old Lohmann white laying hens were randomized to 1 of 5 dietary treatments, either a control diet or a control diet supplemented with 4 or 8% hemp oil provided by HO or HΩ, for a period of 6 wk (n = 8/diet). In experiment 2, 150-day-old mixed-sex (75 male; 75 female) Ross 308 chicks were randomly allocated into 5 dietary treatments, a control diet or a control diet supplemented with either 3 or 6% hemp oil provided by HO or HΩ, each with six replicates of 5 chicks for a 21-d feeding period. Performance of layers and broilers was not affected by dietary treatments. Animals provided with either HO or HΩ diets had greater total n-3 polyunsaturated fatty acids (PUFAs), alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) in egg yolks, thighs, and breasts compared to the control diet (P < 0.01), and monounsaturated fatty acids (MUFAs) content of egg yolks and thighs decreased (P < 0.05). The levels of total n-6 PUFAs, linoleic acid (LA), or arachidonic acid (ARA) of the egg yolk and meat were generally not affected by dietary supplementation with HO or HΩ, but gamma-linolenic acid (GLA) was notably increased (P < 0.01). The current data show that inclusion of hemp oil up to 8% in layer diets and 6% in broiler diets provided by HO or HΩ does not negatively affect overall performance of birds and results in the enrichment of n-3 PUFAs and GLA in eggs and meat.

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Zinc (Zn) is an essential nutrient that is required in humans and animals for many physiological functions, including immune and antioxidant function, growth, and reproduction. The present study was performed to investigate the effects of three Zn levels, including Zn adequate (35.94 mg/kg, as a control), Zn deficiency (3.15 mg/kg), and Zn overload (347.50 mg/kg) in growing male rats for 6 wk. This allowed for evaluation of the effects that these Zn levels might have on body weight, organ weight, enzymes activities, and tissues concentrations of Zn and Cu. The results showed that Zn deficiency has negative effects on growth, organ weight, and biological parameters such as alkaline phosphatase (ALP) and Cu-Zn superoxide dismutase (Cu-Zn SOD) activities, whereas Zn overload played an effective role in promoting growth, improving the developments of organs and enhancing immune system. Hepatic metallothionein (MT) concentration showed an identical increase tendency in rats fed both Zn-deficient and Zn-overload diets. The actual mechanism of reduction of Cu concentration of jejunum in rats fed a Zn-overload diet might involve the modulation or inhibition of a Cu transporter protein by Zn and not by the induction of MT.

The reduced folate carrier (RFC) has been postulated to be a major entity for folate transport activity in humans and other mammals. However, there are limited reports of the importance of RFC in an avian system. In the current study, therefore, the molecular cloning and tissue distribution of RFC, as well as the effect of dietary folate supplementation on the expression of this transporter, were investigated in the chicken. Shaver White laying hens (n=8 per diet) received 3 wheat-based diets containing the following: 1) no supplemental folate, 2) folic acid (10.00 mg/kg), or 3) 5-methyltetrahydrofolate (11.30 mg/kg) for 21 d. The mRNA expression levels were analyzed by quantitative real-time PCR. The results showed that the cloned partial RFC cDNA containing the full coding region from duodenum was 99% homologous to the reference gene available in GenBank. A broad expression profile of RFC transcripts was observed, with RFC mRNA detected in the brain, liver, kidney, spleen, lung, intestine, ovary, and testis, as well as other tissues. Real-time PCR analysis revealed that no significant differences (P>0.05) due to diet were found in the mRNA levels of RFC in the duodenum and cecum. However, compared with the basal diet, jejunal mRNA levels of RFC were decreased (P<0.05) in hens fed with the 5-methyltetrahydrofolate diet, but the reduction did not reach significance (P=0.077) in the hens fed the folic acid diet. Overall, the current study demonstrated that the RFC cDNA containing the full coding region was successfully cloned from the duodenum of laying hens. The wide tissue distribution of RFC transcripts is suggestive of an important role of RFC in the process of folate transport in the chicken. Moreover, dietary folate supplementation could downregulate the jejunal mRNA expression of RFC. Such findings will lay the foundation of future work involving the RFC in avian systems, including laying hens.

The present study was conducted to investigate the effects of dietary folic acid (FA) supplementation on performance, serum biochemical indices, and mRNA abundance of intestinal folate transporters in young and older laying hens after acute lipopolysaccharide (LPS) challenge. Two experiments were conducted separately involving 48 Shaver White young laying hens (24 wk of age) in experiment 1 and 48 Shaver White older laying hens (58 wk of age) in experiment 2. Birds were fed 2 diets in a complete randomized design. The diets were wheat-soybean meal based, with or without supplemental 4 mg of FA/kg of diet. Birds were fed for 8 wk, during which time feed consumption and egg production were monitored. At the end of each feeding experiment, 6 hens from each dietary treatment were injected intravenously with 8 mg/kg of BW of either Escherichia coli LPS or sterile saline. Four hours after injection, blood and intestinal samples were collected for further analysis. Compared with the control, dietary FA supplementation increased egg weight and egg mass and decreased serum glucose levels in the young laying hens, and reduced serum uric acid in the older laying hens (P < 0.05). Relative to saline injection, plasma homocysteine, serum calcium, and phosphorus levels were found to be lower in both young and older laying hens after LPS challenge (P < 0.05). Other serum biochemical variables and the mRNA expression of 2 folate transport genes in the small and large intestine were differentially affected by LPS challenge, and some of those responses varied with the age of the birds. Additionally, interactions between diet and LPS challenge were specifically found in the older laying hens. In summary, in addition to improving production performance, there were effects of dietary FA supplementation and its interaction with LPS challenge on biochemical constituents, and age played a role in the development of responses to diet and bacterial LPS infections.

The objectives of the current study included the characterization of the temporal changes in indices of sulphur amino acid metabolism in piglets in response to vitamin B 6 deficiency and repletion with graded levels of pyridoxine hydrochloride. In Experiment 1, 12 piglets (average initial weight 5 5.3 kg; n 5 6 per group) were fed a semi-purified diet containing either 0 (deficiency group) or 3 mg (control group) pyridoxine Á HCl/kg diet, using a pair-feeding design, for 6 weeks. Piglets consuming vitamin B 6 -deficient diets exhibited decreased average daily gains on the 4th week and feed conversion efficiency from the 4th week until the end of the trial ( P , 0.05). Plasma pyridoxal-5 0 -phosphate (PLP), in pigs consuming vitamin B 6 -deficient diets, was significantly lower than controls throughout the experiment ( P , 0.01), reaching a nadir of 14% of the control animals' value by the end of the trial. Indices of sulphur amino acid metabolism, including activities of hepatic cystathionine-b-synthase (CBS), cystathionine-g-lyase (CGL) and serine hydroxymethyltransferase, as well as hepatic-free cysteine concentrations were markedly decreased after 6 weeks of B 6 deficiency ( P , 0.05). Total hepatic mRNA expressions for CBS and CGL were not affected. Concurrently, hepatic-free homocysteine concentrations increased by more than eight-fold ( P , 0.01) at the end of the trial. An examination of plasma total homocysteine and cysteine concentrations revealed significant ( P , 0.05) differences between treatments, with evidence of an abrupt shift in concentrations at 3 weeks post-initiation of dietary treatments (.25-fold increase in homocysteine; halving of cysteine values). At the end of Experiment 1, vitamin B 6 deficiency significantly increased plasma methionine and serine levels, but decreased plasma glycine concentrations ( P , 0.05). In Experiment 2, 20 pigs of 14 days old (initial BW 5 5.0 kg) were subjected to a 4-week vitamin B 6 depletion protocol, based on results obtained in Experiment 1. After the depletion period and assessment of baseline status (four pigs), remaining pigs were allocated to one of four dietary vitamin B 6 repletion treatments: 0.75, 1.5, 2.25 and 3 mg/kg diet as pyridoxine Á HCl (n 5 4 per level) for 14 days. Significant dose-dependent increases in plasma PLP and cysteine, and decreases in homocysteine were observed, and these were sensitive to the duration of repletion. In conclusion, data from the current studies support the use of both plasma PLP and homocysteine as sensitive indices of vitamin B 6 status in the pig. Additionally, the observed patterns of responses in vitamin B 6 -sensitive metabolites are supportive of an inclusion level of 2.25 mg/kg diet, as pyridoxine Á HCl, in diets for young pigs.Keywords: cysteine, homocysteine, pig, sulphur amino acid, vitamin B 6 ImplicationsThe current study has provided a temporal characterization of the impact of B 6 deficiency and subsequent repletion on indices of sulphur amino acid metabolism in young pigs. The use of plasma and h...

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