42 research outputs found
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The effect of rearing system and cooking method on the carnosine and anserine content of poultry and game meat
Poultry meat has been shown to be a rich source of carnosine and anserine (CRC) but little is known of the effects of bird species and the system under which it is reared have on the concentrations of CRC. Retail samples of breast meat from conventional chicken, free range chicken and pheasant, and breast meat from wild caught pheasant were procured and subjected to five different cooking methods: frying, grilling, boiling, microwaving and roasting. CRC were greater in uncooked pheasant than chicken (P< 0.05) and greater in free range than conventionally reared chicken (P<0.05). There were no differences in CRC between retail and wild caught pheasant. Cooking method affected CRC content; boiling and microwaving resulted in lower CRC contents than grilling, roasting or frying (P < 0.05). Pheasant is a richer source of CRC than conventionally reared chicken, although free range chicken produces meat of similar CRC content to pheasant
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Effects of dietary selenium supplementation on tissue selenium distribution and glutathione peroxidase activity in Chinese Ring Necked Pheasants
The objective of this study was to determine the concentration of total selenium (Se) and the proportions of total Se comprised as selenomethionine (SeMet) and selenocysteine (SeCys) in the post mortem tissues of female pheasants (Phasianus Colchicus Torquator) offered diets containing graded additions of selenized enriched yeast (SY) or sodium selenite (SS). Thiobarbituric acid reactive substances (TBARS) and tissue glutathione peroxidase (GSH-Px) activity of breast (Pectoralis Major) were assessed at 0 and 5 d post-mortem. A total of 216 female pheasant chicks were enrolled onto the study. 24 birds were euthanased at the start of the study and samples of blood, breast muscle, leg muscle (Peroneus Longus and M. Gastrocnemius), heart, liver, kidney and gizzard collected for determination of total Se. Remaining birds were blocked by live weight and randomly allocated to one of four dietary treatments (n=48 birds/treatment) that either differed in Se source (SY vs. SS) or dose (Con [0.2 mg total Se/kg], SY-L and SS-L [0.3 mg/kg total Se as SY and SS, respectively], and SY-H [0.45 mg total Se/kg]). Following 42 and 91 days of treatment 24 birds/treatment were euthanased and samples of blood, breast muscle, leg muscle, heart, liver, kidney and gizzard retained for determination of total Se and the proportion of total Se comprised as SeMet or SeCys. Whole blood GSH-Px activity was determined at each time point. Tissue GSH-Px activity and TBARS were determined in breast tissue at the end of the study. There were positive responses (P<0.001) in both blood and tissues to the graded addition of SY to the diet but the same responses were not apparent in the blood and tissues of selenite supplemented birds receiving comparable doses. Although there were differences between tissue types in the distribution of SeMet and SeCys there were few differences between treatments. There were effects of treatment on erythrocyte GSH-Px activity (P = 0.012) with values being higher in treatments SY-H and SS-L when compared to the negative control and treatment SY-L. There were no effects of treatment on tissue GSH-Px activity which is reflected in the overall lack of any treatment effects on TBARS
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Bio-potency of Selenium and Protein supplements on reproductive traits of male rabbits: a review
The inclusion of both micro and macro nutrients has been investigated in the field of animal production
and research, expressing promising effects. Perhaps incorporation of both dietary Selenium and
Protein at appropriate levels has presented a tremendous impact on productive and reproductive
performance of livestock, particularly in tropical environments. However the efficiency of growth and
normal physiological functions depends on composition and bioavailability of these nutrients in the
diets. These effects could be mediated via the hypothalamic- pituitary-axis in regulating thyroid and
growth hormones that have been shown to affect differentiation and proliferation of somatic and
gonadal cells. However, under high ambient temperature and humidity the efficiency of feed utilization
would be compromised and reproductive function deteriorates, as a consequence of impairment in
appetite and subsequent oxidative stress due to hyperthermia. In addition consequent effects of
thermal stress may also involved activation and or inhibition of the hypothalamus-pituitary liver axis.
Apparently rabbits require a high protein diet in order to compensate for low feed intake under hot
climatic conditions; and dietary selenium as a potent antioxidant. Therefore dietary protein and
selenium supplementation at appropriate level of inclusion apparently have the potential to improve
male rabbit general performance at reasonable cost
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Selenium persistency and speciation in the tissues of lambs following the withdrawal of dietary high-dose selenium-enriched yeast
The objective was to determine the concentration of total selenium (Se) and the proportion of total Se comprised as selenomethionine (SeMet) and selenocysteine (SeCys) in post mortem tissues of lambs in the six weeks period following the withdrawal of a diet containing high dose selenized yeast (SY), derived from a specific strain of Saccharomyces cerevisae CNCM (Collection Nationale de Culture de Micro-organism) I-3060. Thirty Texel x Suffolk lambs used in this study had previously received diets (91 days) containing either high dose SY (HSY; 6.30 mg Se/kg DM) or an unsupplemented control (C; 0.13 mg Se/kg DM). Following the period of supplementation all lambs were then offered a complete pelleted diet, without additional Se (0.15 mg Se/kg DM), for 42 days. At enrollment and 21 and 42 days later, five lambs from each treatment were blood sampled, euthanased and samples of heart, liver, kidney and skeletal muscle (Longissimus Dorsi and Psoas Major) tissue were retained. Total Se concentration in whole blood and tissues was significantly (P < 0.001) higher in HSY lambs at all time points that had previously received long term exposure to high dietary concentrations of SY. The distribution of total Se and the proportions of total Se comprised as SeMet and SeCys differed between tissues, treatment and time points. Total Se was greatest in HSY liver and kidney (22.64 and 18.96 mg Se/kg DM, respectively) and SeCys comprised the greatest proportion of total Se. Conversely, cardiac and skeletal muscle (Longissimus Dorsi and Psoas Major) tissues had lower total Se concentration (10.80, 7.02 and 7.82 mg Se/kg DM, respectively) and SeMet was the predominant selenized amino acid. Rates of Se clearance in HSY liver (307 µg Se/day) and kidney (238 µg Se/day) were higher compared with HSY cardiac tissue (120 µg Se/day) and skeletal muscle (20 µg Se/day). In conclusion differences in Se clearance rates were different between tissue types, reflecting the relative metabolic activity of each tissue, and appear to be dependant upon the proportions of total Se comprised as either SeMet or SeCys
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Intake, growth and meat quality of steers given diets based on varying proportions of maize silage and grass silage
Simmental × Holstein-Friesian steers were offered four forage diets. These comprised grass silage (G); proportionately 0·67 grass silage, proportionately 0·33 maize silage (GGM); 0·33 grass silage, 0·67 maize silage ( MMG); maize silage ( M) from 424 (s.d. = 11·5) kg to slaughter at a minimum weight of 560 kg. Forages were mixed and offered ad libitum. Steers were offered 2 kg of a concentrate daily, the concentrate being formulated such that all steers had similar crude protein intakes across dietary treatments. A sample of steers was slaughtered at the beginning of the experimental period to allow the calculation of the rate of gain of the carcass and its components. Carcass dissection of a sample of steers allowed the development of a prediction equation of carcass composition based on thoracic limb dissection of all carcasses. Forage dry matter intake and live-weight gain increased linearly as maize silage replaced grass silage in the forage mixture, resulting in improvements in food conversion ratio (all P = 0·001). Killing-out proportion increased with maize silage inclusion ( P < 0·001) but fat and conformation scores did not differ significantly between diets. However, increasing maize inclusion in the diet resulted in a greater weight ( P = 0·05) and proportion ( P = 0·008) of fat in the carcass, and significant increases in internal fat deposition. The inclusion of maize led to a progressive increase in the daily gains of carcass ( P < 0·001), and significant increases in the daily gains of both fat ( P < 0·001) and lean tissue ( P < 0·001). Fat colour was more yellow in cattle given diets G and GGM than diets MMG and M ( P < 0·001) and colour intensity was lower on diet M than the other three diets ( P < 0·001). There were no significant differences in any aspects of eating quality between diets. Therefore, maize silage has the potential to reduce the time taken for finishing beef animals to achieve slaughter weight with no apparent detrimental effects on subsequent meat quality
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Selenium supplementation of lactating dairy cows: effects on milk production and total selenium content and speciation in blood, milk and cheese
Forty-multiparous Holstein cows were used in a 16-wk continuous design study to determine the effects of either selenium (Se) source, selenized yeast (SY) (derived from a specific strain of Saccharomyces cerevisiae CNCM I-3060 Sel-Plex®) or sodium selenite (SS), or inclusion rate of SY on Se concentration and speciation in blood, milk and cheese. Cows received ad libitum a TMR with 1:1 forage:concentrate ratio on a dry matter (DM) basis. There were four diets (T1-T4) which differed only in either source or dose of Se additive. Estimated total dietary Se for T1 (no supplement), T2 (SS), T3 (SY) and T4 (SY) was 0.16, 0.30, 0.30 and 0.45 mg/kg DM, respectively. Blood and milk samples were taken at 28 day intervals and at each time point there were positive linear effects of SY on Se concentration in blood and milk. At day 112 blood and milk Se values for T1-T4 were 177, 208, 248, 279 ± 6.6 and 24, 38, 57, 72 ± 3.7 ng/g fresh material, respectively and indicate improved uptake and incorporation of Se from SY. While selenocysteine (SeCys) was the main selenised amino acid in blood its concentration was not markedly affected by treatment, but the proportion of total Se as selenomethionine (SeMet) increased with increasing inclusion rate of SY. In milk, there were no marked treatment effects on SeCys content, but Se source had a marked effect on the proportion of total Se as SeMet. At day 112 replacing SS (T2) with SY (T3) increased the SeMet concentration of milk from 36 to 111 ng Se/g and its concentration increased further to 157 ng Se/g as the inclusion rate of SY increased further (T4) to provide 0.45 mg Se/kg TMR. Neither Se source nor inclusion rate effected the keeping quality of milk. At day 112, milk from T1, T2, and T3 was made into a hard cheese and Se source had a marked effect on total Se and the proportion of total Se comprised as either SeMet or SeCys. Replacing SS (T2) with SY (T3) increased total Se, SeMet and SeCys content from 180 to 340 ng Se/g, 57 to 153 ng Se/g and 52 to 92 ng Se/g, respectively.
Key words: dairy cow, milk and cheese, selenomethionine, selenocysteine, milk keeping qualit
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Effect of liquid feeding at different water-to-feed ratios on the morphological adaptations in the gastrointestinal tract of growing pigs
The study examined the morphology of the gastro-intestinal tract (GI) of growing pigs offered dry feed or liquid feed with differing water-to-feed ratios. Twenty male pigs were randomly allocated to one of four treatment groups; treatments included a standard dry pelleted diet (D) or the same diet soaked in water at a feed-to-water ratio of 1:1.5 (T1:1.5), 1:3 (T1:3) or 1:3 with the addition of lactic acid to adjust the feed to pH 4 (T1:3[4]). Animals were humanely slaughtered after 6 weeks to enable sampling and histological examination (light, scanning electron (LSEM) and binocular dissection microscope) of the GI tract. Samples were taken at the 2% position (duodenum), the 20% position and 50 % position (jejunum) along the small intestines (SI). Liquid-fed pigs were heavier (P < 0.05) and exhibited improved feed conversion ratios (FCR) when compared to D animals. These differences in live weight were attributed to alterations in the weight and volume of the stomach and SI, which were also heavier and larger in liquid-fed pigs (P < 0.05). However, these differences were no longer apparent when intestinal weights and stomach volumes were adjusted for animal live weight. Differences in villus type between the treatments were noted throughout, particularly in the duodenum and proximal jejunum sections. Mean villus height was taller in all liquid-fed animals when compared to D pigs (P<0.05); this was particularly apparent in T1:1.5 and T1:3[4] pigs. There were no differences in crypt depths between treatment groups at the 2% and 20 % positions, but at the 50 % position the T1:1.5 group crypts were deeper (P < 0.05) than those in the D and T1:3 pigs. It is concluded that liquid feeding alters the morphology of the GI tract, which may in part, explain the differences in growth performance observed between liquid and D fed pigs. The inclusion of organic acid in the diets of T1:3[4] pigs appeared to exert an effect on villus height and crypt depth when compared to those pigs receiving the T1:3 diet
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Effect of milk type and processing on iodine concentration of organic and conventional winter milk at retail: implications for nutrition
Milk is the largest source of iodine in UK diets and an earlier study showed that organic summer milk had significantly lower iodine concentration than conventional milk. There are no comparable studies with winter milk or the effect of milk fat class or heat processing method. Two retail studies with winter milk are reported. Study 1 showed no effect of fat class but organic milk was 32.2% lower in iodine than conventional milk (404 vs. 595 μg/L; P < 0.001). Study 2 found no difference between conventional and Channel Island milk but organic milk contained 35.5% less iodine than conventional milk (474 vs. 306 μg/L; P < 0.001). UHT and branded organic milk also had lower iodine concentrations than conventional milk (331 μg/L; P < 0.001 and 268 μg/L: P < 0.0001 respectively). The results indicate that replacement of conventional milk by organic or UHT milk will increase the risk of sub-optimal iodine status especially for pregnant/lactating women
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Supplementing sow diets with palm oil during late gestation and lactation; effects on milk production, sow hormonal profiles, and growth and development of her offspring
The supplementing of sow diets with lipids during pregnancy and lactation has been shown to reduce sow condition loss and improve piglet performance. The aim of this study was to determine the effects of supplemental palm oil (PO) on sow performance, plasma metabolites and hormones, milk profiles, and pre-weaning piglet development. A commercial sow ration (C) or an experimental diet supplemented with 10% extra energy in the form of PO, were provided from d 90 of gestation until weaning (24-28 d post-partum) in two groups of 8 multiparous sows. Gestation length of PO sows increased by 1 day (P<0.05). Maternal body weight changes were similar throughout the trial, but loss of backfat during lactation was reduced in PO animals (C: -3.6±0.8 mm; PO: -0.1±0.8 mm; P<0.01). Milk fat was increased by PO supplementation (C d3: 8.0±0.3% fat; PO d3: 9.1±0.3% fat; C d7: 7.8±0.5% fat; PO d7: 9.9±0.5% fat; P<0.05) and hence milk energy yield of PO sows was also elevated (P<0.05). The proportion of saturated fatty acids was greater in colostrum from PO sows (C: 29.19±0.31 g/100g of fat; PO: 30.77±0.36 g/100g of fat; P<0.01). Blood samples taken on 105 days of gestation, within 24 hours of farrowing, day 7 of lactation and at weaning (28 ± 3 days post-farrowing) showed there were no differences in plasma concentrations of triacylglycerol, non-esterified fatty acids, insulin or insulin-like growth factor-1 throughout the trial. However, circulating plasma concentrations of both glucose and leptin were elevated during lactation in PO sows (P< 0.05 and P<0.005, respectively) and thyroxine was greater at weaning in PO sows (P < 0.05). Piglet weight and body composition were similar at birth, as were piglet growth rates throughout the pre-weaning period. Seven days after birth, C piglets contained more body fat, as indicated by their lower fat free mass per kg (C: 66.4±0.8 arbitrary units/kg; PO: 69.7±0.8 arbitrary unit/kg; P<0.01), but by day 14 of life this situation was reversed (C: 65.8±0.6 arbitrary units/kg; PO: 63.6±0.6 arbitrary units/kg; P<0.05). Following weaning, PO sows exhibited an increased ratio of male to female offspring at their subsequent farrowing (C: 1.0±0.3; PO: 2.2±0.2; P<0.05). We conclude that supplementation of sow diets with PO during late gestation and lactation appears to increase sow milk fat content and hence energy supply to piglets. Furthermore, elevated glucose concentrations in the sow during lactation may be suggestive of impaired glucose homeostasis
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Holstein calves' preference for potential physical enrichment items on different presentation schedules
Impoverished housing environments are thought to prevent motivated behaviors and may result in frustration. We first aimed to investigate an effective physical enrichment protocol to improve dairy calves' welfare and initially determine their use of various items. Thereafter, we aimed to determine dairy calves' preference for and ways of interacting with various items, and whether this was influenced by social housing. In experiment 1, at 21 ± 3 d of age, 27 individually housed calves were assigned alternately into 1 of 3 treatments: control (CON, no additional items), rotating enrichment (RE, one item each week on a rotating presentation schedule), and fixed enrichment (FE, 4 types of item at the same time). The items were stationary brushes, ropes, springs, nets filled with strawberry-scented hay, and dry teats. Calves' behaviors were observed from 4 to 7 wk of age using focal observations after feeding, followed by instantaneous scan sampling. Their behavioral responses to a novel object were assessed at 43 ± 1 d of age. In the instantaneous scans, calves in FE tended to interact with items more often than calves in RE. Calves in RE and FE expressed less non-nutritive oral behavior than those in CON. Latency to touch novel objects did not differ significantly between treatments. Calves in RE and FE interacted with nets filled with strawberry-scented hay more often than with other items in instantaneous scans. In experiment 2, 24 calves were assigned alternately into 8 individual pens and 8 pair pens at 2 d of age. All pens were provided with a stationary brush, plastic chain, net filled with strawberry-scented hay, and dry teat. Calves' behaviors were collected from 2 to 5 wk of age using instantaneous scan sampling. Calves interacted with nets filled with strawberry-scented hay more often than with other items. Pair housing reduced calves' interactions with items compared with individual housing. Individually and pair-housed calves' frequencies of overall interaction with items varied with time of day, with frequencies increasing to peaks at 0700, 1500, and 1900 h. Calves showed scratching, sniffing, sucking, butting, and hay intake toward nets filled with strawberry-scented hay and showed the first 3 behaviors toward stationary brushes, plastic chains, and dry teats. In conclusion, dairy calves are likely to prefer a fixed multi-item enrichment presentation schedule over a rotating schedule with a single enrichment item presented at one time. For the fixed multi-item enrichment presentation schedule, items were used more in individual pens than in pair pens, and a diurnal pattern was observed for use of the items. Nets filled with scented hay might be the most multifunctional and attractive item of the items tested