Influence of dietary fat source on sow and litter performance,colostrum and milk fatty acid profile in late gestation and lactation

The objective of this study was to investigate the effects of dietary supplementation with various fat sources (3.8–3.9% of diet) during late pregnancy and lactation on the reproductive performance, fatty acids profile in colostrum, milk and serum of sow progeny. A total of 80 multiparous sows were randomly fed a control (adding no oil), palm oil (PO), fish oil (FO) or soybean oil (SO) supplemented diet from 90 days of pregnancy to weaning. Supplementation of FO increased litter size of weak piglets, compared with the control‐fed sows (P < 0.05). Dietary FO and SO supplementation, enhanced the weaning survival rate, litter weaning weight, litter weight gain and fat content in milk (P < 0.05). The highest immunoglobulin (Ig)G and IgM levels in colostrum and milk were observed in the FO group (P < 0.05). Meanwhile, the highest concentration of C22:5 (n‐3) and C22:6 (n‐3) in colostrum, milk and piglet serum was observed in the FO group (P < 0.05). Taken together, dietary inclusion of FO or SO improved growth performance of nursing piglets by increasing milk fat output, and FO consumption by sows might benefit the piglets via increasing n‐3 polyunsaturated fatty acid availability and immunoglobulins (IgG and IgM) secretion.     

Effects of epigallocatechin gallate on lipid metabolism and its underlying molecular mechanism in broiler chickens

The objective of this study was to investigate the effects of epigallocatechin gallate (EGCG) on fat metabolism and to establish the molecular mechanism of these effects in broilers. Seventy‐two 28‐day‐old male Ross 308 broiler chickens were divided into three groups with different levels of EGCG supplementation for 4 weeks: normal control (NC) group, L‐EGCG (a low‐level supplement of EGCG, 40 mg/kg body weight daily) and H‐EGCG (a high‐level supplement of EGCG, 80 mg/kg body weight daily). After 4 weeks of oral administration, EGCG significantly reduced the level of abdominal fat deposition in broilers. The serum triglycerides and low‐density lipoprotein cholesterol of chickens in H‐EGCG group were also significantly decreased compared with the NC group, and the high‐density lipoprotein cholesterol was notably increased at the same time. Moreover, the vital role of the liver and abdominal adipose tissue in lipid metabolism of poultry animals was examined through gene expression and enzyme activities related to fat anabolism and catabolism in these organs. Our data show that EGCG supplementation for 2 weeks significantly downregulated the expression of fatty acid synthesis and fat deposition‐related genes, and upregulated the expression of genes involved in fatty acid β‐oxidation and lipolysis genes. Simultaneously, the activities of hepatic fatty acid synthesis enzymes (fatty acid synthase and acetyl CoA carboxylase) were significantly decreased, and the activity of carnitine palmitoyl transferase‐1 was notably elevated. The results suggest that EGCG could alleviate fat deposition in broilers through inhibiting fat anabolism and stimulating lipid catabolism in broilers.     

The effect of different high‐fat diets on erythrocyte osmotic fragility,growth performance and serum lipid concentrations in male,Japanese quail (Coturnix coturnix japonica)

Poultry diets are formulated with additional animal fat or vegetable oils to improve growth rate and feed conversion efficiency. High‐fat diet feeding in rats and fish has been shown to result in alterations in the phospholipid composition and cholesterol content of the erythrocyte membrane, in turn affecting erythrocyte osmotic fragility. In contrast, the few studies performed using high‐fat diet feeding in avian species show no changes in erythrocyte osmotic fragility. This study made use of the Japanese quail as no data exists on investigation of this species with respect to high‐fat diet feeding and erythrocyte osmotic fragility. Fifty‐seven male quail were randomly divided into six groups and fed either a standard diet (commercial poultry feed) or one of five high‐fat diets (commercial poultry feed with 22% of either coconut oil, lard, palm oil, soya bean oil or sunflower oil on a weight/weight basis) for 12 weeks. All birds on the high‐fat diets were significantly heavier (p < 0.05) after the 12‐week feeding period, than when commencing the dietary intervention. Serum triglyceride concentrations of birds in all high‐fat diet groups were significantly lower (p < 0.05) than birds in the standard diet group, whereas only birds in the palm oil group had significantly lower (p < 0.05) serum cholesterol concentrations compared to the standard diet group. Fragiligrams of erythrocytes from birds in the various dietary groups were similar. High‐fat diet feeding with different types of additional fat did not affect the osmotic fragility of the quail erythrocytes. Feeding quail high‐energy diets of varying degrees of fatty acid saturation was well tolerated and did not seem to affect the overall health status of the birds. Resistance of avian erythrocytes to modification by excess dietary fat may be a general characteristic of avian erythrocytes.     

l‐carnitine and fat type in the maternal diet during gestation and lactation modify the fatty acid composition and expression of lipid metabolism‐related genes in piglets

This study examined the influence of adding different amounts of maternal dietary l ‐carnitine and two fat types on fatty acid (FA) composition and the expression of lipid metabolism‐related genes in piglets. The experiment was designed as a 2 × 2 factorial with two fat types (3.5% soyabean oil, SO, and 3.5% fish oil, FO) and two levels of l ‐carnitine (0 and 100 mg/kg) added to the sows' diets. A higher proportion of n‐3 polyunsaturated fatty acids (PUFA) and a lower ratio of n‐6/n‐3 PUFA in sow milk and piglet tissues were observed in the FO groups than in the SO groups. Adding l ‐carnitine increased the proportion of C16:1 in sow milk and decreased n‐3 PUFA in piglet subcutaneous fat. Hepatic peroxisome proliferator‐activated receptor α (PPAR‐α) was more abundantly expressed in piglets from the FO groups than from the SO groups (p < 0.05), whereas stearoyl‐CoA‐desaturase (SCD), sterol regulatory element binding protein‐1 (SREBP1) and ?6‐desaturase (D6D) genes were less expressed in the FO groups compared with piglets from the SO groups. The expression of fatty acid synthase (FAS) genes was decreased in the SO groups with l ‐carnitine compared to that of the other dietary treatments. No differences among dietary treatments were observed with regard to the expression of acetyl‐CoA carboxylase (ACC). In conclusion, FO and l ‐carnitine supplementation in sows affect FA composition and hepatic gene expression in piglets.     

Pulmonary hypertension and right ventricular failure in broiler chickens reared at high altitude is affected by dietary source of n‐6 and n‐3 fatty acids

The present study evaluated the development of pulmonary hypertension and right ventricular failure in broiler chickens reared at high altitude (2100 m) as affected by dietary intake of n‐3 and n‐6 fatty acid sources. Flax oil and soy oil were used as sources of n‐3 and n‐6 fatty acids, respectively, either with or without α‐tocopheryl acetate. A total of 192 day‐old broiler chicks (Ross 308) were used in a completely randomized design using isoenergetic and isonitrogenous experimental diets. Results showed that dietary flax oil significantly (p < 0.05) improved feed conversion ratio during 21–42 days of age. However, body weight gain did not significantly differ among the experimental groups in entire trial. Birds received flax oil had significantly higher serum concentration of nitric oxide (NO) but they had lower serum concentration of malondialdehyde when compared with their counterparts fed with soy oil. Liver and abdominal fat weights were significantly (p < 0.05) reduced by substitution of soy oil for flax oil. The right‐to‐total ventricle weight ratio (RV/TV) and mortality from pulmonary arterial hypertension (PAH) were significantly (p < 0.05) decreased in birds that received flax oil. In conclusion, n‐3 fatty acids could significantly reduce RV:TV and PAH mortality in birds by increasing circulatory level of NO and suppressing hepatic lipogenesis.     

Increased fatty acid β‐oxidation as a possible mechanism for fat‐reducing effect of betaine in broilers

Two hundred and forty 1‐day‐old male Arbor Acres broiler chickens were randomly assigned to five dietary treatments with six replicates of eight chickens per replicate cage for a 42‐day feeding trial. Broiler chickens were fed a basal diet supplemented with 0 (control), 250, 500, 750 or 1000 mg/kg betaine, respectively. Growth performance was not affected by betaine. Incremental levels of betaine decreased the absolute and relative weight of abdominal fat (linear P < 0.05, quadratic P < 0.01), low‐density lipoprotein cholesterol (LDL‐C), triglyceride (TG) and total cholesterol (TC) (linear P < 0.05), and increased concentration of nonesterified fatty acid (NEFA) (linear P = 0.038, quadratic P = 0.003) in serum of broilers. Moreover, incremental levels of betaine increased linearly (P < 0.05) the proliferator‐activated receptor alpha (PPARα), the carnitine palmitoyl transferase‐I (CPT‐I) and 3‐hydroxyacyl‐coenzyme A dehydrogenase (HADH) messenger RNA (mRNA) expression, but decreased linearly (P < 0.05) the fatty acid synthase (FAS) and 3‐hydroxyl‐3‐methylglutaryl‐CoA (HMGR) mRNA expression in liver of broilers. In conclusion, this study indicated that betaine supplementation did not affect growth performance of broilers, but was effective in reducing abdominal fat deposition in a dose‐dependent manner, which was probably caused by combinations of a decrease in fatty acid synthesis and an increase in β‐oxidation.     

Effect of dietary high-oleic acid sunflower seed, palm oil and vitamin E supplementation on broiler performance, fatty acid composition and oxidation susceptibility of meat

1. A study was conducted to evaluate the effect of inclusion of two fat sources: high-oleic acid sunflower seed (HOASS; 0, 50, 100, 150 and 200 g/kg diet) and palm oil (PO), and dietary supplementation of vitamin E (alpha-tocopheryl acetate, 200 mg/kg diet) on performance, fatty acid composition and susceptibility to oxidation of white and dark chicken meat during refrigerated storage. Female chicks (3 to 6 weeks) were given one of 5 diets containing 90 g/kg of added fat with increasing monounsaturated fatty acid (MUFA) content, adjusted by progressively replacing PO by HOASS. 2. Body weight gain and gain:food ratio of birds were depressed in diets containing the highest proportions of HOASS (150 and 200 g/kg). Relative abdominal fat was reduced in birds fed diets including HOASS, except in the diet containing 100 g HOASS/kg. The inclusion of alpha-tocopheryl acetate improved body weight gain and gain:food ratio. 3. According to the fatty acid profile of the diets, saturated and polyunsaturated fatty acid (SFA and PUFA, respectively) contents were significantly reduced and MUFA content was significantly increased in white and dark chicken meats when the saturated oil, PO, was replaced progressively by HOASS in the diet. The inclusion of alpha-tocopheryl acetate increased PUFA content in both meats. 4. After 4 and 7 d of refrigerated storage, white and dark meat samples obtained from birds fed on diets containing HOASS had significantly lower thiobarbituric acid reacting substance (TBARS) values than those derived from the PO diet. The addition of alpha-tocopheryl acetate significantly reduced the lipid oxidation in white and dark meat. 5. Overall, the results showed that increasing MUFA content of chicken meat by replacing dietary PO with HOASS (up to 100 g/kg) did not adversely affect broiler performance and reduced the susceptibility of meat to oxidation during refrigerated storage. Dietary alpha-tocopherol supplementation improved chicken performance and was effective in protecting lipid meat from oxidation.     

Antibiotics promote abdominal fat accumulation in broilers

Antibiotics stimulate the growth of animals but result in drug residues and bacterial resistance. In this study, the negative effect of antibiotics on abdominal fat deposition was evaluated in broilers. The results showed that adding both chlortetracycline (50 g/1,000 kg) and tylosin (50 g/1,000 kg) significantly increased abdominal fat weight, abdominal fat percentage (p < .05), and triglyceride and cholesterol levels (p < .05) in blood. Also, both products synchronously stimulated intestinal absorption and synthesis of liver fat. The expression levels of the peroxisome proliferator‐activated receptor γ (PPARγ), diacylgycerol acyltransferase 2 (DGAT2), lipoprotein lipase (LPL), and fatty acid‐binding protein (FABP4) genes in abdominal fat tissue significantly increased (p < .05 or 0.01) when antibiotics were added to the feed. However, no significant difference was found in expression of the fatty acid synthesis (FAS) or acetyl CoA carboxylase (ACC) genes. Further in vitro study results revealed that antibiotics had no effect on fat content or the related gene expression levels in preadipocytes. In summary, the antibiotics induced fat deposition in adipose tissues by activating extracellular absorption of fatty acids from intestinal absorption and synthesis of liver fat. However, it shows no direct regulation by adipose tissue.     

Effects of lactulose supplementation on performance,blood profiles,excreta microbial shedding of Lactobacillus and Escherichia coli,relative organ weight and excreta noxious gas contents in broilers

This study was to evaluate the effects of lactulose supplementation on performance, blood profiles, excreta microbial shedding of Lactobacillus and Escherichia coli, relative organ weight and excreta noxious gas contents in broilers. A total of 720 ROSS 308 broilers with a body weight of 46 ± 0.1 g (1 day of age) were used in a 28‐d experiment. Broilers were randomly allotted to 4 experiment diets with 12 replicate pens and 15 birds per pen. Dietary treatments were as follows: NC, negative control (without antibiotic); PC, NC + 0.1% tiamulin; L1, NC + 0.1% lactulose; and L2, NC + 0.2% lactulose. Broilers were fed with phase 1 (1–8 day), phase 2 (9–18 day) and phase 3 (19–28 day) diets in the form of mash. During day 1–8, broilers fed the PC and L2 diets had higher (p < 0.05) body weight gain than those fed the NC diet. During day 19–28, broilers fed the L1 and L2 diets had lower (p < 0.05) feed intake than those fed the NC diet. The feed conversion ratio (FCR) was decreased (p < 0.05) in L1 treatment compared with NC treatment. Overall, the FCR was improved (p < 0.05) in all supplementation treatments compared with NC treatment. The apparently metabolizable nitrogen in L1 treatment was higher (p < 0.05) than that in NC treatment at day 28. The excreta Lactobacillus was increased and E. coli was decreased in PC and L2 treatments compared with NC treatment at day 28 (p < 0.05). The excreta NH₃, H₂S and acetic acid contents were decreased (p < 0.05) in L1 and L2 treatments compared with NC treatment. The relative weight of abdominal fat of broilers fed the PC diet was lowest (p < 0.05) compared with other treatments. In conclusion, this study indicated that dietary supplementation of 0.1% or 0.2% lactulose could improve growth performance, decrease excreta E. coli and excreta NH₃ and H₂S contents.     

Effect of dietary fish oil on the expression of genes involved in lipid metabolism in liver and skeletal muscle of lactating sows

This study investigated the hypothesis that dietary supplementation of fish oil as a source of n‐3 polyunsaturated fatty acids (PUFA) influences the expression of target genes of sterol regulatory element‐binding proteins (SREBP)‐1 and (SREBP)‐2 involved in triacylglycerol (TAG) synthesis and fatty acid and cholesterol metabolism in the liver, and moreover activates the expression of target genes of peroxisome proliferation‐activated receptor (PPAR)‐α involved in TAG and fatty acid catabolism in liver and skeletal muscle. Twenty lactating sows were fed a control diet or a fish oil diet with either 50 g of a mixture of palm oil and soya bean oil (4:1, w/w) or fish oil per kg. The diet of the fish oil group contained 19.1 g of n‐3 PUFA (mainly 20:5 n‐3 and 22:6 n‐3) per 100 g of total fatty acids, while the diet of the control group contained 2.4 g of n‐3 PUFA (mainly 18:3 n‐3) per 100 g of total fatty acids. The fish oil group had reduced relative mRNA concentrations of various target genes of SREBP‐1 involved in fatty acid and TAG synthesis in comparison with the control group (p < 0.05). Relative mRNA concentrations of target genes of PPARα involved in fatty acid catabolism in both liver and muscle, and mRNA concentrations of target genes of SREBP‐2 involved in cholesterol synthesis and uptake were not influenced by fish oil supplementation. Concentrations of cholesterol and TAG in plasma, fat content of milk and weight gains of litters during the suckling period were not different between the two groups of sows. In conclusion, this study suggests that fish oil has only minor effects on hepatic lipid metabolism, which are non‐critical with respect to milk production in sows.     

The effect of dietary fish oil soapstock on the performance,carcass fat and flavour of broilers 1

Three hundred and thirty six male broilers were fed on diets containing two levels (2% and 4%) of either acidulated soybean oil soapstock (SOS), acidulated fish oil soapstock (FOS), or a combination of the two. Some of the replicates were changed from FOS diets to diets containing 4% SOS at 5 or 6 1/2 weeks of age.

Dietary FOS was slightly, but significantly, inferior to SOS with regard to live performance, apparently due to an adverse effect on food intake. All birds fed on FOS were unpalatable due to a pronounced “fishy” flavour, thigh meat being more objectionable than breast meat and cooked broth more than roasted meat. About 3 to 4 weeks after transfer to SOS diets, the broilers were acceptable.

Both soapstocks contained over 65% free fatty acids, but their fatty acid composition differed, with the FOS containing more C₁₂ to C₁₆ saturated fatty acids, palmitoleic acid and the typical long‐chain polyenoic fatty acids, but much less linoleic acid. These patterns were reflected in the total dietary lipids and in the abdominal adipose tissue. After the type of dietary soapstock was altered, there was a gradual change in the composition of body fat, which, after about 3 weeks, approached the fatty acid pattern of the birds fed on a diet containing 4% SOS throughout their growing period.     

Body weight,meat quality and blood metabolite responses to carbohydrate administration in the drinking water during pre‐slaughter feed withdrawal in broilers

This study was conducted to determine weights of body (BW), carcass (CW), gastrointestinal tract (GTW), meat quality and some blood metabolite responses to corn starch, saccharose or glucose administration in the drinking water during pre‐slaughter feed withdrawal (FW) in broilers. On day 42 of age, 200 broilers (Ross 308) were allocated randomly to five treatments with four replicates. During a 10‐h FW, control broilers (C) were provided with non‐treated water and the standard finisher diet ad libitum, whereas fasted broilers provided with non‐treated (NFW) or treated water, 3 g glucose (G), saccharose (S) or corn starch (CS)/L. Eight birds (four males and four females) per treatment were slaughtered. Birds receiving non‐treated or treated water had lower BW and higher carcass yield than the full‐fed broilers. The full‐fed broilers had higher absolute and relative GTW than the fasted birds. Broilers consumed more readily treated water compared with non‐treated water. While the a* value of breast meat from CS birds was higher than that from NFW, the b* value of that was higher than S and C birds. The c* values of breast meat from S birds were lower compared with that from the CS treatment. The thigh meat from NFW broilers had higher h* value than that from C and G broilers. The thigh meats of C and CS broilers had higher c* value than that of G birds. The full‐fed broilers had higher plasma triglyceride concentration than NFW, S and G birds. The full‐fed broilers had higher plasma uric acid and uric acid nitrogen concentrations than S birds. These results show that carbohydrate administration in the drinking water cannot be a good alternative for the FW period before slaughter due to the fact that the carbohydrates do not reduce BW losses and do not lead to increases in meat quality.     

Impact of mash and crumble diets on intestinal amino acids transporters,intestinal morphology and pancreatic enzyme activity of broilers

The objective of this study was to evaluate effects of mash and crumble pre‐starter diets on pancreatic enzyme activity, intestinal morphology, gene expression of intestinal peptide and amino acid (AA) transporters of broilers. Broilers in battery cages were assigned to different feed forms of pre‐starter diet from 1 to 10 days of age. Significantly increased body weight gain (BWG), feed intake (FI) and lowered FCR were observed in birds fed crumble pre‐starter diet (CPD, p < 0.05). Feed forms had no effect on whole and small intestine length, but relative intestinal length and relative small intestinal length significantly increased in the broilers fed a mash pre‐starter diet (MPD, p < 0.05). Feeding CPD increased the weight of pancreas (p < 0.05), but relative weight of the pancreas was not influenced by treatments. Pancreatic protease and amylase activities significantly increased in the broilers fed CPD (p < 0.05) but the activity of lipase was not influenced. Crypt depth (CD) and villus height (VH) were higher in broilers fed CPD (p < 0.05) but villus width (VW), villus surface area (VSA) and villus height‐to‐crypt depth ratio (VCR) were not influenced by treatments. mRNA levels for peptide transporter 1 (PepT1), Na⁺‐independent cationic AA transporter1 (CAT1), Na⁺‐independent cationic and Na⁺‐dependent neutral AA transporter 1 (y⁺LAT1) and Na⁺‐dependent neutral AA transporter (B⁰AT) were lower in birds fed CPD (p < 0.05). There were no differences in mRNA abundance of Na⁺‐independent cationic and zwitterionic AA transporter (b^0,+AT) among treatments. Overall, the present data showed that feeding crumble diet during first 10 days of age, through higher FI, enhanced intestinal histomorphology, increased digestive enzyme activity is beneficial to growth performance of broilers. Indeed, dietary form can be an important factor in the expression of jejunal transporters.     

Evaluating two multistrain probiotics on growth performance,intestinal morphology,lipid oxidation and ileal microflora in chickens

An experiment was conducted to investigate the supplementation of two commercially available multistrain probiotics as an alternative to antibiotics on growth performance, intestinal morphology, lipid oxidation and ileal microflora in broiler chickens. A total of 280‐day‐old ROSS 308 mixed‐sex broiler chickens with an average initial body weight of 42 ± 0.5 g were randomly divided into four treatments with five replicate cages of 14 birds each cage in a completely randomized design and fed with the following diets for 42 day: (a) control (CON) (antibiotic‐free diet), (b) antibiotic (ANT) (CON + Avilamycin 150 g/ton feed), (c) probiotic A (CON + Protexin^® 150 g/ton feed) and (d) probiotic B (CON + Bio‐Poul^® 200 g/ton feed). The results showed the broilers fed the ANT diet had greater average daily gain than broilers fed the CON diet during day 1–14 (p < 0.05). At day 42, two birds were randomly selected per replicate for evaluation intestinal morphology, lipid oxidation and ileal microflora. birds fed diet supplemented with probiotic A and probiotic B increased villus height and goblet cells numbers in the jejunum and villus height to crypt depth ratio and villus height in the ileum as compared to birds fed CON diet (p < 0.05). The malondialdehyde value was reduced (p < 0.05) in the ANT, probiotic B and probiotic A groups compared with the CON group. The Lactobacillus population was increased and Clostridium spp. population decreased in the ileum of broilers fed diets containing the probiotic B and probiotic A compared with those fed CON diet (p < 0.05). The results from this study indicate that the probiotic A (Protexin^®) and probiotic B (Bio‐Poul^®) used in this trial may serve as alternatives to ANT.     

Effect of dietary polyphenol‐rich grape seed on growth performance,antioxidant capacity and ileal microflora in broiler chicks

In this study, we examined the effect of dietary supplementation with grape seed (GS) on the performance, carcass traits, plasma biochemistry, antioxidant status and ileal microflora in broilers. Experiment diets included a control diet (without additive) and three levels of GS powder (10, 20 and 40 g/kg of diet). Each diet was fed to a total of 300 one‐day‐old Cobb‐500 chicks for 42 days. The addition of 20 g/kg of GS to the basal diet increased final body weight and body weight gain, improved the feed conversion ratio and did not affect feed intake. Dietary 20 g GS significantly increased (p < .05) the percentage of carcass yield %, dressing % and gizzard. However, the addition of 40 g/kg of GS significantly reduced the percentage of abdominal fat in the birds. Diets supplemented with GS showed the lowest content of ether extract compared with the control group (p < .05). The physical characteristics of meat and the chemical composition of DM, CP and ash were not significantly influenced by treatments. In the GS groups, plasma protein, albumin, globulin, aspartate aminotransferase and alanine aminotransferase concentrations showed no significant change compared with the control group. Broilers fed a diet supplemented with GS had lower levels of plasma glucose, total lipids, triglycerides and cholesterol compared with the control birds (p < .05). The addition of 40 g of GS significantly (p < .05) enhanced the activity of reduced glutathione, catalase, superoxide dismutase, glutathione peroxidase and GST, and correlated with significantly decreased thiobarbituric acid‐reactive substances levels compared with the control group. The value of ileal pH was not significantly affected by the GS levels. Broilers fed diets supplemented with GS had lower ileal Streptococcus spp. and Escherichia coli populations but higher Lactobacillus spp. populations (p < .05). No adverse effects on birds’ health were detected due to the use of GS. Thus, GS could be recommended as an herbal supplement in the diet of broiler chickens to improve performance, reduce blood lipids, enhance antioxidant capacity and decrease detrimental bacteria in the ileum.     

Can breeder reproductive status,performance and egg quality be enhanced by supplementation and transition of n‐3 fatty acids?

The aim of this experiment was to investigate the effect of n‐3 fatty acid (FA) supplemented diets on breeder performance, productivity and egg quality. Breeders (n = 480) were fed the supplemented diet from 18 weeks onwards; the inclusion level of n‐3 FA was increased from 1.5% to 3.0% from 34 weeks of age onwards until 48 weeks of age. Ross‐308 broiler breeders (n = 480) were fed one of four different diets: a basal diet rich in n‐6 FA (control diet) or one of three diets rich in n‐3 FA. For the n‐3 FA diets, eicosapentaenoic acid (EPA, 20:5 n‐3) and docosahexaenoic acid (DHA, 22:6 n‐3) were fed to the broiler breeders at different ratios formulated to obtain EPA/DHA ratios of 1/1, 1/2 or 2/1. Differences in performance, reproduction and egg quality parameters due to n‐3 supplementation were noted more for the 1.5% followed by the 3.0% fed broilers than their 1.5% supplemented counterparts. Egg weight (p < 0.001) and egg mass (p = 0.003) were significantly lower and feed conversion (p = 0.008) significantly higher for the n‐3 FA (at 3.0% inclusion level) fed broilers compared to the control group. For the EPA‐ and DHA‐fed breeders, a higher proportional abdominal fat percentage (p = 0.025) and proportional albumen weight (%) (p = 0.041) were found respectively. Dietary treatments did not affect reproduction. It can be concluded that the results of the present experiment indicate no significant differences between treatments at 1.5% inclusion levels. However, increasing this level to 3.0% is not recommended due to the rather negative effects on the measured parameters. It should be further investigated whether these adverse effects were obtained due to (i) the higher supplementation level, (ii) combining a supplementation level of 1.5% with 3% or (iii) the duration of supplementation.     

Lysolecithin,but not lecithin,improves nutrient digestibility and growth rates in young broilers

ABSTRACT

1. The potential of lecithin and lysolecithin to improve lipid digestion and growth performance was investigated in three experiments: 1. an in vitro model that mimics the intestinal conditions of the chick, 2. a digestibility trial with chicks (5–7 days of age), and 3. a performance trial until 21 days of age.

2. In experiment 1, palm oil (PO), palm oil with lecithin (PO+L), and palm oil with lysolecithin (PO+LY) were subjected to in vitro hydrolysis and applied to Caco-2 monolayers to assess lipid absorption.

3. The in vitro hydrolysis rate of triglycerides was higher in PO+LY (k = 11.76 × 10³/min) than in either PO (k = 9.73 × 10³/min) or PO+L (k = 8.41 × 10³/min), and the absorption of monoglycerides and free fatty acids was highest (P < 0.01) for PO+LY. In experiment 2, 90 broilers were assigned to three dietary treatments: a basal diet with 4% palm oil, and the basal diet supplemented with either 250 ppm lecithin or lysolecithin.

4. ATTD of crude fat was higher in broilers supplemented with lysolecithin, but was lower in broilers supplemented with lecithin. DM digestibility and AMEn in birds supplemented with lysolecithin were significantly higher (3.03% and 0.47 MJ/kg, respectively).

5. In experiment 3, 480 broilers were randomly allocated to four dietary treatments: basal diet with soybean oil (2%), basal diet with lecithin (2%), soybean oil diet with 250 ppm lysolecithin, or lecithin oil diet with 250 ppm lysolecithin.

6. Lecithin diets significantly reduced weight at day 10 and 21 compared with soybean oil. However, the addition of lysolecithin to lecithin-containing diets significantly improved bird performance.

7. The results of these studies showed that, in contrast to lecithin, lysolecithin was able to significantly improve the digestibility and energy values of feed in young broilers.     

Effects of dietary betaine on growth performance,fat deposition and serum lipids in broilers subjected to chronic heat stress

We evaluated the effects of supplementing betaine on growth performance, fat deposition and lipid metabolism status in broilers kept under chronic heat stress. Five hundred and forty chicks were randomly divided into six groups and the two normal temperature groups were held at normal ambient temperature and fed the basal diet (CONT) and basal diet plus 0.1% betaine, respectively. Heat stressed (HS) broilers were held at 32 ± 1°C from days 22 to 42 and fed the basal diet containing variable levels of betaine. Broilers were examined at days 28, 35 and 42 for body weight, feed consumption, fat deposition and serum lipids. The CONT and betaine‐supplemented groups showed higher (P < 0.01 or P < 0.05) feed consumption, body weight gain, and lower feed : gain ratio compared with the HS‐CONT group. Meanwhile, heat stress increased abdominal, intermuscular and subcutaneous fat deposition, whereas the supplemental betaine significantly decreased those compared with the HS‐CONT group. Additionally, betaine supplementation significantly decreased triglyceride, free fatty acids, low‐density lipoprotein cholesterol and high‐density lipoprotein cholesterol compared with HS‐CONT. Chronic HS reduces broiler production performance. However, betaine can reverse these negative effects partially and thus improve carcass composition by changing lipid metabolism.     

发酵棉粕对肉仔鸡生长性能、屠宰性能、营养物质表观消化率和脂肪沉积的影响

试验旨在研究棉粕经热带假丝酵母菌发酵后得到的发酵棉粕对白羽肉鸡生长性能、屠宰性能、营养物质表观消化率和脂肪沉积的影响。试验选取180羽1日龄科宝白羽肉鸡,随机分成3组,每组6个重复,每个重复10羽鸡。对照组饲喂不加菌发酵棉粕（CSM）,两个试验组分别饲喂热带假丝酵母菌发酵棉粕（FCSM）、CSM+热带假丝酵母菌（CT-USCM,活菌量同FCSM）。21日龄试验结束。结果表明：①FCSM组肉鸡末重、平均日增重均显著高于对照组（P<0.05）,FCSM和CT-USCM组肉鸡的料重比显著低于对照组（P<0.05）;②CT-USCM组肝重率显著高于对照组（P<0.05）,FCSM和CT-USCM组的腹脂率和皮下脂肪厚度显著低于对照组（P<0.05）;③FCSM和CT-USCM组肉鸡干物质和粗蛋白质表观消化率均显著高于对照组（P<0.05）,粗脂肪和粗灰分表观消化率在各组间差异不显著（P>0.05）;④FCSM和CT-USCM组肉鸡血糖（Glu）、甘油三酯（TG）和低密度脂蛋白（LDL）浓度均显著低于对照组（P<0.05）;⑤FCSM和CT-USCM组肉鸡肝脏和腹脂中激素敏感酯酶（HSL）活性和生长激素（GH）水平均显著高于对照组（P<0.05）,两组之间差异不显著（P>0.05）;FCSM组肝脏和腹脂中乙酰辅酶A羧化酶（ACC）和苹果酸酶（ME）活性均显著低于对照组（P<0.05）,而肝脏中脂蛋白酯酶（LPL）活性均显著高于对照组（P<0.05）,腹脂中脂肪酸合成酶（ME）活性显著低于其他两组（P<0.05）。综上所述,在日粮中添加FCSM和热带假丝酵母菌均能不同程度地促进肉鸡生长性能、屠宰性能,提高营养物质表观消化率,同时还能通过影响脂肪代谢相关酶活和激素参与肉鸡脂肪合成和分解,降低肉鸡腹脂率和皮下脂肪厚度。