Abdominal Fat Deposition In Broilers Research Articles

Effects of Different Dietary Starch Sources and Digestible Lysine Levels on Carcass Traits, Serum Metabolites, Liver Lipid and Breast Muscle Protein Metabolism in Broiler Chickens.

This study investigated the effects of digestible lysine (dLys) in different dietary starch sources on liver lipid metabolism and breast muscle protein metabolism in broiler chickens. The experimental design was a 3 × 3 two-factor completely randomized design. A total of 702 one-day-old male Arbor Acres Plus broilers were randomly divided into nine treatments of six replicate cages with thirteen birds each. The treatments consisted of three different starch sources (corn, cassava and waxy corn) with three different dLys levels (1.08%, 1.20% and 1.32%). The trial lasted from 1 to 21 days. Carcass traits, serum metabolites, breast muscle protein and liver lipid metabolism were evaluated. A significant interaction effect (p < 0.05) for dietary starch sources and dLys levels was noted in the percentage of abdominal fat and gene expression related to breast muscle protein metabolism throughout the experimental period. The waxy corn starch diet and a 1.08% dLys level in the diet increased both the percentage of abdominal fat (p < 0.01) and blood total cholesterol (p < 0.05) in the broilers. The waxy corn starch diet significantly upregulated the mRNA expressions of Eif4E, AMPK, FABP1, ACC and CPT1 (p < 0.05). The 1.32% dLys level significantly upregulated the mRNA expressions of mTOR, S6K1, Eif4E, AMPK and PPARα (p < 0.05) and significantly downregulated the mRNA expressions of MuRF and Atrogin-1 (p < 0.05). In summary, the waxy corn starch diet resulted in significantly higher expression levels of fat-synthesis-related genes than lipolysis-related genes, leading to abdominal fat deposition in broilers. Increasing the level of dLys in the diet increased the protein content in muscle by promoting protein synthesis and inhibiting protein degradation and also promoted the expression of lipolysis-related genes, thereby degrading the generation of abdominal fat in broilers. Our findings signify that increasing the dLys level to 1.32% when using the waxy corn starch diet could improve carcass traits.

Transcriptome analysis reveals steroid hormones biosynthesis pathway involved in abdominal fat deposition in broilers

Excessive abdominal fat deposition reduces the feed efficiency and increase the cost of production in broilers. Therefore, poultry breeders have the important of developing a breed with reduced abdominal fat deposition. Abdominal fat deposition is a highly complex biological process, and its molecular basis remains elusive. In this study, we performed transcriptome analysis to compare gene expression profiles at different stages of abdominal fat deposition to identify the key genes and pathways involved in abdominal fat accumulation. We found that abdominal fat weight (AFW) increased gradually from day 35 (D35) to 91 (D91), and then decreased at day 119 (D119). Accordingly, after detecting differentially expressed genes (DEGs) by comparing gene expression profiles at D35 vs. D63 and D35 vs. D91, and identifying gene modules associated with fat deposition by weighted gene co-expression network analysis (WGCNA), we performed intersection analysis of the detected DEGs and WGCNA gene modules and identified 394 and 435 intersecting genes, respectively. The results of the gene ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses showed that the steroid hormone biosynthesis and insulin signaling pathways were co-enriched in all intersecting genes, steroid hormones have been shown that regulated insulin signaling pathway, indicating the importance of the steroid hormone biosynthesis pathway in the development of broiler abdominal fat. We then identified six hub genes (ACTB, SOX9, RHOBTB2, PDLIM3, NEDD9, and DOCK4) related to abdominal fat deposition. Further analysis also revealed that there were direct interactions between 6 hub genes. SOX9 has been shown to bind to proteins required for steroid hormone receptor binding, and RHOBTB2 indirectly regulates the steroid hormones biosynthesis through cyclin factor, and ultimately affect fat deposition. Our results suggest that the genes RHOBTB2 and SOX9 play an important role in fat deposition in broilers, by regulating steroid hormone synthesis. These findings provide new targets and directions for further studies on the the mechanisms of fat deposition in chicken.

Heat stress exposure changed liver lipid metabolism and abdominal fat deposition in broilers

To evaluate the effects of heat stress on lipid metabolism in the liver and abdominal adipose deposition in broilers, totally, 120 female 21-day old broilers were selected and randomly allocated to 2 groups with 6 replication and 10 broilers per each replication. Broilers in the control group (CON) were reared at 24 °C, and broilers in the heat stress group (HS) were reared at 34 °C. Heat stress exposure increased (P < 0.05) rectal temperature, relative weight of abdominal adipose and liver, serum triacylglycerol (TG) and total cholesterol (TC) level, liver TG, TC, and very low-density lipoprotein (VLDL) content. Hepatic mRNA expression level of fatty acid synthase (FAS), acetyl-coenzyme A carboxylase (ACC), and abdominal adipose mRNA expression level of ACC and CCAAT/enhancer-binding protein-α (C/EBPα) were up-regulated (P < 0.05) when compared with the CON group. Heat stress exposure increased serum and hepatic TC and TG content, up-regulated the mRNA expression of FAS and ACC in liver, and promoted preadipocytes differentiation by increasing C/EBPα mRNA expression in abdominal adipose. Therefore, heat stress exposure increased abdominal adipose deposition, which related to increase in hepatic de novo lipogenesis, and promoted preadipocytes differentiation in abdominal adipose. HIGHLIGHTS Heat stress increased abdominal adipose deposition Heat stress increased hepatic de novo lipogenesis Heat stress promoted preadipocytes differentiation in abdominal adipose

Chicken Protein S Gene Regulates Adipogenesis and Affects Abdominal Fat Deposition.

Simple SummaryLow-fat meat is increasingly desired by the public due to the growing popularity of healthy diets, and the excessive accumulation of abdominal fat increases costs in the broiler breeding industry, all of which have encouraged breeding changes in the broiler industry. Investigating fat accumulation at a cellular level from a genetic perspective will help us understand gene-mediated abdominal fat accumulation in chickens. This study aimed to explore the role of the PROS1 gene in adipose cells and its application prospect in broiler breeding. Based on our findings, we found that the PROS1 gene can contribute to adipose cell proliferation and can reduce fat deposits at the cellular level, and its mutations are highly correlated with chicken fat traits.(1) Background: Excessive abdominal fat deposition in broilers not only causes feed waste but also leads to a series of metabolic diseases. It has gradually become a new breeding goal of the broiler industry to improve growth rates and to reduce abdominal fat rates. In a previous study, PROS1 was highly expressed in low-abdominal fat broilers, suggesting a potential role in broilers adipogenesis. However, the function of PROS1 in preadipocytes and its association with abdominal fat traits need to be characterized. (2) Methods: qRT-PCR and Western Blot were used to quantify gene expression at the RNA and protein levels; flow cytometry and EdU were carried out to detect cell proliferation; and a GLM analysis was used to determine the association between PROS1 SNPs and carcass traits. (3) Results: PROS1 was downregulated in high-abdominal fat chicken; PROS1 contributed preadipocyte proliferation but suppressed preadipocyte differentiation; and the SNPs in the PROS1 5′ flank were significantly associated with the abdominal fat weight rate. (4) Conclusions: Chicken PROS1 is able to suppress adipogenesis, and its polymorphisms are associated with the abdominal fat weight rate, which can be considered the molecular markers for chicken breeding, indicating that PROS1 is an effective potential gene in regulating abdominal fat deposition.

Liver fat metabolism of broilers regulated by Bacillus amyloliquefaciens TL via stimulating IGF-1 secretion and regulating the IGF signaling pathway.

Bacillus amyloliquefaciens TL (B.A-TL) is well-known for its capability of promoting protein synthesis and lipid metabolism, in particular, the abdominal fat deposition in broilers. However, the underlying molecular mechanism remains unclear. In our study, the regulations of lipid metabolism of broilers by B.A-TL were explored both in vivo and in vitro. The metabolites of B.A-TL were used to simulate in vitro the effect of B.A-TL on liver metabolism based on the chicken hepatocellular carcinoma cell line (i.e., LMH cells). The effects of B.A-TL on lipid metabolism by regulating insulin/IGF signaling pathways were investigated by applying the signal pathway inhibitors in vitro. The results showed that the B.A-TL metabolites enhanced hepatic lipid synthesis and stimulated the secretion of IGF-1. The liver transcriptome analysis revealed the significantly upregulated expressions of four genes (SI, AMY2A, PCK1, and FASN) in the B.A-TL treatment group, mainly involved in carbohydrate digestion and absorption as well as biomacromolecule metabolism, with a particularly prominent effect on fatty acid synthase (FASN). Results of cellular assays showed that B.A-TL metabolites were involved in the insulin/IGF signaling pathway, regulating the expressions of lipid metabolism genes (e.g., FASN, ACCα, LPIN, and ACOX) and the FASN protein, ultimately regulating the lipid metabolism via the IGF/PI3K/FASN pathway in broilers.

Consensus module analysis of abdominal fat deposition across multiple broiler lines

BackgroundDespite several RNA-Seq and microarray studies on differentially expressed genes (DEGs) between high- and low-abdominal fat deposition in different broiler lines, to our knowledge, gene coexpression analysis across multiple broiler lines has rarely been reported. Here, we constructed a consensus gene coexpression network focused on identifying consensus gene coexpression modules associated with abdominal fat deposition across multiple broiler lines using two public RNA-Seq datasets (GSE42980 and GSE49121).ResultsIn the consensus gene coexpression network, we identified eight consensus modules significantly correlated with abdominal fat deposition across four broiler lines using the consensus module analysis function in the weighted gene coexpression network analysis (WGCNA) package. The eight consensus modules were moderately to strongly preserved in the abdominal fat RNA-Seq dataset of another broiler line (SRP058295). Furthermore, we identified 5462 DEGs between high- and low-abdominal fat lines (FL and LL) (GSE42980) and 6904 DEGs between high- and low-growth (HG and LG) (GSE49121), including 1828 overlapping DEGs with similar expression profiles in both datasets, which were clustered into eight consensus modules. Pyruvate metabolism, fatty acid metabolism, and steroid biosynthesis were significantly enriched in the green, yellow, and medium purple 3 consensus modules. The PPAR signaling pathway and adipocytokine signaling pathway were significantly enriched in the green and purple consensus modules. Autophagy, mitophagy, and lysosome were significantly enriched in the medium purple 3 and yellow consensus modules.ConclusionBased on lipid metabolism pathways enriched in eight consensus modules and the overexpression of numerous lipogenic genes in both FL vs. LL and HG vs. LG, we hypothesize that more fatty acids, triacylglycerols (TAGs), and cholesterol might be synthesized in broilers with high abdominal fat than in broilers with low abdominal fat. According to autophagy, mitophagy, and lysosome enrichment in eight consensus modules, we inferred that autophagy might participate in broiler abdominal fat deposition. Altogether, these studies suggest eight consensus modules associated with abdominal fat deposition in broilers. Our study also provides an idea for investigating the molecular mechanism of abdominal fat deposition across multiple broiler lines.

Effect of Vitamin E Supplementation on Deposition and Gene Expression Profiling of Abdominal Fat in Broiler Chickens

The aim of this study was to study the regulation of abdominal fat deposition by DL-α-tocopherol acetate (vitamin E) in broilers. Diets supplemented with 50 IU vitamin E significantly diminished abdominal fat deposition in broilers at day 35. Transcriptome sequencing results for abdominal fat tissues of the control (FC) and 50 IU vitamin E-supplemented (FT) groups identified 602 differentially expressed genes (DEGs), which were enriched in cellular process, cell and cell part, and binding Gene Ontology terms. Pathway functional analysis revealed that the DEGs were enriched in 42 metabolic pathways. Notably, the most enriched pathway, fatty acid biosynthesis, was found to play a key role in lipid metabolism. Further, the key regulators of lipid metabolism, including fatty acid synthase, acetyl-CoA carboxylase alpha, and acyl-CoA synthetase long-chain family member 1, demonstrated decreased expression following vitamin E supplementation. Herein, we have identified pathways and genes regulated by vitamin E, thereby providing novel insights into the nutrients regulating abdominal fat deposition in broilers.

Lactobacillus johnsonii 3-1 and Lactobacillus crispatus 7-4 promote the growth performance and ileum development and participate in lipid metabolism of broilers.

Long-term use of antibiotic growth promoter (AGP) in animal production is the main cause of antimicrobial resistance of pathogenic bacteria. Therefore, seeking alternatives to AGP is crucial for animal husbandry. Among all AGP alternatives, probiotics are promising candidates. In this study, two strains of lactic acid bacteria, L. johnsonii 3-1 and L. crispatus 7-4, were isolated from the feces of wild Gallus gallus, which exhibited obvious anti-pathogenic activity and improved the growth performance of broilers. Furthermore, we found that these two strains participated in the lipid metabolism of broilers by reducing the content of TC and TG in ileal epithelial cells and up-regulating the liver AMPKα/PPARα/CPT-1 pathway, which affects abdominal fat deposition. In summary, L. johnsonii 3-1 and L. crispatus 7-4 have the potential to be used as AGP substitutes and participate in the lipid metabolism of broilers to reduce abdominal fat deposition. Importantly, our study reveals for the first time that L. crispatus participates in liver lipid metabolism to reduce abdominal fat deposition in broilers.

Whole-genome bisulfite sequencing of abdominal adipose reveals DNA methylation pattern variations in broiler lines divergently selected for fatness.

The methylation status of pivotal genes involved in fat deposition in chickens has been extensively studied. However, the whole-genome DNA methylation profiles of broiler abdominal adipose tissue remain poorly understood. Using whole-genome bisulfite sequencing, we generated DNA methylation profiles of chicken abdominal adipose tissue from Northeast Agricultural University broiler lines divergently selected for abdominal fat content. We aimed to explore whether DNA methylation was associated with abdominal fat deposition in broilers. The whole-genome DNA methylation profiles of fat- and lean-line broilers abdominal adipose tissue were constructed. The DNA methylation levels of functional genomic regions in the fat broiler were higher than those in the lean broiler, especially in the 3' untranslated regions (UTRs) and exons in the non-CG contexts. Additionally, we identified 29,631 differentially methylated regions and, subsequently, annotated 6,484 and 2,016 differentially methylated genes (DMGs) in the gene body and promoter regions between the two lines, respectively. Functional annotation showed that the DMGs in promoter regions were significantly enriched mainly in the triglyceride catabolic process, lipid metabolism-related pathways, and extracellular matrix signal pathways. When the DMG in promoter regions and differentially expressed genes were integrated, we identified 30 genes with DNA methylation levels that negatively correlated with their messenger RNA (mRNA) expression, of which CMSS1 reached significant levels (false discovery rate < 0.05). These 30 genes were mainly involved in fatty acid metabolism, peroxisome-proliferator-activated receptor signaling, Wnt signaling pathways, transmembrane transport, RNA degradation, and glycosaminoglycan degradation. Comparing the DNA methylation profiles between fat- and lean-line broilers demonstrated that DNA methylation is involved in regulating broiler abdominal fat deposition. Our study offers a basis for further exploring the underlying mechanisms of abdominal adipose deposition in broilers.

MiR-429-3p/LPIN1 Axis Promotes Chicken Abdominal Fat Deposition via PPARγ Pathway.

To explore the regulatory mechanism of abdominal fat deposition in broilers, 100-day-old Sanhuang chickens (n = 12) were divided into high-fat and low-fat groups, according to the abdominal fat ratio size. Total RNA isolated from the 12 abdominal fat tissues was used for miRNA and mRNA sequencing. Results of miRNA and mRNA sequencing revealed that miR-429-3p was highly expressed in high-fat chicken whereas LPIN1 expression was downregulated. Further, we determined that miR-429-3p promoted preadipocyte proliferation and differentiation, whereas LPIN1 exerted an opposite effect. Notably, we found that the miR-429-3p/LPIN1 axis facilitated PPARγ pathway activation, which is closely associated with the progression of adipogenesis. In conclusion, our results provide evidence that a novel miR-429-3p/LPIN1 axis is involved in the regulation of adipogenesis, which may have a guiding role in the improvement of breeding for abdominal fat traits in broiler chickens.

Functional microRNA screening for dietary vitamin E regulation of abdominal fat deposition in broilers

ABSTRACT 1. Functional microRNA (miRNA) screening for abdominal fat tissue with different dietary vitamin E (VE) levels was performed to reveal miRNAs, genes and metabolic pathways involved in abdominal fat deposition in broilers. 2. A total of 240, one-day-old healthy female chicks were randomly allocated into five dietary treatments containing either 0, 20, 50, 75 or 100 IU DL-α-tocopherol acetate. The sequencing of miRNAs from abdominal fat tissues was performed. The target genes of miRNAs were predicted and enrichment analysis for these genes was performed. Diets supplemented with 50 IU VE significantly diminished abdominal fat deposition in broilers at day 35 of age. 3. A total of 29 miRNAs were differentially expressed between control and 50 IU VE treatment. Ten of the 23 target genes were enriched in four signalling pathways: tight junction, SNARE interactions in vesicular transport, regulation of autophagy and proteasome. 4. This study identified miRNA, target genes and pathways in dietary VE treatment for broilers, providing new insights into the miRNA regulation of abdominal fat deposition in broilers.

Folic Acid Reduced Triglycerides Deposition in Primary Chicken Hepatocytes.

Abdominal fat or fatty liver cause huge economic losses in the poultry industry, and nonalcoholic fatty liver disease (NAFLD) is also a global health issue in humans. More than 90% of de novo lipogenesis in humans and chickens is undertaken by the liver, which is proved to be full of lipids in new-born chickens. Folic acid was thought to have correlation with lipid metabolism. Primary hepatocytes from new-born chickens were employed as a natural model of early stage fatty liver in vitro and further to explore whether folic acid could prevent fatty liver in the current study. We found that folic acid addition reduced triglyceride deposition by suppressing de novo fatty acid synthesis and coordinately promoting triglyceride hydrolysis and exportation in primary chicken hepatocytes from new-born chickens. In addition, lipogenesis suppression was through the PI3K/AKT/SREBP pathway mediated by weakening insulin/IGF signal. Our data suggested that folic acid may be considered as a precautionary strategy for abdominal fat deposition in broilers or fatty liver in laying hens and humans. In addition, mechanism regulation also implied that an IGF2 inhibitor and PI3K inhibitor may be used for the NAFLD precautionary measure to reduce TG deposition.

Dietary enrichment of broiler chicken with omega-3 fatty acids and beneficial role in human cardiovascular health: A Review

Broiler meat consumption in the world increases annually with the development of modern diet pattern. Saturated fatty acid content of the meat causes high risk of cardiovascular disease in human. Fish is an important source of omega-3 fatty acids, which reduce the risk of cardiovascular disease in human. However, access to food fish, which are rich in omega-3 fatty acids, is questionable for many people in the world. Fortunately, studies revealed that the dietary enrichment of broiler chicken ration with omega-3 fatty acids enriched the broiler chicken meat with omega-3 fatty acids. Hence, consumption of such broiler chicken meat may supplement the scarcity of consumption of omega-3 fatty acids rich foods viz. fish. Moreover, dietary enrichment of omega-3 fatty acids improves carcass by reducing the abdominal fat deposition in broilers. However, shelf-life of broiler chicken meat that is enriched with omega-3 fatty acid is low due to high levels of lipid oxidation. However, usage of antioxidants improves the shelf-life of omega-3 fatty acid enriched broiler chicken meat.

Performances and haematological profile of broilers fed fermented dried cassava (Manihot esculenta Crantz).

The effect of feeding fermented dried cassava (gathot) on the performances and haematological profile of broilers was investigated. There were four dietary treatments arranged in a completely randomized design, i.e. control diet and diets containing 25, 50 or 100g/kg gathot. The birds were provided with the treatment diets ad libitum from 8 to 35days of age. Body weight, feed intake and feed conversion ratio (FCR) were determined weekly. At day 32, the birds were blood sampled, sacrificed and immediately the internal organs and abdominal fat were removed and weighed. Feeding gathot at various levels did not affect (P > 0.05) the growth and FCR, but tended (P = 0.09) to reduce the feed cost per kilogramme live weight gain of broilers. The dietary treatments did not cause toxicological effect on broilers, indicated by the values of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) that were not different from those in the control diet. Dietary inclusion of gathot lowered heterophils to lymphocytes ratio (H/L ratio) (P < 0.05) and albumin to globulin ratio (A/G ratio) (P = 0.14) of broilers as compared to the control diet. Total triglyceride was lower (P < 0.05) in the serum of broilers fed diets containing 5 and 10% of gathot, when compared with that in the control diet. The treatments resulted in reduced abdominal fat deposition in broilers. In conclusion, dietary inclusion of gathot at up to 10% had no negative impact on the growth performance of broilers. Feeding gathot has potential to improve the health and physiological stress responses as well as reduce body fat deposition in broilers.

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 4weeks: normal control (NC) group, L-EGCG (a low-level supplement of EGCG, 40mg/kg body weight daily) and H-EGCG (a high-level supplement of EGCG, 80mg/kg body weight daily). After 4weeks 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 2weeks 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.

Expression profiling of candidate genes for abdominal fat mass in domestic chicken Gallus gallus

The quantitative traits of mass and percentage of abdominal fat in chicken and various types of obesity in mammals are homologous and functionally similar. Therefore, the genes involved in obesity development in humans and laboratory rodents as well as those responsible for pig lard thickness could be involved in abdominal fat deposition in broilers. Expression of candidate genes FABP1, FABP2, FABP3, HMGA1, MC4R, PPARG, PPARGC1A, POMC and PTPN1 was studied in fat, liver, colon, muscle, hypophysis, and brain in chicken (broilers) using real-time PCR. Significant difference in the HMGA1 gene expression in the liver of broiler chicken with high (3.5 +/- 0.18%) and low (1.9 +/- 0.56%) abdominal fat concentration has been revealed. The expression of this gene was been shown to correlate with the amount (0.7, P < or = 0.01) and mass (0.7, P < or = 0.01) of abdominal fat. The PPARG gene expression in liver in the same chicken subsets was also significantly different. Correlation coefficients of the gene expression with the abdominal fat amount and mass were respectively 0.55 (P < or = 0.05) and 0.57 (P < or = 0.01). Based on these results, we suggest that the HMGA1 and PPARG genes are involved in abdominal fat deposition. The search for single nucleotide polymorphisms (SNPs) in the HMGA and PPARG regulatory regions could facilitate identifying genetic markers for broiler breeding according to the mass and percentage of abdominal fat.

Dietary fatty acid profile modifies abdominal fat deposition in broiler chickens

An experiment was conducted to study the effect of different dietary fatty acid profiles on abdominal fat deposition in broilers. Diets with four types of fats (tallow, olive oil, sunflower oil, and linseed oil), at two levels of fat inclusion (either 6 or 10%), were administered to males from 21 to 42 d and to females from 21 to 49 d of age. The sexes were studied separately. Performance parameters, abdominal fat, muscle fat and cholesterol, and fatty acid profile of thigh, breast, and abdominal fat were determined. Broilers fed sunflower and linseed oils presented better values of feed efficiency. Abdominal fat and cholesterol content of thigh muscle were significantly lower in animals fed sunflower and linseed oils than in those fed tallow or olive oil (P < 0.001). In females, abdominal fat increased with level of fat inclusion only in birds fed tallow or olive oil, whereas it remained constant in birds fed sunflower or linseed oil. Muscle fat content was lower for birds fed tallow or olive oil but not significantly. The fatty acid profile of the different tissues reflected dietary fatty acid profile. Monounsaturated fatty acids were higher in abdominal fat, whereas polyunsaturated fatty acids were higher in muscle fat. These results suggest that polyunsaturated fatty acids produce lower abdominal fat deposition than saturated or monounsaturated fatty acids.

Effects of early feed restriction on the performance of broilers

An experiment was conducted to compare the effects of early feed restriction on the performace and abdominal fat deposition in broilers. The treatments consisted of providing feed ad libitum (Full-fed) and three feed restriction treatments of restricting feeding between 8-21 days of age (DOA) either for a duration of 7 days or 14 days. The three feed restriction treatments were Restrict 8-14 DOA, Restrict 8-21 DOA and Restrict 15-21 DOA. Liveweights and feed consumption were obtained at weekly intervals. Samples of both male and female broilers broilers were taken at 43 DOA to determine the weight of abdominal fat, liver and gizzards. Feed efficiency was generally improved by feed restriction, but a compensatory gain was not observed in the restricted groups. Broilers on restricted feeding also had lower mortality as compared to the full-fed broilers. There is no effect of early feed restriction on the weight of the abdominal fat and the dressing percentages but the weights of the liver and gizzard were affected by restriction. Also there was an effect of sex on the weights of the abdominal fat, the liver and gizzard of the males and females.

Effect of Differing Light Intensities on Abdominal Fat Deposition in Broilers

Two trials were conducted in an attempt to determine if light intensity affected fat content of broilers as measured by the amount of abdominal fat. The light regimens used from 10 days of age had constant intensities of 2 or 52 lx. Results obtained showed that light intensity did not significantly influence the amount of abdominal fat produced by males or females at either 49 or 63 days of age. Light intensity had no significant effect on body weight, feed conversion (grams feed per gram body weight), or mortality at either 48 or 62 days of age for broilers of the same sex. The amount of light used was the amount produced from either 7.5 or 75-W incandescent bulbs in an enclosed house that was 11 m wide with two strings of light bulbs 2.1 m high on 3-m centers equidistant from the ends and sidewalls of the house.

Feather Meal as a Nonspecific Nitrogen Source for Abdominal Fat Reduction in Broilers During the Finishing Period

Earlier studies have shown that excessive abdominal fat deposition in broilers can be overcome by feeding feather meal (FM) during the finishing period (7 or 14 days prior to slaughter). Studies were conducted to determine if the observed fat reduction in FM-fed birds was due to factors other than supplying excess protein.The FM was added at levels of 4, 6, and 8% and glycine at levels of .125, .25, and .5%, similar to amounts contributed by corresponding levels of FM. Corn-soybean diets were also formulated at protein levels corresponding to those of FM diets. All experimental diets were fed from 35 to 49 or from 42 to 49 days of age.There were no significant differences in weight gain and feed efficiency of treatment and control groups during the study. The addition of glycine resulted in a significant (P<.05) reduction in abdominal fat content and appeared to be partially responsible for the observed reduction in FM-fed birds. Increasing the dietary protein level also significantly (P<.05) reduced abdominal fat deposition regardless of protein source. The study indicates that lower quality protein sources such as FM can be effectively used as a nonspecific nitrogen source for reducing abdominal fat deposition during the finishing period.