The effect of increasing feeding frequency on performance, plasma hormones and metabolites, and hepatic lipid metabolism of broiler breeder hens

Polysaccharide from Hericium erinaceus improved laying performance of aged hens by promoting yolk precursor synthesis and follicle development via liver-blood-ovary axis

Little information is available on the effect of Hericium erinaceus polysaccharides (HEP) on laying hens, especially on improving liver and ovarian health and function. Therefore, this study was conducted to investigate the impacts of HEP on liver and ovarian function to delay the decline in the laying performance of aged hens. A total of 360 fifty-eight-wk-old laying hens were randomly allocated to 4 treatments, with 6 replicates of 15 birds each. After 2 wk of adaptation, the birds were fed basal diet (CON) or basal diets supplemented with 250, 500, and 750 mg/kg of HEP (HEP250, HEP500, and HEP 750, respectively) for 12 wk. The results showed that, compared with CON, hens fed HEP had significantly increased laying performance (P < 0.05) and promoted follicle development, as evidenced by the increased numbers of hierarchical follicles, small follicles, and total follicles (P < 0.05). Birds fed 500 mg/kg of HEP improved the liver function by increasing T-AOC activity (P < 0.05) and decreasing hepatic oxidative stress and inflammatory responses (inflammatory cell infiltration) caused by aging. The lipid metabolism was improved, and yolk precursor synthesis was promoted in the liver of HEP-treated laying hens by upregulating the mRNA expression of FAS, MTTP, PPAR-α, APOVLDL-Ⅱ, and VTG-Ⅱ (P < 0.05). In addition, HEP significantly decreased ovarian inflammation by regulating the mRNA levels of NF-κB, IL-1β, IL-6, and TNF-α (P < 0.05). As a result, the contents of E2, LH, and FSH in serum and the gene expression of ERα of the liver and FSHR of the ovary increased in HEP-treated hens (P < 0.05). In conclusion, dietary HEP supplementation exhibited potential hepatic and ovarian protective effects, thereby increasing the laying performance of aged hens by enhancing reproductive hormone secretion hormone secretion and promoting yolk precursor synthesis and follicle development via the liver-blood-ovary axis. The optimal supplementation level of HEP in aged hens was 500 mg/kg.

Daily feeding frequency affects feed intake and body weight management of growing layers

The objective of this study was to investigate the effect of feeding behavior on feed intake and body weight in growing layers and the underlying mechanisms, thereby providing a scientific foundation for optimal feeding practices in growing layers' management. A total of 144 Hy-line brown growing layers of 10 wk old and similar body weight, were divided into 3 treatment groups with different feeding frequency and equal cumulative daily feeding amount: the once-a-day feeding group (F1) was fed at 9:00 am every day, with feeding amount of 150 g/layer; the twice-a-day feeding group (F2) were fed at 9:00 am and 13:00 pm every day, with each feeding amount of 75 g/layer; the 4 times-a-day feeding group (F4) were fed at 9:00 am, 11:00 am, 13:00 pm, and 15:00 pm every day, with each feeding amount of 37.5 g/layer. Pre-experiment lasted for 1 wk and formal experiment lasted for 8 wk. The results indicated that the daily feed intake and body weight were decreased (P < 0.05) while feed conversion ratio was not affected (P > 0.05) as daily feeding times increased. The glandular stomach proportion was significantly increased in twice-a-day feeding group, while liver proportion and ileum length were significantly increased in 4 times-feeding group (P < 0.05). Additionally, 4 times-feeding daily resulted in a significant elevation of blood glucose levels, which may have suppressed feed intake (P < 0.05). In 4 times-feeding group, the plasma triglyceride levels increased as feeding times, accompanied by a notable up-regulation in the mRNA level of appetite-suppressing gene, hypothalamic pro-opiomelanocortin (POMC) and glandular stomach ghrelin. This modulation effectively suppressed the subsequent feed intake and body weight. Therefore, 4 times feeding daily is recommended in growing layers' management, because it reduced the feed cost without affecting the feed conversion efficiency.

Effects of feeding strategies during lay on broiler breeder production performance, eggshell quality, incubation traits, and behavior

An experiment was conducted to investigate the effects of a standard diet twice a day or split-feeding in broiler breeders on production performance, eggshell quality, incubation traits, and behavior. A total of 720 Ross 308 female breeders (45 weeks of age [WOA]) and 24 males (25 WOA) were randomly placed in 24 floor pens. The birds followed 3 feeding strategies: 1) Standard breeder diet fed once a day (100% at 0730 h) (CON), 2) Standard breeder diet fed twice a day (50% at 0730 h and 50% at 1600 h) (TAD), and 3) Split-feeding fed twice a day, with a morning (0730 h) and afternoon (1600 h) diet (SF). The morning diet contained more energy, protein, and phosphorus (P) and less calcium (Ca) than the control and afternoon diets. The afternoon diet had lower energy, protein, and P and higher Ca content than the control and morning diets. The TAD and SF birds tended to have a lower water intake (P = 0.055) and water-to-feed ratio (P = 0.054) compared to the CON birds. A 2.1% points higher hen-day egg production was found for the SF birds compared to the CON birds (P = 0.063), whereas the TAD birds did not differ from the other treatments. No differences were found for egg weight, eggshell quality, fertility, embryonic mortality, or average feather cover. A tendency toward a higher albumen percentage (P = 0.060) and lower yolk percentage (P = 0.069) was found for the TAD birds compared to the SF birds. The albumen-to-yolk ratio was higher (P = 0.022) for the TAD birds than for the CON and SF birds. Due to the twice-a-day feed distribution, the TAD and SF birds showed considerably different behavioral patterns than the de CON birds. In conclusion, twice-a-day feeding decreases the water intake and water-to-feed ratio, whereas split-feeding tended to an improved egg production in broiler breeders. However, no effects were observed on eggshell quality and incubation traits, whereas the behavioral patterns of the birds fed twice a day differed considerably with potential better welfare.

Plasma metabolomic profiling reveals potential onset of lay biomarkers in broiler breeders

Changes in the metabolic fingerprint of plasma during the onset of lay in broiler breeders were investigated. We used metabolomics to identify biomarkers of sexual maturity and to provide a comprehensive understanding of breeder metabolome during the pullet to hen transition period. A total of 36 pullets were used, in which 30 pullets were randomly assigned to one of 10 unique growth trajectories and 6 birds were assigned to an unrestricted group. The growth trajectories were designed using a 3-phase Gompertz growth model with 10 levels of BW gain in the prepubertal and pubertal growth phases ranging from the breeder-recommended target BW to 22.5% higher, in 2.5% increments. The BW trajectories were applied to each individual bird using a precision feeding (PF) system, which collected BW and feed intake data for each individual bird. The birds were classified based on age at first egg (AFE), and 12 pullets were chosen from the lower and upper AFE extremes (early and late onset of lay) at 18, 20, 22, 24, and 26 wk of age to run repeated blood plasma metabolomic assays. The metabolomic profile data were collected using a direct-injection liquid chromatography-tandem mass spectrometry and steroid assays. Univariate analysis identified 87 differential metabolites between the early- and late-onset of lay groups at 24 wk of age and 104 differential metabolites between the pullet and hen groups. Further investigation of differential metabolites showed 15 potential biomarkers for pullet to hen transition by analyzing the receiver operating characteristic (ROC) curve, mainly consisting of carnitine and choline metabolites. Differential metabolites during the pullet to hen transition were mainly associated with lipid, energy, and amino acid metabolism pathways, which gave clues to the physiological and metabolic shifts resulting from sexual maturation. At 24 wk of age, the main pathways involved in differentiation of the early- and late-onset of lay groups were related to lipid and amino acid metabolism. These metabolites could be involved in biosynthesis of egg yolk precursors in the liver.

Age-related changes in liver metabolism and antioxidant capacity of laying hens

This study aimed to investigate the age-related changes of hepatic metabolism and antioxidant capacity of laying hens at 3 different ages. A total of 192 Hy-line Brown laying hens were assigned into 3 groups: 1) 195-day-old (D195 group); 2) 340-day-old (D340 group); 3) 525-day-old (D525 group). Each group replicated 8 times with 8 hens at the same age. Higher activity of aspartate aminotransferase and lower contents of total protein and globulin were observed in the serum of 525-day-old hens in comparison with their 195-day-old counterparts (P < 0.05). The 525-day-old hens accumulated higher contents of total cholesterol and triglyceride in the liver than 195-day-old birds. Additionally, compared with hens from D195 or D340 group, 525-day-old birds exhibited a lower circulating estradiol level (P < 0.05). For antioxidant capacity, birds in the D525 group showed a higher malondialdehyde concentration in both serum and liver as compared with D195 or D340 group (P < 0.05). The 525-day-old hens also exhibited lower glutathione peroxidase activities in both serum and liver when compared with 195-day-old birds (P < 0.05). Simultaneously, there was a decline of hepatic superoxide dismutase activity in the D525 group in comparison with D195 group (P < 0.05). Compared with 195-day-old counterparts, 340-day-old birds upregulated the mRNA abundance of nuclear factor erythroid-2 related factor 2 and glutathione peroxidase 1 in the liver (P < 0.05). In contrast, hens from D525 group showed the downregulation of hepatic nuclear factor erythroid-2 related factor 2, NAD(P)H quinone dehydrogenase 1, and superoxide dismutase 1 when compared with D340 group (P < 0.05). These results indicated that increasing age can adversely affect liver metabolism and function of laying hens.

Effects of twice a day feeding and split feeding during lay on broiler breeder production performance, eggshell quality, incubation traits, and behavior

Eggshell quality of broiler breeders' eggs decreases at the end of the laying period. Feeding a limited daily allowance of feed in the morning does not supply the necessary nutrients, particularly calcium for eggshell formation, at the right time of the day. Therefore, an experiment was conducted to study the effects of providing a standard diet twice a day or split feeding (special morning and afternoon diet) in broiler breeders on production performance, eggshell quality, incubation traits, and behavior. At 50 wk of age (WOA) 576 females and 48 males were randomly allotted to 24 floor pens and assigned to one of three treatments: 1) Standard breeder diet fed once a day (100% at 0730 h) (CON1x), 2) Standard breeder diet fed twice a day (50% at 0730 h and 50% at 1400 h) (CON2x), and 3) Split feeding fed twice a day, with a special morning (0730 h) and afternoon (1400 h) diet composition (SP2x). The morning diet was energetically comparable with the control diet, but it contained more protein and phosphorus (P) and less calcium (Ca). The afternoon diet had a lower energy, protein and P and a higher Ca content than the control and morning diet. The SP2x birds tended to have a higher egg production between 51 and 55 WOA (27.0 vs. 25.9 eggs; P = 0.088) compared to the CON1x birds, while the CON2x birds (26.6 eggs) did not differ from the other treatments. No differences were found on egg production for the total period (51-60 WOA) and on other production parameters. The different feeding strategies did not affect eggshell quality and incubation traits. However, the feeding strategies affected the behavioral patterns considerably. Twice a day feeding (CON2x and SP2x) resulted in more time spent on eating and sitting, and in less time spent on foraging and object pecking (P ≤ 0.05) compared to feeding once a day (CON1x). In conclusion, twice a day feeding improves behavior and split feeding improves both egg production and behavior in broiler breeders, however, no effects were observed on eggshell quality and incubation traits.

Expression of Lipid Metabolism-Associated Genes in Male and Female White Feather Chicken

Differential lipid metabolic requirements of sexually-mature males and females may influence the regulation of lipid metabolism-associated genes and hence the content of adipose tissue. We measured the expression of eight lipid metabolism-associated genes (fatty acid synthase, FASN; acylglycerol- 3- phosphate O-acyltransferase 9, AGPAT9; peroxisomal proliferator-activated receptor γ, PPARγ; lipoprotein lipase, LPL; carnitine palmitoyl transferase 1 A, CPT1A; carnitine palmitoyl transferase 1 B, CPT1B; acyl-COA dehydrogenase long chain, ACADL; monoglyceride lipase, MGL) in eight tissues (hypothalamus, HYP; liver; heart; pectoralis major muscle, PM; gastrocnemius muscle, GAS; abdominal fat, AF; clavicular fat, CF; subcutaneous fat, SF) of five male and five female white feather chickens using real time PCR at 217 d (when the females were at peak egg production). There were no difference between sexes, nor were there sex by tissue interactions for CPT1A and MGL. In both cases expression was greater for liver than the other tissues. When interactions of sex by tissue were significant, the FASN mRNA abundance in HYP, liver, and PM was greater for females than males. There was no sexual dimorphism for any tissue for PPARγ. Overall values were greater for adipose depots than HYP and liver with muscles intermediate for AGPAT9. LPL mRNA abundance in PM and AF was greater for females than males, with the pattern reversed for heart and SF. CPT1B mRNA abundance in GAS and CF was greater for females than males, with the relationship reversed for liver. ACADL mRNA abundance in HYP, liver, and GAS was greater for females than males, and lower in PM than males. The results demonstrated that expression of lipid metablism–associated genes varies among sexes in mature chickens depending on the gene and the tissue.

Effect of Two-step Time-restricted Feeding on the Fattening Traits in Geese

The present study was conducted to determine whether the two-step time-restricted feeding improves the fattening traits of one-step time-restricted feeding in geese. Thirty-six 8-wk-old geese were allotted into one of three groups. Group R1 (the 1-step restricted feeding group) was allowed access to feed for 2 h in the morning from 8 wk to 14 wk of age. Group R2 (the 2-step restricted feeding group) was treated as Group R1, but was additionally fed for 2 h in the afternoon from 12 wk to 14 wk of age. Group C (the control group) was fed ad libitum from 8 wk to 14 wk of age. Feed intake and body weight (BW) were recorded daily and weekly, respectively. At 14 wk of age, the blood samples were collected to determine the fasting plasma levels of glucose, triacylglycerols and uric acid before sacrifice. The results showed that daily feed intake (DFI) was lower, feed efficiency (FE) was higher in both Groups R1 and R2 than in Group C, and daily gain (DG) in Group R2 was higher than in Group R1 during the whole experimental period (p<0.05). Group R1 exhibited lower abdominal and visceral fat weights in carcass than did Group C (p<0.05), and Group R2 was in intermediate. The fasting plasma glucose levels in Group C were higher, and triacylglycerol levels in Group R1 were higher, compared with the other groups (p<0.05). It is concluded that time-restricted feeding in the fattening period not only increases FE but reduces DFI, and the additional meal during the late fattening period improves the DG without the expense of FE in geese.