Effects of flavonoids from Allium mongolicum Regel on growth performance and growth related hormones in meat sheep Accepted Manuscript Effects of flavonoids from Allium mongolicum Regel on growth perf[.]
Trang 1Effects of flavonoids from Allium mongolicum Regel on growth performance and
growth-related hormones in meat sheep
Muqier, Sarula Qi, Terigele Wang, Renwei Chen, Cuifang Wang, Changjin Ao
PII: S2405-6545(16)30156-1
DOI: 10.1016/j.aninu.2017.01.003
Reference: ANINU 133
To appear in: Animal Nutrition Journal
Received Date: 29 August 2016
Accepted Date: 10 January 2017
Please cite this article as: Muqier Qi S, Wang T, Chen R, Wang C, Ao C, Effects of flavonoids from
Allium mongolicum Regel on growth performance and growth-related hormones in meat sheep, Animal Nutrition Journal (2017), doi: 10.1016/j.aninu.2017.01.003.
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Effects of flavonoids from Allium mongolicum Regel on growth performance and
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growth-related hormones in meat sheep
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Muqier, SarulaQi, Terigele Wang, Renwei Chen, Cuifang Wang, ChangjinAo*
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College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018,
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China
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* Corresponding author
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E-mail address: changjinao@aliyun.com (C Ao)
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ABSTRACT
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This study was conducted to investigate the effects of different doses of flavonoids
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from Allium mongolicum Regel on the production performance and neuroendocrine
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hormones in meat sheep and to determine the optimum dosage of Allium mongolicum
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Regel flavonoids to add to the basal diet of dry lot-feeding meat sheep Sixty meat
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sheep (initial body weight = 39.9 ± 3.2 kg; 6-month-old) were randomly assigned to 4
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groups (15 sheep per group) The sheep in the control group were fed a basal diet, and
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the 3 experimental groups were fed the basal diet supplemented with flavonoids at 11,
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22 and 33 mg/kg Blood samples were collected via the jugular vein at d 0, 15, 30, 45,
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and 60 to determine the neuroendocrine hormone levels The fasting weight of the
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sheep was measured during the experimental period, and feed offered and refusals
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were recorded daily The basal diet supplemented with flavonoids from 11 to 33 mg/kg
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significantly increased the daily weight gain and average daily feed intake (P < 0.05)
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and significantly decreased the feed conversion ratio (P < 0.05), but there were no
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differences among the supplementation groups (P > 0.05) Starting on d 30, the growth
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hormone (GH) and insulin-like growth factor-I (IGF-I) levels in the sera of the sheep in
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the supplementation groups increased significantly (P < 0.05), and the increases
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occurred in a time-dependent manner Compared with control group, after d 30, the
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serum corticosterone (CORT) levels were reduced in the sheep that consumed the basal
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diet supplemented with 22 mg/kg flavonoids (P < 0.05), but among the other
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experimental groups, there was a non-significant effect (P > 0.05) The serum
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adrenocorticotropic hormone (ACTH) levels were increased by the supplementation of
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flavonoids, but compared with the control group, the effect was not significant The
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basal diet supplemented with flavonoids at levels of 11 to 33 mg/kg had a significant
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effect on the production performance and neuroendocrine hormone levels of meat
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sheep, and the effect occurred in a time-dependent manner The effect was especially
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obvious after 30 d of feeding
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Key words: Allium mongolicum Regel, Flavonoids, Growth performance, Hormones,
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Meat sheep
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1 Introduction
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Allium mongolicum Regel, also known as the Mongolia leek, is a type of
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Liliaceous allium plant that grows in high altitude desert steppe and desert areas; it is
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perennial and xerophytic (Wang et al., 2013) It is mainly found in desert land in
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Qinghai, Gansu, Xinjiang and Inner Mongolia, and is especially abundant in the
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western areas of Xilingol, Ordos, and Alxain Inner Mongolia Allium mongolicum
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Regel, as a characteristic wild vegetable, is a natural and healthy food with a high
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nutritional value, unique flavour and supreme palatability (Chen et al., 2000) Allium
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mongolicum Regel and its extracts have been shown to increase the average daily gain
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(ADG), feed intake and feed remuneration of broiler chickens (Ha, 2008) and to
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significantly affect growth-related hormones (Zhang, 2005)
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Flavonoids are active ingredients in natural plants that can promote growth,
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neuroendocrine and immune function of animals Related research found that the
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isoflavone daidzein promoted animal growth (Han, 1999), improved immune function
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(Guo et al., 2004), and enhanced lactation and laying (Hu and Zhang, 2009; Yang,
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2006) Flavonoids are an important active substance in Allium mongolicum Regel (Sa,
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2014a) According to research, Allium mongolicum Regel flavonoids show
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biological efficacy as anti-oxidants and have anti-bacterial and immune regulation
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abilities Allium mongolicum Regel provides small doses, low toxicity, and high
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efficacy in practical application; consequently, it offers good latent capacity for new
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types of feed additives Animal growth is a complicated metabolic process influenced
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by genes, nutrients, hormones and the environment and regulated by neuroendocrine
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function (Tao, 2006), of which the hypothalamic-pituitary-growth axis is the key
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regulator(Sarah, 2003)
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Currently, research on the flavonoids from Allium mongolicum Regel has mainly
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focused on its in vitro anti-oxidant, anti-bacterial and anti-viral activities; studies of
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growth performance and growth-related hormones in meat sheep are rare On the basis
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of a preliminary in vitro study (Bao, 2015; Sa, 2014b), this study selected the
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flavonoids from Allium mongolicum Regel as feed additives for meat sheep Different
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doses of flavonoids from Allium mongolicum Regel were added to the basal diet, and
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the effect on growth performance and growth-related hormones in meat sheepwas
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explored A suitable amount of flavonoids from Allium mongolicum Regel was
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determined for use as a natural feed additive
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2 Materials and methods
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2.1 Experimental flavonoids from Allium mongolicum Regel
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The flavonoids from Allium mongolicum Regel were extracted using the
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extraction processing method described by Saruli (Sa, 2014b) An ultrasonic extraction
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method was adopted using the following parameters: extraction time = 15 min,
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extraction temperature = 40 °C, alcohol density =75%, and material-to-liquid ratio =
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1:30 The projected total flavonoid yield was 12.85 mg/g The flavonoids from Allium
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mongolicum Regel are yellow in colour and insoluble in water According to early
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research regarding structure identification (Sa, 2014b), the structure contains
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saccharides, naphthenic hydrocarbon,3',4' -epoxygroup-7-0-5-methoxy flavonols,
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7-0-5,4'-dimethoxy-3'-hydroxide radical flavones, rutin, quercitrin, saccharides,
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mignonette element - 5 0 - glucose - 4 - hydroxybenzoic acid, and acacia
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2.2 Reagents and apparatus
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Testing kits were used to determine the levels of serum growth hormone (GH;
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HY-C0018), serum insulin-like growth factor-1 (IGF-1; HY-H0024), serum
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corticosterone (CORT; HY-D0032), and serum adrenocorticotropic hormone (ACTH;
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HY-D0023) The testing method was radioimmunoassay, and the test apparatus was an
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r-911 auto radio free counter (provided by the Science and Technology Industrial
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Company of the University of Science and Technology of China) All
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reagents and apparatuses were provided by the Beijing Sino-UK Institute of Biological
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Technology
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2.3 Experimental method
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2.3.1 Selection of experimental animals
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A total of 60 six-month-old healthy meat sheep with initial body weight of 39.9 ±
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3.2 kg were divided into 4 groups of 15 sheep, which included the control group, test
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group1, test group 2 and test group 3
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2.3.2 Experimental diet
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The control group was fed a basal diet, and the 3 test groups were supplemented
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with 11, 22, and 33 mg/kg flavonoids from Allium mongolicum Regel According to the
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stability test of flavonoids from Allium mongolicum Regel in the rumen, adding 22
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mg/kg of total flavonoids from Allium mongolicum Regel to the rumen could improve
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parameters related to rumen microbial fermentation gas production, pH, ammonia
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nitrogen, microbial protein, and volatile fatty acids and could optimize the effects of
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the flavonoids (Bao, 2015) This study referred to these previous results when choosing
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the supplementation doses (11, 22, and 33 mg/kg) of flavonoids from Allium
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mongolicum Regel The components of the experimental diet testing method (Zhang,
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2003) were as follows: 1) The crude protein of the feedstuff was tested using the
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Kjeldahl Nitrogen Determination method; 2) The Van Soest detergent fibre analysis
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method was used for the determination of neutral detergent fibre (NDF) and acid
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detergent fibre (ADF) contents; 3) The calcium content of feedstuff was tested using
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potassium permanganate titration; 4) The phosphorus content was determined using
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colorimetry with molybdenum yellow The basic dietary composition and nutritional
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levels are shown in Table 1
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2.3.3 Feeding management
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The entire experimental period lasted 75 d, and the adaptation period lasted 15d
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Parasites were expelled, and disinfection and epidemic prevention efforts were applied
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to the experimental sheep The normal experimental period was 60 d, during which
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feed was given at 06:00 and 18:00, and water was given ad libitum The ratio of the
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roughage to concentrate was 7:3 The control group was given the basal diet, and the
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test groups were given the appropriate experimental diet
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2.3.4 Sample collection and treatments
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During the experimental period, feed offered and refusals were recorded, and
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sheep was weighted before feeding at 0, 15, 30, 45, and 60 d, which were prepared to
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calculate the performance index Meanwhile, sterile blood samples from the jugular
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veins of the sheep were bottled into 5-mL tubes containing no anti-coagulant Blood
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samples were stood for 40 min, and centrifuged by an 800 × g vertical centrifuge for
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10 min After sera were separated out, samples were stored at -20 ℃ and prepared for
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hormones testing
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2.3.5 Determination index
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The following variables were measured: average daily gain (ADG), average daily
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intake, average feed conversion ratio, growth hormone (GH), insulin-like growth
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factor-I (IGF-1), corticosterone (CORT), and adrenocorticotropic (ACTH)
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2.4 Statistical analysis
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Statistical analyses were performed using the method for double-factor variance
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analysis GLM in SAS9.0 The values are given as means ± standard deviations The
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significance level of 0.05 was adopted
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3 Results
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3.1 Effect of flavonoids from Allium mongolicum Regel on growth performance
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The growth performance included average daily gain (ADG), average daily feed
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intake and feed conversion ratio
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3.1.1Average daily gain
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The results indicated the F value of experimental time was 2.97, which had an
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obvious effect on ADG (P = 0.03) The results show after 30 d of feeding, ADG
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changed significantly (P < 0.05) However the F value of the interaction effect
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between experimental time and treatment was 0.95, so there were no significant
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interaction effects between them (P = 0.48) Table 2 shows the flavonoids from Allium
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mongolicum Regel had a clear effect on ADG The ADG of the sheep that consumed
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the diet supplemented with flavonoids for 15 d showed no significant change (P > 0.05)
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compared with the control group However, after 30 d, the ADG of the 3 test groups
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showed an increasing trend, and far surpassed that of the control group (P < 0.05)
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After 45 d, the ADG in test group 3 was significantly higher than that of the control
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group (P < 0.05), but the ADG did not vary significantly among the experimental
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groups (P > 0.05) Between d 45 and 60, the flavonoids from Allium mongolicum
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Regel continued to increase the ADG, but increased rate was lower in test group 3 At d
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60, ADG of the 3 test groups was much higher than that of the control group (P < 0.05);
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the ADG of test group 2 was the highest, but it did not differ significantly from the
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ADG of the other 2 test groups (P > 0.05)
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3.1.2 Average daily feed intake
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The analysis showed the experimental time and treatment had an interaction effect,
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and the F value was 12.34 Table 2 shows flavonoids from Allium mongolicum Regel
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could improve the daily feed intake (DFI) of sheep After 15 d of feeding, the DFI did
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not differ among groups, nor did the test groups exhibit any significant alteration (P >
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0.05) compared with the control group However, starting at d 30, the DFI of all groups
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gradually changed; the DFI of test group 3 was the highest and significantly higher
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than that of the control group (P < 0.05) After d 45, the DFI of the 3 test groups
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showed an increasing trend but no big difference (P > 0.05), and their DFI were higher
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than that of the control group At d 60, the DFI of all groups showed increases, but
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those of 3 test groups were significantly higher than that of the control group (P <
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0.05) At d 60, the DFI of test group 3 was the highest, but it did not differ significantly
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from that of other 2 test groups (P > 0.05) Thus, when the experimental time was 60 d,
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the basal diet supplemented with 33 mg/kg flavonoids groups plays an important role
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to the DFI
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3.1.3 Feed conversion ratio
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The results showed the experimental time and treatment had an interaction effect,
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and the F value was 3.1 Table 2 indicates after d 15, basal diet supplement with
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flavonoids from Allium mongolicum Regel had no obvious effect on the feed
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conversion ratio (P > 0.05) After d 30, the feed conversion ratios of the 3 test groups
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decreased and were significantly lower than that of the control group (P < 0.05) At 45
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d, the feed conversion ratios of all groups continued to decrease, with the same
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difference among groups, and the feed conversion ratio of test group 2 was the lowest
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(P < 0.05) From d 45 to 60, the feed conversion ratios of the 3 test groups were
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significantly lower than that of the control group (P < 0.05) The feed conversion ratio
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of test group 3 was lower than that of test group 2, by an insignificant amount (P >
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0.05), and was significantly lower than that of test group 1 (P < 0.05) The flavonoids
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from Allium mongolicum Regel affected the feed conversation ratio from d 30, and the
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effect of test group 3 was the best, until d 60, the feed conversion ratio in test group 3
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was the lowest
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3.2 Serum GH, IGF-1, ACTH and CORT contents in sheep
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3.2.1 Serum GH levels
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At d 45, the content of serum GH was significantly changed (P < 0.05), and
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increased until d 60 when the content was the highest But the results indicated the
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experimental time and treatment did not have interaction effect (F = 1.48) Thus, Table
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3 is the analysis of treatment; it shows at d 0, the GH levels of the control group and
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test groups showed no obvious change (P > 0.05) At d 15, the GH content of test
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group 1 was higher than that of the control group (P < 0.05), but no significant
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difference among test groups (P > 0.05) At d 30, the GH content of the control group
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increased but did not differ significantly from those of other groups (P > 0.05) After d
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45, the GH contents of all 3 test groups were higher than that of the control group (P <
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0.05), but values of test group 2 and 3 did not differ significantly (P > 0.05) After d 60,
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the GH contents of test groups 1 and 2 were higher than that of the control group (P <
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0.05), but there was no significant difference between groups in the amount of GH
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change (P > 0.05) The GH content showed an increasing trend with feeding time, and
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after d 45, the GH content showed significant changes (P < 0.05) Although there were
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no interaction effect on the experimental time and treatment, but at d 60, the test group
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2 exerted its’ best effect on the content of GH levels
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3.2.2 Serum IGF-1 content
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The content of serum IGF-1 was affected by experimental time Result shows
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from d 30 the serum content was changed (P < 0.05) And the results indicated the
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experimental time and treatment did not have interaction effect (F = 0.72) Table 3
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clearly shows at d 0, the addition of flavonoids from Allium mongolicum Regel to the
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basal diet had no obvious effect on the serum IGF-1 content, and the control group and
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all test groups did not show significant differences (P > 0.05) At d 15, the IGF-1
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content increased in all test groups with no significant difference (P > 0.05);
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furthermore, the increase since d 0 was not significant (P > 0.05) After d 30, the
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IGF-1 content of the 3 test groups increased with no significant changes compared with
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that of the control group (P > 0.05) Forty-five days later, the IGF-1 contents of test
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groups 1 and 3 became significantly higher than that of the control group (P < 0.05)
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and non-significantly higher than that of test group 2 (P > 0.05) The IGF-1 contents of
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3 groups were significantly higher than that of the control group at d 60 (P < 0.05); test
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group 3 had the highest IGF-1 levels at this time point, but with no significant
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difference (P > 0.05) The IGF-1 content was the highest after 60 d of feeding and
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showed significant changes (P < 0.05) compared with the contents at d 0 and 15 But
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there were no interaction effect between the experimental time and treatment, thus the
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basal diet supplemented with 33 mg/kg flavonoids from Allium mongolicum Regel and
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fed 60 d would play the best role in the secretion of serum IGF-1
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3.2.3 Serum CORT content
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Result shows at d 30 of feeding, the content of serum CORT level was changed
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obviously (P < 0.05), and at d 45 and 60, the content was higher than values at d 0, 15
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and 30 (P < 0.05) Table 3 shows the basal diet with flavonoids from Allium
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mongolicum Regel did not lead to variations in the serum CORT content (P > 0.05) at
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d 0 After 15 d of feeding, the CORT contents of all test groups decreased, and test
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groups 2 and 3 showed the lowest levels; however, there was no significant difference
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between any of the test groups and the control group (P > 0.05) At d 30, all test groups
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still showed a decreasing trend, and the CORT content of test group 2 was significantly
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lower than that of the control group (P <0.05) and non-significantly lower than those
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of the other 2 test groups (P > 0.05) At d 45, all of the CORT contents of the 3 test
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groups and the control group decreased; the CORT contents of the 3 test groups were
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lower than that of the control group with no significant difference (P > 0.05) At d 60,
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the CORT contents of the 3 test groups were lower than that of the control group, still
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not to a significant degree (P > 0.05) These findings indicate the flavonoids from
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Allium mongolicum Regel could decrease the serum CORT contents in sheep At d 60,
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the content of serum CORT in 3 test groups was the highest
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3.2.4 Serum ACTH content
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Results indicated feeding time affected the serum ACTH levels from d 30 (P <
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0.05), and the contents at d 45 and 60 were higher than the level at d 30 (P < 0.05)
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