The objective of this study was to estimate genetic parameters of body width(BW)to body length(BL)ratio(BW/BL)and of body weight traits(BWT)in turbot,and to elucidate the genetic mechanism of the two traits during ont...The objective of this study was to estimate genetic parameters of body width(BW)to body length(BL)ratio(BW/BL)and of body weight traits(BWT)in turbot,and to elucidate the genetic mechanism of the two traits during ontogeny by dynamic genetic analysis.From 3 to 27 months,BW,BL and BWT of each communally stocked fish were measured every 3 months.The BW/BL ratio was measured at different sampling ages.A twotrait animal model was used for genetic evaluation of traits.The results showed that the heritability values of BW/BL ratio ranged from 0.2168 to 0.3148,corresponding to moderate heritability.The BWT heritability values ranged from 0.2702 to 0.3479 corresponding to moderate heritability.The heritability of BW/BL ratio was lower than that of BWT,except at 3 months of age.Genetic correlation between BW/BL ratio and BWT decreased throughout the measurement period.Genetic correlations were higher than the phenotypic correlations.The current results for estimating genetic parameters demonstrate that the BW/BL ratio could be used as a phenotypic marker of fast-growing turbot,and the BW/BL ratio and BWT could be improved simultaneously through selective breeding.展开更多
<span style="font-family:Verdana;">The growth productivity of broilers is influenced by improving growth performance through improving body weight, average daily gain</span><span style="f...<span style="font-family:Verdana;">The growth productivity of broilers is influenced by improving growth performance through improving body weight, average daily gain</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and feed conversion rate. The objective of the study was to determine the effect of quantitative feed restriction duration on growth performance and carcass characteristics of broilers. A total of 144 day-old broiler chicks were reared in a deep litter system until slaughter at 42 days. Chicks were randomly allocated to three treatments which were replicated three times with 16 birds per replicate. The three treatments were the control (T1), one week of feed restriction (T2), and two weeks of feed restriction (T3). Birds were fed with starter, grower and finisher diets. The average daily gain (ADG), average daily feed intake (ADFI)</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and the feed conversion ratio (FCR) were computed for each week. Carcass weight</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">and internal organs weights were measured. The body weight gained by the birds in T1 was similar </span><span style="font-family:Verdana;">to</span><span style="font-family:Verdana;"> the birds that were restricted for a week. The treatments had a significant effect on the average daily gain in week</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> 4, 5</span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> and 6. The ADG for T2 was higher (P < 0.05) at week 5 after 1 week of restriction, than T1 and T3. The feed conversion ratio was significantly higher in T3 after 2 weeks of restriction. In T2 and T3, feed intake was significantly lower than in birds fed </span><i><span style="font-family:Verdana;">ad</span></i></span><i><span style="font-family:;" "=""> </span></i><i><span style="font-family:Verdana;">libitum</span></i><span style="font-family:Verdana;"> at week 4 at the start of the treatment. There was no significant effect on the relative weights of heart weights, liver, gizzard, feet</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and heads among the treatment groups except for intestine weight which was lower (P < 0.05) in T1 than T2 and T3. It was concluded that broilers that were restricted for one week had a positive result in growth performance. Feed restriction had minimal effect on the organ weights of broiler chickens.</span>展开更多
基金The Earmarked Fund for Modern Agro-Industry Technology Research System under contract No.CARS-47-G01the Ao Shan Talents Cultivation Program supported by Qingdao National Laboratory for Marine Science and Technology under contract No.2017ASTCP-OS04+2 种基金the Agricultural Fine Breed Project of Shandong under contract No.2016LZGC031the Chinese Academy of Fishery Sciences Basal Research Fund under contract No.2016HY-JC0302the National Key Research and Development Program under contract No.2018YFD0900102
文摘The objective of this study was to estimate genetic parameters of body width(BW)to body length(BL)ratio(BW/BL)and of body weight traits(BWT)in turbot,and to elucidate the genetic mechanism of the two traits during ontogeny by dynamic genetic analysis.From 3 to 27 months,BW,BL and BWT of each communally stocked fish were measured every 3 months.The BW/BL ratio was measured at different sampling ages.A twotrait animal model was used for genetic evaluation of traits.The results showed that the heritability values of BW/BL ratio ranged from 0.2168 to 0.3148,corresponding to moderate heritability.The BWT heritability values ranged from 0.2702 to 0.3479 corresponding to moderate heritability.The heritability of BW/BL ratio was lower than that of BWT,except at 3 months of age.Genetic correlation between BW/BL ratio and BWT decreased throughout the measurement period.Genetic correlations were higher than the phenotypic correlations.The current results for estimating genetic parameters demonstrate that the BW/BL ratio could be used as a phenotypic marker of fast-growing turbot,and the BW/BL ratio and BWT could be improved simultaneously through selective breeding.
文摘<span style="font-family:Verdana;">The growth productivity of broilers is influenced by improving growth performance through improving body weight, average daily gain</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and feed conversion rate. The objective of the study was to determine the effect of quantitative feed restriction duration on growth performance and carcass characteristics of broilers. A total of 144 day-old broiler chicks were reared in a deep litter system until slaughter at 42 days. Chicks were randomly allocated to three treatments which were replicated three times with 16 birds per replicate. The three treatments were the control (T1), one week of feed restriction (T2), and two weeks of feed restriction (T3). Birds were fed with starter, grower and finisher diets. The average daily gain (ADG), average daily feed intake (ADFI)</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and the feed conversion ratio (FCR) were computed for each week. Carcass weight</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">and internal organs weights were measured. The body weight gained by the birds in T1 was similar </span><span style="font-family:Verdana;">to</span><span style="font-family:Verdana;"> the birds that were restricted for a week. The treatments had a significant effect on the average daily gain in week</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> 4, 5</span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> and 6. The ADG for T2 was higher (P < 0.05) at week 5 after 1 week of restriction, than T1 and T3. The feed conversion ratio was significantly higher in T3 after 2 weeks of restriction. In T2 and T3, feed intake was significantly lower than in birds fed </span><i><span style="font-family:Verdana;">ad</span></i></span><i><span style="font-family:;" "=""> </span></i><i><span style="font-family:Verdana;">libitum</span></i><span style="font-family:Verdana;"> at week 4 at the start of the treatment. There was no significant effect on the relative weights of heart weights, liver, gizzard, feet</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and heads among the treatment groups except for intestine weight which was lower (P < 0.05) in T1 than T2 and T3. It was concluded that broilers that were restricted for one week had a positive result in growth performance. Feed restriction had minimal effect on the organ weights of broiler chickens.</span>
