scholarly journals The Effects of Feed Restriction and Isolated or Group Rearing on the Measurement of Individual Feed Intake and Estimation of Feed Conversion Ratio in Juvenile Nile Tilapia (Oreochromis niloticus) for Selective Breeding Purposes

2021 ◽  
Vol 11 ◽  
Author(s):  
Charles Rodde ◽  
Marc Vandeputte ◽  
Trong Quoc Trinh ◽  
Vincent Douchet ◽  
Marc Canonne ◽  
...  

Accurately measuring the phenotype at the individual level is critical to the success of selective breeding programs. Feed efficiency is a key sustainability trait and is typically approached through feed conversion ratio (FCR). This requires measurements of body weight gain (BWG) and feed intake (FI), the latter being technically challenging in fish. We assessed two of the principal methods for measuring feed intake in fish over consecutive days: (1) group rearing 10 fish per group and video recording the meals and (2) rearing fish individually on a restricted ration. Juvenile Nile tilapia (Oreochromis niloticus) from the Genetically Improved Farmed Tilapia (GIFT) strain and the Cirad strain were entered into the study (128 GIFT and 109 Cirad). The GIFT strain were reared over three consecutive periods of 7 days each under different feeding, recording, and rearing scenarios (i) in groups fed an optimal ration (g100) or (ii) fed a 50% restricted ration (g50) both with video records of all meals and (iii) reared in isolation and fed a 50% restrictive ration. The Cirad strain were tested similarly but only for scenarios (i) and (iii). All fish were fed twice daily with a calculated ration. Correlations showed the same trends for the GIFT and the Cirad strains. For the GIFT strain, correlations were positive and significant for BWG and FI measured in scenarios (i) and (ii), 0.49 and 0.63, respectively, and FI measured in scenarios (i) and (iii) (0.50) but not for BWG measured in scenarios (i) and (iii) (0.29, NS). The phenotypic correlation estimated for FCR between scenarios (i) and (ii) with fish fed an optimal or a 50% restricted ration was low and not significant (0.22). Feed Conversion Ratio for GIFT fish reared in groups or in isolation and fed with a restricted ration [scenarios (ii) and (iii)] were not significantly correlated either. Social interactions between fish, potentially impacting their efficiency, may explain the results. Therefore, selective breeding programs seeking to improve feed efficiency will need to carefully plan the feeding rate and the rearing system used to estimate FCR in order to optimize selection for the targeted production system.

Author(s):  
Tsukasa Yoshidomi ◽  
Kazuaki Tanaka ◽  
Tatsuya Takizawa ◽  
Satoshi Nikaido ◽  
Tetsuya Ito ◽  
...  

Copy number variation (CNV) of the AMY gene in humans has been enthusiastically studied for its association with starch digestibility and obesity. The alpha-amylase (AMY) is a major starch digestive enzyme in mammals. This study aimed to determine the association between CNV of the porcine pancreatic amylase (AMY2B) gene and feed efficiency. Improvement of feed efficiency in growing pigs is of great economic interest. We assayed the copy number of AMY2B by using real-time quantitative PCR (qPCR) in a Large White pig population. We identified three genotypes for AMY2B CNVs, namely I/I (homozygotes of haplotype I; a chromosome with one copy of AMY2B), I/II (heterozygotes of haplotype I and II; a chromosome with two copies) and II/II (homozygotes of haplotype II). We tested the genotypes of the parental generation consisting of six males, 21 females and 265 offspring piglets to validate the AMY2B CNV genotyping. With very few mistyping exceptions, copy numbers of AMY2B were transmitted to piglets in segregation ratios following Mendelian inheritance. Finally, we performed an association analysis between the CNV of the AMY2B gene and feed efficiency traits in 207 uncastrated male pigs. The generalised linear model analysis showed the significant effects of AMY2B CNV genotype on average daily feed intake, total feed intake and feed conversion ratio during growth from 30 kg to 100 kg body weight. However, it was not associated with average daily gain, backfat thickness and loin eye muscle area. Individuals with the genotype I/I had about 76.6 ± 27.1 g lower average daily feed intake, 5.35 ± 1.90 kg lower total feed intake and 0.089 8 ± 0.026 5 lower feed conversion ratio than individuals with I/II and II/II genotypes. Thus, AMY2B CNV has the potential to be an effective genetic marker that could reduce feed costs for pig farming.  


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 42-43
Author(s):  
Ufuoma G Sorhue ◽  
Ikenna Omeje ◽  
Ifeanyichukwu udeh ◽  
Adimabua M Moemeka ◽  
Raphael E Onainor

Abstract This study was conducted to examine the growth performance and expression patterns of growth hormone gene and insulin-like growth factor in metabolic tissues of pigs fed different unconventional feed sources. A total of 45 growing pigs were randomly assigned to 5 dietary treatments at 9 animals per treatment and 3 animals per replicate. Treatment one (T1) comprise of whole maize (WM) which served as the control, T2: brewers dried grain (BDG), T3: cassava peel meal (CPM), T4: plantain peel meal (PPM) and T5: corn husk meal (CHM) at 35% inclusion in the diet. Data collected and analyzed includes; initial body weight (IBW), final body weight (FBW), average daily feed intake (ADFI), average daily weight gain (ADG), feed conversion ratio (FCR) and feed efficiency (FE). At the end of the feeding trial, three animals per treatment (one animal per replicate) were slaughtered; the duodenum and liver were collected and stored using RNALater prior to RNA extraction. Real-time qPCR was performed in 40cycles using the PowerUp SYBR Green reagent and analysed using the Delta-Delta Ct method. All data were subjected to analysis of variance in a completely randomized design. The results showed that the treatment diets had effect on growth performance with significant differences (P < 0.05) observed for average final weight, average total weight gain, average daily feed intake, feed conversion ratio and feed efficiency while the initial weight were not significantly different (P > 0.05). IGF-2 was differentially expressed in the liver and duodenum across treatments while significant differences were not observed in the expression pattern of the growth hormone gene in both tissues. This study showed promise for the use of unconventional feeding stuffs in pig feeding and reveals that genes influencing performance characters are differentially expressed in relation to the source of unconventional feeds used in compounding pig diet.


2001 ◽  
Vol 52 (4) ◽  
pp. 471 ◽  
Author(s):  
P. F. Arthur ◽  
G. Renand ◽  
D. Krauss

Data on young Charolais bulls were used to evaluate the effect of age of dam, and provide genetic parameter estimates for growth and feed efficiency traits in weaners compared with yearlings. Records on 510 performance test bulls born from 1985 to 1989 and 792 progeny test bulls born from 1988 to 1997 were used, plus available pedigree information (total n = 5493). After weaning (approximately 225 days of age), progeny test bulls were housed in barns and tested until 15 months for all bulls and 19 months of age for half of the bulls. From the records, the test period was artificially partitioned into a weaner and a yearling test. Both tests were for 140 days, with the weaner test commencing at approximately 274 days of age (6–8 weeks after weaning), and the yearling test commencing at approximately 430 days of age. For each test (weaner or yearling), average daily gain, daily feed intake, feed conversion ratio (feed intake per unit weight gain), and residual feed intake (feed intake net of the expected requirements for growth and maintenance) were calculated. Liveweights at 12 and 18 months of age were also studied. Age of dam effect was significant (P < 0.05) for weight at 12 and 18 months of age, and for all weaner traits except residual feed intake. All the traits studied were moderately heritable (0.20–0.46) except for feed conversion ratio in yearlings (0.10). Genetic correlations for the same traits measured in weaners and later in yearlings were less than unity (0.42–0.95), with the 3 highest correlations obtained for weight (0.950.03), feed intake (0.900.07), and residual feed intake (0.750.12). Therefore, for genetic improvement purposes, traits measured in weaners should be considered different from those measured in yearlings, except for weight and feed intake. However, the medium to very high genetic correlations between weaner and yearling tests for most of the traits studied indicate that selection based on weaners will have a positive correlated response in yearlings and vice versa.


2021 ◽  
Vol 41 (2) ◽  
pp. 61-70
Author(s):  
E. O. Ewuola ◽  
B. A. Omoniyi ◽  
J. O. Omotoso

The use of feed additives and plant extracts in rabbit husbandry offers an acceptable way to improve welfare, health and meat quality of rabbits as alternative to the use of antibiotics. In a six-week feeding trial, growth rate, nutrient digestibility, haematology and serum biochemical indices of weaned rabbits fed dietary prebiotics and probiotics as natural growth promoters were investigated. Thirty–two weaned crossbred rabbits of 6–week old with average weight of 446.75±32.1g were randomly allotted to 4 dietary treatments. Diet 1 served as the control without test ingredients while diets 2 (prebiotics-Biotronic®at 4kg/ton), 3 (probiotics- Biovet®-YC at 500g/ton) and 4 (symbiotics: Biotronic® SE and Biovet®-YC) were other treatments. Feed intake, weight gain, feed conversion ratio, feed efficiency, nutrient digestibility, haematological and serum biochemical variables were monitored. The design of the experiment was a completely randomized design. Feed intake was similar among dietary treatments while weight gain of rabbits fed diets 1, 2 and 3 was the same but significantly (p<0.05) higher than rabbits fed diet 4. Feed conversion ratio was not significantly influenced by the treatments. Feed efficiency was significantly (p<0.05) higher in rabbits fed symbiotic supplemented diets compared to others. The dry matter, crude protein, crude fibre, ash, nitrogen free extracts and ether extract digestibility were significantly (p<0.05) higher in rabbits fed diets 2 and 3 than those on diets 4 and the control. Packed cell volume and haemoglobin were significantly (p<0.05) higher in rabbits fed diets 3 and 4 than diets 1 and 2. Erythrocyte and leukocyte count were not significantly different among the treatments. Total protein, albumin and globulin examined revealed that they were not significantly influenced by the dietary treatments, however, alkaline phosphatase was significantly (p<0.05) higher in rabbits fed test diets than the control. Biotronic®SE and Biovet® -YC in this study had a potential to enhance growth in rabbit when used as feed additive without any adverse effect on health status of the animal.


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