scholarly journals Genetic improvement of feed conversion ratio via indirect selection against lipid deposition in farmed rainbow trout (Oncorhynchus mykiss Walbaum)

2016 ◽  
Vol 116 (9) ◽  
pp. 1656-1665 ◽  
Author(s):  
Antti Kause ◽  
Anders Kiessling ◽  
Samuel A. M. Martin ◽  
Dominic Houlihan ◽  
Kari Ruohonen

AbstractIn farmed fish, selective breeding for feed conversion ratio (FCR) may be possible via indirectly selecting for easily-measured indicator traits correlated with FCR. We tested the hypothesis that rainbow trout with low lipid% have genetically better FCR, and that lipid% may be genetically related to retention efficiency of macronutrients, making lipid% a useful indicator trait. A quantitative genetic analysis was used to quantify the benefit of replacing feed intake in a selection index with one of three lipid traits: body lipid%, muscle lipid% or viscera% weight of total body weight (reflecting visceral lipid). The index theory calculations showed that simultaneous selection for weight gain and against feed intake (direct selection to improve FCR) increased the expected genetic response in FCR by 1·50-fold compared with the sole selection for growth. Replacing feed intake in the selection index with body lipid%, muscle lipid% or viscera% increased genetic response in FCR by 1·29-, 1·49- and 1·02-fold, respectively, compared with the sole selection for growth. Consequently, indirect selection for weight gain and against muscle lipid% was almost as effective as direct selection for FCR. Fish with genetically low body and muscle lipid% were more efficient in turning ingested protein into protein weight gain. Both physiological and genetic mechanisms promote the hypothesis that low-lipid% fish are more efficient. These results highlight that in breeding programmes of rainbow trout, control of lipid deposition improves not only FCR but also protein-retention efficiency. This improves resource efficiency of aquaculture and reduces nutrient load to the environment.

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1157
Author(s):  
Kerry Houlahan ◽  
Flavio S. Schenkel ◽  
Dagnachew Hailemariam ◽  
Jan Lassen ◽  
Morten Kargo ◽  
...  

The inclusion of feed efficiency in the breeding goal for dairy cattle has been discussed for many years. The effects of incorporating feed efficiency into a selection index were assessed by indirect selection (dry matter intake) and direct selection (residual feed intake) using deterministic modeling. Both traits were investigated in three ways: (1) restricting the trait genetic gain to zero, (2) applying negative selection pressure, and (3) applying positive selection pressure. Changes in response to selection from economic and genetic gain perspectives were used to evaluate the impact of including feed efficiency with direct or indirect selection in an index. Improving feed efficiency through direct selection on residual feed intake was the best scenario analyzed, with the highest overall economic response including favorable responses to selection for production and feed efficiency. Over time, the response to selection is cumulative, with the potential for animals to reduce consumption by 0.16 kg to 2.7 kg of dry matter per day while maintaining production. As the selection pressure increased on residual feed intake, the response to selection for production, health, and fertility traits and body condition score became increasingly less favorable. This work provides insight into the potential long-term effects of selecting for feed efficiency as residual feed intake.


2021 ◽  
Vol 42 (6supl2) ◽  
pp. 4009-4022
Author(s):  
Thiago Rodrigues da Silva ◽  
◽  
Karina Márcia Ribeiro de Souza Nascimento ◽  
Charles Kiefer ◽  
Luanna Lopes Paiva Copat ◽  
...  

The present study proposes to examine the effect of dietary levels of metabolizable energy, under a fixed nutrient:calorie ratio, on the production performance; body fat and protein deposition; and carcass characteristics of free-range broilers from 1 to 84 days of age. Nine hundred unsexed chicks were allocated to six treatments in a completely randomized design with six replicates of 25 birds each. Treatments consisted of diets with varying levels of metabolizable energy (2700, 2800, 2900, 3000, 3100 and 3200 Kcal ME/kg of diet) and a fixed proportion of nutrients relative to the energy level according to the nutritional requirements for each rearing phase. Body weight, weight gain, feed intake, feed conversion, production viability, metabolizable energy intake, protein intake, lysine intake, body fat deposition, body protein deposition and carcass characteristics were evaluated. Data were subjected to analysis of variance and, later, to regression analysis. Increasing levels of metabolizable energy, coupled with a fixed nutrient:calorie ratio, reduced feed intake, increased body weight and weight gain, improved feed conversion and did not affect carcass characteristics. In conclusion, adjusting the nutrient supply according to the dietary energy level improves production performance by improving feed conversion, ensuring adequate nutrient intake and preserving fat and protein deposition in the carcass when the metabolizable energy level is raised up to 3200 Kcal/kg in all rearing stages.


2021 ◽  
Vol 15 (2) ◽  
pp. 154-161
Author(s):  
Eliete Souza Santana ◽  
José Neto Cassiano de Camargo ◽  
Michele Laboissière ◽  
Roberto Moraes Jardim Filho

The objective of this work was to evaluate the effects of two types of incubation and two types of feeding on the performance of chickens and intestinal development of chicks during the pre-starter phase (1 to 7 days of age). One-year-old male Ross® chicks were used. The experimental design was a randomized complete block design, in a 2x2 factorial design, with two types of feed processing (bran and micropelleted) and two types of incubation machines (single and multiple stage), totaling four treatments, with four treatment repetitions each. Twelve birds per experimental unit were used, totaling 192 animals. Performance evaluations were conducted, such as mean weight, weight gain, feed intake, feed conversion, bowel weight and size, and percentage of intestine in relation to live weight. Histomorphometric tests on the height of the villi and depth of the duodenal crypts were also performed. The two incubation machines did not influence any of the analyzed variables. Even though both had the same composition, the micropelleted feed resulted in positive gains for the performance variables: average weight, weight gain, feed intake, and feed conversion when compared to the meal, but was unable to significantly influence the morphometric measurements of the duodenum of chicks in the pre-starter phase.


1995 ◽  
Vol 25 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Claudia Helena Tagliaro ◽  
Maria Helena Lartigau Pereira Franco ◽  
Werner Meincke ◽  
Gilberto Silva

Fourteen protein systems coded by 15 structural loci were typed by horizontal electrophoresis to determine possible associations betweem the protein phenotypes and productive traits in Landrace (N=109), Largo White (N= 116) and Duroe (N=57) pigs, reared in Southern Brazil. Signiticant associations between protein phenotypes and production traits were detected. The most consistent interaction were observed between two protein systems (phosphogluconate dehydrogenase - Pgd and Hemopexin -Hpx) and at least one of the four performance variables considered. In Duroc breed, the Pgd phenotypes were associated with daily weight gain (P < 0.01), feed conversion ratio (P < 0.01) and selection index (P < 0.001), while in Landrace significant associations were observed only with feed convertion ratio (P < 0.05). The Hpx phenotypes were associated with daily weight gain (P < 0.05) and backfat thickness (P < 0.05) in Large White and with this last variable (P < 0.01) and selection index (P < 0.05) in Duroc pigs. Since these results had not been reported previously, turther studies are need to confirm these associations.


2011 ◽  
Vol 27 (3) ◽  
pp. 769-776 ◽  
Author(s):  
H. Pingel

Increasing breast muscle percentage by selection for breast layer thickness (muscle and skin) of living ducks by needle probe improves carcass quality as could be demonstrated by experiments and by applied breeding programs. In addition direct selection for individual feed conversion ratio can increase the efficiency of duck meat production. Divergent selection for feed conversion ratio from the age of 4 - 7 weeks over 11 generations has differentiated the feed efficiency by about 25 %. Causes for the reduction in feed conversion ratio are lower fat content of carcass, lower locomotor activity, higher enzymatic activity (alkaline phosphatase and creatinkinase in blood plasma) and better feed protein utilization. Because of lower feed consumption in the line selected for lower feed conversion ratio the emission of nitrogen and phosphorus via manure was reduced by about 39 and 26 %, respectively. That means, selection for better feed efficiency is not only an important economical but also an important ecological factor.


2014 ◽  
Vol 92 (3) ◽  
pp. 955-965 ◽  
Author(s):  
A. L. Grion ◽  
M. E. Z. Mercadante ◽  
J. N. S. G. Cyrillo ◽  
S. F. M. Bonilha ◽  
E. Magnani ◽  
...  

2020 ◽  
Vol 44 (2) ◽  
pp. 262-270
Author(s):  
O. O. Egbewande ◽  
A. A. Jimoh ◽  
B. Y. Amore ◽  
B. Y. Amore

In this study, the effect of three different sources of maggot meals was conducted to evaluate the performance and slaughter characteristics of broiler chickens. Five diets were formulated to include Diet 1 (control) which contained 3.5 % fish meal, while Diets 2, 3 and 4 contained 3.5% maggot meal from broiler droppings (BMM),maggot meal from layers droppings (LMM) and maggot meal from rabbit faeces (RMM) respectively. Eighty (80) dayold unsexed Marshall Broilers were randomly allotted to four dietary treatments in a completely randomized design (CRD). Thedietary treatments had 20 birds each with two (2) replicates. Data were generated on proximate analysis and performance indices including feed intake and weight gain, slaughter characteristics and mortality rate. They were subjected to analysis of variance (ANOVA) and means significantly different were separated using Duncan's Multiple Range Test (DMRT) at 5% probability level. Results from proximate analysis showed that maggots from layer droppings had the highest crude protein and ether extract. Results on performance indices showed that birds fed on diet 3 (layer maggot meal) had significantly (P<0.05) best performance than others as regards feed intake. Layer maggot meal (LMM) in this study enhanced bestproductive performance compared to those from broiler and rabbit maggot.Birds fed layer maggot meal had the best (1.85) feed conversion ratio. They also had the best body weight gain (2501g) and feed intake (4627g). In conclusion, layer maggot meal is recommended as analternative animal protein source to expensive fish meal.


2020 ◽  
Vol 47 (3) ◽  
pp. 67-76
Author(s):  
D. N. Onunkwo ◽  
O. A. Ekine

This study was conducted to assess the effects of abattoir wastes (bovine blood and rumen content mixture) on the haematology and growth performance characteristics of broiler birds. One hundred and twenty (120) unsexed day old Abor acre broiler chicks were randomly assigned to 4 treatments and replicated 3 times in a completely randomized design (CRD) experiment. Four experimental diets were formulated to meet the nutrient requirement of broilers such that the birds were fed sundried abattoir waste (bovine blood and rumen content mixture) included at 0%, 5%, 10% and 15% representing Diet 1, 2, 3 and 4 respectively, with Diet 1 as the control. Each dietary treatment consists of 30 birds with 10 birds per replicate. The experimental diets and clean water were supplied at- libitum throughout the experimental period. Data were collected on feed intake, daily weight gain, final body weight, weight gain. Feed conversion ratios were calculated. Blood samples for hematology was collected, analyzed and recorded. At the end of the 56 days feeding trials, data collected on different parameters were subjected to analysis of variance (ANOVA). Results showed that mixtures of bovine blood and rumen content significantly (P<0.05) improved the final weight (1767.02g -1931.44g), weight gain (1367.02g -1528.44g), feed intake (107.47g -118.99g) and feed conversion ratio (4.87 – 4.08) of the broilers. Significant (P<0.05) improvements were observed on the RBC, WBC, MCV, MCH, eosinophyls and the lymphocytes of the haematological parameters of the broilers. These results showed the complementary potentials of bovine blood and rumen content mixture in broiler diets, which can be included up to 15% in the ration of broilers without detrimentally affecting the growth performance and haematology of the broilers.


2020 ◽  
Vol 46 (4) ◽  
pp. 9-15
Author(s):  
A. A. Famakinwa ◽  
O. A. Adebiyi ◽  
T. O. Bankole ◽  
P. O. Idahosa

This study was carried out to determine the effect of object combination as environmental enrichment on behaviour of growing pigs. Thirty-six (36) crossbreed (Large White X Landrace) growing pigs with average weight of 34-36Kg were allotted randomly into four treatments, replicated three times in a completely randomized design. The four treatments were; Control (without enrichment), PRope (2 pieces of polyester rope), treatment SWood (2 pieces of soft wood) and treatment PRope+SWood (1 piece of soft wood and 1 piece of polyester rope). Behavioural observations were monitored by CCTV and recordings were made for 6 hours/day and 3days/week. At the end of the experiment, data collected includes average feed intake and average weight gain while feed conversion ratio was calculated. Likewise, behavioural observations; enrichment use, general activities, pen manipulation and pen-mate manipulation were observed. Behavioural data were analyzed using repeated measures analysis of variance (ANOVA) while performance data were analysed using one-way ANOVA. Performance data were significantly influenced (P<0.05) by enrichments for all the parameters measured. PRope+SWood had the highest value for the final weight (50.63kg), average weight gain (15.95kg) and average feed intake (56.61kg) while PRope had the highest FCR 4.18). Penmate manipulation (10.48%), pen manipulation (19.02%) and general activities (14.62%) were lower and significantly better for PRope+SWood compared to PRope and SWood and the highest interaction with enrichment objects was observed in the PRope+SWood (55.88%). It can be concluded that the use of combination of enrichment objects enhanced the performance and behaviour of pigs.


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