Economic efficiency of fattening on different genotypes slow-growing and fast-growing broiler chickens

  1. Oblakova*, Y. Popova, P. Hristakieva, N. Mincheva, M. Lalev

 

Agricultural Institute, 6000 Stara Zagora, Bulgaria

(Manuscript received 21 June 2017; accepted for publication 16 January 2018)

 

Abstract. In the present study six lines from the National Gene Pool (Bulgaria) were used, four of which – line NG (New Hampshire G), line E (Barred Plymouth Rock), line Ss (Sussex) and line F (NG x Red Rhode Island) as maternal forms in the crossing schedule and two sire lines, meat type – line L (White Plymouth Rock) and line M (Cornish), for production of slow-growing broilers. The effect of genotype on meat quality traits was studied with 5 groups of 150 unsexed day-old chicks from each genotype, and after the manifestation of sexual dimorphism – male and female chickens at 70 and 84 days of age. In valuation on revenues and costs of the fattening of the compared groups current prices at the time of the experiment were used. Cost of feed is determined according to the actual feed. In determining the economic efficiency of fattening, three variants of sales prices per kg of meat – 3.60 BGN/kg, 4.65 BGN/kg and 5.30 BGN/ kg have been analysed. The rate of profitability is a synthetic indicator for economic efficiency, calculated by the formula: NP = (Profitability / Production costs) * 100, %. Feed expenses for experimental group I were lowered by 22.8%, while in groups II, III, and IV- by 13.48%, 9.42% and 9.05%, respectively, compared to group V, which registered the highest consumption of feed in the amount of 5.52 BGN. The share of feed expenses in group I was 53.45% of total expenses, and in groups II, III, and IV group they were 59.88%, 56.30%, 57.50%, and 56.87%, respectively. The highest profits per the accepted sale prices were observed in group V- 10.71 BGN, 13.68 BGN and 15.52 BGN, respectively, followed by group IV with 8.56 BGN, 10.92 BGN, and 12.38 BGN, respectively.  At a level of sale prices of 3.60 BGN/kg a positive value of profitability was registered for the fattening of chickens from group V – 16.03%. In all other groups, the profitability norm was negative. At a level of sale prices of 4.65 BGN/kg, the highest profitability was observed in the chickens of group V – 48.21%, followed by group IV – 25.37%, while the lowest cost efficiency was in group III – 4.24%. In the variant with a sale price of 5.30 BGN/kg, the profitability norm was the highest in group V – 68.14%, followed by group IV – 42.13% and group II – 40.98%, while the lowest level was in group III – 18.21%.

Effect of dietary garlic powder and probiotics supplementation on growth performance of male classic broilers

  1. Lukanov1*, I. Pavlova2, A. Genchev1

 

1Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

2Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 6 December 2017; accepted for publication 24 January 2018)

 

Abstract. This study was conducted to evaluate the growth performance of male classic broiler chickens whose feed was supplemented with either garlic powder, probiotics or both. A total of 120 day-old male Ross 308 broiler chickens were divided into 4 groups: first group – control; second group: fed feed supplemented with Lactobacillus spp. probiotic combination; third group: fed feed supplemented with 0.4% garlic powder and fourth group: fed both 0.4% garlic powder and Lactobacillus spp. The experiment lasted until the 35th day of age. The results showed that the highest live weight at the end of the experiment was established in the group supplemented with probiotic+garlic powder (2257.51±3.87g), and the lowest – in the control group (2171.37±4.71g). The group supplemented with probiotic+garlic powder exhibited the highest average weekly weight gain during the 2nd, 3rd and 4th week of life and the highest total weight gain (2211.58±3.91g). The groups fed probiotic and probiotic+garlic powder had the most efficient feed conversion ratios (1.43±0.2). During the study period, there was no substantial decline in the consumption of feed containing 0.4% garlic powder. The supplementation of feed with garlic powder+Lactobacillus spp., had a beneficial effect on the growth performance of broiler chickens. Our data, in line with those of other research studies, suggested that the addition of 0.4% garlic powder combined with Lactobacillus spp. to poultry feed increased meat production in broiler chickens.

Carcass traits and meat quality of different slow growing and fast growing broiler chickens

M. Oblakova1, N. Mincheva1, P. Hristakieva1, I. Ivanova1, M. Lalev1, Sv. Georgieva2

1Agricultural Institute – Stara Zagora, 6000, Bulgaria
2Department of Genetic, Breeding and Reproduction, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 3 July 2017; accepted for publication 5 October 2017)

Abstract. The experiment was conducted in the breeder farm of department Population genetics, reproduction and technologies of poultry and rabbits at the Agriculture Institute of Stara Zagora. Five lines from the National Gene Pool of Bulgaria: line Ss (Sussex), line E (Barred Plymouth Rock), line NG (New Hampshire), line F (NG x Red Rhode Island), line L (White Plymouth Rock) were used as maternal forms in the crossing schedule and line M (Cornish) as a paternal form for production of slow-growing broilers. The birds were grown to 84 days. Feeding was done with compound feeds according to the age: starter (1/14 days of age), grower (14/28 days of age), finisher (28/84 days of age). By the end of the experiment, slaughter analysis was performed with 3 female and 3 male broiler chickens per group with live weight corresponding to the average of each genotype. The live weight was determined, as well as the grill weight, the weights of cuts (breast, thighs, wings), edible offal (heart, liver, gizzard) and abdominal fat. On the basis of these data, the slaughter yield and body parts ratios were calculated. The data for the live body weights of birds at slaughtering indicated the highest values for group V – 4040g, followed by groups ІV and ІІ – 3271.67g and 3186.67g, respectively (p<0.05). There was a statistically significant difference between the sexes with superiority of male birds (p<0.001). In the other 3 groups, breast meat percentage ranged from 19.48 to 19.84%. The share of thighs from the grill was the greatest in slow-growing chickens from group II – 33.01%, followed by group І – 32.35%, group IV – 32.18%, and the lowest- in groups ІІІ and V (31.91% and 31.18%, respectively). The analysis of data exhibited a significant effect of the genotype on water content of breast meat (resp. Dry matter), with lower values in slow-growing birds from group III – 73.19% (p<0.05), whereas in the other groups it ranged between 73.44 and 73.62%. The dry matter higher percentage was associated with better lavor of meat. The analysis of the effect of genotype on meat protein content showed that protein content was the highest in the breast of slow-growing chickens from group III- 24.89% and lowest in the breast meat of conventional broilers from group V – 23.86% (p<0.05). In the other 3 groups, it ranged from 24.55 to 24.59%. The protein content of thighs was the lowest in slow-growing birds from group I- 19.49%, and the difference was the highest when compared to groups II and III, also slow-growing (p<0.05). With respect to the thigh fat content, it was the highest in slow-growing chickens from group IV (5.84%), followed by fast-growing from group V (5.33%) and the lowest- in slow-growing birds from group І – 4.12% (p<0.05). The analysis of data showed a statistically significant effect of the sex on water content (p<0.001), fat (p<0.001) and ash (p<0.01). In males, thigh meat contained water and ash and in females more fat. The interaction of genotype and sex effects were important for thigh meat fat content, with highest values in fast-growing females from group V – 5.98% and lowest in slowly growing males from group I – 3.88% (p<0.001). Weak but statistically significant interaction between both factors was found with respect to thigh protein and ash (p<0.05). The highest protein content was established in slow-growing females from group IV (19.81%), whereas thigh ash was with highest percentage in slow-growing males from group II (1.11%).

Histopathological pancreatic changes in broiler chickens with experimental aflatoxicosis

I. Valchev1*, N. Grozeva2, D. Kanakov1, Y. Nikolov1

1Department of Internal Non-infectious Diseases, Faculty of Veterinary Medicine, Trakia University, 6000, Stara Zagora, Bulgaria 2Department of General and Clinical Pathology, Faculty of Veterinary Medicine, Trakia University, 6000, Stara Zagora, Bulgaria

Abstract. Morphological changes in the pancreas of broiler chickens were followed out after experimental aflatoxicosis В1. Also, the possibility to prevent the deleterious effects of AFB1, through dietary supplementation of Mycotоx NG (Ceva Sante Animale, France) was evaluated. The 42-day experiments were carried out with 50 Cobb broiler chickens, divided in 5 groups of 10 chickens: Group I – control; Group II – supplemented with 1 g/kg Mycotox NG; Group III – supplemented with 0.5 mg/kg aflatoxin B1; Group IV –supplemented with 0.8 mg/kg aflatoxin B1; Group V –supplemented with 0.5 mg/kg aflatoxin B1 and 1 g/kg Mycotox NG. Gross pancreatic changes in broilers treated at 0.5 mg/kg AFB1 comprised generalised vascular hyperaemia, interlobular oedema, initial disintegration of glandular acini. Birds treated at 0.8 mg/kg AFB1 exhibited complete glandular acini disorganisation, and mononuclear cell infiltrations. The supplementation with Mycotox NG alleviated the frequencty and severity of observed histological lesions: slight interlobular oedema, generalised hyperaemia and early granular dystrophy of the cytoplasm of Langerhans islet cells.

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Histopathological changes in small intestines of broiler chickens with experimental aflatoxicosis

N. Grozeva1*, I. Valchev2, Ts. Hristov2, L. Lazarov2, Y. Nikolov2

1Department of General and Clinical Pathology, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria 2Department of Internal Non-infectious Diseases, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria

Abstract. Aflatoxins are toxic metabolites produced by moulds of Aspergillus genus (the most relevant producers are Aspergillus flavus and Aspergillus parasiticus). The primary aim of the current research is to follow out the toxic effects of aflatoxin В1 on the morphology of small intestine, which is important for digestion and absorption of feeds and at the same time, to investigate the possibility for prevention of toxic AFB1 effects by addition of the mycosorbent Mycotоx NG (Ceva Sante Animale, France) to the feed. The experiments were carried out with 50 Cobb broiler chickens, divided in 5 groups of 10 chickens (5 male : 5 female in the groups): Group I – control (receiving feed according to species and age); Group II – supplemented with 1 g/kg Mycotox NG; Group III – supplemented with 0.5 mg/kg aflatoxin B1; Group IV – supplemented with 0.8 mg/kg aflatoxin B1; Group V – supplemented with 0.5 mg/kg aflatoxin B1 and 1 g/kg Mycotox NG. The experiment’s duration was 42 days. After conventional histological technics the light microscopical analyze determined that the morphological changes in all small intestine (duodenum, jejunum, ileum) in birds treated at 0.5 mg/kg AFB1 consisted in vascular hyperaemia, single haemorrhagies, partial desquamation of villous epithelium, rarefaction of cells in intestinal lymphatic follicles and in some areas, cup cell hypertrophy and weak distrophy of Lieberkühn glands. Chickens treated with 0.8 mg/kg AFB1 showed more intense dystrophic changes – necrobiotic to necrotic changes of intestinal villi, atrophy of Lieberkühn glands, mononuclear cell infiltration of the propria and severe rarefaction of lymphatic follicular cells. The dietary supplementation of chickens with Mycotox NG resulted in fewer and less severe histological changes – no haemorrhagies but only vascular hyperaemia.

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