The aim of the study is to monitor the changes in the main indicators of the chemical composition of Guinea fowl eggs at 2 storage temperature regimes (0-4 degrees & Scy; and 15 degrees & Scy;) after 3 storage periods (1, 30, and 90 days), compared to chicken eggs. In both temperature regimes, the storage period has a significant effect on the reduction of water content, both in the egg white and in the yolk. The water content decrease in chicken eggs is more significant, compared to those of Guinea fowl, especially at 90 days of storage. Regarding the protein content in dry matter of egg white, the following changes were observed: At 0-4 degrees C: chicken - from 89.10 (first day) to 90.65% (90 day); Guinea fowls - from 89.10 (first day) to 90.49% (90th th day); temperature 15 degrees C: chicken - from 89.10 (first day) to 90.36% (90th th day); Guinea fowls - from 90.65 (first day) to 90.36% (90th day). Regarding the content of protein in the dry matter of the yolk, the following changes were observed (1-90 days): 0-4 degrees C: chicken - 29.11-31.11%; Guinea fowls - from 30.58-31.93%; 15 degrees C: chicken - 29.11-31.83%; Guinea fowls - 30.58-32.15%. Changes in the fat content in egg white dry matter (1-90 days): temperature 0-4 degrees C: chicken - 0.89-0.81%; Guinea fowls - 0.76-0.73%; 15oC: o C: chicken - 0.89-0.73%; Guinea fowls - 0.76-0.64%. Fat content in the dry substance of the yolk (1-90 days): temperature 0-4oC: o C: chicken - 68.47-61.65%; Guinea fowls - 63.35-60.83%; temperature 15oC: o C: chicken - 68.47-60.65%; Guinea fowls - 63.35-60.55%. In both white and yolk, the reduction in Guinea fowl's eggs is significant lower. The observed results are due to the specificity of the shell of Guinea fowl eggs.

A study was carried out on the muscle microstructure in a local population of Guinea foul with a pearl-colored plumage. The experiment was performed with three groups of Guinea foul chicks, 30 birds in each group (equal number of both sexes) fattened to different ages (16, 20 and 24 weeks). The results of the histological analysis were consistent with the values of pH, WHC and meat tenderness in both sexes for the respective ages of the Guinea foul. The muscle fibers of male and female individuals at 16 weeks of age had the finest structure and the smallest diameter. Although the diameter of the muscle fibers increased with age in both sexes, no significant differences were found in tenderness of the breast muscle meat. At 25 min after slaughter pH in tights was higher than pH in breasts non depending of the age. To 24 h post mortem pH significantly decreased both in breast and tights, regardless of sex and age. The decrease in WHC was most affected by age (from 16 to 24 weeks) in m. femorotibialis both for males and females guinea towl (Numida meleagris) while m. pectoralis superficialis was slightly affected by age and sex.

Установени са интензивност на яйцеснасяне и разход на комбиниран фураж при местна популация токачки през две последователни продуктивни години. Средната интензивност на снасяне за 30-седмичен продуктивен период през първата година е 70,11% (139,71 яйца от носачка), а през втората – 44,22% (89,70 яйца от носачка). Конверсията на фураж е 162 g/яйце (3,88 kg/kg яйчна маса) през първата и 311 g/яйце (7,42 kg/kg яйчна маса). Установената висока интензивност на яйцеснасяне е предпоставка за провеждане на успешна селекция по показателя носливост.

The effect of the fattening period on the slaughter performance of a local Bulgarian population of free-ranged pearl-gray Guinea fowls was studied. The pre-slaughter weight varied from 1041.00 to 1296.00 g in the group of female fowls and from 1029.50 to 1292.83 g in the group of male fowls, depending on the fattening period duration. The data of grill weight were 605.15–839.81 g for the females and 643.52–826.23 g for the male individuals and of bratfertig: 683.50–915.99 g and 721.82–910.52 g, respectively, depending on gender and duration of the fattening period. Grill meat varied from 459.56 to 643.07 g for a group of male fowls and from 441.15 to 649.55 g for a group of female fowls, while breast meat was 190.84–283.94 g (male) and 186.77–286.7 g (female), depending on the studied factors. The slaughter yields (bratfertig, %) ranged from 65.72% to 70.71% depending on the two factors of influence. The carcass weight (grill, %) of both sexes was 60.36% for the 16-week fattening period, over 61% for the 20-week and 64% for the 24-week fattening period. The proportions of the pectoral muscles in the carcass were higher for the older Guinea fowl, while the percentages of thigh muscles decreased from 31% to 29% with increasing of the age. The relative values of breast and leg muscles increased with the increase of the fattening period duration of the slaughtered birds. Grill’s bones had the highest values in the 16-week-old Guinea fowls (29.09%). Besides sex, the slaughter age had a significant effect on almost all the slaughter characteristics except for the weight of the by-products.

A study on the basic technological properties of meat (pH, water-holding capacity, cooking loss, and meat tenderness) from a free-ranged, pearly-gray local Bulgarian population of Guinea fowl was conducted. The effect of three fattening periods (16, 20, and 24 weeks) in two consecutive economic years was investigated. The average pH values of the breast muscles, reported for the period from 25 minutes to 24 hours after slaughter, varied from 6.70 to 5.74 for the group of male fowls and from 6.80 to 5.74 for the group of female fowls, respectively. The mean pH values of the thigh muscles for the same period were: from 7.21 to 6.32 for the male fowls and from 7.53 to 6.21 for the female individuals. The data analysis showed that bird sex and age did not affect the pH values of meat. As the slaughter age increased, the values of WHC in the analyzed muscles decreased, which is the reason for the breast and thigh muscles of Guinea fowls fattened for the longest period, to be evaluated as being of the best quality. The investigation of the two types of muscles revealed that the thigh muscles have better water-holding capacity compared to the breast muscles. No significant differences between both sexes were reported for that characteristic. A significant effect of the fattening period on the cooking loss was found, varying between 26.91% and 46.16% depending on the muscle type, sex, and age of the birds. Meat tenderness was not affected by the bird sex and age at slaughter, with average values ranging from 293.09 °P to 309.75 °P.

Penkov, D. & Nikolova, M. (2020). Study on the conversion of energy and protein in fattening of Guinea-fowls up to 16 weeks of age by introducing “Clarc of distribution/ transformation”. Bulg. J. Agric. Sci., 26 (5), 1029–1033 The energy and crude protein distribution from fodder to the breast and thigh muscles was calculated. New indexes “Clarc of energy distribution (CED)” and “Clarc of protein transformation (CPT)” were introduced. Fodder consumption was calculated as the difference between the offered fodder and the collected residues, in total for the group. The growth rate for each period (week) was calculated as the difference between final and the initial live weight. In order to equalize to a conventional unit (A), a recalculation of the weight of the breast and thigh muscles on a basis of 1 kg of weight gain was made. The “Clarc’s” were calculated by using the following formula: CED = Total energy content in A/Total metabolizable energy intake for 1 kg growth; CPT = Total (crude) protein content in A/Total (crude) protein intake for 1 kg growth. The following average values for both sexes were established: CDE to the breast muscle – 0.0255; to the thigh muscle – 0.0215; CPT to the breast muscle – 0.0514; to the thigh muscle – 0.0398.

A study was carried out on the egg productivity of pearl-gray guinea fowl of a local population for Bulgaria over two productive years. The birds were reared under the conditions of a semi-intensive free range production system. Using the regression analysis methods in combination with Principal Component Analysis (PCA), two models were developed - a Linear model and a Compound model, with the aim of studying the effect of the major meteorological factors (air temperature and humidity, wind speed, precipitation and cloud cover) on egg productivity. Different rates of response to the studied climatic factors were established depending on the age of the laying guinea fowl.

Проведено е проучване върху продължителността на ембрионалното развитие и масата на пилето при излюпване при Черен африкански щраус (Struthio camelus). Експериментът е изведен с пет женски и две мъжки птици при полово съотношение 1:2,5 Средната за петте проучвани възрасти абсолютна маса на щраусчетата при излюпване е 896,69 ± 4,77g, а средната им относителна маса – 57,40 ± 0,20%. С нарастване възрастта на носачките абсолютната маса на излюпените пилета достоверно нараства, а относителната се запазва почти константна. Средната продължителност на ембрионалния период при проучвания вид е 42,68 ± 0,14 денонощия, като той трае най-дълго при ембрионите от петгодишните и най-кратко при тези от тригодишните носачки.

Проведен е опит за установяване влиянието на Vemoherb-T (сух екстракт от Tribulus terrestris), произведен от фирма “Вемо 99” ООД, София, върху консумацията и разхода на фураж за яйцеобразуване при токачки. Проучването е изведено с 30 Бисерносиви токачки – местна популация, отглеждани полуинтензивно върху дълбока несменяема постеля, в боксове с дворчета – волиерен тип, и разпределени по равен брой в опитна и контролна групи при полово съотношение 1:4 (12 женски и 3 мъжки в група). Ежедневният прием с фуража на изпитваната добавка в концентрация 10 mg/kg жива маса в продължение на 12 седмици довежда до достоверно понижение на консумацията и до по-нисък разход на фураж за единица яйчна маса, като след 6-та седмица на прилагането влиянието е статистически достоверно.

A comparative study of the effect of the Bulgarian product Vemo Herb (dry extract of Tribulus terrestris) produced on the histological structure of liver in Guinea fowl (Numida meleagris) and Japanese quail (Coturnix coturnix japonica) was carried out with 2 groups (control and experimental) from both poultry species: 15 Pearl-gray Guinea fowls (12 females and 3 males) per group, and 17 Japanese quails -Pharaon breed (13 females and 4 males) per group.The poultry in the experimental groups received 10 mg/kg body weight/day of the tested additive.The trial lasted 11 weeks (1 week of preparatory and 10 weeks of experimental period).It was found that VemoHerb-T in a daily dose of 10 mg•kg -1 body weight causes a high degree of liver fat dystrophy in male and female poultry from both species.There were no significant differences in the liver histological structure between males and females from both species.Significant effect of the additive is observed on body weight in both male and female Guinea fowls, weight of liver in both male and female Japanese quails and liver's histostructure of the two species -being higher in Japanese quails.

The aim of the study was to investigate the chemical composition and energy content of the meat of young guinea-fowls, with different duration of the fattening period, raised in a free-range, semi-intensive production system. The authors establish the following data: dry matter content- from 27.08 to 28.82% in breast muscle and from 23.83 to 26.56% in thigh muscle; crude protein in dry matter –from 86.19to 93.54% in breastand from 82.02 to 87.84% in thigh muscle; crude fat in dry matter - from 5.64 to 7.58% in breast and from 9.02 to 11.05% in thigh muscles. The average energy content in 100 g dry matter varies from 23.7 (breast muscle, 16 weeks of age) to 25.07 kJ (thigh muscle, 24 weeks of age).

An investigation of Vemo Herb® additive on the forage consumption rate in Japanese quail (Pharaoh breed) has been conducted. The experiment was carried out for 10 weeks with 52 female and 16 male sexually matured Japanese quails (Coturnix coturnix japonica) distributed in four groups: control group (without additive), first experimental group - 4 mg*kg-1 of live weight for 10 weeks; second experimental group - 10 mg*kg-1 of live weight during the first five weeks of the study (after that the product was no more supplemented) and third experimental group - 10 mg*kg-1 of live weight during the whole study period. It was observed, a tendency of decreasing of the forage consumption rate for the whole experimental period (no statistical significance) for all the experimental groups compared to the control group, but some of the weekly differences are significant.

This experiment was designed to evaluate the effect of different doses of Bulgarian product Vemoherb-T (dry extract of Tribulus terrestris) on egg production, serum level of testosterone and histological structure of gonads and kidneys in Japanese quail. In the experiment a total of 52 female and 16 male Japanese quail from Pharaon breed at the initial age of 44 days were involved. Quails were randomly divided in control and three experimental groups, 13 female and 4 male in each. Experimental groups received with the drink water the tested product in following daily doses: 4 mg/kg body weight (10 weeks); 10 mg/kg body weight (the first 5 weeks of the trial); 10 mg/kg body weight (10 weeks) for I st , II nd , III rd treated groups respectively. A significant increase of ovary weight in quails from III rd experimental group (P < 0.01) in comparison with the control was measured. Egg production in II nd and III rd treated groups increased significantly (P < 0.01) than the control group. Testosterone level of males from III rd experimental group enhanced significantly (P < 0.05; P < 0.01) than other groups. The ovary core part of females from III rd experimental group contained a much lower number of mature follicles in comparison to the other groups and its central medulla was highly vascularized. Tribulus terrestris extract in a dose of 10 mg/kg stimulates the production of male reproductive cells, while the dose of 4 mg/kg caused a delay of spermatozoa production. Histological analysis showed that in all experimental groups the structure of the kidneys was preserved and that the higher doses lead to certain reduction of the parenchyma.