Wyniki wyszukiwania - Biblioteka Nauki

1

Properties of drinking yogurt obtained from cow’s and goat’s organic milk fermented by traditional yogurt cultures

100%

Mituniewicz-Małek A. , Ziarno M. , Dmytrów I. , Tuma P. , Witczak A. , Vovk S.

Infrastruktura i Ekologia Terenów Wiejskich

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2017

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tom nr IV/3

1755--1771

EN

This paper presents an assessment of selected qualitative attributes of fermented drinks obtained from organic cow’s and goat’s milk by using yogurt cultures in 10-day refrigeration storage process (5 ± 1°C). The raw material was purchased in organic farms located in north-west Poland. Two yogurt starters obtained from the Chr. Hansen company were used in the study: YC-X16 and YF-L811. Both cultures contained Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. These cultures did not differ in the qualitative content of the lactic acid bacteria but their use allows for obtaining products with different qualitative properties. Four variants of yogurt were produced: i. J-X16 - yogurt from cow’s milk with YC-X16 culture, ii. J-L811 - yogurt from cow’s milk with YF-L811 culture, iii. KJ-X16 - yogurt from goat’s milk with YC-X16 culture, iv. KJ-L811 - yogurt from goat’s milk with YF-L811culture. All samples of fermented milk were subjected to microbiological, physico-chemical, rheological (hardness) analyzes and a sensory assessment (PN-EN ISO 6658:1998). It was determined that the yogurt cultures (YE-L811 and YC-X16) used in the experiment are worthy of recommendation for the production of fermented milk from both organic acidity, pH and hardness), the vitality of the microflora as well as sensory properties of yogurt from organic cow’s and goat’s milk depended on the type of used yogurt culture and time of refrigeration storage. The type of used milk has no impact on the vitality of the microflora.

2

Perspectives for goat milk in human nutrition

100%

Finocchiaro R. , Van Kaam J. T.

Animal Science Papers and Reports

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2004

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tom 22

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nr 3

3

Changes in texture of yoghurt from ultrafiltrated goat's milk as influenced by different membrane types

100%

Domagala J. , Kupiec B. E.

Electronic Journal of Polish Agricultural Universities. Series Food Science and Technology

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2003

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tom 06

|

nr 1

EN

The influence of type of ultrafiltration membrane on yoghurt texture produced with ultrafiltrated (UF) milk was investigated. Goats milk was concentrated with three membranes of the following pore sizes: 10 kDa, 30 kDa and 100 kDa. Ultrafiltration was carried out to complete 2-fold concentration (v/v) of milk. Concentrated milk was used for production of set yoghurt with Chr. Hansen starter culture YC-180. Yoghurt samples were also produced using unaltered milk. The ultrafiltration process had a significant effect on composition of retentates, sensory evaluation of yoghurts, their viscosity and most of their texture parameters. The type of membrane used influenced significantly dry matter, protein, fat and lactose levels as well as acidity of milk retentates. In consequence sensory evaluation scores, viscosity, hardness and cohesiveness of yoghurt gel were also influenced. The size of membranes had a significant effect on ultrafiltration rate.

4

Effect of goats nutrition on milk yield, its chemical composition and fatty acid profile of fat

75%

Klebaniuk R. , Kowalczuk E. , Kochman G. , Patkowski K. , Lechtanska M.

Annales Universitatis Mariae Curie-Skłodowska. Sectio EE: Zootechnica

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2008

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tom 26

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nr 4

1-9

5

Milk as a new diagnostic tool for rapid detection of fascioliasis in dairy goats using excretory/secretory antigen

75%

Saad M. F. , Attia M. M.

Acta Parasitologica

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2021

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tom 66

|

nr 2

6

The application of the Plackett-Burman design in investigating ACE inhibitory peptide-producing conditions and media for Lactobacillus bulgaricus LB6

75%

Shi X. , He C. , Meng J. , Xin N. , Ji Z.

Acta Scientiarum Polonorum. Technologia Alimentaria

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2018

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tom 17

|

nr 2

7

Quality of goat pasture in less-favoured areas (LFA) of the Czech Republic and its effect on fatty acid content of goat milk and cheese

75%

Cermak B. , Kral V. , Frelich J. , Bohacova L. , Vodraskova B. , Spicka J. , Samkova E. , Posednicek M. , Weglarz A. , Makulska J. , Zapletal P.

Animal Science Papers and Reports

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2013

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tom 31

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nr 4

EN

The aim of the study was to assess the quality of pastures located in less-favoured areas (LFA) of Czech Republic, to evaluate the influence of that quality on the content of fatty acids of milk in grazing goats and in farm natural cheese made of their milk. Samples of forage were collected in 2008 and 2009, on 5 July, 9 August, 6 September and 4 October. Goat milk samples were taken on the same days of both years and additionally on May 31. The highest content of protein and fat of the forage dry matter and, consequently, the highest feeding value of pasture were found in July and October. It was associated with a high content of clovers and herbs in the available herbage. During grazing the content of saturated fatty acids (SFA) of goat milk fat continuously decreased while the trend for the content of monounsaturated fatty acids (MUFA) was opposite. A significant increase in herb of the total crop observed in autumn contributed to a highest content of polyunsaturated fatty acids (PUFA) in fat of goat milk. The fatty acid profile of goat cheese was related to that of the milk. Thus, a high content of PUFA, including CLA, observed in milk of grazing goats guarantees that the cheese made of that milk fulfills the requirements for functional foods.

8

Kozie mleko – wybryk czy dar natury

63%

Kycia K. , Szymczak P.

Przemysł Spożywczy

|

2013

|

tom T. 67, nr 10

11--14

PL

W ostatnich latach zwiększa się zainteresowanie mlekiem kozim i coraz częściej znajduje ono zastosowanie w przetwórstwie żywności. Do jego popularyzacji przyczynia się wysoka zawartość składników odżywczych, takich jak pełnowartościowe białko, lekko strawny tłuszcz, dobrze przyswajalny wapń, magnez i witaminy. Pod wieloma względami mleko kozie różni się od mleka krowiego. Pomimo niedogodności związanych z technologicznym przetwarzaniem mleka koziego, jest ono z powodzeniem wykorzystywane do produkcji mleka spożywczego, serów podpuszczkowych, twarogów, śmietanki, napojów mlecznych fermentowanych, mleka w proszku, masła oraz deserów. Walory prozdrowotne mleka koziego i jego przetworów sprawiają, że są one polecane zwłaszcza dzieciom, osobom starszym i alergikom.

EN

In the recent years there has been observed an increasing interest in consumption of goat milk and its use for processing. The high content of nutrients such as complete protein, easily digestible fats, well absorbed calcium, magnesium and vitamins, leads to the growth of its popularity. In many aspects goat milk differs from cow milk. Despite some inconveniences that occur while the goat milk is processed, it is successfully used for production of milk, rennet cheese, quark, fermented milks, milk powder, butter and desserts. Because of the health benefits, goat milk and its products are especially recommended for children, elderly and people suffering from allergies.

9

Methodology of udder description and the effect on somatic cell count in Czech White Shorthaired goat breed

63%

Novotna K. , Svitakova A. , Rychtarova J. , Fantova M. , Nohejlova L.

Medycyna Weterynaryjna

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2018

|

tom 74

|

nr 08

EN

This study evaluated the effect of the linearly described shape traits of goat udders on somatic cell count. In a herd of 487 white shorthaired goats, seven traits (udder symmetry, udder depth, udder width, teat length, teat placement, rear udder attachment and udder cleft) were assessed in relation to somatic cell count in milk. The average somatic cell count was 1.3 mill cells/ml when considering the environmental effects (month and year of performance testing, lactation number. The somatic cell count is influenced by the depth (p = 0.0015) and width (p = 0.0268) of the udder. The results demonstrate that some traits of the udder shape influence the somatic cell count and can be considered as functional traits indicating animal health and herd profitability. After further studies, the methodology for linear description of the udder could be used for other dairy goat breeds, not only in the Czech Republic.

10

Fatty acids profile of sheep’s and goat’s milk used in production of cheese introduced as innovative products

63%

Baran J. , Pieczonka W. , Pompa-Roborzynski M.

Towaroznawcze Problemy Jakości. Polskie Towarzystwo Towaroznawcze

|

2014

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nr 2

11

Changes in physico-chemical characteristics, somatic cell count and fatty acid profile of Brown Short-haired goat milk during lactation

63%

Kuchtik J. , Kralickova S. , Zapletal D. , Weglarzy K. , Sustova K. , Skrzyzala I.

Animal Science Papers and Reports

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2015

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tom 33

|

nr 1

EN

The main aim of this study was to evaluate the effect of the lactation stage (SL) on the fatty acids (FA) profile of raw milk of Brown Short-haired goats reared under organic regime. An integraf part of the study was also to assess the effect of the SL on the physico-chemical characteristics and somatic cell count (SCC) of milk. Milk records and samplings of each goat were carried out seven times from April to October. SL had a significant effect on contents of almost all monitored physicochemical properties, somatic cell counts (SCC) and FA of milk and also on average daily milk yield (DMY). DMY gradually decreased with advanced lactation (from 3.44 to 1.44 litre), whereas the content of total solids (TS) increased in the course of lactation (from 10.9 to 14.0%). Also the content of milk fat (F) increased in the course of lactation (from 3.2 to 4.7%). Contents of total protein (TP) and casein (C) were relatively high in early lactation, decreased as lactation peaked and increased towards to late lactation (3.7% of TP and 2.6% of C). Titratable acidity (TA) gradually increased from 90th day (6.2°SH) to the end of lactation (8.5°SH), while positive correlations with TS, F, TP,C and lactose were found. SCC increased as lactation advanced, moreover, a positive correlation among SCC and TA and TS was found. The SL had a significant effect on all FA groups. PUFA gradually decreased towards to late lactation, which was caused mainly by the content of linoleic acid. Similarly, the presence of linolenic acid and PUFA/SFA ratio showed a decreasing tendency with advanced lactation. Also the CLA content was the lowest at the end of lactation. PUFA n-6/n-3 ratio increased in mid lactation (7.8) and hereafter decreased towards to late lactation (3.5). In our opinion, a less favourable presence of particular groups of FA in late lactation was related with a decrease in pasture quality under organic conditions.

12

Influence of inulin and storage time on colour parameters of fermented goat's milk products

63%

Pyrzynska E.

Towaroznawcze Problemy Jakości. Polskie Towarzystwo Towaroznawcze

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2018

|

nr 2

13

Anthelmintic residues in goat and sheep dairy products

63%

Jedziniak P. , Olejnik M. , Rola J. G. , Szprengier-Juszkiewicz T.

Bulletin of the Veterinary Institute in Puławy

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2015

|

tom 59

|

nr 4

EN

A multiresidue method (LC-MS/MS) for determination of wide range of anthelmintics was developed. The method covered benzimidazoles: albendazole (and metabolites), cambendazole, fenbendazol (and metabolites), flubendazole (and metabolites), mebendazole (and metabolites), oxibendazole, thiabendazole (and metabolites), triclabendazole (and metabolites); macrocyclic lactones: abamectin, doramectin, emamectin, eprinomectin, ivermectin, moxidectin; salicylanilides: closantel, ioxynil, nitroxynil, oxyclosamide, niclosamide, rafoxanid and others: clorsulon, derquantel, imidocarb, monepantel (and metabolites), morantel, praziquantel, and pyrantel. The method was used to examine the potential presence of anthelmintics in goat and sheep milk and dairy products from the Polish market. A total of 120 samples of milk, yoghurt, cottage cheese, cream cheese, and curd were analysed. None of the samples were found positive above CCa (1-10 µg/kg) except for one cottage cheese in which traces of albendazole sulfone were detected (5.2 µg/kg) and confirmed. The results of the study showed negligible anthelmintic residues in the goat and sheep milk and dairy products and confirm their good quality.

14

Impact of pasteurisation and type of packaging on probiotic bacteria in bio-yoghurts of goats' milk during storage

63%

Kudelka W.

Medycyna Weterynaryjna

|

2010

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tom 66

|

nr 02

109-112

EN

The objective of the research was to determine the impact of the pasteurization process of raw material and of the type of packaging on the survival rate of probiotic bacteria in bio-yoghurts from goats’ milk during storage. The bio-yoghurts investigated were manufactured from goats’ milk using a container method. The milk under processing was centrifuged and normalized to a fat level of 2%. Next, it was pasteurised at a temperature of 95 °C during 5 min and at 90 °C during 10 min, after which it was cooled to 40 °C. The cooled milk was inoculated with DVS ABT1 inoculants added. The bioyoghurts were thermostated (controlled) in containers at a temperature of 40 °C (+/-1 °C) until they reached a pH level of 4.7. Then, they were cooled again to a temperature below 20 °C and poured into 4 different packagings made of polypropylene (PP), polystyrene (PS), polyethylene (PEHD), and glass (G), each of a capacity of 200 cm³. The bio-yoghurts were subsequently stored in the dark for 21 days at temperatures ranging from 2 to 5 °C. The presence of probiotic bacteria in bio-yoghurt was determined 12 h after the bio-yoghurts were manufactured, and on the 7th, 14th, and 21st day of storage. In total 240 samples were analysed. The applied packagings did not statistically significantly differentiated the count of bacteria in bio-yoghurts manufactured from goats’ milk, except for the Str. thermophilus bacteria count that changed only on the 14th day after manufacturing. The statistically significant impact of the pasteurisation temperature of raw material was found in the case of the L. acidophilus count immediately upon manufacturing. A lower pasteurisation temperature of goats’ milk had a favourable effect on the growth of bacteria, and in such bio-yoghurts the population of all the bacteria was higher. It was found that irrespective of the applied pasteurization temperature of raw material and of the type of packagings, the count of individual bacterial genera was at a level significantly higher than 10⁶ cfu/ml, which ensures that the milk drinks studied achieve the therapeutic minimum. Thus, expanding the production of goat milk bio-drinks can enhance the assortment of healthful diary products available in the market.

15

Decreased antibiotic susceptibility and enhanced probiotic production potential of goat milk fermented curd in comparison with cow and buffalo milk

63%

Lakhanpal J. , Gupta J.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

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2017

|

tom 98

|

nr 2

16

Zmiany wybranych cech jakościowych biojogurtów z mleka koziego w czasie chłodniczego przechowywania

63%

Mituniewicz-Małek A. , Dmytrów I. , Skryplonek K.

Chłodnictwo : organ Naczelnej Organizacji Technicznej

|

2013

|

tom R. 48, nr 11

40--43

PL

Celem pracy było przeanalizowanie zmian wybranych cech jakościowych biojogurtów z mleka koziego przechowywanych w warunkach chłodniczych (5±I°C). Wyprodukowano dwa warianty biojogurtów, które zaszczepiono kulturami starterowymi pochodzącymi od dwóch różnych producentów, ale o identycznym składzie jakościowym bakterii (Lactobacillus delbrueckii ssp. Bulgaricus, Streptococcus salivarius ssp. Thermophilus, Bifidobacterium sp. i Lactobacillus acidophilus). Do otrzymania pierwszego wariantu mleka fermentowanego (BJ-A) użyto kulturę All in 1000 firmy PM-International z Niemiec, a w przypadku biojogurty BJ-B szczepionkę ABT Culture Kanadyjskiego Instytutu Rosell Inc. Pierwsza z wymienionych kultura w swoim składzie zawierała dodatkowo białko serwatkowe w proszku, inulinę, niacynę oraz aromat. Próby doświadczalne poddano ocenie sensorycznej, analizie fizykochemicznej i Teologicznej odpowiednio po 1, 3, 7, 14 i 21 dobie chłodniczego przechowywania (5±1°C). Uzyskane wyniki wskazują na możliwość produkcji z mleka koziego biojogurtu o pożądanych cechach jakościowych charakterystycznych dla mleka fermentowanego, przy czym cechy sensoryczne napojów doświadczalnych uwarunkowane były rodzajem użytej szczepionki, która również w istotny sposób wpływała na wszystkie analizowane wskaźniki fizykochemiczne i reologiczne.

EN

Selected qualitative factors of bioyoghurts produced from goat's milk during refrigerated storage were analysed. Two batches of beverage were inoculated by starters with the same composition of bacterias (Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus salivarius ssp. Thermophiles, Bifidobacterium sp. and Lactobacillus acidophilus) were produced, but in the culture All in 1000 of PM-International additionally contained whey protein powder, mu I m niacin and aroma. After 1, 3, 7, 14 and 21 day of refrigerated storage selected sensory, physicochemical and Theological properties of experimental bioyoghurts were analysed. Bioyoghurts had typical appearance, varied texture, pure sour smell and strongly felt goat's flavour. However, the sensory properties depended on a kind of starters, which also have a significant influence on the analyzed physicochemical and rheological properties.

17

Physicochemical and sensory changes of goat milk permeate following its fermentation and storage

63%

Cais-Sokolinska D. , Pikul J. , Dankow R.

Polish Journal of Food and Nutrition Sciences

|

2006

|

tom 15/56

|

nr Spec.Issue 1

EN

The aim of the research project was to assess the quality parameters of goat milk permeate subjected to the fermentation process with the assistance of thermophilic cultures of traditional composition and enriched with probiotic strains. The fermented permeates were stored in refrigerated conditions for 6 weeks and during this period, changes in their active and titratable acidity were estimated, their colour parameters were measured instrumentally and their sensory profiles were examined. The type of the bacterial cultures applied did not affect the pH value of the permeates over the entire storage period. After the termination of the fermentation process, permeates treated with traditional cultures were characterised by the highest titratable acidity and this relationship did not change until the end of the storage period. Regardless of the type of the bacterial culture applied, the fermentation process resulted in a significant decrease of sample L* lightness and increase of their C* colour. After 6 weeks, values of the L* and C* coefficients of the fermented permeates decreased significantly, whereas the non-fermented permeats failed to exhibit any changes in the colour parameters in the course of their storage. The permeate fermented with the assistance of the traditional bacterial culture received the highest number of points for its overall desirability after 6 weeks of storage. During this period, the ‘metallic’ taste of the permeate disappeared and, simultaneously, we could observe an increase in the intensity of a refreshing taste and fresh smell.

PL

Celem pracy była ocena wyróżników jakości permeatu mleka koziego poddanego procesowi ukwaszenia przy udziale termofilnych kultur o tradycyjnym składzie i wzbogaconych w szczepy probiotyczne. Ukwaszone permeaty przechowywano przez 6 tygodni w warunkach chłodniczych. W tym okresie oceniono zmiany kwasowości czynnej i miareczkowej permeatów, zmierzono instrumentalnie parametry barwy i zbadano ich profil sensoryczny. Rodzaj zastosowanych kultur bakteryjnych nie miał wpływu na wartości pH permeatów w trakcie całego okresu przechowywania. Po zakończonej fermentacji największą kwasowością miareczkową charakteryzowały się permeaty ukwaszone kulturą tradycyjną. Zależność ta utrzymywała się do końca okresu ich przechowywania. Niezależnie od rodzaju zastosowanej kultury proces fermentacji spowodował istotne obniżenie jasności L* próbek oraz wzrost nasycenia ich barwy C*. Po 6 tygodniach wartości współczynnika L* i C* permeatów ukwaszonych istotnie obniżały się. Podczas przechowywania nie wykazano zmian parametrów barwy permeatu nieukwaszonego. Największą liczbę punktów za ogólną pożądalność uzyskał permeat ukwaszony kulturą tradycyjną po 6 tygodniach przechowywania. W tym okresie dochodzi do zanikania smaku metalicznego permeatu i jednocześnie wzrostu natężenia smaku orzeźwiającego i zapachu świeżego.

18

Application of a duplex-PCR for detection of cows' milk in goats' milk

63%

Kotowicz M. , Adamczyk E. , Bania J.

Annals of Agricultural and Environmental Medicine

|

2007

|

tom 14

|

nr 2

EN

A duplex-PCR method, with 2 pairs of primers recognizing sequences of mitochondrial D-loop region, was developed to identify cows’ milk in the milk of goats. The PCR was shown to be specifi c and sensitive, enabling the detection of less than 1% of cows’ milk added to the milk of goats. Simultaneous use of a primer pair for goats’ and cows’ mitochondrial DNA fragment prevented false negative results. The method was applied to track the presence of cow DNA in goat milk available on the Polish market. A total of 54 milk samples from 3 Polish (34) and one foreign producer (20) were examined. In 33 samples, cow DNA was detected, while 21 samples, including all of the 20 samples from foreign producers, produced the goat-specific product only.

19

Effect of the feeding period on the chemical composition and fatty acid profile of milk from French Alpine dairy goats

63%

Czarniawska-Zajac S. , Brzostowski H. , Zielazny M.

Polish Journal of Food and Nutrition Sciences

|

2006

|

tom 15/56

|

nr Spec.Issue 1

EN

The chemical composition and fatty acid profile of milk from French Alpine dairy goats, obtained during the period of summer feeding and winter feeding, were studied. Milk samples were collected at one-month intervals, to determine dry matter, solids non-fat, protein, fat, fatty acid profile, lactose, urea and somatic cell count. The fatty acid composition of milk fat was determined for particular experimental twice during lactation, i.e. in the middle of the winter season and in the middle of the summer season. It was found that goat’s milk produced in winter had higher levels of dry matter, fat, protein and urea, and a lower lactose content. Goat’s milk obtained over this feeding period had a higher urea content. The somatic cell count recorded in milk from the experimental goats remained within the physiological norms for goat’s milk. The feeding period had a significant effect on the fatty acid profile of goat’s milk. Milk produced in summer had higher levels of unsaturated fatty acids, especially polyunsaturated fatty acids, as well as a more favorable ratio between unsaturated fatty acids and saturated fatty acids, and a lower ratio between monounsaturated fatty acids and polyunsaturated fatty aThe chemical composition and fatty acid profile of milk from French Alpine dairy goats, obtained during the period of summer feeding and winter feeding, were studied. Milk samples were collected at one-month intervals, to determine dry matter, solids non-fat, protein, fat, fatty acid profile, lactose, urea and somatic cell count. The fatty acid composition of milk fat was determined for particular experimental twice during lactation, i.e. in the middle of the winter season and in the middle of the summer season. It was found that goat’s milk produced in winter had higher levels of dry matter, fat, protein and urea, and a lower lactose content. Goat’s milk obtained over this feeding period had a higher urea content. The somatic cell count recorded in milk from the experimental goats remained within the physiological norms for goat’s milk. The feeding period had a significant effect on the fatty acid profile of goat’s milk. Milk produced in summer had higher levels of unsaturated fatty acids, especially polyunsaturated fatty acids, as well as a more favorable ratio between unsaturated fatty acids and saturated fatty acids, and a lower ratio between monounsaturated fatty acids and polyunsaturated fatty acids. Goat’s milk obtained over this period had higher concentrations of linoleic acid (C18:2), linolenic acid (C18:3) and conjugated dienes of linoleic acid.

PL

Badano sk³ad chemiczny i profil kwasów tłuszczowych w mleku kóz rasy alpejskiej francuskiej pochodzącym z okresu żywienia zimowego i letniego. W próbkach mleka pobieranych w odstępach miesięcznych oznaczono zawartość: suchej masy, suchej masy beztłuszczowej, białka, tłuszczu, laktozy, mocznika i komórek somatycznych. Skład kwasów tłuszczowych tłuszczu mleka koziego dla poszczególnych kóz doświadczalnych ustalono dwukrotnie w okresie laktacji, tj. w połowie sezonu żywienia zimowego i żywienia letniego. Badania wykazały, że mleko kozie pozyskiwane w okresie żywienia zimowego charakteryzowało się wyższą zawartością suchej masy, tłuszczu i białka, a niższą zawartością laktozy. W mleku kóz z tego okresu żywienia wykazano wyższą zawartość mocznika. Liczba komórek somatycznych stwierdzona w mleku badanych grup kóz mieoeci się w granicach norm fizjologicznych, przyjętych dla mleka koziego. Badania wykazały wpływ sezonu żywienia na profil kwasów tłuszczowych mleka. Mleko kozie pochodzące z okresu żywienia letniego charakteryzuje się wyższym udziałem kwasów nienasyconych, a szczególnie wielonienasyconych. Mleko z tego okresu żywienia kóz odznaczało się korzystniejszym stosunkiem kwasów UFA do SFA, a także niższym stosunkiem kwasów MUFA do PUFA. W mleku z sezonu żywienia letniego stwierdzono wyższą zawartość kwasów: linolowego (C18:2), linoleinowego (C18:3) i sprzężonego dienu kwasu linolowego (SKL).

20

Polymorphism of caprine milk alphaS1-casein in relation to performance of four Polish goat breeds

63%

Barlowska J. , Litwinczuk Z. , Kedzierska-Matysek M. , Litwinczuk A.

Polish Journal of Veterinary Sciences

|

2007

|

tom 10

|

nr 3

EN

Polymorphism of goat milk asrcasein was determined and potential relations between genetic variants of this protein fraction and goat performance were evaluated. The investigations were performed on 598 goats assigned to of 4 breed groups (White improved 254 units, Coloured improved -124, White non-improved - 146 and Coloured non-improved - 74). For each goat, asrcasein polymorphism was determined in Polyacrylamide gel by the PAGE-SDS method and percentage of milk asrcasein and gene frequency established. There was evaluated goat performance at successive lactations. In the goat population investigated, AA, AB, BB, AE, BE and EE αs1-casein genotypes were identified. In all four breeds, αs1-casein genotype EE clearly predominated (27.2-39.2%), recognized as "medium" and its share was higher in the groups of non-improved goats. It was conditioned by high frequency of gene E αs1-casein (0.419-0.622). Generally, EE genotype percentage was higher in the non-improved goat groups. The improved goats, though, obtained higher productivity in each of the lactation studied. Analysis of relationships between αs1-casein genetic variants and goats performance confirmed a significant influence on milk, protein and fat yields only in the Coloured improved goat group. There was revealed a more general tendency indicating a significant impact of "strong" αs1-casein genotypes on a concentration of basic milk components, i.e. fat and protein, especially casein. In a group of goats producing milk of the highest casein content (over 2.4%) and protein (over 3.0%), the animals showing "strong" αs1-casein variants dominated (85 and 70 %).