Аграрен факултетhttp://digilib.nalis.bg/xmlui/handle/nls/303352024-03-29T14:30:49Z2024-03-29T14:30:49ZПроучване на химичния състав, технологичните и органолептичните качества на месо от некастрирани и кастрирани мъжки прасетаhttp://digilib.nalis.bg/xmlui/handle/nls/326932020-03-06T11:14:26Z2019-01-01T00:00:00ZПроучване на химичния състав, технологичните и органолептичните качества на месо от некастрирани и кастрирани мъжки прасета
The objective of this dissertation thesis was to study the chemical composition, technological traits and incidence of boar taint of meat from entire male and castrated pigs.
The study was carrier our in a slaughterhouse in Stara Zagora, Bulgaria. Total of 387 pigs (307 entire male and 80 castrated) were investigated. The pigs were reared under uniform feeding and housing conditions and fattened to average live weight of 90 kg. The „M. longissimus thoracis et lumborum (LTL) and M. semimembranosus (SM) were sampled for proximate analysis, and evaluation of technological and organoleptic traits. In the slaughter of pigs, all requirements of Ordinance ‡‚22 from 14.12.2005 (reduction to minimum the suffering of animals during slaughter) were observed.
Meat „‚„N values were measured on 45 min (pH1) and 24 h (pH2) post mortem by means of Testo 205 „‚„N-meter. Detection of boar taint was done by a trained evaluator who smelled heated fat tissue by the so-called hot iron method (Aluwe et al., 2012). The boar taint score was evaluated on a 4-point scale as followed: .0 g - lack of boar taint (odourless); g1 g - weak perceptible boar taint; g2 g - perceptible (pronounced) boar taint and g3 g - strong (offensive) boar taint.
The proximate analysis comprised water, protein fat, mineral and dray matter contents of pork meat (Bulgarian State Standard . BSS 5712, 1974; BSS 8549, 1992; BSS 9373, 1980; BSS 9374, 1982). The water holding capacity of both muscles was determined by the method of Zahariev and Pinkas (1979). Cooking loss was evaluated after roasting meat samples at 150 ‹„R for 20 min. Meat marbling was evaluated on M. longissimus thoracis et lumborum (LTL) according to the standard of the National Pork Producers Council, USA (NPPC, 1999). One point of the NPPC score corresponded to 1% intramuscular fat content.
The analysis of results from chemical analysis and technological traits evaluation of pork meat from entire and castrated male pigs allowed concluding that fattening entire male pigs to 90 kg have some significant effects on meat chemical composition. The meat of entire male pigs was outlined with insignificantly lower fat and higher water and protein content than castrated pigs. Surgical castration of male pigs has no effect on the mineral content of the meat.
Some technological traits of meat: pH, PSE meat, WHC and cooking loss not differed significantly between the evaluated two groups of male pigs. Surgical castration of male pigs has a significant impact on the color, tenderness and marbling of the meat. Raw meat in entire male pigs has higher L *, a * and b * values and a higher marbling than that of castrated male pigs. This should be taken into consideration by technology experts during pork quality scoring as well as at the time of making recipes for production of cooked and raw meat products.
A relatively high incidence of unpleasant boar taint in the meat of entire male pigs was found. Half of the tested entire male pigs from the crossbreed "F1" have signs of an unpleasant boar taint. Surgery castrated male pigs also detect meat with signs of boar taint but only with "Grade 1". Data about the prevalence of boar taint of meat suggested that fattening entire male pigs to a body weight of 90 kg could pose some problems for modern pork production.
2019-01-01T00:00:00ZЕкологично проучване на бентосни мекотели в защитена зона „Поморийско езеро“http://digilib.nalis.bg/xmlui/handle/nls/309812019-05-13T12:04:05Z2019-01-01T00:00:00ZЕкологично проучване на бентосни мекотели в защитена зона „Поморийско езеро“
The dissertation focuses on the condition of the Malaccofauna in Pomorie Lake and its water composition, which is essential for the lake's sustainable management and preservation for future generations. The survey was conducted in the period 2015-2016. 12 taxa were established, 5 of them were reported for the first time in Pomorie Lake. The dissertation examines some basic physico-chemical indicators, the dynamics and biomass of molluscs and their distribution across the lake. This dissertation contribution is of methodical, scientific, scientific-applied and applied character.
2019-01-01T00:00:00ZПроучване на пролактин рецепторен (PRLR), ретинол-свързващ протеин 4 (RBP4) и простагландин-ендопероксид синтаза 2 (PTGS2) гените при свине като кандидат гени свързани с признаците на прасилотоhttp://digilib.nalis.bg/xmlui/handle/nls/309802019-05-13T12:23:11Z2019-01-01T00:00:00ZПроучване на пролактин рецепторен (PRLR), ретинол-свързващ протеин 4 (RBP4) и простагландин-ендопероксид синтаза 2 (PTGS2) гените при свине като кандидат гени свързани с признаците на прасилото
The purpose of the thesis was to investigate the effects of PRLP, RBP4 and
PTGS2 as candidate gene markers and their impact on selection with regard to genetic
improvement of litter traits in Danube White and Landrace pigs. The study was
conduced with purebred Danube White and Landrace pigs bred in the pig farm at Khan
Asparuhovo, near Stara Zagora. The pigs genotyped for PCR-RFLP polymorphisms in
PRLP, RBP4 and loci PTGS2 included 77 sows, 54 replacement pigs, 12 boars from the
Danube White breed and 66 sows and 7 boars from Landrace breed. The frequency of
alleles and genotypes of PRLP, RBP4 and PTGS2 genes in both studied pigs breeds
were established and analysed. The effects of genotypes at loci associated with litter
traits in sows from both breeds and the results from phenotype test in sows from both
breeds were studied. The sire boar effect of genotypes at studied loci on litter traits of
Danube White sows was also analysed.
2019-01-01T00:00:00ZЕфект на системите на торене върху продуктивността на двуполно сеитбообръщение твърда пшеница – памукhttp://digilib.nalis.bg/xmlui/handle/nls/309792019-05-13T12:21:28Z2019-01-01T00:00:00ZЕфект на системите на торене върху продуктивността на двуполно сеитбообръщение твърда пшеница – памук
Effect of fertilization with increasing levels N ( 0; 80; 120; 160 kg.ha-1 and P (0; 80; 120 kg.ha-1) on productivity of durum wheat and cotton in rotation was investigated. The highest durum wheat grain yield was obtained at combined fertilization N120P120 - 3.94 t.ha-1***. Alone N 120 kg.ha-1 fertilization led to obtaining of 3.75 t.ha-1 which exceeds fertilization with N 160 kg.ha (3.55 t.ha-1). Alone phosphorus fertilization is insignificant. The N fertilization rate is the strongest source of variation (66.80% of total effect) and phosphorous nutrition has 1.73% influence. Agronomic efficiency (AE) for N and P decreased with increasing of fertilizing rates. AEN was average 6.53-11.15 kg.kg-1, and AEP - 0.83-1.17 kg.kg-1. The harvest index of durum wheat grain variety Predel was average 0.353.
The total yield of seed-cotton without fertilization was on average 1.32 t.ha-1. As a result of N fertilization, the average yield increased with 26.6 (N80) to 32.9% (N120) compared to non-fertilized, and for phosphorous fertilization - to 2.9% for P80. In the case of combined fertilization, the N120P80 recorded the highest average yield – 1.82 t.ha-1, 37.8% above the non-fertilized. An optimal nitrogen norm of those tested in moderate soil stock is N120.
2019-01-01T00:00:00Z