Wioletta Sawicka-Zugaj

This study was based on data obtained from a total of 9518 cows belonging to seven cattle breeds: local breeds—Polish White-Backed (249), Polish Red (269), Polish Black-and-White (255), and Polish Red-and-White (290)—and international breeds—Polish Holstein-Friesian (5917), Jersey (940), and Simmental (1598). The breeds were characterised in terms of the following parameters: length of life, length of productive life, milking life, longevity index, percentage share of yield in the first 305-day lactation and first complete lactation in the lifetime yield, and functional longevity. Reasons for culling and the relationship between the length of life/productive life and milk performance parameters were determined as well. The analysis of the length of life and length of productive life in seven different cattle breeds kept in Poland unequivocally demonstrates that local breeds clearly stand out in this regard in comparison to international breeds. They may in the future constitute a valuable gene reservoir for improving longevity in other breeds. The length of life of Polish White-Backed and Polish Red cows was 2817 days and 3607 days, respectively, while that of Polish Holstein-Friesian and Jersey cows was only 2131 and 1956 days, respectively, and the most common cause of culling of cows in Poland (39.07%), irrespective of breed, was reproductive problems. The favourable results of parameters related to the longevity of the local breeds of Polish Red and White-Backed show that they can become a tool for improving the longevity of international breeds.

This paper aims to review the current state of knowledge on the significance of livestock genetic resources in the context of increasing global food availability. The still unresolved problem of world hunger and the rapidly rising human population, especially in underdeveloped areas, mainly in Africa and Southeast Asia, requires numerous measures to ensure food security. Global production of food of animal origin is generally determined by international breeds selected for high performance in the production of a particular product (meat, milk, or eggs). These breeds, as well as industrial food production systems, are crucial to ensuring global food security. Unfortunately, they exert significant pressure on the environment. In developing countries, extensive, low-input production systems relying on local animal breeds are also important in food production. These breeds are less productive, but having lived in a given region for decades, they have acquired many adaptive traits, i.e. better utilization of poorer quality feed, adaptation to adverse climatic conditions (high/low temperature or drought), and resistance to parasites or diseases. These breeds are also often used for crossbreeding with imported exotic high-yielding breeds to increase productivity while retaining the adaptive traits of the local breed. Local breeds have found their niche in food production in developed countries as well. Meat, meat products, cheese, and other dairy products from these breeds are increasingly reaching consumers with quality labels, including information about their origin, and consequently obtaining higher prices.

Longevity is a trait influenced by numerous factors, including environmental factors, animal health, and productivity, which translate into economic considerations. In addition to many others, genetic factors are also very important. One of the genes indirectly associated with longevity parameters is the growth hormone receptor gene (GHR). Therefore, an attempt was made to link polymorphism in the 5’UTR region of the GHR gene with longevity and productivity parameters, as well as the content of individual components of milk dry matter. The study was conducted among 100 individuals of the Polish White-Backed breed, covered by genetic resources conservation. The PCR-RFLP method was used. The 836 pz product was digested with the restriction enzyme AluI, and three genotypes were identified: AA, AB, and BB, with frequencies of 0.60, 0.32, and 0.08, respectively. The results obtained were compared with the utility parameters of the animals, and the following indicators were estimated: herd life, productive life, and milking life. The conducted research shows that GHR AluI polymorphism is associated with indicators of longevity, the number of milking days, milk yield, and the content of individual components of milk dry matter.

In view of the threat to local breeds resulting from intensive animal production, many studies are conducted in search of arguments confirming their importance in food production. In the case of milk production, not only is its quantity important, but its quality is as well, including its chemical composition. Particular focus has recently been placed on the casein proteins beta-casein (CSN2) and kappa-casein (CSN3), due to their potential impact on human health or on the suitability of milk for cheese production. The present study analysed the polymorphism of these proteins in 1777 cows belonging to two local cattle breeds, Polish Red and Polish White-Backed, using Illumina Infinium XT SNP technology on a EuroGenomics MD chip. The results indicate that the Polish White-Backed breed is predisposed to produce ‘A2 milk’, as the frequency of the CSN2 A2 allele in the population was 61.2%. The Polish Red breed was characterised by a higher frequency of the CNS3 B allele (35%), which according to extensive scientific literature is associated with better coagulation properties, and increased whey expulsion. The highest yield of milk and its constituents, confirmed at p ≤ 0.01, was obtained for Polish White-Backed cows with the A2A2 genotype in CSN2 and cows with the AA genotype in CSN3. In the Polish Red breed, no statistically significant differences were obtained between means for milk production traits.

The aim of the study was to assess the adaptability of Polish Red cows to extensive housing and feeding conditions. The study was carried out using 22 cows together with their offspring, kept on a certified organic family farm, from 15 October 2017 – the start of the winter feeding season – to 30 October 2018 – the end of the pasture season. The animals were kept as beef suckler cows, which stayed in the pasture during the summer and were kept in buildings with permanent access to a large cattle run in winter. The following were determined in the study: changes in the cows’ weight and body condition, daily gains in calves, 210-day standardized body weight, and estimated milk yield of suckler cows. To evaluate the cows’ health, blood was collected from them twice and analysed for haematological and biochemical parameters. The results indicated that during the study period the Polish Red cows had adequate body condition, normal vital parameters, and a normal course and development of pregnancy despite the sparse winter diet. This definitively confirms the breed’s high capacity to adapt to an extensive system.

Local breeds are the main reservoir of biodiversity of farm animals. According to FAO, they account for 87% of all described breeds in the world. To ensure that they are adequately protected, they should be continually monitored for genetic variation. Another crucial factor is reproduction, which is the most important guarantee of population growth. In the present study, genetic variation in 372 Polish White-Backed cows was determined using DNA microsatellite sequences, taking into account their parentage. Reproductive parameters were analysed as well, based on data from 3658 lactations of 1128 Polish White-Backed cows. The results indicate that despite the small initial population and the implementation of a moderate selection of animals, the existing population of Polish White-Backed cattle has a high level of genetic variation, reflected in the degree of heterozygosity (0.761). Regarding reproductive traits, despite their late age at first calving, Polish White-Backed cows were shown to be distinguished by very good fertility parameters in comparison to other breeds raised in Poland. These findings not only confirm the value of protecting local cattle breeds around the world but may also be of importance in developing selection indices for highly productive breeds, in which reproductive functioning should be one of the most important factors considered.

The objective of this study was to determine the effect of the oxyhumolite supplementation in the feed of cows on the profile and the nutritional indices of fatty acids (FA) in milk and cheese. To the diet of 30 cows, a 100 g/per cow/per day humic-mineral supplement with 65% humic acids was included. Milk was sampled three times: control (0 day, before the dietary modification) and on days 30 and 60 after the introduction of the supplement. For chemical analyses, samples from each cow and for cheese manufacture samples of bulk milk were taken. Fat content in the milk and the cheese, and partial sums of fatty acids profile, nutritional fatty acid ratios and indices were determined. The indicated changes in milk fat quality are difficult to unequivocally assess from a dietary point of view. Negative changes were found in the increase in the proportion of hypercholesterolemic acids (HSFA), atherogenic (AI) and thrombogenic (TI) indices, and a decrease in the hypocholesterolemic/hypercholesterolemic (h/H) ratio, the proportion of desired (DFA) and monounsaturated (MUFA) FA over time of supplementation. Positive changes were also found: the increase in polyunsaturated (PUFA), branched-chain (BCFA), short- and medium-chain (SCSFA) and long-chain (LCSFA) FA percentages, and also content was reported. The cheese (30 and 60 d) showed an increase in the content (mg/100 g) of SFA (including SCFA and LCSFA), OCFA (odd-chain FA), BCFA, MUFA, and DFA. Adverse changes were observed with an increase in PUFA n6, the n6/n3 ratio, and HSFA and TI. No significant differences were found for the AI index. The preliminary results obtained are promising, although further research is needed.

There are many genes responsible for the appearance of different coat colours, among which the melanocortin 1 receptor gene (MC1R) plays an important role. The aim of the study was to characterize genetic variation in Central European cattle breeds based on polymorphism of the MC1R gene and factors determining their coat colour. The study was conducted on 290 individuals of the following breeds: Polish White-Backed (PW), Lithuanian White-Backed (LW), Polish Red (PR), Lithuanian Red (LR), Carpathian Brown (CB), Ukrainian Grey (UG), and Slovak Pinzgau (SP). Polymorphism at the MC1R gene locus was analysed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using two restriction enzymes: Cfr10I and SsiI. The proportions of alleles and genotypes in the MC1R locus indicates a strong relationship between polymorphism and the coat colour of cattle: The E^D allele proved to be characteristic for the breeds with a white-backed coat (PW and LW), while the dominant allele in the red breeds (PR and LR) was E⁺. It is noteworthy that coat colour in the SP population was determined only by the recessive e allele, which resulted in the formation of a separate clade in the phylogenetic tree.