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Simple Summary: Simple Summary: This study examines how breeding dairy cows with high immune response (HIR) sires affects their reproductive performance. We looked at factors like calving time, how long they stay open for insemination, and the ease of calving. We found that cows related to HIR sires tended to have shorter intervals between calving, which is good for farm productivity. However, there were also more cases of twin pregnancies and difficult births among these cows. This suggests that while there are some benefits to breeding with HIR sires, there are also potential challenges. Understanding these effects can help farmers make better decisions about breeding strategies, ultimately contributing to the efficiency and success of dairy farming. Reproductive traits in dairy cattle are crucial for herd productivity and profitability. This study investigates the influence of relatedness to high immune response (HIR) Immunity+ sires on reproductive performance indicators in Polish Holstein-Friesian cows. A total of 5094 cows were analyzed, categorized based on their relatedness to HIR Immunity+ sires, and assessed for various reproductive parameters, including age at first insemination, gestation length, days open, calving interval, and calving ease. The results showed that the level of relatedness to HIR Immunity+ sires influenced certain reproductive traits, such as service period, gestation length, and age at first and second calving. Additionally, cows related to HIR Immunity+ sires exhibited a higher frequency of twin pregnancies and more complicated births. While some benefits were observed in certain reproductive traits among cows related to HIR Immunity+ sires, such as reduced age at first insemination and shortened gestation length, the overall impact on reproductive efficiency remains inconclusive. Further studies are needed to fully elucidate the effects of using semen from HIR Immunity+ sires on reproductive performance in dairy cattle. [ABSTRACT FROM AUTHOR]

Simple Summary: In some species of birds, asynchronous hatching occurs when incubation begins before completion of clutch, resulting in age differences between nestlings. According to the brood reduction hypothesis, which explains the reason for asynchronous hatching, selective survival is permitted only for older nestlings when availability of food is unpredictable. Due to the feature of food distribution, passerines are not likely to practice selective feeding of older nestlings. The essential purpose of this study is to determine whether the brood reduction hypothesis can explain asynchronous hatching in passerines. Infrared cameras were installed inside nest boxes to determine whether great tit (Parus major) parents, which show asynchronous hatching, practices selective feeding of older nestlings. The results of this study showed that great tit parents did not practice selective feeding of older nestlings, highlighting that using the brood reduction hypothesis to explain asynchronous hatching of great tits is not reasonable. Further research is needed in order to explain the adaptiveness of asynchronous hatching. The brood reduction hypothesis, which explains asynchronous hatching in birds, as an adaptation that enables selective survival of older nestlings when availability of food is unpredictable. This study was conducted in order to determine whether the brood reduction hypothesis can explain asynchronous hatching in passerines. Infrared cameras were installed inside nest boxes where great tits (Parus major) were attempting to reproduce in order to determine whether the parents practiced selective feeding of older nestlings. According to the results of the study, no significant difference was observed between the hatching order and the average number of feedings per nestling. In addition, when examining the distribution of food according to hatching order over time, every 30 min, beginning at 9 a.m., selective distribution of food to older nestlings was not observed. In conclusion, use of the brood reduction hypothesis, which supports selective provision of beneficial feeding of older and larger nestlings, to explain the asynchronous hatching of passerines is problematic, thus conduct of future studies focusing on other hypotheses in order to explain the asynchronous hatching of this passerine bird will be necessary. [ABSTRACT FROM AUTHOR]

Simple Summary: Scrapie is a transmissible spongiform encephalopathy affecting sheep and goats. Due to similarities with mad cow disease (BSE) which is transmissible to humans, scrapie is considered of significance for its theoretical zoonotic potential. A variety of control strategies have been proposed and applied over the years. While herd depopulation, culling of affected susceptible animals, and disinfection measures are poorly successful, selective breeding schemes focused on amino acid substitutions (polymorphisms) in prion protein (PrP) would be the best way for eradication. In sheep, the association between PrP gene polymorphism argininine on codon 171 is highly effective for scrapie resistance breeding. Although in goats this polymorphism is absent, three other candidate PrP amino acid polymorphisms have been recognized for resistance breeding. For Greece with the largest goat population in Europe, the frequencies of these polymorphisms has yet to be sufficiently documented. This study performed a large-scale, cross-sectional survey for a large part of the country, regarding PrP polymorphic codons 110, 146, 211, and 222, and estimated effects of these polymorphisms on (i) the likelihood to be infected by scrapie, and (ii) scrapie status at the herd level, revealing possible candidate PrP amino acid polymorphisms to be used in breeding for scrapie-resistance programs. Scrapie is considered an endemic disease in both sheep and goats in Greece. However, contrary to sheep, in goats more than one prion protein (PrP) polymorphism has been recognized as a candidate for resistance breeding against the disease. For an impression, candidates which are circulating, (i) brain samples (n = 525) from scrapie-affected (n = 282) and non-affected (n = 243) animals within the national surveillance program, and (ii) individual blood samples (n = 1708) from affected (n = 241) and non-affected (n = 1467) herds, in a large part of mainland Greece and its islands, were collected and assayed. A dedicated Taqman method was used to test for amino acid polymorphisms 110T/P, 146N/S/D, 211R/Q, and 222Q/K. Highly prevalent genotypes were 110TT, 146NN, 211RR, and 222QQ. The frequencies of polymorphisms in blood and negative brain samples for codons 110P, 211Q, and 222K were 4.0%, 3.0%, and 1.9%, respectively, while 146D (0.7%) was present only on Karpathos island. Codon 110P was exclusively found in scrapie-negative brains, and homozygous 110P/P in two scrapie-negative goats. It is concluded that breeding programs in Karpathos could focus on codon 146D, while in other regions carriers of the 110P and 222K allele should be sought. Case-control and challenge studies are now necessary to elucidate the most efficient breeding strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: The Nero di Parma is an Italian pig breed with a peculiar breed history. It originates from a native breed called "Nera Parmigiana", which, in the beginning of the 20th century, was crossed with highly productive breeds, causing the extinction of the original type in the 1970s. During the 1990s a growing interest for organic products and outdoor farming brought the attention back to the local type and a breed recovery project started to reestablish the original breed. The aim of the study was to investigate the genetic diversity of the Nero di Parma breed to provide further insights for breed conservation and to propose breeding strategies. Nero di Parma is an endangered swine breed reared in the North of Italy which nowadays counts 1603 alive pigs. The aims of this study were (i) to explore the genetic diversity of the breed at pedigree level to determine the actual genetic structure, (ii) to evaluate the effectiveness of the breeding recovery project and (iii) to potentially propose breeding strategies for the coming generations. The pedigree dataset contained 14,485 animals and was used to estimate demographic and genetic parameters. The mean equivalent complete generations was equal to 6.47 in the whole population, and it reached a mean value of 7.94 in the live animals, highlighting the quality of the available data. Average inbreeding was 0.28 in the total population, whereas it reached 0.31 in the alive animals and it decreased to 0.27 if only breeding animals were considered. The rate of inbreeding based on the individual increase in inbreeding was equal to 7%. This study showed the effectiveness of the recovery project of the breed. Nevertheless, we found that inbreeding and genetic diversity have reached alarming levels, therefore novel breeding strategies must be applied to ensure long-term survival of this breed. [ABSTRACT FROM AUTHOR]