Modeling honey yield, defensive and swarming behaviors of Italian honey bees (Apis mellifera ligustica) using linear-threshold approaches

Background: Genetic improvement of honey bees is more difficult compared to other livestock, due to the very different reproductive behavior. Estimation of breeding values requires specific adjustment and the use of sires in the pedigree is only possible when mating of queens and drones is strictly controlled. In the breeding program of the National Registry for Italian Queen Breeders and Bee Producers the paternal contribution is mostly unknown. As stronger modeling may compensate for the lack of pedigree information, we tested two models that differed in the way the direct and maternal effects were considered. The two models were tested using 4003 records for honey yield, defensive and swarming behaviors of Italian honey bee queens produced between 2002 and 2014. The first model accounted for the direct genetic effect of worker bees and the genetic maternal effect of the queen, whereas model 2 considered the direct genetic effect of the queen without maternal effect. The analyses were performed by linear (honey production) and threshold (defensive and swarming behavior) single-trait models; estimated genetic correlations among traits were obtained by a three-trait linear-threshold model. Results: For all traits, the highest predictability (correlation between breeding values estimated with and without performance records) was obtained with model 2, where direct genetic effect of queens was considered. With this model, heritability estimates were 0.26 for honey yield, 0.36 for defensive behavior, and 0.34 for swarming behavior. Multi-trait estimation resulted in similar or higher heritability estimates for all traits. A low, positive genetic correlation (0.19) was found between honey yield and defensive behavior, whereas the genetic correlation between honey yield and swarming behavior was moderate (0.41). A strong, positive genetic correlation was found between defensive and swarming behaviors (0.62). Predictability for multi-trait evaluations was higher for honey yield (0.46) and defensive behavior (0.30) but almost identical for swarming behavior (0.45) compared to corresponding single-trait predictability. Conclusions: Multi-trait evaluation using a model that accounts for the direct genetic effect of queen was the best approach for breeding value estimation of Italian honey bees. The results suggest a new direction for selection of linear and categorical traits in breeding programs where drone origin is unknown

Rizični čimbenici vimena važni za pojavu kliničkog mastitisa u mliječnih krava.

A cross-sectional longitudinal survey was carried out between February 2009 and January 2010 to evaluate udder-related risk factors for clinical mastitis occurring in dairy herds. Data were used from three dairy farms. Research was divided into four calendar seasons. Cows with clinical mastitis were detected by clinical examination of the udder and determination of abnormalities in milk. Udder level variables, conformation characteristics of udder and teats and teat end to floor distances were included in the logistic regression analysis. The estimated incidence risk for CM in the population of dairy cows observed was 85.02 cases per 100 cowyears at risk. The relative risk of CM was lower for primiparous cows, and increased with further parity. The median number of days in milk at diagnosis was 108 days, ranging from a median of 55 to 150 days in lactation. The rear udder quarters had a higher risk of CM incidence compared to the front udder quarters. A Chi square test revealed that farm management and cow parity were significantly connected with incidence of clinical mastitis. Spring was the season with the highest percentage of diagnosed cases of CM, with the exception of farm A, where Fall was the season with the highest percentage of cases. All udder level factors entered in the models were significantly linked with the occurrence of CM. The odds ratio of CM increased significantly as udder morphology worsened, teat ends were flat and the distance from teat ends to floor decreased. It was concluded that conformation udder traits could be used for the genetic selection of dairy cows for mastitis resistance.Između veljače 2009. i siječnja 2010. provedeno je presječno longitudinalno istraživanje s ciljem procjene vimena kao rizičnog čimbenika kod pojave kliničkog mastitisa u stadima mliječnih krava. Korišteni su podatci s tri farme, a istraživanje je podijeljeno u četiri kalendarske sezone. Krave s kliničkim mastitisom otkrivane su uz pomoć kliničkog pregleda vimena i utvrđivanjem abnormalnosti u mlijeku. Vime, konformacija vimena i sisa, te udaljenost od vrha sisa do poda uključeni su kao varijable u analizu logističkom regresijom. Procijenjeni rizik incidencije za klinički mastitis u promatranoj populaciji mliječnih krava bio je 85,02 slučaja na 100 krava s rizikom. Relativni rizik za klinički mastitis bio je niži kod prvotelki i povišen kod višetelki. Medijan za vrijeme postavljene dijagnoze iznosio je 108 dana, uz granične vrijednosti od 55 do 150 dana laktacije. Stražnje četvrti vimena imale su veći rizik incidencije za klinički mastitis u usporedbi s prednjim četvrtima. Hi-kvadrat testom utvrđeno je da management farme i redni broj telenja krave pokazaju signifikantnu povezanost s incidencijom kliničkog mastitisa. Proljeće je bila sezona s najvišim postotkom dijagnosticiranih slučajeva kliničkog mastitisa, uz izuzetak farme A na kojoj je to bila jesen. Svi čimbenici koji se odnose na vime uključeni u model bili su signifikantno povezani s pojavom kliničkog mastitisa. Omjer izgleda za klinički mastitis signifikantno je porastao s pogoršanjem morfologije vimena, vrhovi sisa bili su pločasti, a udaljenost od vrha sisa do poda je opadala. Zaključeno je da obilježja konformacije vimena mogu biti korištena u genetskoj selekciji mliječnih krava s ciljem veće otpornosti na mastitis

Should performance at different race lengths be treated as genetically distinct traits in Coldblooded trotters?

Speed, in the form of racing time per kilometre (km), is a performance trait of the Swedish-Norwegian Coldblooded trotter included in the joint Swedish-Norwegian genetic evaluation. A few popular stallions have dominated Coldblooded trotter breeding, which has led to an increasing average relationship between individuals in the population. This study investigated the scope for broadening the breeding goal by selecting for racing time per km over different race lengths (short: 1640 m, medium: 2140 m and long: 2640 m), as this could encourage the use of breeding sires that are less related to the population. Performance data on three- to 12-year-old Coldblooded trotters in all Swedish races run 1995-2021 were obtained from the Swedish Trotting Association. These data consisted of 46,356 observations for 8375 horses in short-distance races, 430,512 observations for 11,193 horses in medium-distance races and 11,006 observations for 3341 horses in long-distance races. Variance components and genetic correlations were calculated using a trivariate animal model with Gibbs sampling from the BLUPF90 suite of programs. Breeding values for the three traits were then estimated using univariate animal models with the same fixed and random effects as in the trivariate model. Heritability estimates of 0.27-0.28 and genetic correlations between racing time per km at the different distances of 0.97-0.99 were obtained. Despite the strong genetic correlation between the traits, there was some re-ranking among the top 10 and top 30 stallions based on distance-specific breeding values. Estimated rank correlation between breeding values for racing time per km in short- and medium-distance races was 0.86, while between short- and long-distance races and between medium- and long-distance races it was 0.61. Mean relationship within the top 10 and top 30 stallions based on breeding values for racing time per km at each distance was 0.31-0.33 and 0.23-0.24 while mean relationship to the rest of the population ranged from 0.17 to 0.18 for all groups, although the 10 and 30 top-ranking stallions differed somewhat in the traits. Estimated average increase in inbreeding was 0.1% per year of birth and 1.2% per generation. The strong genetic correlation between racing time per km at different distances did not support their use as genetically distinct traits. Re-ranking of stallions for racing time per km at different race lengths could favour the use of a larger number of stallions in breeding, but according to our results it would not promote the use of stallions that are less related to the total population. Other traits like longevity or health traits, for example, career length and orthopaedic status, may be more relevant in broadening the breeding goal and preventing a few sires dominating future breeding, and this would be interesting to study further

Temperature-humidity index is associated with heat stress and milk yield of dairy cows

Exposure of dairy cows to a thermal environment is a major risk factor for decreased milk production, especially in high-yielding cows. Temperature humidity index (THI) is an important indicator of heat stress loading. Heat stress in dairy cows occurs when THI is higher than 72. The objective of this study was to evaluate the effect of THI on the daily production of dairy cows. The survey was conducted in the summer season from 15th of June to 15th of September. There were include two small family dairy farms with installed cooling systems for microclimate controlling. Totally 18 dairy cows from Holstein black-white breed were subjected to the study (6 cows in farm A and 12 cows in farm B). During the trial period daily average air temperature and relative humidity, as well THI were calculated from the hourly data gained from the automated temperature and humidity data loggers on-farm. The daily milk yield per cow was estimate as sum of milk yield gaining during the morning and evening milking. Test-days data were analyzed using General linear model, univariate procedure to determine the threshold of THI and heat stress and their influence on decline of milk production. The value of THI was ranged from 61.82 to 89.34, which indicates the existence of the moderate intensity of heat stress. THI was in a significant negative correlation with the milk yield and there was existing high positive correlation between THI and heat stress. The present results revealed that the combined effects of air temperature and humidity associated with the level of thermal stress make the considerable loss in the milk production of the dairy cows. Keywords: lactation, dairy barn, thermal comfor

Antioxidant status in dairy cows during transition period

During the transition period important metabolic changes occur in dairy cows, which can also experience oxidative stress. The two years prospective study was carried out to assess the changes occurring in the activity of antioxidant enzymes superoxid dismutase (SOD) and glutathion peroxidase (GPX) in three physiological periods: dry period 21 days before calving, period from beginning of lactation until 21st day in lactation, and period from 22nd to 42nd day in lactation. Determination of the enzyme activity was assayed on blood serum by using spectrofotometric methods. The average activity of SOD in period before calving was 24.20±2.319 mU/mg proteins, reaching the value of 43.94±3.864 mU/mg proteins in the second period and in the third period from 22nd to 42nd day in lactation, the activity was 26.77±2.201 mU/mg proteins. The average activity of GPx in period before calving was 251.79±9.363 mU/mg proteins, than increasing in period from beginning of lactation until 21st day in lactation (372.45±17.533 mU/mg proteins) and in the third period from 22nd to 42nd day in lactation, the activity was 319.40±14.307 mU/mg proteins. Physiological stages in transition period when blood samples was taken, showed statistical significant influence (p<0.001) on SOD and GPx activity in blood serum. Significant difference in the activity of SOD in blood serum was found in period before calving as compared to period from calving to 21st day in lactation, and also in period from calving to 21st day in lactation as compared to period from 22nd to 42nd day in lactation. Significant differences in the activity of GPx in blood serum was found between all three physiological periods, but biggest significant difference in activity was found in period before calving as compared to periods in lactation. There were statistically significant positive correlations between the activity of GPx and SOD in blood serum. Dairy cows experience oxidative stress in transition period from gestation to lactation. Key words: dairy cows, oxidative stress, superoxid dismutase, glutathion peroxidase

Kinetika difuzije soli i randman nekih tipova kozjih sireva

This paper studies the dynamics of salt diffusion during the ageing of three types of cheese from goat\u27s milk: Mozzarella, White Brined and Pecorino. The salt concentration was consistently analyzed at the 72nd hour and on the 5th, 10th, 20th, 40th, 50th, 60th and 90th day of the cheese ageing period. The distribution of salt in the three layers of cheese – inner (I), middle (II) and outer (III) was also studied. The salt equilibration in the cheese mass of Mozzarella occurred on the 15th day, in the White Brined - on the 60th day, whereas in Pecorino the content of salt even on the 90th day was by 1% lower, in the inner layer than in the two other layers of this cheese. The utilization rate of dry matter was 52.17% in Mozzarella, 50.64% in the White Brined and 48.32% in Pecorino. Accordingly, the yield of Mozzarella is 18.13 ±0.43%, of White Brined - 12.50 ±0.37% and the yield of Pecorino is 9.18 ±0.13%.Istražena je kinetika difuzije soli tijekom zrenja tri vrste kozjeg sira (Mocarela, Bijeli salamureni sir i Pekorino). Analize su učinjene periodično svakih 72 sata, 5-tog, 10-tog, 40-teog, 50-tog, 60-tog i 90-tog dana od zrenja sira. Istovremeno smo ispitivali koncentraciju soli u tri sloja sira: unutrašnjem (1), srednjem (2), vanjskom (3). Izjednačavanje soli u sirnoj masi kod sira Mocarela počinje 15-tog dana; kod Bijelog salamurenog sira 60-tog dana dok kod Pekorino sira sadržaj soli je 90-tog dana za 1% manji u unutrašnjem sloju nego u druga dva sloja. Stupanj iskorištavanja suhe tvari kod Mocarela sira je 52,17 %, kod Bijelog salamurenog sira je 50,64 % i kod Pekorino 48,32 %. Suglasno tome, randman sira Mocarela je 18,13±0,43 %, kod Bijelog salamurenog sira je 12,70±0,37 % i kod Pekorino sira 9,58±0,37 %

Udder-related risk factors for clinical mastitis in dairy cows

A cross-sectional longitudinal survey was carried out between February 2009 and January 2010 to evaluate udder-related risk factors for clinical mastitis occurring in dairy herds. Data were used from three dairy farms. Research was divided into four calendar seasons. Cows with clinical mastitis were detected by clinical examination of the udder and determination of abnormalities in milk. Udder level variables, conformation characteristics of udder and teats and teat end to fl oor distances were included in the logistic regression analysis. The estimated incidence risk for CM in the population of dairy cows observed was 85.02 cases per 100 cow�years at risk. The relative risk of CM was lower for primiparous cows, and increased with further parity. The median number of days in milk at diagnosis was 108 days, ranging from a median of 55 to 150 days in lactation. The rear udder quarters had a higher risk of CM incidence compared to the front udder quarters. A Chi square test revealed that farm management and cow parity were signifi cantly connected with incidence of clinical mastitis. Spring was the season with the highest percentage of diagnosed cases of CM, with the exception of farm A, where Fall was the season with the highest percentage of cases. All udder level factors entered in the models were signifi cantly linked with the occurrence of CM. The odds ratio of CM increased signifi cantly as udder morphology worsened, teat ends were fl at and the distance from teat ends to fl oor decreased. It was concluded that conformation udder traits could be used for the genetic selection of dairy cows for mastitis resistance. Key words: dairy cows, clinical mastitis, risk factor

Direct Economic Impact Assessment of Winter Honeybee Colony Losses in Three European Countries

Honeybees are of great importance because of their role in pollination as well as for hive products. The population of managed colonies fluctuates over time, and recent monitoring reports show different levels of colony losses in many regions and countries. The cause of this kind of loss is a combination of various factors, such as the parasitic mite Varroa destructor, viruses, pesticides, management practices, climate change, and other stress factors. Having in mind that the economic aspect of honeybee colony losses has not been estimated, a pioneer effort was made for developing a methodology that estimates the economic impact of honeybee colony losses. Winter loss data was based on 2993 answers of the COLOSS standard questionnaire survey of honeybee winter colony losses for 2016/2017. In addition, market and financial data were used for each country. In a comparative analysis, an assessment on the economic impact of colony losses in Austria, Czechia, and Macedonia was made. The estimation considered the value of the colonies and the potential production losses of the lost colonies and of surviving but weak colonies. The direct economic impact of winter honeybee colony losses in 2016/2017 in Austria was estimated to be about 32 Mio; in Czechia, 21 Mio; and in Macedonia, 3 Mio. Economic impact reflects the different value levels in the three countries, national colony populations, and the magnitude of colony losses. This study also suggests that economic losses are much higher than the subsidies, which underlines the economic importance of honeybees for the agricultural sector

Cutting corners: The impact of storage and DNA extraction on quality and quantity of DNA in honeybee (Apis mellifera) spermatheca

The purpose of our study was to investigate methods of short-term storage that allow preservation, transport and retrieval of genetic information contained in honeybee queen's spermatheca. Genotyping of the honeybee colony requires well ahead planned sample collection, depending on the type of data to be acquired. Sampling and genotyping of spermatheca's content instead of individual offspring is timesaving, allowing answers to the questions related to patriline composition immediately after mating. Such procedure is also cheaper and less error prone. For preservation either Allprotect Tissue Reagent (Qiagen) or absolute ethanol were used. Conditions during transportation were simulated by keeping samples 6-8 days at room temperature. Six different storing conditions of spermathecas were tested, complemented with two DNA extraction methods. We have analysed the concentration of DNA, RNA, and proteins in DNA extracts. We also analysed how strongly the DNA is subjected to fragmentation (through amplification of genetic markers ANT2 and tRNA(leu)-COX2) and whether the quality of the extracted DNA is suitable for microsatellite (MS) analysis. Then, we tested the usage of spermatheca as a source of patriline composition in an experiment with three instrumentally inseminated virgin queens and performed MS analysis of the extracted DNA from each spermatheca, as well as queens' and drones' tissue. Our results show that median DNA concentration from spermathecas excised prior the storage, regardless of the storing condition and DNA extraction method, were generally lower than median DNA concentration obtained from spermathecas dissected from the whole queens after the storage. Despite the differences in DNA yield from the samples subjected to different storing conditions there was no significant effect of storage method or the DNA extraction method on the amplification success, although fewer samples stored in EtOH amplified successfully in comparison to ATR storing reagent. However, we recommend EtOH as a storing reagent due to its availability, low price, simplicity in usage in the field and in the laboratory, and capability of good preservation of the samples for DNA analysis during transport at room temperature

Managed honey bee colony losses in Canada, China, Europe, Israel and Turkey, for the winters of 2008-9 and 1009-10

In 2008 the COLOSS network was formed by honey bee experts from Europe and the USA. The primary objectives set by this scientific network were to explain and to prevent large scale losses of honey bee (Apis mellifera) colonies. In June 2008 COLOSS obtained four years support from the European Union from COST and was designated as COST Action FA0803 – COLOSS (Prevention of honey bee COlony LOSSes). To enable the comparison of loss data between participating countries, a standardized COLOSS questionnaire was developed. Using this questionnaire information on honey bee losses has been collected over two years. Survey data presented in this study were gathered in 2009 from 12 countries and in 2010 from 24 countries. Mean honey bee losses in Europe varied widely, between 7-22% over the 2008-9 winter and between 7-30% over the 2009-10 winter. An important finding is that for all countries which participated in 2008-9, winter losses in 2009-10 were found to be substantially higher. In 2009-10, winter losses in South East Europe were at such a low level that the factors causing the losses in other parts of Europe were absent, or at a level which did not affect colony survival. The five provinces of China, which were included in 2009-10, showed very low mean (4%) A. mellifera winter losses. In six Canadian provinces, mean winter losses in 2010 varied between 16-25%, losses in Nova Scotia (40%) being exceptionally high. In most countries and in both monitoring years, hobbyist beekeepers (1-50 colonies) experienced higher losses than practitioners with intermediate beekeeping operations (51-500 colonies). This relationship between scale of beekeeping and extent of losses effect was also observed in 2009-10, but was less pronounced. In Belgium, Italy, the Netherlands and Poland, 2008-9 mean winter losses for beekeepers who reported ‘disappeared’ colonies were significantly higher compared to mean winter losses of beekeepers who did not report ‘disappeared’ colonies. Mean 2008-9 winter losses for those beekeepers in the Netherlands who reported symptoms similar to “Colony Collapse Disorder” (CCD), namely: 1. no dead bees in or surrounding the hive while; 2. capped brood was present, were significantly higher than mean winter losses for those beekeepers who reported ‘disappeared’ colonies without the presence of capped brood in the empty hives. In the winter of 2009-10 in the majority of participating countries, beekeepers who reported ‘disappeared’ colonies experienced higher winter losses compared with beekeepers, who experienced winter losses but did not report ‘disappeared’ colonies