Guernsey Breeds Research Articles

Farmers' Perceptions of Dairy Cattle Breeds, Breeding and Feeding Strategies: A Case of Smallholder Dairy Farmers in Western Kenya.

ABSTRACTTo understand farmers’ preference and perceptions of breed attributes, breeding and feeding practices, 419 households in western Kenya were interviewed in a cross-sectional survey. Respondents scored their preference for cattle breeds, traits and breeding methods on a scale of 1 (most preferred) to 5 (least preferred). Preferences were compared using multinomial logistic regression models on weighted scores. The Ayrshire breed was most preferred followed by the Friesian. Using hardship tolerance as a reference trait, the Friesian was preferred 4.86 times more for high milk production and Ayrshire, Jersey and Guernsey breeds 4.61, 4.60 and 4.18 times (p < 0.01) more, respectively, for milk fat content. The Ayrshire was preferred 4.16 times more for its perceived low feed requirement and 1.22 times more (p < 0.01) for resistance to diseases. Friesian was the only breed preferred (3.18 times more) (p < 0.01) for high growth rate of calves. Artificial insemination (AI) was the breeding method of choice, but majority (>68%) of respondents used natural mating, because it was readily available and cheaper. The current study highlights the importance of taking into account farmers’ objectives and the production environment when designing breed improvement programmes and recommends packaging of breeding together with feeding interventions.

Cow genotyping strategies for genomic selection in a small dairy cattle population

This study compares how different cow genotyping strategies increase the accuracy of genomic estimated breeding values (EBV) in dairy cattle breeds with low numbers. In these breeds, few sires have progeny records, and genotyping cows can improve the accuracy of genomic EBV. The Guernsey breed is a small dairy cattle breed with approximately 14,000 recorded individuals worldwide. Predictions of phenotypes of milk yield, fat yield, protein yield, and calving interval were made for Guernsey cows from England and Guernsey Island using genomic EBV, with training sets including 197 de-regressed proofs of genotyped bulls, with cows selected from among 1,440 genotyped cows using different genotyping strategies. Accuracies of predictions were tested using 10-fold cross-validation among the cows. Genomic EBV were predicted using 4 different methods: (1) pedigree BLUP, (2) genomic BLUP using only bulls, (3) univariate genomic BLUP using bulls and cows, and (4) bivariate genomic BLUP. Genotyping cows with phenotypes and using their data for the prediction of single nucleotide polymorphism effects increased the correlation between genomic EBV and phenotypes compared with using only bulls by 0.163±0.022 for milk yield, 0.111±0.021 for fat yield, and 0.113±0.018 for protein yield; a decrease of 0.014±0.010 for calving interval from a low base was the only exception. Genetic correlation between phenotypes from bulls and cows were approximately 0.6 for all yield traits and significantly different from 1. Only a very small change occurred in correlation between genomic EBV and phenotypes when using the bivariate model. It was always better to genotype all the cows, but when only half of the cows were genotyped, a divergent selection strategy was better compared with the random or directional selection approach. Divergent selection of 30% of the cows remained superior for the yield traits in 8 of 10 folds.

Genomic evaluation, breed identification, and population structure of Guernsey cattle in North America, Great Britain, and the Isle of Guernsey

As of December 2015, 2,376 Guernsey bulls and cows had genotypes from collaboration between the United States, Canada, the United Kingdom, and the Isle of Guernsey. Of those, 439 bulls and 504 cows had traditional US evaluations, which provided sufficient data to justify investigation of the possible benefits of genomic evaluation for the Guernsey breed. Evaluation accuracy was assessed using a traditional 4-yr cutoff study. Twenty-two traits were analyzed (5 yield traits, 3 functional traits, and 14 conformation traits). Mean reliability gain over that for parent average was 16.8 percentage points across traits, which compares with 8.2, 18.5, 20.0, and 32.6 percentage points reported for Ayrshires, Brown Swiss, Jerseys, and Holsteins, respectively. Highest Guernsey reliability gains were for rump width (44.5 percentage points) and dairy form (40.5 percentage points); lowest gains were for teat length (1.9 percentage points) and rear legs (side view) (2.3 percentage points). Slight reliability losses (1.5 to 4.5 percentage points) were found for udder cleft, final score, and udder depth as well as a larger loss (13.6 percentage points) for fore udder attachment. Twenty-one single nucleotide polymorphisms were identified for Guernsey breed determination and can be used in routine genotype quality control to confirm breed and identify crossbreds. No haplotypes that affect fertility were identified from the current data set. Principal component analysis showed some divergence of US and Isle of Guernsey subpopulations. However, the overlap of US, Canadian, UK, and Isle of Guernsey subpopulations indicated the presence of gene flow, and the similarities in the subpopulations supports a common genomic evaluation system across the regions.

Genetic diversity of Guernsey population using pedigree data and gene-dropping simulations

The objectives of this study were to analyze the trend of within-breed genetic diversity and identify major causes leading to loss of genetic diversity in Guernsey breed in three countries. Pedigree files of Canadian (GCN), South African (GSA) and American (GUS) Guernsey populations containing 130 927, 18 593 and 1 851 624 records, respectively, were analyzed. Several parameters derived from the in-depth pedigree analyses were used to measure trends and current levels of genetic diversity. Pedigree completeness index of GCN, GSA and GUS populations, in the most recent year (2007), was 97%, 74% and 79%, respectively, considering four generations back in the analysis. The rate of inbreeding in each population was 0.19%, 0.16% and 0.17% between 2002 and 2007, respectively. For the same period, the estimated effective population size for GCN, GSA and GUS was 46, 57 and 46, respectively. The estimated percentage of genetic diversity lost within each population over the last four decades was 8%, 3% and 5%, respectively. The relative proportion of genetic diversity lost due to random genetic drift in the three populations was 93%, 91% and 86%, respectively. In conclusion, the results suggested that GCN and GUS have lost more genetic diversity than GSA over the past four decades, and this loss is gaining momentum due to increasing rates of inbreeding. Therefore, strategies such as optimum contribution selection and migration of genetic material are advised to increase effective population size, particularly in GCN and GUS.

Calving interval genetic parameters and trends for dairy breeds in South Africa

Calving interval (CI) is a fertility trait that can be used in selection programmes to minimize the negative effects that selection for production have on fertility. CI can be derived from milk recording data, therefore this fertility trait can easily be implemented in the National Dairy Genetic Evaluations of South Africa. The aim of this study was to estimate genetic parameters for CI for estimation of breeding values and genetic trends to enable South African dairy breeders to assess and select for improved fertility. Breeds included in the study were Ayrshire, Guernsey, Holstein and Jersey. Genetic parameters and trends were based on the first three CIs for all breeds. The genetic software package, VCE4, was used to estimate genetic parameters for CI. Heritabilities ranged from 0.011 for CI1 to 0.069 for CI2, both for the Guernsey breed. Genetic correlations ranged from 0.606 between CI2 and CI3 for the Guernsey breed, to 0.810 between CI1 and CI2 for the Ayrshire breed. Breeding value estimation was done using the genetic software package, PEST. The estimated breeding values were combined into an index value, using weighting factors based on the amount of information available for each trait. Genetic trends were calculated by averaging the CIindices of measured cows per year of birth. These genetic trends indicated that CI increased genetically for all breeds. The genetic parameters will now be implemented for the estimation of CI breeding values, which can be included in selection programmes for improvement of fertility of dairy breeds in South Africa.Keywords: Ayrshire, genetic correlations, fertility, Guernsey, heritability, Holstein, Jersey

Phenotypic analysis of pregnancy effect on milk, fat, and protein yields of Canadian Ayrshire, Jersey, Brown Swiss, and Guernsey breeds

Pregnancy has a negative impact on milk production in dairy cattle. Estimates of the effects of pregnancy are required in genetic evaluation models. Test-day records of Ayrshire, Jersey, Brown Swiss, and Guernsey breeds were analyzed phenotypically for the effect of pregnancy using 4 different models. Milk, fat, and protein yields were analyzed separately. The first model used a fourth-order Legendre polynomial regression on days in milk within classes of 10 d open. The second model fitted stage of pregnancy within days open classes to investigate the possible interaction between lactation stage and gestation stage. The third model included a fourth-order Legendre polynomial regression on days pregnant. In the fourth model, test-day records were divided into stage of pregnancy classes. Given that the effect of pregnancy was significant for all models, and that the adjusted R-squared values were consistent across the models, implying that the models for each trait fitted equally well within breeds, models were therefore compared based on the practicality of the results. Analysis of the first model indicated that milk production for cows with ≤180 d open tended to have low yields in the last part of lactation. Cows with longer days open, however, had proportionally higher milk yield throughout lactation, suggesting a possible confounding effect of production level with days open effects. Results from the analysis involving the second model illustrated that there was no apparent interaction between lactation stage and gestation stage. Results from the third and fourth models showed that milk and fat yields began to decline after about 4 mo of pregnancy for all breeds, and protein yield began to decline after about 2 mo of pregnancy for all breeds. A lack of records during the final 60 d of pregnancy (the typical dry period) severely limited the third model, as pregnancy effects could not be estimated accurately. This problem was lessened, however, with the fourth (stage of pregnancy) model, because test-day records for cows ≥210 d pregnant were grouped together, allowing for a moderate number of test-day records in the final class of days pregnant. Because the stage of pregnancy model showed a decline in production that increased as gestation progressed, and because there was not a lack of test-day records at the end of pregnancy, the fourth model provided the most realistic estimate of the effect of pregnancy on milk production. Further investigation is needed into the incorporation of stage of pregnancy effects into genetic evaluations.

298 COMPARISON OF THREE DIFFERENT PROTOCOLS FOR SUPERSTIMULATION OF DAIRY CATTLE

Traditionally, successful superstimulation of cattle depended on initiating injections of gonadotrophin at mid-cycle, approximately at second follicular wave emergence. This approach limited the convenience of scheduling donors for superstimulation. With the use of intravaginal progesterone-releasing devices and estradiol 17β, superstimulation can be initiated successfully at any time of the estrous cycle. However, because estradiol cannot be legally injected into cattle in an increasing number of countries, the efficacy of GnRH as an estradiol substitute was investigated. A retrospective analysis was performed on data collected in a commercial bovine embryo transfer program over a period of several years. All donors were lactating dairy cows at least two years of age; approximately 75% were comprised of Holstein and the remainder of Jersey, Guernsey, or Brown Swiss breeds. The three treatments employed were (1) Controls injected twice daily for 4 days with a total of 240 to 400 mg of porcine FSH (Folltropin-V, Bioniche Animal Health, Inc.) in decreasing doses starting between day 7 and day 14 of diestrus, with PG (Lutalyse, Pfizer Animal Health) given at the time of FSH injections no. 5 (35 mg) and 6 (25 mg); (2) Estradiol females received a CIDR (Pfizer Animal Health), 5.0 mg estradiol 17β and 100 mg progesterone in oil on random days of the estrous cycle; FSH was initiated 4 days later as described for controls with CIDR removal at the time of FSH injection no. 6; (3) GnRH females received a CIDR on random days of the estrous cycle and 100 μg GnRH on day 1.5 following CIDR insertion; FSH was initiated 60 h after GnRH injection as described for controls with CIDR removal at the time of FSH injection no. 6. All donors were inseminated with one straw of frozen semen 12 and 24 h after the onset of estrus. Embryos were nonsurgically recovered 7 to 8 days after onset of estrus. Only embryos of grades 1 to 3 (IETS classification) were included in the data. Data were analyzed by ANOVA and Tukey’s hsd test was used to distinguish significance among means as shown in Table 1. Estradiol females produced approximately 2 more ova/embryos per procedure than Control and GnRH groups and an average of 0.8 more embryos per female than did the Control group, but there was no difference compared to the GnRH group. Similar to what has been shown in other commercial embryo transfer data sets, nearly 25% of the donors in each group failed to produce at least one good embryo. Clearly, all three treatments resulted in efficacious superstimulation. In light of the legality issues surrounding the use of estradiol, this study shows that GnRH can be used quite successfully to superstimulate dairy cattle at random times of the estrous cycle. Table 1.Average numbers of ova and embryos recovered from dairy cows superstimulated with three different protocols We thank G.E. Seidel, Jr. and S.C. Purcell for assistance with statistical analysis.

Test-day models for South African dairy cattle for participation in international evaluations

Variance components and breeding values of production traits and somatic cell score of South African Guernsey, Ayrshire, Holstein and Jersey breeds have been estimated using a multi-lactation repeatability test-day model, including tests of the first three lactations as repeated measures and fitting the permanent environmental effect across lactations. Multitrait evaluations were done for the production traits (milk, butterfat and protein) and single trait evaluations for somatic cell score. Heritability estimates were comparable with yield and somatic cell score estimates obtained by test-day models from other countries (17-24% for milk yield; 10-13% for butterfat yield; 14-19% for protein yield and 6-8% for somatic cell score). Proofs of qualifying sires were sent to the International Bull Evaluation Service (INTERBULL) for participation in the March 2005 test runs. Genetic correlations between South Africa and other participating countries, estimated by INTERBULL, compared well with those amongst the other participating countries. Trend validation tests were successful using this methodology for all traits and breeds except for somatic cell score of the Guernsey breed, due to insufficient data for this trait. South Africa can now participate in routine INTERBULL evaluations to obtain Multiple Across Country Evaluation (MACE) breeding values, using this methodology.

Crossbreeding Effects in Dairy Cattle: The Illinois Experiment, 1949 to 1969

A crossbreeding project involving the Holstein and Guernsey breeds was conducted at the Illinois Agricultural Experiment Station from 1949 to 1969. All surviving male calves, 989 of the 1061 born, were sold within 2 or 3 d following birth. All surviving female calves born in the first four generations, 723 of the 788 born, were given an opportunity to conceive and produce milk. Those female calves born in the fifth generation (152 of 166 born) were placed in the University herd or sold to commercial dairy farmers. On a basis of a total of 2015 calves born, crossbreds had a 15.6% greater survival rate to sale or 1 wk of age than purebreds. Of the 778 surviving females born in the first four generations, 18.4% more crossbreds than purebreds calved once, and 24.5% more crossbreds than purebreds calved twice. For weight at 18, 24, 30, 36, and 48 mo of age, crossbreds exceeded purebreds by 5.0, 7.0, 4.4, 3.6, and 5.3%, respectively. Crossbreds were 9.3 d older at calving than purebreds and had an average calving interval that was 9.4 d longer than that for purebreds. For yield of milk, fat, protein, and SNF, crossbreds exceeded purebreds by 8.0, 8.5, 7.5, and 3.0%, respectively. The measures of survival, growth, milk yield, and reproduction were appropriately combined into an index of income produced per cow. On a basis of income per cow per lactation, crossbreds exceeded purebreds by 14.9%. On a basis of income produced per cow per year, crossbreds exceeded purebreds by 11.4%.

Upper-normal prediction limits of lymphocyte counts for cattle not infected with bovine leukemia virus

SUMMARY A study was conducted to develop valid estimates of lymphocyte count (lc; cells per microliter) of individual, clinically normal dairy cattle. Estimated weighted regression was used on repeated measures of individual lc to examine 6 models predicting lc as a function of age in cattle not infected with bovine leukemia virus. The generalized growth curve model of analysis of variance was used to estimate intercepts, slopes, and prediction limits for the models and to compare the lc-to-age relationship between Holstein and Guernsey breeds. The bestfitting model (P = 0.0001) with the narrowest prediction interval was lc = 4,414.4 − 84.6X, where X = (age -48) if age ≤ 48 months, and X = 0 if age &gt; 48 months, and 163.6 and 8.1 are the se of the estimates, respectively. Upper one-sided 95%-predicted normal lc tended to be higher than estimates derived from traditional hematologic keys that use confidence limits of mean lc. Difference was not found in the lc-to-age relationship between the Holstein and Guernsey cattle (P = 0.67). Results of this study provided estimates of normal lc that are more specific in diagnosing lymphocytosis in individual cattle.

Parturient Paresis and Hypocalcemia in Ruminant Livestock

Parturient paresis (hypocalcemia) is most likely to affect dairy cattle around the time of parturition. It causes progressive neuromuscular dysfunction and flaccid paralysis. Older dairy cows, cows with a history of parturient paresis during a previous lactation, high-producing cows, and cows from the Jersey and Guernsey breeds are at highest risk for developing parturient paresis. Nonparturient hypocalcemia may also occur and is related to events other than parturition, such as severe stress, that temporarily overwhelm the mechanisms of calcium homeostasis. Beef cattle, sheep, and goats are affected less frequently by hypocalcemia than are dairy cows. Because these species are not as stressed for milk production as dairy cattle, nonparturient hypocalcemia makes up a higher proportion of cases in nondairy ruminants. Clinical signs of hypocalcemia in beef cattle, sheep, and goats tend toward hyperesthesia and tetany rather than the classic flaccid paralysis that occurs in dairy cattle with parturient hypocalcemia. Prompt and effective treatment of hypocalcemia helps to reduce the incidence of secondary complications, such as muscle damage or mastitis. The standard treatment regimen of 500 ml of 23 per cent calcium gluconate, administered intravenously, will elicit a favorable response in approximately 75 per cent of recumbent cows within 2 hours of treatment. Relapses following successful initial therapy are common and may be prevented in part by supplementation of intravenous treatment with an additional 500 ml of 23 per cent calcium gluconate administered subcutaneously. Proper nursing care following treatment speeds recovery and reduces the incidence of secondary complications owing to hypocalcemia.

Milk compositional ranges and trends

The effects of breed, stage of lactation, age and seasonality on the compositional quality of milk are discussed. The Jersey breed has the highest fat and protein contents, 51.9 and 38.5 g/kg milk, respectively, followed by the Guernsey breed, with 46.4 and 36.3 g/kg milk. The British Holstein has the lowest fat and protein contents, at 37.3 and 32.0 g/kg milk, respectively, whilst the Ayrshire is intermediate between the Channel Island and the Friesian and Holstein breeds. The range of fat within a breed may be over 20 g/kg milk. The variation in protein content is less than this value but may be over 10 g/kg milk. Lactose values vary less than those for fat and protein. Mean lactose values are 45.5 g/kg, with a range from 41.0 to 50.0 g/kg milk.The protein content of milk is high in early lactation, falls rapidly to reach a minimum at approximately 6 weeks after calving, increases slowly to 6 months after calving and then increases rapidly to the end of lactation. The fat content of milk is also high in early lactation and falls to a minimum between the 6th and 10th weeks of lactation. It then rises in a manner similar to protein. Converse changes occur with lactose: the content is low in colostrum and increases to twice its initial value within the 1st week. It remains steady until the 5th or 6th week of lactation, after which it declines slowly and then more rapidly towards the end of lactation.The fall in the fat content of milk from the 1st to the 5th lactation is progressive and of the order of 2 g/kg milk. Solids-not-fat content declines by approximately 4 g/kg. This fall in solids-not-fat is largely a fall in lactose; the change in protein content is small. In Friesian herds, a decrease in average lactose content from 46.9 to 44.7 g/kg milk from 1st to 3rd lactation and over has been observed.The average fat content of bulk milk in England and Wales is highest in October and November and lowest in May and June. The protein content of milk falls to a low level in March, rises rapidly during April and May and shows a slight fall in July, followed by an increase until October, when a progressive fall occurs during the winter months. The lactose content of milk does not vary as much as protein, with values being 0.5 g/kg higher in June and 0.8 g/kg lower in September than the overall average.

Pheochromocytomas and ultimobranchial (C-cell) neoplasms in the bull: evidence of autosomal dominant inheritance in the Guernsey breed.

Pheochromocytomas and ultimobranchial (C-cell) neoplasms were diagnosed at a high frequency in a family of Guernsey bulls. The incidence supported the hypothesis of autosomal dominant inheritance of the neoplasms. These two neoplasms also occur in man as multiple endocrine adenomatosis type 2, which has autosomal dominant inheritance.

Optimal Culling Strategies for Dairy Cows of Different Breeds

Dynamic programming models were developed to optimize culling decisions for Holstein, Jersey, Guernsey, and Ayrshire cows. Parameters of individual breeds for milk yield, milk fat percent, body weight, and disposal reasons were considered. Replacement heifers were allowed to vary in these traits by a probability distribution function. Maximum discounted returns over major variable costs were computed for 10-yr planning for each breed for five prices.Regardless of prices, Holsteins had the highest weighted average value of discounted returns over variable costs followed in decreasing order by Ayrshires, Guernseys, and Jerseys. Effects of the traits on these values were determined by response surfaces. Holsteins and, to a less extent, Ayrshires, would benefit from increased emphasis on milk fat percent as an effective method of increasing discounted 10-yr returns over variable costs. Values for the Jersey and Guernsey breeds would increase substantially if major emphasis were placed on milk yield. Little would be gained by increases in milk fat percent for these two breeds. These results were consistent over changes in prices of milk and feed.Within breeds, body weight had little effect on response surfaces and had only a slight positive effect on 10-yr discounted returns over variable costs. Body weight could be conveniently omitted from the models.

Selenium and Vitamin E and Incidence of Retained Placenta in Parturient Dairy Cows. II. Prevention in Commercial Herds with Prepartum Treatment

In a series of field experiments in Ohio involving 193 parturient cows of the Holstein and Guernsey breeds, the prophylactic efficacy of selenium and vitamin E was tested under field conditions. Herds initially were chosen because of a chronic problem with retained placenta which could not be related to a known etiological factor. Each herd was divided into three groups. Group A received an injection of 50 mg of sodium selenite 40 days prepartum and 680 units of alpha tocopherol acetate followed by the same treatment 20 days prepartum. Group B received a single injection of 50 mg of sodium selenite 20 days prepartum, and 680 IU of vitamin E. Group C served as the control. Incidence of retained placenta was reduced from a mean of 51.2% in control cows to 8.8% for animals injected with selenium and vitamin E. No differences in efficacy were between Group A and B, and it appears that the single 20 day prepartum injection of 50 mg of sodium selenite and 680 IU of alpha tocopherol acetate is an effective prophylactic for prevention of retained placenta.

AGE–MONTH ADJUSTMENT OF CANADIAN DAIRY PRODUCTION RECORDS

Records of Performance (ROP) in dairy production for Ayrshire, Guernsey, Holstein and Jersey breeds were analyzed to estimate constants (age–month subclass averages adjusted for herd differences, time trend and cow culling effect) which can be used for a new Breed Class Average system for simultaneous adjustment of age and month of calving differences. Age, month, and age by month interaction effects were highly significant and thus we conclude that a joint adjustment for age and seasonal variation is necessary. Seasonal variation was sufficiently continuous to warrant age adjustment within individual month. Within breed adjustment for age–month of calving is necessary, but within geographical region and/or lactation number adjustment is not recommended.

Inherited casein variants in cow's milk: II. Breed differences in the occurrence of β-casein variants

SummaryA survey was made of the frequency of β-casein variants in the milk of cows of five major British breeds. Three variants A, B and C differing in electrophoretic mobility were found to occur either singly or in pairs, as expected if each were determined by a single allele. The A variant was the most common and found in all breeds. Ayrshires and Shorthorns produced no other variant, whilst the B variant occurred in Jerseys and, at low frequency, in Guernseys and Friesians. Production of the C variant was restricted to the Guernsey breed in which it occurred at low frequency. The technique of paper electrophoresis, used for β-casein ‘typing’ of some 600 cows, is described in detail.

Congenital Abnormalities in Cattle: Their Association with Hereditary and Environmental Factors

Summary The purpose of this paper is to indicate the frequency of congenital anomalies in cattle and to record data dealing with the influence of environmental and hereditary factors on their occurrence. Approximately 5,000 calves of the Holstein, Guernsey, and Jersey breeds were divided into normal and abnormal animals. Abnormality was defined as any anatomical defect observed by the cooperating dairymen. The abnormalities reported were divided into five major groups: general abnormalities, abnormalities of ectodermal, mesodermal, and neurectodermal derivatives and calves born dead with no other observable defect. Environmental and genetic factors were tested for an association with the number of abnormal animals reported and the type of abnormality reported, by the chi-square test of independence; 6.26% of the calves born were abnormal. A significant association of sire, with the number of abnormal animals reported, was demonstrated. A highly significant association of twins and abnormal gestation length with the number of abnormal animals was shown. Twins were highly significantly associated with type of abnormality reported, as was breed. No significant association was found between sex, number of services required for conception, breed, level of herd production or inbreeding, and the number of abnormal animals reported. No significant association could be shown between number of services required for conception or sex and type of abnormality reported.

Effect of a Simple High-Fiber Feed on Dairy Calves

Summary Thirteen pairs of calves including Jersey, Guernsey, and Holstein breeds were used to evaluate the effect of complexity and fiber content of concentrate mixtures for young calves. A simple high-fiber mixture containing 13.9% fiber was consumed as readily as was a complex low-fiber feed containing 6% fiber. No differences in tendency to consume hay were observed. All calves gained considerably more than the expected gain as computed by use of the Ragsdale standard (6), and no differences in rate of growth or general health were apparent.

Blood group studies on cattle of Red Polish breed

Blood samples from 262 Polish Red Cattle, 9 Danish Red Cattle and 123 cattle produced by crossing were examined for the presence of 45 erythrocyte antigenic factors.The frequencies of most of the factors are given and estimates are made of the appropriate gene frequencies within the Polish Red breed as a whole.Segregation of 42 B alleles was observed of which 9 have not previously been reported. The H′ factor hitherto recorded as marking an independent system is assigned to the SU system on genetical grounds and renamed S2.It is concluded from the blood group data that the Polish Red breed has signs of a genetic relationship with Holstein-Friesian, Brown Swiss and Guernsey breeds but the relationship with the Danish Red breed is closer. The existence of the new alleles distinguish the Polish Red breed of cattle from all others investigated.