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Normal calf alpha-mannosidase activity exists in at least three forms separable by chromatography on DEAE-cellulose and by starch-gel electrophoresis. Two components, A and B, have optimum activity between pH3.75 and 4.75, but component C has an optimum of pH6.6. Components A and B are virtually absent from the tissues of a calf with mannosidosis and the residual activity is due to component C. The acidic and neutral forms of alpha-mannosidase differ in their molecular weights and sensitivity to EDTA, Zn(2+), Co(2+) and Mn(2+). An acidic alpha-mannosidase component (pH optimum 4.0) accounts for most of the activity in normal plasma but it is absent from the plasma of a calf with mannosidosis. Although the acidic alpha-mannosidase component is probably related to tissue components A and B, it can be distinguished from them by ion-exchange chromatography and gel filtration. The optimum pH of the low residual activity in the plasma from a calf with mannosidosis is pH5.5-5.75. The results support the hypothesis that Angus-cattle mannosidosis is a storage disease caused by a deficiency of lysosomal acidic alpha-mannosidase activity.

SUMMARY: Severe lameness in a large proportion of an Angus cattle herd was attributed to phosphorus deficiency. The diagnosis was supported by a rapid response to phosphorus supplementation of the diet. A brief review of the development and diagnosis of phosphorus deficiency is presented. Practical considerations severely limit the choice of a phosphorus supplement. Directions for the use of the supernatant of high-phosphorus fertiliser and water mixtures, as feed or stock water additive and the production of a phosphorus lick are described. Other phosphorus supplements are discussed with particular reference to the fluorine hazard.

Extract Diseases inherited as simple recessives frequently reflect simple anomalies of structural or enzymic proteins. Many such inherited diseases of humans have now been defined in biochemical terms (McKusick, 1971) but relatively few have been described adequately in domestic animals. When the biochemical anomaly is known, then it is frequently possible to develop screening programmes to detect diseased young before the disease is manifest clinically. Such programmes may involve families or small populations at risk, or be developed as mass screening programmes for the entire neonatal population of an area or country. In many biochemically defined diseases inherited as recessives, the heterozygous statecan also be recognized. This is either through detection of a mutant structural protein in the otherwise phenotypically normal individual — e.g., the “S” haemoglobin in carriers of sickle-cell anaemia (Lehmann and Huntsman, 1972) — or where an enzyme deficiency is known, by the gene dosage pheno...

Extract Mannosidosis is a lethal lysosolmal storage disease of Angus cattle, inherited as an autosomal recessive and assolciated with a deficiency elf the lysoso,mal enzyme α-mannosidase (Jolly, 1971; Holcking et al., 1972; Jolly et al., 1973). Affected calves fail to thrive and die usually within the first year of life. Many develop ataxia, into-ordination, head tremor and an aggressive tendency (Whittem and Walker, 1957; Jolly, 1970). Investigations have shown that the genotype is very frequent in New Zealand and occurs also in Australia and Scotland (Jolly et al., 1973 and unpublished data). Whereas diseased calves have negligible levels of tissue and plasma α-mannosidase. heterozygous animals have less than half the normal plasma level elf this enzyme (Hocking et al., 1972; Jolly et al., 1973). This observation has formed the basis for a test to identify animals heterozygous for this lethal disease from otherwise phenotypically normal animals. During evaluation studies, it has become evident ...

Tests for the detection of animals heterozygous for alpha-mannosidosis were undertaken on samples taken from 34,203 cattle registered with the Angus Society of Australia. Results indicates 1,836 (5.4%) of the animals were heterozygotes. Heterozygotes were detected in 214 (51%) of the herds examined.

Congenital defects are abnomalities of structure or function present at birth. They may affect only a single anatomical structure such as the eye, an entire system, parts of several systems or involve several body systems, or combine functional and structural defects (syndrome). Many different congenital defects, either of genetic, environmental, or unknown cause, or due to environmentalgenetic interaction have been identified in cattle and other food producing animals and many more undoubtedly exist. Defects range from blemish to severe anomalies and may be manifested by embryonic mortality, fetal death, mummification, abortion, dysmaturity, premature birth, fullterm stillbirth, or nonviable or viable neonate. With increasing use of modern technology such as artificial insemination and embryo transfer in domestic animals, defects no longer are rare; all are important. The majority of studies of pigmentation defects have taken place in the mouse. Since it is easy to handle, has low maintenance cost, and can produce a large number of generations in a short period of time, it is particularly suited for this research. Studies involving cattle necessarily take more time and money. This paper presents clinical, clinipathologic, gross, microscopic and electron microscopic studies of oculocutaneous hypopigmentation in Angus cattle., The Bovine Practitioner, No. 19 (1984 November)

A disease of Angus cattle previously known as pseudolipidosis has been shown to be an inherited lysosomal storage disease, in which an oligosaccharide containing mannose and glucosamine is the storage substance. Diseased animals have a near-absolute deficiency of the lysosomal enzyme, α-mannosidase, whereas heterozygotes have a partial deficiency of this enzyme. The condition is analogous to the human disease known as mannosidosis.

Forty-five steers (9–12 months of age) of Angus (n =15), Brahman (n = 15) and Brahman × Angus (n = 15) breed-types were fed a high-energy diet and then slaughtered after 0, 112 or 224 days of feeding. At 7 days post mortem, the M. longissimus and M. biceps femoris were removed from the left side of each carcass and steaks were obtained for determination of sensory panel ratings, Warner-Bratzler shear force, sarcomere length, collagen content and collagen solubility. Tenderness ratings of steaks from the M. longissimus and M. biceps femoris from Angus were generally higher than ratings for steaks from Brahman or Brahman × Angus steers. Steaks from Brahman × Angus received higher tenderness ratings than steaks from Brahman steers in only a few comparisons. The three breed-types of cattle responded to time-on-feed differently; Brahman cattle needed to have been fed longer than Angus cattle to produce equally tender beef. With increased time-on-feed, M. longissimus tenderness increased for all breed-types, but M. biceps femoris tenderness was not related to time-on-feed. Few significant differences were observed among breed-types and among time-on-feed periods for collagen content or collagen solubility. Tenderness differences were closely correlated with the contractile state of the muscle which, in turn, was associated with weight, subcutaneous fat thickness and temperature decline of the carcass.

A selection experiment to change reproductive traits in Angus cattle has been maintained for 14 years, with first calvings in 1985. Alongside an unselected control line, three lines were established, selected for increased age at puberty in heifers (AGE+ line), reduced age at puberty in heifers (AGE‐ line), or increased scrotal circumference (SC line). The last two lines were merged at the 1992 matings, with the revised objective of applying further selection in both sexes to reduce age at puberty in heifers. Dates at puberty in heifers from an average of 8 to 16 months of age and SC in bulls were recorded in all lines, along with the pregnancy rates (PR) and subsequent calving dates (CD) in heifers and all cow‐age groups. Heritabilities of single‐record SC, standardised age at first behavioural oestrus (SFO), and single‐record CD were 0.41 ± 0.04 (repeatability 0.70 ± 0.01), 0.27 ± 0.04, and 0.09 ± 0.04 (repeatability 0.19 ±0.03), respectively. Genetic correlations of SC with SFO and CD were ‐0....

Dystocia and perinatal mortality are major animal health, welfare and economic issues in beef suckler cow production. The objective of this study was to identify risk factors for dystocia and perinatal mortality and to analyze the relationships of both traits to external pelvic parameters in extensively kept beef suckler cows. Calving ease and calf survival were recorded for 785 births on five Angus cattle farms in Germany. The prevalence of dystocia and perinatal mortality was 3.4% and 4.3%, respectively. A hierarchical model was used to predict dystocia and perinatal mortality. First-parity dams had a higher probability of dystocia (p < 0.0001) than later-parity ones. Increasing birth weight was associated with an increasing risk for dystocia (p < 0.05). The probability of perinatal mortality (p < 0.0001) was higher in assisted births than in unassisted births. Calves from first-parity dams had a higher risk (p < 0.01) of being stillborn than calves from dams in later parities. An increase in the length of the pelvis was associated with an increase in odds for perinatal mortality (p < 0.001). In conclusion, the study indicates that dystocia and perinatal mortality are mainly problems in first-parity suckler cows. Concerning the predictive value of external pelvic parameters, further research is necessary.

Genetic variation in host resistance to nematode infection was studied in two calf crops of Angus cattle under natural pasture challenge conditions in New Zealand, using faecal egg count (FEC) as a marker trait. Genetic and phenotypic correlations of FEC with anti-nematode antibody (Ab) level and live weights were also estimated. Ab to the third larval stages of Cooperia curticei (Cc), Cooperia oncophora (Co), Ostertagia ostertagi (Oo) and Trichostrongylus colubriformis (Tc) were assayed, along with Ab to the adult stages of Co and Oo. Calves were born in the late winter/early spring of 1995 and 1996 over a 7-week period each year; they were weaned at an average of 4 months of age, and faecal samples for FEC were taken at 10 months of age (1995 crop) and at 7 months of age (1996 crop). Blood samples for Ab were taken from both calf crops at intervals between 4 and 20 months of age, and later in peri-partum heifers and cows (23 to 25, and 36 to 37 months of age). For the two calf crops combined, there were 370 animals by 24 sires. Additional blood samples were taken on related animals from the 1993 and 1994 calf crops (218 extra animals, 19 different extra sires). The heritability of loge (FEC + 100) was 0•32 (s.e. 0•16), and heritabilities of loge Ab between 4 and 9 months of age averaged 0•30, between 11 and 20 months of age 0•22, and peri-partum 0•30. Between-animal repeatabilities of Ab levels from samples taken between 4 and 9 months of age averaged 0•40, between 11 and 20 months 0•48, and peri-partum 0•35. Genetic and phenotypic correlations among loge Abs for various nematode species (in hosts aged 4 to 9 months) averaged 0•82 and 0•61, respectively. The corresponding genetic and phenotypic correlations between loge Ab and loge(FEC + 100) averaged –0•48 and –0•07, respectively, whilst those between loge Ab and yearling weight averaged 0•29 and 0•13, respectively. It was concluded that direct selection to reduce FEC should be feasible if required, but index selection combining increased live weight and reduced FEC would often be preferable; anti-nematode Ab levels were repeatable, and FEC and Ab levels were negatively associated genetically.

Weaning weight (WW) and conformation score (CS) records on Angus calves from four New South Wales herds were analysed by least-squares procedures. Paternal half-sib components of variance and covariance were used to obtain estimates of heritabilities of various measures of growth and cs, as well as genetic, phenotypic and environmental correlations. Estimates of the heritabilities of measures of growth ranged from 0.20 (all data) to 0.24 when derived from heifer data only. The heritability of cs was 0.24 when the data were adjusted for ww, and 0.19 when no covariate was included in the analysis. All correlations among different measures of growth were positive and close to unity. There were small positive phenotypic and environmental correlations (0.19 to 0.36) and small negative genetic correlations between ww and cs (–0.02 to –0.41).

Weaning weight (ww) and conformation score (cs) records from Angus calves in five New South Wales herds were analysed by least-squares procedures to assess the nature and magnitude of variation. Herd, year, age of dam and sex were considered as main effects. Covariates included in the models were weaning age (WA) for ww and average daily gain (ADG), and both WA and ww for cs. Male calves (steers and bulls) were 16.6 kg heavier at weaning than female calves. Dams that were 5-8 years of age weaned calves that were 30.1 kg, 15.4 kg and 6.7 kg heavier than 2-, 3- and 4-year-old dams respectively. When ww was not included as a covariate in the model, age of dam effects on cs reflected those on ww, and there was little difference in cs between males and females. When adjusted for differences in ww, males had poorer cs than females, and calves from 3-year-old dams, and from dams over 8 years old, had poorer cs than those from dams of all other ages. Partial regressions of ww and ADG on WA, and of cs on ww, varied considerably between herd/year/sex subgroups.

The width of the dental bridge across the four pairs of incisors was measured in Hereford, Angus, and Shorthorn cattle. Width across the incisors increased rapidly from birth until the age of 7 months. It then remained practically unchanged until the age of 20 months after which width increased rapidly during the eruption of the first pair of permanent incisors. Further rapid increases occurred during the eruption of other permanent incisors. At the age of 13 months when all animals in one group of cattle had reached mature width across their deciduous incisors, this measurement was significantly greater in steers than in heifers. At this same age width across the incisors was significantly greater in Hereford and Angus cattle than in Shorthorns, and significantly greater in Hereford than in Angus cattle. No significant relation was found between width across the incisors and body weight or body weight gain in cattle with normal deciduous incisors. Similarly, the reduction in width following the extraction of the outside lateral deciduous incisors had no significant effect on body weight gain. The heritability of width across the incisors was calculated as twice the standard correlation coefficient between measurements of cows and their qffspring, and was found to be high (2r = 0.656). It is concluded that width across the incisors is a character which was of no economic importance under the grazing conditions used. The mean age (days) at which one or both of the first pair of permanent incisors were fist observed in steers was significantly less in Shorthorns (681.2 ± S.E. 11.5) than in Hereford (724.9 ± S.E. 14.9), with Angus cattle (708.3 ± S.E. 10.7) not significantly different from either of the other breeds. The eruption process for the first permanent incisors has been described in six stages, and the periods to pass through three of these stages have been estimated. The medial time for the whole process was 99 days. No check in body weight gain was associated with the eruptioa process.

Variations in the cross-sectional area of eye muscle of carcasses cut between the tenth and eleventh ribs were investigated, using 105 Hereford and 51 Angus steers aged 20 months. These cattle consisted of three groups, born in successive years. At constant carcass weight, statistically significant differences in eye muscle area were found between breeds and between years. Breed and year differences were also found in eye muscle area with width and depth of eye muscle constant, so that there are limitations to the estimation of eye muscle area from width and depth measurements. A nomograph is given for estimating eye muscle area from width and depth for Hereford and Angus cattle, when all animals are reared in the same year and environment. The use of eye muscle area as an indicator of weight of carcass muscle is discussed.

Skin samples taken from the midsides of Hereford, Angus, and Shorthorn cattle of the same age were analysed for water, crude protein (N x 6.25), and fat contents. Water and crude protein contents were calculated as percentages of fat-extracted fresh skin and fat-extracted dry skin respectively. Breed differences in Chese components were small and not significant. Mean values obtained for all cattle were: water, 69.84�S.E. 0.16; crude protein, 100.68�S.E. 0.29. When fat content was calculated as a percentage of total dry matter, Angus cattle had a significantly lower skin fat content than Shorthorns and Herefords, the mean values for each breed being: Shorthorn 7.40�S.E. 0.88; Hereford, 5.51 �S.E. 0.57; Angus, 3.72�S.E. 0.26. The difference between values for Herefords and Shorthorns was not significant. At slaughter, rib cuts were collected from each beast and dissected into bone, muscle, and fat. The correlation coefficient between the percentage of fat in dry skin samples with the percentage of dissected fat tissue in fresh rib cuts was +0.18 (not significant). In a group of Hereford cattle the effect of plane of nutrition on skin composition was investigated. The percentages of water and crude protein present in skin were almost unaffected by plane of nutrition. However, the absolute contents of water and crude protein increased in animals fed to either gain or lose weight. The percentage of fat in skin increased when animals were gaining weight and decreased when they were losing weight. It is concluded that analyses of skin samples are not likely to be useful in predicting body composition of cattle.

Background Artificial neural networks (ANN) mimic the function of the human brain and are capable of performing massively parallel computations for data processing and knowledge representation. ANN can capture nonlinear relationships between predictors and responses and can adaptively learn complex functional forms, in particular, for situations where conventional regression models are ineffective. In a previous study, ANN with Bayesian regularization outperformed a benchmark linear model when predicting milk yield in dairy cattle or grain yield of wheat. Although breeding values rely on the assumption of additive inheritance, the predictive capabilities of ANN are of interest from the perspective of their potential to increase the accuracy of prediction of molecular breeding values used for genomic selection. This motivated the present study, in which the aim was to investigate the accuracy of ANN when predicting the expected progeny difference (EPD) of marbling score in Angus cattle. Various ANN architectures were explored, which involved two training algorithms, two types of activation functions, and from 1 to 4 neurons in hidden layers. For comparison, BayesCπ models were used to select a subset of optimal markers (referred to as feature selection), under the assumption of additive inheritance, and then the marker effects were estimated using BayesCπ with π set equal to zero. This procedure is referred to as BayesCpC and was implemented on a high-throughput computing cluster. Results The ANN with Bayesian regularization method performed equally well for prediction of EPD as BayesCpC, based on prediction accuracy and sum of squared errors. With the 3K-SNP panel, for example, prediction accuracy was 0.776 using BayesCpC, and ranged from 0.776 to 0.807 using BRANN. With the selected 700-SNP panel, prediction accuracy was 0.863 for BayesCpC and ranged from 0.842 to 0.858 for BRANN. However, prediction accuracy for the ANN with scaled conjugate gradient back-propagation was lower, ranging from 0.653 to 0.689 with the 3K-SNP panel, and from 0.743 to 0.793 with the selected 700-SNP panel. Conclusions ANN with Bayesian regularization performed as well as linear Bayesian regression models in predicting additive genetic values, supporting the idea that ANN are useful as universal approximators of functions of interest in breeding contexts.