Breed Group Differences Research Articles

Breed group differences in the unsolvable problem task: herding dogs prefer their owner, while solitary hunting dogs seek stranger proximity

The communicating skills of dogs are well documented and especially their contact-seeking behaviours towards humans. The aim of this study was to use the unsolvable problem paradigm to investigate differences between breed groups in their contact-seeking behaviours towards their owner and a stranger. Twenty-four dogs of ancient breeds, 58 herding dogs, and 17 solitary hunting dogs were included in the study, and their behaviour when presented with an unsolvable problem task (UPT) was recorded for 3 min. All breed groups interacted with the test apparatus the same amount of time, but the herding dogs showed a longer gaze duration towards their owner compared to the other groups and they also preferred to interact with their owner instead of a stranger. Interestingly, the solitary hunting dogs were more in stranger proximity than the other groups, and they also showed a preference to make contact with a stranger instead of their owner. Hence, we found differences in contact-seeking behaviours, reflecting the dog–human relationship, between breed groups that might not only be related to their genetic similarity to wolves, but also due to the specific breeding history of the dogs.

Comparison of owner-reported behavioral characteristics among genetically clustered breeds of dog (Canis familiaris).

During the domestication process, dogs were selected for their suitability for multiple purposes, resulting in a variety of behavioral characteristics. In particular, the ancient group of breeds that is genetically closer to wolves may show different behavioral characteristics when compared to other breed groups. Here, we used questionnaire evaluations of dog behavior to investigate whether behavioral characteristics of dogs were different among genetically clustered breed groups. A standardized questionnaire, the Canine Behavioral Assessment and Research Questionnaire (C-BARQ), was used, and breed group differences of privately-owned dogs from Japan (n = 2,951) and the United States (n = 10,389) were analyzed. Results indicated that dogs in the ancient and spitz breed group showed low attachment and attention-seeking behavior. This characteristic distinguished the ancient group from any other breed groups with presumed modern European origins, and may therefore, be an ancestral trait.

A comparison of production, reproduction, and animal health for pastured dairy cows managed either conventionally or with use of organic principles

This study examined a seasonally calving pasture-based dairy herd in North Carolina divided into 2 groups of cows that were managed either organically or conventionally with regard to health standards. The herd consisted of Holsteins, Jerseys, and crosses of various percentages between those breeds. The study aimed to compare the effect of organic versus conventional treatment strategies on overall production, reproduction, and animal health across 4 calving seasons within a pasture-based system. There were no differences (P > 0.40) in milk production or milk components between the organic and conventional management groups, but breed group differences showed Holsteins producing at higher levels than Jerseys (P 50% Holstein had higher milk production and protein and fat production than Jerseys or cows > 50% Jersey (all P < 0.05). Somatic cell score from the organic herd (3.09) was numerically lower than in the conventional herd (3.33; P = 0.45). Crossbred cows had (P < 0.05) higher 90-d pregnancy rates than purebred cows. Proportions of cows with clinical mastitis or milk fever were not different between the management groups. Incidences of other health events (blind quarters, cystic ovaries, lameness, metritis, respiratory issues, retained placenta, udder edema) were all low, each < 1.4% and collectively < 3.6% across groups. These results support the hypothesis that an organically managed herd can be competitive with a conventional herd in terms of production, reproduction, and animal health within a pasture-based system.

Human-directed gazing behaviour in puppies and adult dogs, Canis lupus familiaris

Recent evidence indicates that dogs’ sociocognitive abilities and behaviour in a test situation are shaped by both genetic factors and life experiences. We used the ‘unsolvable task’ paradigm to investigate the effect of breed and age/experience on the use of human-directed gazing behaviour. Following a genetic classification based on recent genome analyses, dogs were allocated to three breed groups, namely Primitive, Hunting/Herding and Molossoid. Furthermore, we tested dogs at 2 months, 4.5 months and as adults. The test consisted of three solvable trials in which dogs could obtain food by manipulating a plastic container followed by an unsolvable trial in which obtaining the food became impossible. The dogs’ behaviour towards the apparatus and the people present was analysed. At 2 months no breed group differences emerged and although human-directed gazing behaviour was observed in approximately half of the pups, it occurred for brief periods, suggesting that the aptitude to use human-directed gazing as a request for obtaining help probably develops at a later date when dogs have had more experience with human communication. Breed group differences, however, did emerge strongly in adult dogs and, although less pronounced, also in 4.5-month-old subjects, with dogs in the Hunting/Herding group showing significantly more human-directed gazing behaviour than dogs in the other two breed groups. These results suggest that, although the domestication process may have shaped the dog’s human-directed communicative abilities, the later selection for specific types of work might also have had a significant impact on their emergence.

Owner-reported breed-typical behavior and breed-group differences in the german pet dog population

We study the restricted one-dimensional central extensions of an arbitrary finite dimensional restricted simple Lie algebra for p≥5. For H2(g)=0, we explicitly describe the cocycles spanning H⁎2(g), and in the case H2(g)≠0, we give a procedure to describe a basis for H⁎2(g).

Village dogs at the pacific coast of Mexico: socialization toward humans and human-dog interactions

the primitive and molossoid group. No breed group differences emerged in 2-month-old puppies. In Study 2, 47 4-month-old puppies and 47 adult dogs balanced for breeds were tested. Our results show age differences in the unsolvable trial, with adult spending more time gazing at the researcher (dev 5 6.99, df 5 1, P 5 , 0.001), the owner (dev 5 17.46, df 5 1, P 5 ,0.001) and the apparatus (dev 5 12.44, df 5 1, P 5 , 0.001). Furthermore, adult dogs carried out a greater number of gaze alternations between the experimenter and the bowl (dev 5 14.72, df 5 1, P 5 , 0.001) and the owner and the bowl (dev 5 11.88, df 5 1, P , 0.001) than did puppies. Ontogenetic and phylogenetic aspects influence the dog’s performance in this socio-cognitive task.

Adaptability in tropical beef cattle: genetic parameters of growth, adaptive and temperament traits in a crossbred population

Adaptability in tropical beef cattle can be assessed by measurable traits such as growth under the influence of environmental stressors, by parasite resistance as measured by indicator traits such as tick counts (TICK) and faecal egg counts of worms (EPG), by heat resistance as measured by indicator traits such as rectal temperatures (TEMP) and coat scores (COAT) and, to a certain extent, temperament of the animal as measured by flight time (FT). Data from a crossbreeding experiment involving various genotypes derived from tropically adapted British, Sanga-derived, Zebu cross, Zebu and Continental beef cattle breeds were analysed to estimate variance components and genetic parameters of growth, adaptive and temperament traits. Breed group differences were accounted for by including fractional coefficients of direct and maternal additive and dominance genetic effects as covariates. In the univariate analyses, 6 models were compared ranging from the simplest model with animal as the only random effect to the full model comprising direct and maternal additive genetic variance and their covariance and the permanent environment effect due to dam (growth traits) and animal (adaptive and temperament traits). The heritability estimates were 0.41, 0.21, 0.19, 0.28, 0.41 and 0.15 for birth weight (BWT), weaning weight (WWT), preweaning average daily gain (PREADG), yearling weight (YWT), final weight at about 18 months of age (FWT) and post-weaning average daily gain (POADG), respectively. The maternal component of additive genetic variance as a proportion of phenotypic variance in BWT, WWT and PREADG was 0.15, 0.10 and 0.10, respectively. The heritability estimates for TICK, EPG, TEMP, COAT and FT were 0.13, 0.24, 0.12, 0.26 and 0.20, respectively. High positive genetic and phenotypic correlations were observed among growth traits. Low (insignificant) genetic correlations were observed between TICK, EPG and growth traits. However, genetic correlations between growth traits and heat tolerance traits (TEMP and COAT) were moderately negative implying that as the ability of an animal to handle heat stress increases, growth also increases at the genetic level. Genetic correlations among TICK, EPG and TEMP were moderately positive, suggesting that closely-linked genes affect these adaptive traits. The significant negative genetic relationship between TEMP and FT suggests that cattle with high heat resistance have desirable temperament. With the increasing crossbred populations in the northern Australian beef cattle industry, the best breeding strategy should aim to exploit both crossbreeding and within population selection to make improvements in growth, adaptive and temperament traits to increase overall productivity of the enterprise.

Characteristics of steers of six beef breeds fattened from eight months of age and slaughtered at a target level of intramuscular fat – II. Meat quality

Abstract. Meat quality of Angus (AN), Simmental (SI), Charolais (CH), Limousin (LI), Blonde d'Aquitaine (BL), and Piedmontese (PI) steers (n = 22 per breed group) was measured in the M. longissimus dorsi (M.l.d.) and the M. biceps femoris, regio glutea (M.b.f.). Animals were fattened in two subsequent series on a forage-based diet until a target level of 3.5 % intramuscular fat (IMF) was reached aecording to real-time ultrasound assessments in the live animals or until 15 months of fattening had passed. Series 1 was performed in a tie-stall barn while a loosehousing system with straw bedding was applied in series 2. The actually measured IMF contents in M.l.d. were 3.35, 3.47, 3.49, 3.48, 2.34 and 2.40 % for AN, SI, CH, LI, BL and PI, respectively. Breed group differences in IMF content were mostly accompanied by a contrary Variation either in muscle water or protein content. Muscle cholesterol levels were similar for all breeds amounting to 47 and 51 mg/100 g on average in M.l.d. and M.b.f, respectively. Early and late postmortem muscle pH was relatively similar among breeds, but water-holding capacity, measured as losses due to drip, ageing, thawing and cooking, was unfavourably high in AN (drip loss excepted) in both muscles. Cooking loss tended to be lowest in PI, drip loss in SI. The AN showed the palest meat. In line with lightness, heme iron contents were clearly lowest in both muscles in the AN steers. There was no relationship found between IMF and shear force among breed groups. No significant differences between breed groups occurred in M.l.d. collagen solubility and shear force. Apart from breed differences, there were several differences noted between fattening series, namely clearly better water-holding capacity and lower shear force of the meat from series 2 (group housing) than from series 1 (tied System). The results indicate that in steers of similar IMF content and raised under the same feeding and management conditions, differences in most M.l.d. and M.b.f. quality traits were apparent, with the exception of shear force and M.l.d. collagen solubility.

Feed intake and digestion in the summer and fall by different breeds of ewes consuming forages differing in quality

Sixteen penned, nonpregnant ewes (>3 years of age) of four breed groups (St. Croix, S; St. Croix×Texel, ST; Polypay×Texel, PT; Gulf Coast Native, N) were used in an experiment (west-central Arkansas; 2×4×2 factorial arrangement of treatments) to determine effects and interactions in feed intake and digestion of breed group, forage quality (mature bermudagrass, L; late-boot endophyte-free fescue, H), and season (summer, S; fall, F). Summer temperature humidity index [dry bulb temperature + (0.36×wet bulb temperature) +41.2°C] was considerably above and near 72 at 1600 and 0700 hours, respectively. Organic matter digestibility was similar between seasons for H but lower ( p<0.05) in the summer vs. fall for L (46.1, 51.7, 61.9, and 62.3% for L–S, L–F, H–S, and H–F, respectively; SE 0.98). A comparable interaction between forage quality and season occurred in digestible OM intake (514, 607, 878, and 852 g day −1 for L–S, L–F, H–S, and H–F, respectively; SE 25.0). Digestible OM intake was similar among breed groups with L but greater ( p<0.05) for ST and PT than for S and N with H (27.8, 30.3, 30.3, 26.5, 39.1, 49.5, 46.7, and 38.7 g kg −1 BW 0.75 for L–S, L–ST, L–PT, L–N, H–S, H–ST, H–PT, and H–N, respectively; SE 1.52). Digestible OM intake differed between low and high quality forages more in the summer than fall and varied among breed groups more with high vs. low quality forage; season did not alter the influence of forage quality on breed group differences.

Methodology for adjusting scrotal circumference to 365 or 452 days of age and correlations of scrotal circumference with growth traits in beef bulls

A retrospective analysis was conducted on data collected from 1983 through 1991, where weight and hip height were measured at start of test and every 28 d on 604 bulls completing a 224-d forage-based gain test. Scrotal circumference (SC) was measured at start of test, and at either end of test or end of the weigh period after individual bulls reached 365 d of age. Over 3 yr of this study, SC was additionally measured every 28 d. Bulls were representatives of 5 breed groups: Angus, Santa Gertrudis, Simmental, Continental (predominantly Charolais), and Zebu (predominantly Simbrah). Adjusted 365-d SC and adjusted 452-d SC were calculated by regression analysis and from formulas based on SC growth of individuals to 140 and 224 d on test, respectively. Breed group differences were observed for age of dam, birth weight, hip height, weight per day of age, average daily gain and SC at start of test, 140 d, and end of test (224 d). Scrotal circumference was positively correlated with all growth traits. Scrotal circumference was related to breed group, age, weight, hip height, average daily gain, weight per day of age, age by year, and age-by-breed group (P<0.05), as determined by regression analysis. However, omitting weight, hip height, average daily gain, and weight per day of age from the regression model did not significantly affect R 2 value. Scrotal circumference growth was linear to 140 d on test; however, SC growth to 224 d on test was curvilinear. The 365-d SC predicted from the formula and from regression analysis differed for Simmental and Zebu by 0.3 and 0.4 cm, respectively (P<0.05). The 452-d SC differed for Santa Gertrudis and Zebu by 0.5 and 0.6 cm, respectively (P<0.05). Formulas based on SC growth of individuals are reasonably accurate predictors of SC at 365 and 452 d of age, when compared with more complex regression analysis. Basing SC adjustments on individual growth appears to account for variables known to affect yearling SC.

Evaluation of Overnight Shrinkage in Reduction of Variability of Weights and Gains of Beef Cattle

Overnight shrinkage at three different ages — weaning, yearling, and long-yearling — was evaluated in Angus (AA), Brahman (BB), and reciprocal cross calves (AB, BA) over a 4-yr period to determine changes in precision of estimates of weights and gains. Approximately 454 steers and heifers were evaluated at 205 d, 431 were evaluated at 365 d, and 231 heifers were evaluated at 540 d. Calves were spring-born and managed on either common bermudagrass [Cynodon dactylon (L.) Pers.] or endophyte-infected (Acremonium coenophialum Morgan-Jones and Gams) tall fescue (Festuea arundinacea Schreb.). Breed group differences in shrinkage, as a percentage of full body weight, were small but statistically significant. Percentage shrink at weaning in AA exceeded AB, BA, and BB (P<.05), and BA exceeded AB calves (P<.10). Similarly, AA exceeded other breed groups in percentage shrink at 365 d (P<.01) and 540 d (P<.10). Percentage shrink was larger on tall fescue than on bermudagrass at 205 d (P<.12) and 540 d (P<.01) but was larger on bermudagrass at 365 d (P<.01). Although most variances in actual shrunk weights and gain were slightly less than variances in full weights, differences were not statistically significant from variances of full weights and gains. Additionally, reductions in variances associated with shrinkage were similar to reductions expected when a random variable is multiplied by a positive constant between zero and one. Coefficients of variation for shrunk weights and gains were generally larger than coefficients of variation for full weights and gains, suggesting that shrinkage does little for reduction in relative variation. These data suggest that overnight shrinkage is not beneficial in increasing the precision of comparisons of group means of weights or gains of beef cattle. Consequently, in the interests of enhancing the well-being of experimental animals and avoiding unnecessary costs, shrunk weights for purposes of comparing group means should be avoided.

Comparison of methods for predicting yearling scrotal circumference and correlations of scrotal circumference to growth traits in beef bulls

From 1981 through 1986, BW, hip height, and scrotal circumference (SC) measurements were obtained on 329 bulls at the start of a 140-d gain test (SOT) and every 28 d to the end of test (EOT). Age, overall ADG, weight per day of age, ADG by period, and SC growth (cm/d) were calculated. Data were analyzed in two data sets because age of dam (AOD) and birth weights were unavailable between 1981 and 1983. Correlations of SC to other traits measured and probabilities for bulls attaining 30 or 32 cm SC by 365 d of age were calculated. Two adjusted 365-d SC (365-d SC) were calculated for each individual from regression analysis and from the following formula: 365-d SC = [(SCEOT-SCSOT)/140 d] x [365-ageSOT] + SCSOT. Except for ADG in Data Set 2, breed group differences (P less than .05) were observed for correlations of SC to all growth traits, age, and AOD. To attain 30 cm SC by 365 d of age with nearly 100% probability, Angus, Simmental and Zebu-derived bulls needed a 23-cm SCSOT, whereas continental (other than Simmental) and Polled Hereford bulls required a 26-cm SCSOT. Overall, 365-d SC means calculated by regression analysis or formula method did not differ (P greater than .10) for either data set.

Selection for prolificacy in Finnsheep and in Norwegian sheep

Litter size (LS) at birth and other production traits were recorded for Finnsheep (F), Norwegian(N) breeds Dala (D), Steigar (St) and Spael (Sp), for N sheep crossed with 1/4 F and ½ F and for a group of sheep established by collecting offspring of highly prolific N(N+) ewes. The N breeds and the ¼ F group were part of the national breeding scheme. In the 1/2F and N+, selection was solely for LSB. The other groups were selected normally. There were 4263 lambings. In adults, there were no breed group differences in lambing-% (mean 94 %), but in 1-yr. olds there were differences: Sp 90 %, F and F-crosses 80—85 %, D 70 %, N+ 60 % and St 50 %. F-crosses had clearly the best LS’s (Fca. 3.0, 1/2F2.4, 1/4F2.0). Those of N+ decreased through the 5 years recorded from near 2.0 to 1.8 lambs. The other breed groups gave LS’s of 1.7—1.8. In the two groups selected for LS, no selection response was found. The reasons are not known. Although the pure F and ½ F gave lower weaning weights (34 and 38 kg at 150d.) than the other groups (41—45 kg), their weaned lamb yield per ewe was ca. 20 kg higher. Considering the poorer carcass quality observed in earlier experiments for these groups, the use of 1/4 F is recommended for Norwegian conditions. This breed group gave no reduction in weaning weight, but increased the LS by some 0.2 lambs.

Onset of puberty in heifers of diverse beef breeds and crosses.

Puberty traits of straightbred and crossbred heifers (n = 301) were evaluated under pasture conditions. Breed groups represented were straightbred Hereford and Red Poll, reciprocal crosses of these two breeds, Angus X Hereford, Angus X Charolais-Cross, Brahman X Hereford and Brahman X Angus. Breed group was an important (P less than .01) source of variation in heifer weights and in age at puberty. Straight-bred Red Poll and Red Poll cross heifers were youngest at puberty, Angus X Hereford and Angus X Charolais-Cross were intermediate, and straightbred Hereford and Brahman crosses were oldest at the onset of puberty. At the beginning of their first mating season at 19.5 mo of age, 96% of the straightbred Red Polls, 95% of Red Poll crosses, 81% of Angus X Herefords, 89% of Angus X Charolais-Crosses, 68% of straightbred Herefords, 48% of Brahman X Herefords and 74% of the Brahman X Angus had attained puberty. Results of a diallel analysis of Hereford-Red Pool matings indicated that maternal influence of the Red Poll breed was superior (P less than .01) to Herefords for body weight up to 24 mo of age and incidence of puberty at 11.5 mo. Red Polls also exceeded Herefords in direct effects for puberty percentage at 11.5, 15 and 19.5 mo of age. Heterosis was significant for puberty percentage and weight. Breed group differences in pregnancy rate at 24 mo were not significantly.

FACTORS INFLUENCING CALVING PERFORMANCE IN RANGE BEEF CATTLE

Data from 2964 calving records of cows of all age groups and 1035 calving records of 2-yr-old heifers from three breeding groups (B), Hereford (HE), Beef Synthetic (SY) and Crossbred (XB) maintained at the University of Alberta Ranch at Kinsella were analyzed by the least squares method. Dam weight at calving (DAMWT), age of dam (A), calf birth weight CBWT, sire and dam birth weights and the interactions between A and CBWT, B and A, sex (S) and A and finally B and CBWT had significant influences on calving performance when calving records of all age groups were considered. Among heifers the effects of DAMWT, CBWT, B, S, dam birth weight and interaction between B and DAMWT were significant. DAMWT and CBWT were among the most important factors influencing calving performance. CBWT had a major influence in 2-yr-old dams with no noticeable influence in other age groups. Calving performance score of HE heifers was lower than those from XB and SY heifers, but breed group differences were minor at other age groups. Similarly males had more difficult births than female calves from young dams with no detectable sex influence from older dams. DAMWT had a greater positive impact on calving performance of HE heifers compared with the other two breeding groups. These interactions emphasize the importance of interrelationships of major factors influencing the incidence of dystocia in beef cattle. Key words: Factors, calving difficulty, beef cattle

Using Suffolk sheep for improving lamb production from subtropical Egyptian sheep

SUMMARYThe performance of Suffolk cross-bred ewe lambs produced either by Suffolk crossbred ewes, 70–90% Suffolk (HS), or by Ossimi ewes, 35–45% Suffolk (LS), was investigated. Forty-three ewe lambs from both groups were available, and were given two different levels of feeding.The LS ewe lambs showed, insignificantly, better growth performance than the HS group, and breed group differences increased with age. They also reached puberty earlier (305·4v.334·6 days for the HS ewe lambs). Using the HS breeding rams rather than the imported Suffolk ones, for improving lamb production from the local sheep flocks, is recommended.The LS ewe lambs started their first breeding season 18 days earlier, and ended 34 days later, than the HS ewe lambs. Both cross-bred groups showed clear anoestrous periods of 225·4 and 202·2 days, respectively. The onset of their second breeding season was similar, on average 29 August. These figures are close to those of the purebred Suffolk ewes, and far away from the nonseasonal local parents.

Physiological Parameters and Muscle Characteristics of Purebred Pietrain and Two Specific Pietrain Crosses

Parameters of muscle quality, carcass leanness and muscularity and relevant physiological measurements were studied on 18 Pietrain (P), 11 H×(P×M) and 12 P×(P×M) gilts (H = Hampshire and M = Minn. No. 1). Pigs were sacrificed at 100 ± 4 kg live weight after being heat-stressed (10 min, 43 C) and ear-sampled for plasma creatine kinase (CK) determination. Serum and plasma were prepared from exsanguination blood and 23 parameters of clinical significant determined. Adrenal cortex and thyroid histology were studied. Longissimus pH 45 min postmortem was lowest in P, intermediate in P× (P× M) and highest in H× (P× M). Differences were small and not significant for 24-hr pH. Transmission value was higher in P than cross-breeds. Color and marbling were higher in H× (P× M), although structure scores were not significantly different among breed groups. P exhibited thelargest longissimus muscles; however, both cross-breeds displayed meritorious carcasses, differing from P only by 3 to 4 cm2 for longissimus area. H×(P×M) displayed longer carcasses than P with P× (P× M) intermediate. H× (P× M) and P did not significantly differ in backfat thickness; P×(P×M) exceeded P. Percentage ham plus loin was significantly greater in P than cross-breeds. No death losses caused by acute stress syndrome were noted; however, P and P×(P×M) exhibited higher means for plasma CK (Rosalki) than H× (P× M). Log CK and log CK/kg ham + loin were highest for P, intermediate for P×(P×M) and lowest for Hx(PxM). In contrast, no significant breed differences were noted in serum prepared from blood collected at exsanguination, stored frozen and analyed for CK by measurement of creatine by diacetyl/orcinol. Breed differences were not significant for serum glutamate-oxaloacetate transaminase, lactate dehydrogenase and alkaline phosphatase. Creatinine and total protein were highest in P. Albumin was higher in P× (P× M) than in P. Cholesterol was higher in H× (P× M) than other breeds. P3− was lower in P than in cross-breeds. Hematocrit was higher in P× (P× M) than P but not H× (P× M). No significant breed-group differences were noted for serum glucose, urea nitrogen, triglycerides, Na+, K+, Cl+, CO2−3, Ca2+ and Fe2+; for adrenalweight and cortex width; for widths of zonae glomerulosa, fasciculata and reticularis; for thyroid weight, follicle thickness, ovary weights and follicle number; and for blood corticoster-one, Cortisol and progesterone. Thyroid follicle size was lowest in P.

Carotene and immunoglobulin concentrations in the colostrum and milk of pasture-fed cows

The carotene and immunoglobulin concentrations in colostra and milks of 6 Jersey, 4 Friesian and 6 Jersey x Friesian cows were determined during the first 21 d of lactation. Carotene concentrations of between 50 and 300ug/g milk fat were found at first milking and these declined to normal concentrations, in the range 9-21ug/g milk fat, by the eighth to tenth day of lactation. Immunoglobulin concentrations at first milking were in the range 4-40g/l milk and decreased to normal concentrations, in the range 0.3-0.5g/l, by the fifth to seventh day of lactation. For both substances the data from each cow's milk fitted an exponential decay model. The fractional rates of decrease in concentration of carotene were 0.19-0.57/d and of immunoglobulin were 0.40-0.73/d. Breed-group differences were observed in both carotene and immunoglobulin concentrations in milks after the fourteenth day of lactation. In Jersey milks, the average carotene and immunoglobulin concentrations were respectively 18.5 ug/g milk fat and 0.32g/l of milk, while in Friesian milks the concentrations were respectively 11.4 ug/g milk fat and 0.46 g/l milk. There was also a difference between breed groups in the daily rates of decrease of the immunoglobulin concentrations. The average rate of decrease for the Friesians was about 1.5 times the rate for the Jerseys.

Fatty Acid Composition of Finnsheep Crossbred Lamb Carcasses

The fatty acid composition of subcutaneous fat from Finnsheep crossbred lambs and three domestic breeds, Suffolk, Targhee and Minnesota 100, were compared. Crossbred carcasses included F1 and backcrosses to each parental domestic breed and the Finnsheep breed. Fat samples were obtained from 164 male lambs during a 2-year period. Fatty acids studied were myristic, pentadecanoic, palmitic, palmitoleic, heptadecanoic, stearic, oleic and linoleic. The ratios of (1) palmitic/palmitoleic and (2) oleic/ stearic were also studied. Year differences for relative percentages of the fatty acids were observed. Significant breed group differences were found for amounts of pentadecanoic, heptadecanoic, stearic and The fatty acid composition of subcutaneous fat from Finnsheep crossbred lambs and three domestic breeds, Suffolk, Targhee and Minnesota 100, were compared. Crossbred carcasses included F1 and backcrosses to each parental domestic breed and the Finnsheep breed. Fat samples were obtained from 164 male lambs during a 2-year period. Fatty acids studied were myristic, pentadecanoic, palmitic, palmitoleic, heptadecanoic, stearic, oleic and linoleic. The ratios of (1) palmitic/palmitoleic and (2) oleic/ stearic were also studied. Year differences for relative percentages of the fatty acids were observed. Significant breed group differences were found for amounts of pentadecanoic, heptadecanoic, stearic and ratios 1 and 2. On the average, F1 Finnsheep crosbred lambs had a higher percentage of myristic and heptadecanoic and a lower percentage of stearic and oleic fatty acids than the average of the three domestic breed lamb carcasses. It was suggested that palatability of F1 Finnsheep crossbred lambs carcasses as compared to the three domestic purebreds may be enhanced because of a greater amount of unsaturated to saturated fats, thus reducing the "tallowy" effect sometimes observed in lamb fat.