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PubMed2005

The effect of production level on feed intake, milk yield, and endocrine responses to two fatty acid supplements in lactating cows.

Animal responses to dietary treatment may interact with metabolic state, which differs for cows across a wide range of milk yield. Responses to dietary saturated vs. unsaturated fatty acid (FA) supplement was evaluated using 32 multiparous Holstein cows arranged in a crossover design with 14-d periods. Treatments were 2.5% FA from unsaturated FA (calcium salts of palm FA) or saturated FA (prilled, hydrogenated free FA). Unsaturated FA treatments decreased dry matter intake (0.8 kg/d) and time spent ruminating (25 min/d) compared with saturated FA treatment. Treatments did not differ in milk or 3.5% fat-corrected milk yield. Intake and milk yield responses were not related to milk yield across cows. Saturated FA treatment increased milk protein and lactose concentrations, but treatment did not affect yield of milk components. Saturated FA treatment increased insulin over 25% and decreased nonesterified FA nearly 20% with no effect on plasma somatotropin, glucose, or beta-hydroxybutyrate concentrations. Milk protein concentration and yield responses to treatment were positively correlated with pretrial fat-corrected milk yield. Milk protein response was not related to insulin response, supporting the importance of insulin sensitivity in control of milk protein synthesis. Unsaturated FA treatment decreased dry matter intake and rumination time compared with saturated FA treatment, consistent with reports of unsaturated fat increasing satiety and decreasing gut motility. Decreased milk protein synthesis by fat supplementation may be related to FA saturation and milk yield of cows.

3-Hydroxybutyric Acid↗
PubMed2007

Within-herd heritability estimated with daughter-parent regression for yield and somatic cell score.

Estimates of heritability within herd (h(WH)(2) ) that were generated with daughter-dam regression, daughter-sire regression, and REML were compared, and effects of adjusting lactation records for within-herd heritability on genetic evaluations were evaluated. Holstein records for milk, fat, and protein yields and somatic cell score (SCS) from the USDA national database represented herds in the US Northeast, Southeast, Midwest, and West. Four data subsets (457 to 499 herds) were randomly selected, and a large-herd subset included the 15 largest herds from the West and 10 largest herds from other regions. Subset heritabilities for yield and SCS were estimated assuming a regression model that included fixed covariates for effects of dam yield or SCS, sire predicted transmitting ability (PTA) for yield or SCS, herd-year-season of calving, and age within parity. Dam records and sire PTA were nested within herd as random covariates to generate within-herd heritability estimates that were regressed toward mean h(WH)(2) for the random subset. Heritabilities were estimated with REML using sire models (REML(SIRE)), sire-maternal grandsire models (REML(MGS)), and animal models (REML(ANIM)) for each herd individually in the large-herd subset. Phenotypic variance for each herd was estimated from herd residual variance after adjusting for effects of year-season and age within parity. Deviations from herd-year-season mean were standardized to constant genetic variance across herds, and records were weighted according to estimated error variance to accommodate h(WH)(2) when estimating breeding values. Mean h(WH)(2) tended to be higher with daughter-dam regression (0.35 for milk yield) than with daughter-sire regression (0.24 for milk yield). Heritability estimates varied widely across herds (0.04 to 0.67 for milk yield estimated with daughter-dam regression), and h(WH)(2) deviated from subset means more for large herds than for small herds. Correlation with REML(ANIM) h(WH)(2) was 0.68 for daughter-dam and was 0.45 for daughter-sire h(WH)(2) for milk yield. The correlation between daughter-sire h(WH)(2) and REML(MGS) was greater than the correlation between daughter-dam h(WH)(2) and REML(MGS). Data adjustments had a minimal impact on breeding value bias. Within-herd heritability can be estimated rapidly using regression techniques with moderate accuracy, but adjusting lactation records for h(WH)(2) resulted in only a small improvement in the accuracy of genetic evaluations.

Animals↗
PubMed1979

Endocrine control of energy metabolism in the cow: correlations of hormones and metabolites in high and low yielding cows for stages of lactation.

Measures of hormones and metabolites in blood plasma of high and low yielding cattle matched for diet and stage of lactation were investigated for relationships between milk yield, body weight, and concentrations of hormones (prolactin, growth hormone, insulin, and thyroxine) and metabolites (glucose, nonesterified fatty acids, beta-hydroxybutyric acid, and L-lactic acid) for stages of lactation. A first approach correlated total milk yields of 15 cows with average constituents during the four 24-h blood samplings through the first 27 wk of lactation. The second examined associations of changes with sampling periods in milk yield or body weight with changes in hormones and metabolites. Total milk yield of the high yielding group was correlated positively with ratios of growth hormone/thyroxine and glucose/thyroxine and correlated negatively with thyroxine. Changes in growth hormone and its ratio to insulin, and changes in yield were correlated positively for groups combined. Changes in thyroxine were correlated negatively with changes in yield. Changes in liveweight gain were related positively to insulin and lactic acid and negatively with changes in growth hormone. Changes in growth hormone were related positively to changes in nonesterified fatty acids.

Animals↗
PubMed1983

Heritabilities and correlations of lactation yields and fertility for Holsteins.

First lactations from a total of 5802 cows in the North Carolina Institutional Breeding project from 1950 to 1980 were used. Heritabilities from paternal half-sisters were .05 for days open, .05 for age at first calving, .27 for lactation milk yield, and .29 for fat yield. Corresponding estimates from regressions of cow on dam were .13 for days open, .06 for age at first calving, .35 for milk yield, and .33 for fat yield. Genetic correlations between yields and days open from various methods of estimation and editings of the data were all antagonistic and ranged from .35 to .60. Genetic correlations of yield and age at first calving were favorable, ranging from -.10 to -.36. Heritabilities for days open and genetic antagonism between days open and yield were greater for cows calving prior to the hot summer months than for cows calving in the fall. Heritabilities and variance of sires increased for days open and yield traits from the 1950's to 1980. For records from 1970 to 1980, heritability from paternal half-sisters of days open was .12. Genetic increase of 1000 kg milk would result in 5 to 10 additional days open.

Animals↗
PubMed1991

Milk yield variation concurrent with conception.

Milk yield data from herds at the University of Illinois and the University of Wisconsin-Madison were used to characterize milk yield fluctuations concurrent with conception. Analyses were performed on 118 Illinois and 244 Wisconsin cows; milk yields were recorded for 15 d preceding confirmed conception. Conception was confirmed by calving within 11 d of 281 d postbreeding. Each cow's difference between 7-d rolling means for a.m. and p.m. milking yield was subtracted from a.m. yields as a diurnal adjustment. A pattern matching formula that was applied to adjusted yields [( b - a]/a, where a and b were sequential milkings) produced a mean calculated value for the milking nearest conception that was different from all milkings for 15 d preceding conception in Wisconsin data only. Discriminant analysis failed to differentiate between preceding and conception inclusive sequences of adjusted milk yields. Pattern matching formulas applied to individual cow data failed to isolate more than 2% of conceptions when the threshold value was set to eliminate false positives. Results demonstrated low predictive ability for conception using concurrent milk yield fluctuations despite implications of significant mean differences for values that were enhanced by pattern matching formulas.

Animals↗
PubMed1991

Comparison of ten Friesian strains in Poland for yield traits from first three parities.

Milk yield, fat yield, and fat percentage for the first three parities were compared for crosses of Friesian strains from Canada, Denmark, Israel, The Netherlands, New Zealand, Sweden, the United Kingdom, the US, and West Germany with Polish black-and-white cattle. Mixed model multitrait BLUP solutions for milk yield ranked Holstein strains (US, Canada, and Israel) and New Zealand Friesians higher than European Friesian strains for all three parities. Largest difference for milk yield between highest ranking US strain and lowest ranking Polish strain was 1002 kg for first lactation. Rankings for fat yield were similar to those for milk yield. For all three parities, the New Zealand strain ranked highest for fat percentage and the US strain lowest. Although rankings were consistent across parities for all yield traits, differences between Holstein and Friesian strains decreased as parity increased. Holstein strains maintained their superiority for milk and fat yields for all three parities despite difficult environmental conditions and a feeding regimen worse than in their country of origin.

Animals↗
PubMed1991

Expansion of projected lactation yield to stabilize genetic variance.

Information on partial lactations often is included in genetic evaluations by predicting the cow's eventual 305-d yield. Such projected yields have less phenotypic and genetic variation than completed yields but were modeled as having greater or equal variation in evaluations. Analysis of first lactations from 48,424 daughters of 844 Holstein sires indicated that yields predicted early (46 to 75 d) in lactation had less than one-half as much additive genetic variance as completed yields. Multiple-trait REML estimates of genetic correlations of predicted and completed yields were all above .92, indicating that early lactation information is valuable if modeled appropriately. Expanded records with genetic variances equal to those of completed yields and new lactation length weights were derived. Expanded records have larger error variances than either projected or completed yields and, thus, are given less weight when included in animal model evaluations. Genetic gains are expected to increase only .2 to .3%, but more stable genetic evaluations should result from use of expanded records, particularly for animals evaluated primarily from first lactation records in progress.

Animals↗
PubMed1993

Interrelationships of somatic cell count, mastitis, and milk yield in a low somatic cell count herd.

In a high yielding low SCC herd, changes in milk yield associated with SCC and occurrence of clinical mastitis and differences in SCC with parity, clinical mastitis, and DIM were investigated. Milk yield data were obtained at every milking, and SCC was measured once every 48 h in 117 cows during the first 119 d postpartum. Effects of SCC and clinical mastitis on cumulative milk yield in the first 119 d postpartum were evaluated with least squares linear regression. Repeated measures ANOVA was used to detect changes in SCC. The SCC was highest at lactation onset, and cows with clinical mastitis had significantly higher SCC. During the 10 d prior to onset of clinical mastitis, SCC was higher in affected cows than in matched unaffected controls and surged just prior to diagnosis. During the 10-d period following a mastitis treatment, SCC differences between treated and control cows remained significant but became smaller with time and returned to the premastitis differences. Occurrence of clinical mastitis was associated with 5% milk yield loss. Cows with mean SCC > 245,000 cells/ml over the 119 d showed 6.2% yield loss compared with cows with SCC < or = 90,000 cells/ml. Cows with clinical mastitis had higher SCC prior to and following the end of treatment for mastitis than did controls. Clinical mastitis and SCC were associated with significant yield loss. Milk yield loss attributed to clinical mastitis was greater than that associated with elevated SCC (> 245,000 cells/ml) because a greater percentage of cows (26%) had clinical mastitis than elevated SCC (12.5%).

Animals↗
PubMed1996

The association between cumulative milk yield, days open, and days to first breeding in New York Holstein cows.

The associations among milk yield, days open, and days to first breeding were studied in 15,320 Holstein cows, calving between June 1990 and November 1993, in 26 New York herds. Survival analysis, incorporating the Cox proportional hazards model, was used to quantify the effect of milk yield and other covariables on days open and days to first breeding. Sensitivity analysis was also performed. Sixty-day cumulative individual milk yield, calving season, parity, and herd were included in all models. Several diseases and their lactational risk also were studied as potential confounders: retained placenta (5%), milk fever (1%), ketosis (3%), metritis (6%), abomasal disorder (5%), mastitis (5%), and cystic ovary (3%). Cows yielding milk in the highest quintile had a slightly lower conception rate than did cows yielding milk in the lowest quintile. Conception rate varied with parity and season. Retained placenta, metritis, and cystic ovary lowered the conception rate. High yielding cows were more likely to be inseminated than were low yielding cows. Older cows and those with metritis, mastitis, and cystic ovary had lower rates on insemination. These results indicate that conception and insemination might be influenced by factors related to management (e.g., culling) and to the cow (e.g., disease history) but that increased milk yield plays a very minor role.

Animals↗
PubMed1996

Effects of days dry, previous days open, and current days open on milk yields of cows in Zimbabwe and North Carolina.

Effects of days dry and previous and current days open on milk yields during the first three lactations were determined for Holsteins from Zimbabwe and North Carolina. The animal models used included animal; permanent environmental effects of cows for herd-year, month of calving, age, current days open, and DIM; and the inverse of additive numerator genetic relationships. Model 1 for first lactations included only these effects, but Model 2, the animal model for later lactations, included these effects plus previous days open, previous days dry, and previous milk yield. The dependent variable in both models was unadjusted milk yield for the lactation. Current and previous days open, previous days dry, and DIM were also fitted as dependent variables with Models 1 and 2, except for previous milk yield, when appropriate. As current days open increased, milk yield rose, regardless of milk yield during prior lactations. Milk yields were reduced for lactations following < 60 d dry and showed little advantage for longer dry periods. The effects of previous days open are real but are overestimated unless permanent environmental effects of cows are considered simultaneously. The heritabilities and repeatabilities of current and previous days open and previous days dry were higher for cows in Zimbabwe than for those in North Carolina. Results suggest that, to obtain unbiased estimates of breeding values of sires and cows, yield data should be adjusted for the environmental effects of days dry as well as those of previous and current days open.

Animals↗
PubMed1999

Postpartum body condition score and results from the first test day milk as predictors of disease, fertility, yield, and culling in commercial dairy herds.

The study used field data from a regular herd health service to investigate the relationships between body condition scores or first test day milk data and disease incidence, milk yield, fertility, and culling. Path model analysis with adjustment for time at risk was applied to delineate the time sequence of events. Milk fever occurred more often in fat cows, and endometritis occurred between calving and 20 d of lactation more often in thin cows. Fat cows were less likely to conceive at first service than were cows in normal condition. Fat body condition postpartum, higher first test day milk yield, and a fat to protein ratio of > 1.5 increased body condition loss. Fat or thin condition or condition loss was not related to other lactation diseases, fertility parameters, milk yield, or culling. First test day milk yield was 1.3 kg higher after milk fever and was 7.1 kg lower after displaced abomasum. Higher first test day milk yield directly increased the risk of ovarian cyst and lameness, increased 100-d milk yield, and reduced the risk of culling and indirectly decreased reproductive performance. Cows with a fat to protein ratio of > 1.5 had higher risks for ketosis, displaced abomasum, ovarian cyst, lameness, and mastitis. Those cows produced more milk but showed poor reproductive performance. Given this type of herd health data, we concluded that the first test day milk yield and the fat to protein ratio were more reliable indicators of disease, fertility, and milk yield than was body condition score or loss of body condition score.

Abomasum↗
PubMed2006

Frameless image-guided stereotactic brain biopsy procedure: diagnostic yield, surgical morbidity, and comparison with the frame-based technique.

OBJECT: The gold standard for stereotactic brain biopsy target localization has been frame-based stereotaxy. Recently, frameless stereotactic techniques have become increasingly utilized. Few authors have evaluated this procedure, analyzed preoperative predictors of diagnostic yield, or explored the differences in diagnostic yield and morbidity rate between the frameless and frame-based techniques. METHODS: A consecutive series of 110 frameless and 160 frame-based image-guided stereotactic biopsy procedures was reviewed. Associated variables for both techniques were reviewed and compared. All stereotactic biopsy procedures were included in a risk factor analysis of nondiagnostic biopsy sampling. Frameless stereotaxy led to a diagnostic yield of 89%, with a total permanent morbidity rate of 6% and a mortality rate of 1%. Larger lesions were fivefold more likely to yield diagnostic tissues. Deep-seated lesions were 2.7-fold less likely to yield diagnostic tissues compared with cortical lesions. Frameless compared with frame-based stereotactic biopsy procedures showed no significant differences in diagnostic yield or transient or permanent morbidity. For cortical lesions, more than one needle trajectory was required more frequently to obtain diagnostic tissues with frame-based as opposed to frameless stereotaxy, although this factor was not associated with morbidity. CONCLUSIONS: With regard to diagnostic yield and complication rate, the frameless stereotactic biopsy procedure was found to be comparable to or better than the frame-based method. Smaller and deep-seated lesions together were risk factors for a nondiagnostic tissue yield. Frameless stereotaxy may represent a more efficient means of obtaining biopsy specimens of cortical lesions but is otherwise similar to the frame-based technique.

Adult↗
PubMed1994

Carcass composition and yield of 1991 vs 1957 broilers when fed "typical" 1957 and 1991 broiler diets.

Whole carcass yield and the yield of parts (i.e., wings, saddle and legs, Pectoralis major, Pectoralis minor, breast skin, rack, abdominal fat pad, heart, and lungs), as well as whole carcass analysis for fat, moisture, and ash, were measured in the 1957 Athens-Canadian Randombred Control (ACRBC) and in the 1991 Arbor Acres (AA) feather-sexable strain, when fed "typical" 1957 and 1991 diets. Using the average of both sexes, the carcass weights of the 1991 birds on the 1991 diets were 4.4, 3.9, and 3.5 times heavier than those from the 1957 ACRBC on the 1957 diet at 43, 71, and 84 d of age, respectively. Birds fed the 1991 diets had significantly heavier carcass weights than those fed the 1957 diets. Hot carcass yield of the AA broiler (mean of both sexes) was approximately 6 to 7% higher at the same age than for the ACRBC. Water uptake in the carcass (following a 60-min immersion in ice water) was approximately 2 to 2.5% higher in the ACRBC than in the AA broiler. Yield of saddle and legs as a percentage of live BW was about 4% higher in the AA than in the ACRBC. Dietary regimen did not affect the yield of saddle and legs. Males had 2 to 3% more saddle and legs than the females. The yield of total breast meat for the AA was approximately 3% higher (mean = 16.9%) than for the ACRBC over both sexes and all ages. Breast yield on the 1991 diets was approximately 1.2% higher for the AA than for the ACRBC. Females had slightly higher breast yield (1%) than males. The AA broiler had consistently heavier fat pads and higher percentage carcass fat at the same age and on the same diet than did the ACRBC. The percentage carcass fat was significantly higher on the 1991 vs the 1957 diet and in females vs males. The male-female difference in percentage carcass fat increased with age. Heart and lung size as a percentage of live BW were lower in the AA than in the ACRBC.

Animal Feed↗
PubMed2001

Effect of sewage water on the growth and yield parameters of wheat and blackgram with different fertilizer levels.

Impact of biologically treated domestic sewage water was studied on the growth and yield attributing characters of wheat and blackgram under different fertilizer levels in the field condition. There was no significant difference on the yield and yield attributing characters of wheat. However, yield attributing characters like number of tillers/plant, panicle length (cm), number of grains/panicle and 1,000 grain weight showed increasing trend to the tune of 13.29, 1.59. 5.49 and 3.79 per cent respectively over the tubewell irrigated crop. Yield was also increased to the tune of 3.63 per cent when the crop was irrigated with sewage water. Interactions between irrigation and fertilizer levels were also insignificant. However, sewage water with N60P45K45 responded better on tillering, panicle length, number of grains/panicle and yield of wheat. In case of blackgram, treated sewage water had no significant effect on the grwoth and yield attributing characters, rather sewage water had some negative effect on these parameters. Interactions between irrigation and fertilizer levels were insignificant. But tubewell irrigation with N10P10K10 was more responsive on growth parameters. When the crop was grown with tubewell irrigation and without fertilizer, yield attributing characters were more positively responded.

Agriculture↗
PubMed2001

[The combining ability and heterosis analysis of royal jelly yield and quality properties in western honeybees].

The NC II mating design of 2 x 4 was made in order to evaluate The combining ability and heterosis of royal jelly yield and quality properties that included royal jelly yield, royal jelly yield per cup, acceptance ratio and acidity in Apis mellifera. The results were as follows: (1) For all characters, general combining ability in six parents (GCA) achieved highly significant level (P < 0.01), special combining ability (SCA) only significant (P < 0.05), therefore the additive effect is more important for royal jelly yield and quality properties; (2) The GCA of A. m. acervorum in four characters was higher, and the SCA variance of A. m. carpatica, A. m. caucasica was greater, so they were good parents. ZND-1 Apis mellifera lingustica in royal jelly yield, royal jelly yield per cup, acceptance ratio was an excellent parent, but A. m. carnica only could be used in increasing royal jelly quality; (3) The heterosis over high-parent is negative, thus it is difficult to improve royal jelly yield and quality by cross breeding, but by appropriate choice of parents, high yield and quality combination can be obtained.

Animals↗
PubMed2002

[Variation in seed yield components among varieties of Poa pratensis].

Seed yield and its characteristics of 28 varieties of Poa pratensis in field plots at Lanzhou, China were evaluated in 2001. The results showed that the seed yields among the varieties were significantly different (P < 0.01) by LSD test. The highest yield was 643.4-650.2 kg.hm-2 obtained from varieties of Balin and Monoply, the lowest was 90.1 kg.hm-2 obtained from Elysee, and the other varieties were in the middle groups with the yields varied from 114.7 kg.hm-2 to 435.1 kg.hm-2. Correlation analysis between seed yield and yielding characteristics indicated that the main factors affecting seed yield were the number of fertile tillers per plant (r = 0.785), the height of fertile tiller (r = 0.712), the length of inflorescence (r = 0.743), and the number of spikelets/fertile tiller (r = 0.786). Cluster analysis for seed production capacity based on seed yield and above-mentioned 4 main characteristics showed that the 28 varieties could be divided into 6 grades.

Cluster Analysis↗
PubMed2004

[Yield characteristics and genetic diversity of main alfalfa varieties in China].

The dry matter (DM) yield and its characteristics of 28 alfalfa varieties were evaluated in the 4th year under space sowing condition. The results showed that there existed significant difference (P<0.01) in DM yield and its characteristics among the varieties. The highest and higher DM yield were obtained form varieties Xinjiang Deye (452.8 g x plant(-1)) and Gannong No. 3 (373.0 g x plant(-1)), respectively, and the varieties with the highest height and branch/plant at the 3rd cutting were Gannong No. 3, Xinjiang Deye, Weixian, Tumu No. 2, Xinmu No. 1, and Zhaodong. The correlation analysis between DM yield and its characteristics indicated that the main factors affecting yield were the height and the branch/plant. The genetic diversity of DM yield and its components in 28 alfalfa varieties showed that the variations of DM yield and yield components of within-variety were larger than those of among-variety in majority of test varieties. The CV of all characteristics were presented in order of 3rd No. branch/plant>DM yield/plant>1st No. branch/plant>2nd No. branch/plant>Spring height>3rd height>2nd height>leaf width>budding height>leaf length>1st height.

Biomass↗
PubMed2005

Heritability and expected selection response for yield traits in blanched asparagus.

Despite the continuous breeding that has been conducted with asparagus (Asparagus officinalis L.) since the beginning of the last century, there is little information on parameters for predicting direct and indirect selection response. Yield traits for blanched asparagus production were studied along a two-year period in a half-sib family population planted in Zavalla, Argentina. Half-sib family mean heritability values were low for total yield and marketable spear number (0.31 and 0.35), intermediate for marketable yield and total spear number (0.55 and 0.64), and relatively high for spear diameter and spear weight (0.75 and 0.74). An average increase in marketable yield of 15.9% is expected after each cycle of selection of the top 5% of the families. Total yield failed to express significant genetic correlations with any of the yield components; meanwhile marketable yield showed highly significant relations with market spear number (0.96) and spear weight (0.89). Indirect selection response over yield components (CRx) failed to be advantageous over direct selection (Rx), since the ratio CRx/Rx was always equal or below unity.

Asparagus Plant↗