Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “dairy cattle”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1979

[Studies of Mycoplasma mastitis in cattle. 7. Mycoplasma mastitis in 3 dairy cattle herds].

Reported in this paper is the occurrence of enzootic mastitis in three dairy cattle stocks. The outbreaks had been caused by Mycoplasma bovis, Acholeplasma laidlawii, Acholeplasma axanthum as well as by one unidentified strain of the family of mycoplasmataceae. All animals with positive response to mycoplasma tests were identified an selected by repetitive testing of cultures in milk samples which had been taken from all lactating and dry cows and heifers as well as by evaluation of organ samples obtained from slaughtered cows. Regular cleaning and disinfection of stands in cowsheds, cattle tracks, and milk parlours as well as disinfection of udders and milking cups worked extremely well throughout the action in control of those cases of enzootic mycoplasma mastitis.

Acholeplasma↗
PubMed2026

Comparative analysis of rumen metagenomes with dietary supplementation of 3-nitrooxypropanol revealed divergent modes of action in hydrogen metabolism and reductant pathways between beef and dairy cattle.

BACKGROUND: The compound 3-nitrooxypropanol (3-NOP), an inhibitor of methyl-coenzyme M reductase (MCR), reduces enteric methane production in both beef and dairy cattle. Although the proposed mechanisms of 3-NOP involve on inhibiting the activity of MCR in vivo, it is unknown how this process could affect rumen microbiome as a whole and if it differs between beef and dairy cattle. This study conducted a comparative analysis of the rumen microbiome and its functional shifts in four different cattle studies (two beef and two dairy cattle studies) that evaluated 3-NOP supplementation using metataxonomics and metagenomics. RESULTS: Comparative analysis of 281 rumen metataxonomic datasets (143 beef and 138 dairy cattle) revealed that dietary supplementation with 3-NOP affected rumen bacteria and methanogens. Further, comparative analysis of 54 metagenomic datasets (24 beef and 30 dairy cattle) revealed that 3-NOP inhibited mcrA, decreased the abundances of Methanobrevibacter gottschalkii and the protozoal species Isotricha prostoma, while increased the abundances of Methanobrevibacter ruminantium and Methanosphaera sp., Prevotella sp. was a significant bacterial taxon in both beef and dairy cattle, contributing to various pathways such as propionate and butyrate production. Its increased abundance after 3-NOP supplementation may also be linked to the decrease in Isotricha prostoma. Hydrogenotrophic methanogenesis decreased after 3-NOP supplementation with the abundance of genes involved in methylenetetrahydromethanopterin dehydrogenase decreased in beef cattle, while that of 4Fe-4S ferredoxin gene decreased in dairy cattle. The abundance of protozoal Polyplastron multivesiculatum increased after long-term 3-NOP supplementation in beef cattle, potentially due to changes in hydrogen (H2) partial pressure. During 3-NOP-mediated methanogenesis reduction, abundance of genes encoding methanogenic hydrogenase and H2 producing hydrogenase were decreased, while those encoding H2 sensory hydrogenase increased. Acyl-CoA dehydrogenase gene involved in propionate and butyrate production pathways increased in both beef and dairy cattle, while nitrite reductase increased specifically in beef cattle, indicating a rise in alternative H2 sinks. Video Abstract CONCLUSION: Our findings revealed broad effects of 3-NOP on rumen microbiome and functions in vivo, with varied effects in beef and dairy cattle, which provide mechanistic insights into the supplementation of 3-NOP in both beef and dairy cattle, supporting its more sustainable and effective use in the future.

Metagenome↗
PubMed2026

Integrative analysis of rumen microbiota activity and host metabolism following methanogenesis inhibition in dairy cattle.

Enteric methane emission from dairy cattle is an environmental challenge. The most efficient mitigation strategies nowadays include the use of methanogenesis inhibitors that specifically target the rumen methanogens. Specific inhibitors, such as 3-nitrooxypropanol (3-NOP), reduce methane emissions without negative effects on the products of fermentation that serve as energy metabolites for the host. However, the concomitant effects of methanogenesis inhibition on rumen microbiota and host metabolism are poorly characterized. Thus, the objective of this study was to explore the association between rumen microbiota and host metabolism when methanogenesis is inhibited. Thirteen dairy cows were used as controls, and 12 were supplemented with 3-NOP for 6 weeks. Rumen microbiota composition and activity were characterized using metagenomics and metatranscriptomics. The host metabolism was assessed in a previous publication by a metabolomic analysis of the plasma. Microbiota data were used as explanatory variables of the metabolome data in a multiblock sparse partial least squares analysis. Overall, the association between rumen microbiota and host metabolism was moderate. Notwithstanding this, a few downregulated transcripts related to glycolysis, hydrogen transfer, and protein synthesis, together with a decrease in the proportion of taxa of the Oscillospirales order, showed a correlation with host one-carbon metabolites (|r| > 0.6). These associations raised novel hypotheses that remain to be elucidated, especially with regard to the effects of dihydrogen on the accumulation of microbial glycolysis and methanogenesis metabolite intermediates.IMPORTANCEDairy cattle produce a substantial amount of methane, a potent greenhouse gas. Several strategies have been designed to reduce methane production by targeting the rumen microbiota. One such strategy specifically inhibits methanogens with a molecule called 3-nitrooxypropanol. This study uses an integrative data analysis approach, combining rumen microbiota and host metabolome information, to explore the consequences of inhibiting methanogenesis on the holobiont. This provides additional holistic insight into the effect of methane mitigation strategies on dairy cattle.

Animals↗
PubMed1979

[Fertility of dairy cattle in Kenya (author's transl)].

The fertility of dairy cattle was studied on thirty-three government farms in Kenya for five years. Most parameters of fertility showed marked differences between the various farms. Some farms showed considerable annual variations, whereas others continued to have good results during all these years and other farms only obtained results far below average. Dairy cattle fertility was fairly satisfactory with an average conception rate of 51 per cent after first inseminations and averaging two inseminations for each conception. However, the disappointing average calving-interval of 413 days was primarily due to the long parturition-to-first-insemination interval of ninety-three days on an average, and on average of 123 days in 1975. The frequency of normal heat- en service intervals (17-25 days) was too low by approximately 50 per cent, which was caused by the inefficiency of oestrus detection.

Animals↗
PubMed1979

Evaluation of high protein oat forage for dairy cattle.

Spear, a high protein oat variety, was evaluated during 2 consecutive yr for yields of forage dry matter and for feeding value as a silage to heifers, steers, and lactating cows. In yr 1 and 2, Spear yielded 7% and 13% less forage dry matter per hectare than Burnett, a comparative oat variety. Crude protein contents in silages were similar for varieties both years. In yr 1, Holstein heifers fed high protein and medium protein oat silages gained the same amount of weight but less weight than heifers fed alfalfa-brome hay. In a total collection digestion trial with six lactating cows, digestibilities of Spear were less than Burnett oat silage or alfalfa-brome hay. In yr 2, Spear and Burnett silages were fed ad libitum without a concentrate mixture to seven Holstein heifers each. Average daily gains were higher with Spear than Burnett. Apparent digestibilities as determined with steers tended to be less for Spear than Burnett. Dry matter intakes, milk yield, and composition were similar in a switchback lactation trial with ten cows fed spear or Burnett in oat silage supplemented with a concentrate at 1 kg per 3 kg milk produced.

Animal Feed↗
PubMed1979

Health care requirements of dairy cattle. I. Response to milk yield selection.

To measure direct response to single trait selection for milk yield and correlated response in health problems, two homologous base populations were formed by pairing 66 Holstein females by sire. Base populations and descendants were managed identically except for selection by milk yield. One base and lineage were mated with sires with highest predicted difference milk (selection group); other base and lineage were mated with average sires in 1964 (control group). Milk yield, supplemental labor, and veterinary and semen expense were recorded specific to each cow. Over 9 yr, 130 selection and 163 control cows were observed. Selection cows yielded more milk but with increase in labor and expense for health care. Estimates of labor for the selection group were greater for mammary, locomotion, and digestion categories and for expense in mammary, respiration, first insemination, and later insemination categories. Labor and expense for reproduction did not differ for genetic groups. Differences between groups in annual estimated labor and expense totaled $27.00. Extra income over feed cost more than compensated for greater health care and semen cost; however, the magnitude of the latter indicates a need for them to be considered when economically evaluating breeding programs where major emphasis is on milk yield.

Animals↗
PubMed1977

Occurrence and seasonal behavior of gastrointestinal nematodes infecting Maine dairy cattle.

Gastrointestinal tracts of 48 yearling Maine dairy cattle were examined (8 animals every 2 months) for 1 year. Adult and immature nematodes were identified and counted. Species recovered were Bunostomum phlebotomum, Cooperia mcmasteri, Cooperia oncophora, Cooperia pectinata, Cooperia punctata, Haemonchus placei, Nematodirus helvetianus, Oesophagostomum radiatum, Ostertagia circumcincta, Ostertagia lyrata, Ostertagia ostertagi, Trichostongylus axei, and Trichuris ovis. Strongyle parasitism was observed during every sampling period and the overall incidence was 93.7%. The most commonly encountered genera were Ostertagia spp (85.4%) and Cooperia spp (81.2%). Seasonal fluctuations in the worm burden of various nematodes were observed, with largest numbers seen in the fall. The incidence and degree of parasitism appeared to be related to environmental conditions. Proportions of adult and immature worms were shown to fluctuate with the time of year. Greatest numbers of immature worms were observed during the fall and winter.

Animals↗
PubMed1979

Milk production increase following treatment of Dutch dairy cattle with thiabendazole.

In a trial involving 542 dairy cattle on 28 farms, 276 were treated once with thiabendazole within two days of calving. The treated group showed an average increase in milk yielded over the non-return group of 229.8 kg during the subsequent lactation. In the treated group, total milk fat production was increased over that of the controls by 7.4 kg per cow; milk protein was increased by 6.9 kg per cow. All treatment parameter differences were highly significant at the 1% level of probability.

Animals↗
PubMed1975

Plasma adrenocorticoid response to corticotropin in dairy cattle fed high silage diets.

Responses of plasma corticoids to adrenocorticotropic hormone (.32 U/kg body weight) administered during early lactation were measured in dairy cattle consuming large amounts of concentrate feeds and one of the following forage diets: alfalfa-timothy hay plus corn silage, alfalfa-timothy hay crop silage plus corn silage, or corn silage. Concentrations of plasma corticoids increased to maximum in all groups within 60 to 90 min. Concentrations remained at near maximum for 4 to 5 h and then declined to baseline. Maximum corticoid concentrations following adrenocorticotropic hormone injection differed among forage treatment groups. Responses of corn silage and hay crop silage groups (46.7 +/- 1.1 and 50.1 +/- 2.4 ng/ml) did not differ but were less than those in the hay group (65.5 +/- 2.9 ng/ml). Response measured as area under the curve of plasma corticoid response also differed among forage treatments: hay 443 +/- 17 h (ng/ml) is greater than hay crop silage 334 +/- 34 is greater than corn silage 245 +/- 36. Results are discussed in terms of stress susceptibility in dairy cattle consuming diets containing large amounts of silage.

Adrenal Cortex Hormones↗
PubMed1979

A review of research on genetic variation in physiological characteristics related to performance in dairy cattle.

Genetic influence on physiological characteristics ranges from single gene effects on amino acid substitutions in alternative forms of proteins to quantitative genetic effects on the amounts of enzymes and hormones. The number of loci involved in the control of quantitative variation in physiologically important substances is not known. A number of marker genes that affect blood antigens, serum and milk proteins, and enzymes have been identified in dairy cattle. However, relatively little is known about genetic effects on quantitative physiological traits in dairy cattle. Much more is known about the genetic control of hormones in laboratory animals. About 25% of the variation in milk production of dairy cows results from genetic differences. We need more studies of genetic influences on the various physiological and biochemical processes involved in the secretion of milk to reveal the mechanisms by which genetics influences the quantity and quality of milk produced by individual cows.

Animals↗
PubMed1977

Management factors and grass tetany in dairy cattle.

The relationship between intensity of production and the occurrence of hypomagnesaemia and grass tetany in dairy cattle was investigated from 1966-1970 at the Ellinbank Dairy Research Station, Warragul, Victoria. Hypomagnesaemia and/or grass tetany occurred in cows grazing at both high (3.2 cows/hectare) and low (2.2 cows/hectare) stocking rates over the four-year period. Pasture Mg concentrations remained relatively high (0.2% dry matter) throughout this period, except in the low stocking rate pastures in one year, 1967. It is concluded that hypomagnesaemia and grass tetany was precipitated by a combination of low dry matter intake in winter and the effects of a gradual increase of K concentration in autumn and winter pastures, following the heavy application of K fertilizer. Under these conditions, MgO supplementation was inadequate to prevent grass tetany occurring in some animals.

Animal Husbandry↗
PubMed1979

Milk production of grazing dairy cattle after a single anthelmintic treatment.

The prevalence of nematode infections in lactating dairy cattle was determined by faecal egg counts and cultures from over 350 cows selected at random from twelve herds. The mean egg count was 3 eggs per gram (epg) and 43% of the cows sampled were passing detectable concentrations of eggs (greater than 6 eggs) in their faeces. In June 1976 171 cows in 10 herds were treated with 7.5 mg/kg fenbendazole and their milk production compared over the following 2 months with that of 164 untreated cows in the same herds. Anthelmintic treatment had no significant influence on milk production in any of the herds. The contrasting results of this study and recent studies in the United States of America are discussed.

Animals↗
PubMedDate not supplied

Experimental results of the use of flavofosfolipol in dairy cattle.

In a field trial carried out on a farm with about 100 dairy cows, half of the animals were treated orally with 45 mg flavofosfolipol per animal daily for 370 days, while the other half were untreated controls. The administration of the flavofosfolipol did not produce any residues in the milk. Body functions and fertility were not affected. Milk production was increased, although not with statistical significance. The qualitative characteristics of the milk and its cheese-making properties were normal. The casein content was increased by 6.58% over that of the controls, and thus was statistically significant. There was a statistically significant decrease in the mean cell content of the milk. The high negative correlation between the casein level and the cell content of the milk suggests that an improvement in the function of the mammary parenchyma could be responsible for the higher casein content. This improvement in function could also be due to a favourable effect of the antibiotic, still to be clarified, on the ruminal microflora. In economic terms the use of flavofosfolipol in dairy cattle seems to be of considerable interest.

Animals↗
PubMed1975

Survey of helminth infections in Maine dairy cattle.

The survey was done to determine the incidence and seasonal prevalence of the gastrointestinal helminths infecting Maine dairy cattle. Approximately equal groups of calves, heifers, and cows from 13 dairy farms, managerially and geographically representative of dairying in the state, were sampled at regular 2-month intervals over the period of a year. On the basis of fecal egg counts and identification of cultured larvae, the following results were obtained: Of the 94 adult cows, 78 heifers, and 91 calves sampled continuously in the course of the survey, 95.7%, 98.7%, and 96.7%, respectively, were strongylorid positive (infected with Ostertagia, Cooperia, Trichostrongylus, Haemonchus, and Oesophagostomun), with an overall incidence of 97%. Strongyloides papillosus eggs were in 64.6% of the cattle, Bunostomum in 40.3%, Nematodirus in 27.8%, Trichuris in 27.0%, Capillaria in 9.5%, Moniezia in 25.1%, and Dictyocaulus viviparus larvae in 2.7%. Worm burdens, as reflected by mean nematode egg production per gram of feces, varied. The greatest worm burdens were in the calves, followed by the heifers and the cows. A marked variation in egg production related to season was observed, particularly with the strongylorid worms. Peak strongylorid egg production was observed in the May-June sampling period. After the peak period, worm burdens decreased in all groups of cattle to their lowest point during the winter period of January-February. This pattern of egg production was similar to that reported by workers in other parts of the world. Farm management practices were shown to be related to the degree of parasitism existing in these herds. Those herds classed as poorly managed had significantly higher levels of parasitism in young animals than those classed as having fair or good management.

Animals↗