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Meme ve meme başı süt sığırcılığında hijyen açısından çok önemlidir. Bitkisel ekstraktların 1990'lı yıllarda başlayan meme ve meme başı dezenfektanı olarak kullanımı konulu çalışmalar sonucu üretilmiş pek çok ürün bugün piyasada farklı marka adı altında satışa sunulmaktadır. İyi bir dezenfektanın sadece bakteri öldürme değil aynı zamanda meme başı derisini kuruma, tahriş, yara ve kötü hava koşullarına karşı da koruma sağlaması gerekmektedir. Bu nedenle piyasada mevcut dezenfektanların birkaç ekstraktın karışım halinde kullanıldığı anlaşılmaktadır. Bu derlemede yürütülen bitkisel dezenfektan konulu araştırma sonuçlarını bir arada değerlendirerek kullanıcıların bilgisine sunulması amaçlanmıştır., Udder and teat dipping disinfection is very important in terms of hygiene in dairy cattle. As a result of the trial studies of herbal extracts as an udder and teat dipping disinfectant started in the 1990s, it is offered under a different brand name in the market today. A good disinfectant should not only kill bacteria but also protect against cow udder from dryness, irritation, wound, and bad weather conditions. It is understood that several disinfectants were used as a mixture in disinfectants present in the market. In this review, it has been aimed to evaluate the results of the research on herbal disinfectant carried out in this study together and present it to the information to the users.

Residual feed intake (RFI) is the difference between actual and predicted dry matter intake (DMI) of individual animals. Recent studies with Holstein-Friesian calves have identified an ~20% difference in RFI during growth (calf RFI) and these groups remained divergent in RFI during lactation. The objective of the experiment described here was to determine if cows selected for divergent RFI as calves differed in milk production, reproduction or in the profiles of BW and body condition score (BCS) change during lactation, when grazing pasture. The cows used in the experiment (n=126) had an RFI of −0.88 and +0.75 kg DM intake/day for growth as calves (efficient and inefficient calf RFI groups, respectively) and were intensively grazed at four stocking rates (SR) of 2.2, 2.6, 3.1 and 3.6 cows/ha on self-contained farmlets, over 3 years. Each SR treatment had equal number of cows identified as low and high calf RFI, with 24, 28, 34 and 40/11 ha farmlet. The cows divergent for calf RFI were randomly allocated to each SR. Although SR affected production, calf RFI group (low or high) did not affect milk production, reproduction, BW, BCS or changes in these parameters throughout lactation. The most efficient animals (low calf RFI) lost similar BW and BCS as the least efficient (high calf RFI) immediately post-calving, and regained similar BW and BCS before their next calving. These results indicate that selection for RFI as calves to increase efficiency of feed utilisation did not negatively affect farm productivity variables (milk production, BCS, BW and reproduction) as adults when managed under an intensive pastoral grazing system.

International audience; The main aim of the present study was to examine the effects of long-term supplementing diets with saturated or unprotected polyunsaturated fatty acids from two different plant oils rich in either n-3 or n-6 fatty acids (FAs) plus docosahexaenoic acid (DHA)-rich algae on mammary gene expression and milk fat composition in lactating dairy cows. Gene expression was determined from mammary tissue and milk epithelial cells. Eighteen primiparous German Holstein dairy cows in mid-lactation were randomly assigned into three dietary treatments that consist of silage-based diets supplemented with rumen-stable fractionated palm fat (SAT; 3.1% of the basal diet dry matter, DM), or a mixture of linseed oil (2.7% of the basal diet DM) plus DHA-rich algae (LINA; 0.4% of the basal diet DM) or a mixture of sunflower oil (2.7% of the basal diet DM) plus DHA-rich algae (SUNA; 0.4% of the basal diet DM), for a period of 10 weeks. At the end of the experimental period, the cows were slaughtered and mammary tissues were collected to study the gene expression of lipogenic enzymes. During the last week, the milk yield and composition were determined, and milk was collected for FA measurements and the isolation of milk purified mammary epithelial cells (MECs). Supplementation with plant oils and DHA-rich algae resulted in milk fat depression (MFD; yield and percentage). The secretion of de novo FAs in the milk was reduced, whereas the secretion of trans-10,cis-12-CLA and DHA were increased. These changes in FA secretions were associated in mammary tissue with a joint down-regulation of mammary lipogenic enzyme gene expression (stearoyl-CoA desaturase, SCD1; FA synthase, FASN) and expression of the regulatory element binding transcription factor (SREBF1), whereas no effect was observed on lipoprotein lipase (LPL) and glycerol-3-phosphate acyltransferase 1, mitochondrial (GPAM). A positive relationship between mammary SCD1 and SREBF1 mRNA abundances was observed, suggesting a similar regulation for these genes. Such data on mammary gene expression in lactating cows presenting MFD contribute to strengthen the molecular mechanisms that govern milk fat synthesis in the mammary glands. In purified MEC, the dietary treatments had no effect on gene expressions. Differences between mammary tissue and milk purified MEC gene expression were attributed to the effect of lipid supplements on the number of milk purified MEC and its RNA quality, which are determinant factors for the analysis of gene expression using milk cells.

Fertility in dairy cows has declined over the past five decades as milk production per cow has increased. Many hypotheses have been proposed to explain this including issues of genetics, physiology, nutrition and management, and these factors have been investigated at the animal, organ and cellular level at critical time points of the productive life of dairy cows. This paper reviews the physiological events and their causes and consequences affecting fertility in dairy cows and summarises these in a downloadable poster. We consider the following points to have the greatest negative impact on fertility and that they need to be prioritised in efforts to ameliorate the problem (others have been included in the review). Firstly, minimise negative energy balance and resolve any infection of the post partum uterus. Secondly, expression and detection of oestrus followed by insemination with high quality semen (day 0). Thirdly, ovulation and fertilisation of a high quality oocyte (day 1). Fourthly, an early increase in progesterone secretion from the corpus luteum (days 3-7). Fifthly, the uterine endometrium must produce an early and appropriate environment to stimulate embryo development (days 6-13). This leads to sixthly, a large embryo producing adequate quantities of interferon tau (days 14-18) that alters uterine prostaglandin secretion and signals maternal recognition of pregnancy (days 16-18). Future strategies to improve dairy cow fertility are needed for the benefit of the dairy industry and for cow welfare and should be based upon an integrative approach of these events. (C) 2011 Elsevier B.V. All rights reserved.

Objective. This study was conducted during winter season at rural livestock farm of district Sargodha, Pakistan, in order to define the macrominerals status in blood plasma of lactating and dry Desi breed cows. Material and methods. Twenty lactating and twenty dry cows were used and their blood plasma was analyzed for Ca, Mg, Zn, Cu and Fe using atomic absorption spectrophotometer. Results. In lactating cows, the plasma Ca concentration was lower than dry cows (6.8 vs. 7.6 mg/dl, p

This study explored the ability of an existing lifetime nutrient partitioning model for simulating individual variability in genetic potentials of dairy cows. Generally, the model assumes a universal trajectory of dynamic partitioning of priority between life functions and genetic scaling parameters are then incorporated to simulate individual difference in performance. Data of 102 cows including 180 lactations of 3 breeds: Danish Red, Danish Holstein, and Jersey, which were completely independent from those used previously for model development, were used. Individual cow performance records through sequential lactations were used to derive genetic scaling parameters for each animal by calibrating the model to achieve best fit, cow by cow. The model was able to fit individual curves of body weight, and milk fat, milk protein, and milk lactose concentrations with a high degree of accuracy. Daily milk yield and dry matter intake were satisfactorily predicted in early and mid lactation, but underpredictions were found in late lactation. Breeds and parities did not significantly affect the prediction accuracy. The means of genetic scaling parameters between Danish Red and Danish Holstein were similar but significantly different from those of Jersey. The extent of correlations between the genetic scaling parameters was consistent with that reported in the literature. In conclusion, this model is of value as a tool to derive estimates of genetic potentials of milk yield, milk composition, body reserve usage, and growth for different genotypes of cow. Moreover, it can be used to separate genetic variability in performance between individual cows from environmental noise. The model enables simulation of the effects of a genetic selection strategy on lifetime efficiency of individual cows, which has a main advantage of including the rearing costs, and thus, can be used to explore the impact of future selection on animal performance and efficiency.

The purpose of this study was to evaluate prediction of methane emissions from finishing beef cattle using an extant mechanistic model with pH-independent or pH-dependent volatile fatty acid (VFA) stoichiometries, a recent stoichiometry adjustment for the use of monensin, and adaptation of the underlying model structure, to see if prediction improvements could be made for beef cattle. The database used for independent evaluation of methane predictions consisted of 74 animal means from six studies. For the "Bannink" stoichiometries, pH-dependence of stoichiometry improved the root mean square prediction error (RMSPE) statistic (38.8 to 36.6%) but the concordance correlation coefficient (CCC) statistic was reduced (0.509 to 0.469). Inclusion of monensin in the stoichiometry improved both pH-independent and pH-dependent predictions. For the "Murphy" stoichiometries, pH-dependence worsened the RMSPE (31.2 to 33.7%) as well as the CCC (0.611 to 0.465) statistic. Inclusion of monensin in the stoichiometry improved predictions with the pH-independent but not with the pH-dependent stoichiometry. Results indicate that although improvements have been made to the mechanistic model, further improvement in the representation of VFA stoichiometry, and likely the representation and prediction of pH and neutral detergent fiber digestibility, are required for more accurate prediction of methane emissions for finishing beef cattle. However, inclusion of an adjustment for monensin feeding generally lead to improved methane predictions.

Studio preliminare sulla presenza di aflatossina B1 in alimenti per bovine da latte provenienti dal comprensorio del Parmigiano Reggiano. La presenza di aflatossine, in particolare di aflatossina B1 (AFB1), negli alimenti destinati alle bovine da latte rappresenta un punto di controllo critico sia per gli animali che li assumono, che per l’uomo consumatore di latte e derivati. E’ stato quindi condotto un monitoraggio sugli alimenti zootecnici prodotti in 180 aziende nel corso dell’anno 2003 all’interno del comprensorio del Parmigiano Reggiano, nelle provincie di Bologna, Mantova, Modena, Parma e Reggio Emilia, per un totale di 774 campioni (738 di fieno e 36 di granella). I risultati relativi al contenuto di AFB1 determinato con metodica ELISA (Veratox® HS), dimostrano una buona qualità degli alimenti considerati. Per quanto riguarda i fieni la percentuale di positività risulta pari al 35,9% considerando positivi quelli che superano il limite di rilevabilità della metodica (0,5 µg/kg), con solo 4 campioni caratterizzati da livelli di AFB1, di poco superiori al limite di legge, pari a 0,005 mg/kg. Relativamente alle granelle, solo i campioni di mais evidenziano una certa presenza di aflatossina (88,9% sul totale), il 31,25% dei quali risulta caratterizzato da livelli di AFB1 superiori ai limiti di legge (0,020 mg/kg).

Wheat dried distillers' grain (WDDG) as a co-product has a high content of neutral detergent fiber (NDF) and crude protein (CP), due to the selective removal of starch during the production process. Therefore, it has been proposed to use this by product as a good source of non-forage fiber in ruminant rations. The objective of this study was to evaluate the effect of diets containing different amount of Wheat dried distillers' grain as a partial substitute for alfalfa hay on lactation performance, blood metabolites and chewing activity of lactating Holstein dairy cows. Nine primiparous Holstein lactating dairy cows (76±18 days in milk) were assigned randomly to a replicated 3×3 Latin square design with 21 d periods. Basal diet (BD) was provided using 31.2% alfalfa hay, 15.6% corn silage, 12.5% barley grain, 12.5% corn grain, 8.6% cottonseed, 7.1% wheat bran, 10.5% soybean meal and 2% premix on dry matter basis. Alfalfa hay and soybean meal was partially substituted with WDDG as 5% (BD+WDDG5) and 8.7% (BD+WDDG8.7). Experimental diets were calculated to achieve same amount of CP and metabolizable energy. Throughout the experiment, cows were housed in tie-stalls barn and fed ad libitum a total mixed ration twice daily at 008 and 1800 h. Dry matter intake (DMI) and milk yield was recorded daily. Milk samples were collected weekly at each milking, then, analyzed for protein, lactose and fat. Blood samples were drawn from the jugular vein into heparinized evacuated tubes on the last day of each experimental period at 4 h post-feeding, then, plasma was provided. Plasma samples were analyzed to determine glucose and urea-N concentrations. Chewing activity (i.e. eating, ruminating, idle)for cows were monitored over a 24 h by manually observing individual cows every 5 min. Inclusion of WDDG in the experimental diets did not affect DMI, milk yield, milk composition, blood glucose. Except for total chewing activity (min/kg NDF) that was decreased significantly with inclusion of WDDG, all other evaluating indices were not affected by treatments. However, diet containing WDDG at 5% caused a significant decrease (P

Chantier qualité GA; Microarray analysis was used to identify genes whose expression in the mammary gland of Holstein-Friesian dairy cows was affected by the nonconservative Ala to Lys amino acid substitution at position 232 in exon VIII of the diacylglycerol-O-transferase 1 (DGAT1) gene. Mammary gland biopsies of 9 homozygous Ala cows, 13 heterozygous cows (Ala/Lys), and 4 homozygous Lys cows in midlactation were taken. Microarray ANOVA and factor analysis for multiple testing methods were used as statistical methods to associate the expression level of the genes present on Affymetrix bovine genome arrays (Affymetrix Inc., Santa Clara, CA) with the DGAT1 gene polymorphism. The data was also analyzed at the level of functional modules by gene set enrichment analysis. In this small-scale experimental setting, DGAT1 gene polymorphism did not modify milk yield and composition significantly, although expected changes occurred in the yields of C14:0, cis-9 C16:1, and long-chain fatty acids. Diacylglycerol-O-transferase 1 gene polymorphism affected the expression of 30 annotated genes related to cell growth, proliferation, and development, remodeling of the tissue, cell signaling and immune system response. Furthermore, the main affected functional modules were related to energy metabolism (lipid biosynthesis, oxidative phosphorylation, electron transport chain, citrate cycle, and propanoate metabolism), protein degradation (proteosome-ubiquitin pathways), and the immune system. We hypothesize that the observed differences in transcriptional activity reflect counter mechanisms of mammary gland tissue to respond to changes in milk fatty acid concentration or composition, or both.

High-sugar grass varieties have received considerable attention for their potential ability to decrease N excretion in cattle. However, feeding high-sugar grasses alters the pattern of rumen fermentation, and no in vivo studies to date have examined this strategy with respect to another environmental pollutant: methane (CH(4)). Modeling allows us to examine potential outcomes of feeding strategies under controlled conditions, and can provide a useful framework for the development of future experiments. The purpose of the present study was to use a modeling approach to evaluate the effect of high-sugar grasses on simulated CH(4) emissions in dairy cattle. An extant dynamic, mechanistic model of enteric fermentation and intestinal digestion was used for this evaluation. A simulation database was constructed and analysis of model behavior was undertaken to simulate the effect of (1) level of water-soluble carbohydrate (WSC) increase in dietary dry matter, (2) change in crude protein (CP) and neutral detergent fiber (NDF) content of the plant with an increased WSC content, (3) level of N fertilization, and (4) presence or absence of grain feeding. Simulated CH(4) emissions tended to increase with increased WSC content when CH(4) was expressed as megajoules per day or percent of gross energy intake, but when CH(4) was expressed in terms of grams per kilogram of milk, results were much more variable due to the potential increase in milk yield. As a result, under certain conditions, CH(4) (g/kg of milk) decreased. The largest increases in CH(4) emissions (MJ/d or % gross energy intake) were generally seen when WSC increased at the expense of CP in the diet and this can largely be explained by the representation in the model of the type of volatile fatty acid produced. Effects were lower when WSC increased at the expense of NDF, and intermediary when WSC increased at the expense of a mixture of CP and NDF. When WSC increased at the expense of NDF, simulated milk yield increased and, therefore, CH(4) (g/kg of milk) tended to decrease. Diminished increases of CH(4) (% gross energy intake or g/kg of milk) were simulated when DMI was increased with elevated WSC content. Simulation results suggest that high WSC grass, as a strategy to mitigate N emission, may increase CH(4) emissions, but that results depend on the grass composition, DMI, and the units chosen to express CH(4). Overall, this project demonstrates the usefulness of modeling for hypothesis testing in the absence of observed experimental results.

WOS: 000294879500008, This study was conducted to determine the nutritive value of live yeast culture (RumiSacc, Saccharomyces cerevisiae) and to investigate its effects on milk yield, milk composition and some blood parameters in lactating cows. Six multiparous Holstein cows were allocated to two groups of three cows and assigned randomly to one of two diets in a cross-over experiment. Daily 50 g RumiSacc was top dressed at the p.m. feeding for the treatment group. RumiSacc supplied a high protein and energy with high organic matter digestibility values (83.35%) determined by in vitro enzymatic analysis. Yeast culture supplementation significantly increased milk yield, tended to increase fat yield, protein yield and lactose yield of milk. Methylated fatty acid level of 18:3 (n-3) in milk fat was increased by yeast culture supplementation. The concentrations of methionine, phenyalanine, tyrosine, tryptophan and taurine were significantly increased with dietary inclusion of yeast culture. Live yeast culture supplementation did not affect other performance characteristics, milk quality characteristics and blood parameters. As a conclusion live yeast culture (RumiSacc, Saccharomyces cerevisiae) had high nutritive value and positive effects on milk production and some milk quality characteristics in lactating cows under field conditions.

The aim of this study was to evaluate the effect of feeding grape residue silage on the parameters: intake, nutrients digestibility, blood parameters and also production, chemical composition, fatty acid and oxidative stability of milk. It was used four Holstein cows, confined, average live weight of 504 +-} 26 kg and 136 +-} 28 days in milk, they were assigned in a Latin square with four treatments and four periods of 21 days each. The diets studied were: control diet with 4% soybean oil, diet with 4% soybean oil and 5% of grape residue silage, diet with 4% soybean oil and 7.5% of grape residue silage, diet with 4% soybean oil and 10% grape residue silage. It was determined the intake of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), non-fiber carbohydrates (NFC) . The estimated total apparent digestibility was performed for DM and nutrients, CP, EE, NDF, ADF and NFC. The blood was sampled from animals in starvation for analyzing glucose, triglycerides, total cholesterol, HDL, LDL and VLDL and N-urea. Milk production and milk yield corrected to 3.5% fat and density were measured as the milk components protein, fat, lactose, total solids, N-urea, somatic cell count (SCS) and composition of fatty acids. The oxidative stability of milk was determined by analysis of determination of total polyphenols, flavonoids, antioxidant activity and conjugated diene hydroperoxides (CD). It was observed that the grape residue silage did not alter the intake of DM, OM, NDF, ADF and NFC (P>0.05), however, the supply of this food diets resulted in higher EE intake (P=0.02). The total apparent digestibility of nutrients was affected by the levels of grape residue silage. DM digestibility was reduced linearly (P=0.02) as OM (P=0.03) and CP (P=0.03) with level of 7.5% DM of grape residue silage. The diets affected the digestibility of the NDF linearly negative (P=0.02) and ADF (P=0.01) and the results showed this effect with the 5% level in DM. The digestibility of EE and NFC were not influenced by treatments. Regarding blood parameters, concentrations of glucose, triglycerides, total cholesterol and HDL, LDL, VLDL and urea were not affected (P>0.05) by diets. Cows fed with the different levels of grape residue silage showed milk production equally as well as milk production adjusted to 3.5% fat (P>0.05). Milk components were not changed, however, there was a decreased (P=0.05) in levels of N-urea with diets containing 7.5% and 10% grape residue on dry matter. There was also no effect (P>0.05) of treatments on individual fatty acid composition and proportions. The concentrations of polyphenols in milk with the inclusion of grape residue silage were not significant, as the flavonoid content (P>0.05). The parameter of power reducing of milk was affected by diet (P=0.002) and the level of 10% grape residue silage showed higher power reducing, however, the higher antioxidant activity of milk did not result in lower production of CD (P>0.05). Grape residue silage can be used in feed for dairy cows because it keeps the production and milk quality and increases the antioxidant activity. O objetivo deste estudo foi avaliar o efeito do fornecimento da silagem de resíduo de uva sobre os parâmetros: consumo, digestibilidade dos nutrientes, parâmetros sanguíneos e também a produção, composição química e em ácidos graxos, estabilidade oxidativa do leite. Foram utilizadas quatro vacas da raça Holandesa, confinadas, com peso vivo médio de 504 } 26 kg e 136 } 28 dias de lactação, distribuídas em um quadrado latino com quatro tratamentos e quatro períodos de 21 dias cada. As dietas estudadas foram: dieta controle com 4% de óleo de soja, dieta com 4% de óleo de soja e 5% de silagem de resíduo de uva, dieta com 4% de óleo de soja e 7,5% de silagem de resíduo de uva, dieta com 4% de óleo de soja e 10% de silagem de resíduo de uva. Foi determinado o consumo de materia seca (MS), materia orgânica (MO), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro (FDN), fibra em detergente acido (FDA), carboidratos não fibrosos (CNF). A estimativa da digestibilidade aparente total foi realizada para MS e nutrientes, PB, EE, FDN, FDA e CNF. Realizaram-se coletas de sangue com os animais em jejum para analise da concentração de glicose, triglicerídeos, colesterol total, HDL, LDL e VLDL e uréia. A produção de leite e a produção de leite corrigida para 3,5% de gordura, densidade foram mensuradas e os componentes do leite, proteína, gordura, lactose, sólidos totais, N-ureico, contagem de células somáticas (CCS) e composição de ácidos graxos. A estabilidade oxidativa do leite foi avaliada por meio de analise de determinação de polifenois totais, flavonóides, atividade antioxidante e hidroperoxidos digno conjugados (DC). Foi observado que a silagem de resíduo de uva não alterou a ingestão de MS, MO, PB, FDN, FDA e CNF (P>0,05), entretanto, o fornecimento de dietas contendo esse alimento resultou em maior consumo de EE (P=0,02). A digestibilidade aparente total dos nutrientes foi afetada pelos níveis da silagem de resíduo de uva. A digestibilidade da MS foi reduzida linearmente (P=0,02), assim como a MO (P=0,03) e PB (P=0,03) a partir do nível de 7,5% na MS de resíduo de uva. A digestibilidade do EE foi reduzida linearmente com os níveis de inclusão da silagem de resíduo de uva (P=0,02). As dietas estudadas afetaram a digestibilidade de forma linear negativa a FDN (P=0,02) e FDA (P=0,01) e os resultados mostraram esse efeito com o nível 5% na MS. A digestibilidade dos CNF não foi influenciada pelos tratamentos. Com relação aos parâmetros sanguíneos, as concentrações de glicose, triglicerídeos, colesterol total e frações HDL, LDL, VLDL e uréia não foram afetadas (P>0,05) pelas dietas experimentais. Vacas alimentadas com os diferentes níveis de resíduo de uva apresentaram produção de leite igual, assim como produção de leite corrigida para 3,5% de gordura (P>0,05). Os componentes do leite não foram alterados, entretanto, houve redução (P=0,05) dos teores de N-ureico com os níveis 7,5% e 10% de resíduo de uva na matéria seca. Também não houve efeito (P>0,05) dos tratamentos sobre a composição de ácidos graxos individuais e as proporções de ácidos graxos. As concentrações de polifenois no leite com a inclusão da silagem de resíduo de uva não foram significativas, assim como para o teor de flavonóides (P>0,05). O parâmetro de forca de redução do leite foi afetado pelas dietas (P=0,002) e o nível 10% de resíduo de uva apresentou maior forca de redução, no entanto, a maior atividade antioxidante do leite não resultou em menor produção de hidroperoxidos digno conjugados (P>0,05). A silagem de resíduo de uva pode ser utilizada na alimentação de vacas leiteiras porque manter a produção e qualidade do leite e aumenta a atividade antioxidante. xi, 63 [3] f

International audience; Dietary changes alter dairy cow milk fat concentration (MFC) and yield (MFY) through modifications in the supply of nutrients, which act as precursors or inhibitors of mammary fat synthesis. The current models used to formulate dairy cow diets cannot predict changes in milk fat. The knowledge of the effects of the nutrients on milk fat would help to progress toward this prediction. To this end, we quantified and compared the milk fat responses to variations in the supply of seven nutrients derived from digestion: volatile fatty acids, glucose, proteins, long-chain fatty acids (LCFA) and t10,c12-conjugated linoleic acid (CLA). A database was compiled from studies involving digestive infusions of these nutrients in dairy cows. It included 147 comparisons between a nutrient infusion and a control treatment. The nutrient infusions were limited to the range of physiological variations to mimic nutrient changes after dietary modifications. We established models for the response of MFC, MFY and milk fatty acid (FA) composition to the supply of each nutrient. MFC and MFY responses to the nutrients were significant and linear, except for the MFC response to glucose that was curvilinear. The nutrients differed in their effects on MFC and MFY: acetate, butyrate and LCFA increased MFC and MFY, whereas propionate, glucose and t10,c12-CLA decreased them. Protein infusions increased MFY and decreased MFC because of an increase in milk yield. The effects of numerous interfering factors related to animals, diets or experimental conditions were tested on the residuals of the response models. The responses of milk FA percentages are also provided. When adjusted to the in vivo variations in the nutrients observed after dietary changes, the effects of the different nutrients were moderate. Finally, this study showed that several of these nutrients could contribute to the changes in milk fat production and composition observed after dietary changes. This is a first step toward predicting milk fat response to changes in nutrient supply.

In vitro and in vivo studies were conduced to evaluate the potential of flaxseed to increase concentration of mammalian lignans in milk. In a first trial, flax seeds and hulls were incubated to determine the in vitro conversion of plant lignans from two flax products (hull and seed) into the mammalian lignans enterolactone and enterodiol by bovine ruminal and fecal microbiota. Plant lignans in flax seeds and hulls averaged 9.2 and 32.0 nmol mg`1, respectively. The highest net production of enterodiol at 72 and 96 h of incubation was obtained with flax hulls incubated with fecal microbiota. There was no difference in net production of enterodiol between flax products within the first 24 h of incubation. ln general, net production of enterolactone over the 96 h time course was significantly higher for flax products incubated with ruminal than with fecal microbiota. Net production of enterolactone at 72 and 96 h of incubation was greater for flax hulls than flax seeds. A second experiment, was conducted in vivo with four lactating Holstein cows assigned to a 4 x 4 Latin square design that were fed one of the four treatments: control with no flaxseed hulls (CO), control with flaxseed hulls (FH), monensin (16 ppm) with no flaxseed hulls (MO), and monensin (16 ppm) with flaxseed hulls (HM). The apparent digestibility of CP was higher for diets containing flaxseed hulls and for diets supplemented with monensin. Significant higher digestibility of ether extract was observed for treatments with flaxseed hulls compared with treatments without flaxseed hulls. Feeding flaxseed hulls increased concentrations of total trans fatty acids (FA), monounsaturated FA, polyunsaturated FA, long-chain FA and n-3 FA, and the polyunsaturated to saturated FA ratio in milk fat. The n- 6 to n-3 ratio in milk fat was lower for cows fed flaxseed hulls compared with those fed no flaxseed hulls. Monensin supplementation increased the concentrations of cis9-l6:l and cis9,l2-18:2 in milk fat. Intake of dry matter (DM) was higher for treatments without flaxseed hulls than for treatments with flaxseed hulls. Moreover, milk production was decreased for cows fed flaxseed hulls. Concentration of enterolactone in both ruminal fluid and milk was higher for cows fed flaxseed hulls compared with those fed no flaxseed hulls. Concentration of ferric reducing antioxidant power was similar among treatments. A third experiment was conducted in vivo with four Holstein cows used in a 4 x 4 Latin square design. The four treatments were: a control diet containing no flaxseed products (CO), 4.l8 g/kg DM of whole flaxseed (WF), 1.87 g/kg DM of calcium salts of flaxseed oil (CF) or a mixture of 2.30 g/kg DM of whole flaxseed and 0.83 g/kg DM of calcium salts of flaxseed oil (MF). Dry matter intake, digestibility, and milk production and composition were similar among treatments except for milk fat percentage that was lower for CF compared to CO with no difference between CF and WF and MF. Concentrations of intermediates of biohydrogenation of FA in the rumen were higher when calcium salts of flaxseed oil were fed, and rumenic acid (cis9,transl l-1822) concentration was higher for CF compared to WF treatment. Milk fat concentration of alpha-linolenic acid was higher for CF and MF than CO, but was similar to WF. Feeding whole flaxseed did not alter enterolactone in milk compare to calcium salts of flaxseed oil. Both ruminal and fecal microbiota are able to transform plant lignans into mammalian lignans. Feeding flaxseed hulls was a good strategy to improve milk FA composition and increase enterolactone concentration in milk. Calcium salts of flaxseed oil depressed milk fat concentration and whole flaxseed had no effect on milk enterolactone concentration. Estudos, in vitro e in vivo, foram conduzidos para avaliar o potencial da linhaça em transferir lignanas mamíferas para o leite. No Primeiro Experimento, semente e casca de linhaça foram incubadas para determinar, in vitro, a conversão de lignanas vegetais em lignanas mamíferas (enterolactona e enterodiol) pela microflora ruminal e fecal. A concentração de lignanas vegetais na semente e na casca de linhaça foi em média 9,2 e 32,0 nmol mg-1, respectivamente. A maior produção de enterodiol, à 72h e 96h de incubação, foi obtida com casca de linhaça incubada com o inóculo fecal. Não houve diferença na produção de enterodiol entre a casca e a semente de linhaça nas primeiras 24h de incubação. Em geral, a produção de enterolactona no decorrer das 96h foi significativamante maior para a casca e a semente de linhaça incubadas com o inóculo ruminal do que com o inóculo fecal. A produção de enterolactona à 72h e 96h de incubação foi maior para a casca do que para a semente de linhaça. No Segundo Experimento, conduzido in vivo, quatro vacas da raça Holandesa em lactação foram distribuídas em um delineamento em quadrado latino 4 x 4 nos seguintes tratamentos: controle sem casca de linhaça (CO), controle com casca de linhaça (CL), monensina (16 ppm) sem casca de linhaça (MO), e monensina (16 ppm) com casca de linhaça (CM). A digestibilidade aparente da PB foi maior para as dietas que continham casca de linhaça e para as dietas suplementadas com monensina sódica. Um aumento significativo da digestibilidade do extrato etéreo foi observado para os tratamentos com casca de linhaça comparados com os tratamentos sem casca de linhaça. O fornecimento de casca de linhaça aumentou as concentrações de ácidos graxos trans totais, ácidos graxos mono-insaturados, poli­insaturados, de cadeia longa, n-3 total e a razão poli-insaturados/saturados na gordura do leite. A razão n-6/n-3 na gordura do leite foi menor para as vacas que receberam casca de linhaça em comparação àquelas que não a receberam. A suplementação com monensina sódica aumentou as concentrações dos ácidos graxos cis9-16:1 e cis9,12-18:2 na gordura do leite. A ingestão de MS foi maior para os tratamentos sem casca de linhaça do que para os tratamentos com casca de linhaça. Além disso, a produção de leite foi diminuída para as vacas que receberam casca de linhaça. A concentração de enterolactona tanto no líquido ruminal como no leite foi maior para as vacas que receberam casca de linhaça quando comparada com as vacas que não receberam casca de linhaça. O poder antioxidante ferro­redutor medido no leite foi similar entre os tratamentos. Um Terceiro Experimento in vivo foi conduzido com quatro animais da raça Holandês distribuídos em um delineamento em quadrado latino 4 x 4. Os tratamentos foram: uma dieta controle sem adição de produtos de linhaça (CO), 4,18 g/kg de MS de grãos de linhaça inteiros (LI), 1,87 g/kg de MS de sais de cálcio de óleo de linhaça (SC) e uma mistura de 2,3 g/kg de MS de grãos de linhaça inteiros e 0,83 g/kg de MS de sais de cálcio de óleo de linhaça (LS). A ingestão e digestibilidade da MS, produção e composição do leite, com excessão da gordura, a qual foi menor para SC quando comparado ao CO, mas sem diferença entre SC, LI e LS. Os ácidos graxos (AG) intermediários da biohidrogenação no rúmen foram maiores quando sais de cálcio foram fornecidos e o ácido rumênico (cis9,trans11-18:2) aumentou no tratamento SC comparado ao LI. O AG alfa linolênico no leite foi maior para SC e LS do que CO, mas não diferiu de LI. O fornecimento de linhaça inteira não alterou a concentração de enterolactona no leite em comparação aos sais de cálcio. Tanto a microflora ruminal como a fecal foram capazes de transformar lignanas vegetais em lignanas mamíferas. Casca de linhaça foi uma boa estratégia para melhorar a composição em ácidos graxos e aumentar a concentração de enterolactona no leite. Sais de cálcio de óleo de linhaça causaram depresão na gordura do leite e grãos de linhaça inteiros não alteraram a concentração de enterolactona no leite. xx, 91[1] f

International audience; The water intake of 41 lactating dairy cows managed according to current dairy farm practices was individually and continuously monitored to 1) investigate drinking behavior and 2) determine factors affecting water intake. The cows were housed in a free-stall barn and fed once daily with a corn silage and concentrate-based total mixed ration (48% dry matter content; 20.6 ± 3.3 kg/d of dry matter intake). Cows were milked twice daily, with a yield of 26.5 ± 5.9 kg/d. The daily free water intake (FWI) was 83.6 ± 17.1 L, achieved during 7.3 ± 2.8 drinking bouts. The drinking bout water intake was 12.9 ± 5.0 L. Almost three-fourths of the FWI occurred during working hours (0600 to 1900 h). Consumption peaks corresponded to feeding and milking times. More than one quarter of the daily FWI was met during the 2 h after each milking. About 75% of the present cows visited the watering point at least once during the 2 h after the evening milking. It is probable that drinking behavior evolved with lactation, but further studies are required to identify the relationship between lactation stage and drinking behavior. The most relevant factors affecting the daily FWI of lactating cows were best combined according to the following predictive equation: (R2 = 0.45; n = 41 cows, n = 1,837): FWI, L/d = 1.53 x dry matter intake (kg/d) + 1.33 x milk yield (kg/d) + 0.89 x dry matter content (%) + 0.57 x minimum temperature (°C) – 0.30 x rainfall (mm/d) – 25.65. The results obtained using these equations were in agreement with the equations developed by other researchers.

The objective of these studies was to determine the effects of forage fiber, social hierarchy, and stocking density on stress in lactating cows during relocation to new dairy facilities. In experiment one, 23 lactating cows were fed a basal ration, or the basal ration plus grass or alfalfa hay at 10% of DM offered from 3 wk pre-move to 9 wk post-move. In experiment two, 17 lactating cows were housed together before and after relocation and evaluated for dominance rank. In experiment three, 44 cows were housed together before relocation, then in pens of varying stocking density (0.67, 0.83, 1.0, or 1.17 cows per stall) post-move. In these studies, the effects of treatment on MY, lameness, behaviors, plasma cortisol, cow cleanliness, and DMI were monitored. In experiment one, cows fed grass or alfalfa hay diets had higher plasma cortisol concentrations on the day of relocation than cows fed TMR, but there were no differences in DMI or MY. Cows fed alfalfa hay or TMR had increased lameness scores following relocation; cows fed grass hay did not have increased lameness scores. In experiment two, there were no differences in plasma cortisol or lameness scores between dominant and subordinate cows. Subordinate cows had lower MY following relocation compared to dominant cows. In experiment three, cows housed at a stocking rate of 1.17 had higher plasma cortisol than cows housed at a stocking rate of 0.67. All cows had higher lameness scores following relocation, but cows housed at a stocking rate of 0.67 tended to have higher lameness scores than cows housed at stocking rates of 0.83, 1.0, and 1.17. In summary, some management practices may decrease the negative effects of stress on lactating cows during relocation. Master of Science

WOS: 000082732000011 Growth and feeding studies were conducted to determine effects of hazelnut kernal oil meal (HKOM) on growth performance (as protein efficiency), and milk production and composition. In the growth study, 24 individually fed Karayaka lambs (4 mo. and 25.55 kg LW) were used to determine protein efficiency calculated using the Slope Ratio Technique. In the feeding trial, 4 Jersey cows were arranged in 4 x 4 Latin squares experiment to measure effects of diets containing HKOM, soybean meal (SBM) corn gluten meal (CGU) and urea (U) on milk production and composition. Protein efficiencies for HKOM, SBM and CGM were found as 1.342 +/- 0.499, 0.879 +/- 0.488 and 1.833 +/- 0.893, respectively. Milk production for the cows consuming concentrates, containing HKOM, SBM, CGM and U, were 13.97 +/- 0.99, 13.20 +/- 1.09, 14.86 +/- 0.68 and 13.06 +/- 1.23 kg/d (p0.05) among diets for milk protein content were statistically different (p

International audience; Effects of providing a limiting AA on milk secretion and mammary nutrient uptake were investigated using four lactating dairy cows given duodenal infusions of graded amounts of L-Lys.HCl (0, 9, 27, and 63 g/d). Infusions were administered over 4-d periods according to a Latin square design. Diets consisted of a 70:30 corn silage:concentrate ratio supplemented with 1.5 kg of DM/d as dehydrated alfalfa. The basal diet met requirements for energy and protein and was deficient in Lys. Cows were fitted with indwelling catheters inserted into the left carotid and left subcutaneous abdominal veins, and a transit-time flow probe was implanted around the left external pudic artery. Milk, fat, and protein yields were unaffected by infusions of Lys. Milk protein content increased to a maximum with the third treatment, and fat content showed opposite variation. Although arterial concentrations and arteriovenous differences of Lys increased to a plateau with the third treatment, the relationship between arteriovenous differences and arterial concentrations was curvilinear. Infusions of Lys tended to increase the efficiency of N utilization and the mammary extraction rates of AA to synthesize more milk proteins. Initially, Lys was extracted in a direct ratio to its milk output and then taken up in excess by the secretory cells, suggesting that Lys was no longer a limiting factor in milk protein synthesis.

A model based on the dual-labelled tracer technique of Backwell and co-workers is proposed which allows detailed resolution of isotope dilution data that can be generated by this technique, provided these data are supplemented with appropriate arterio-venous difference and blood flow measurements. The proposed model is constructed and solved in the steady state. Model solution permits, if assumptions are made, calculation of the uptake of an amino acidYfrom the arterial blood supply in both peptide-bound and free form, oxidation ofY, export ofYinto the venous drainage, and synthesis and degradation of milk protein and constitutive tissue protein within the gland. The model provides a means of evaluating the role of amino acids of peptide origin in milk and constitutive protein synthesis in the mammary gland of the lactating ruminant.