Effect of Feeding Mixed Forage Diets on Milk Production

End of Project ReportsFor dairy farmers involved in winter milk production a high intake of forage is required by autumn calved dairy cows to produce a high milk yield with a moderate level of concentrate supplementation. Since intake of grass silage is often limiting, alternative forages or feeds may be needed to maximise forage intake. In areas not suitable for growing maize alternative forages need to be considered. These could include limited amounts of very high quality grass silage (DMD 750-800 g /kg), grazed autumn pasture or bulky by-product feeds, e.g. superpressed sugar beet pulp. An experiment was conducted involving 5 treatments in which a standard good quality grass silage (S) was partially replaced with either very high quality grass silage, which was either unwilted (U) or wilted (W), ensiled pressed sugar beet pulp (P) or with autumn pasture (G). These additional feeds were fed at a level of 5 kg DM/day to autumn calved cows in early lactation over a period of 8 weeks from late October to late December. The pressed pulp diet (P) included 0.5 kg DM soyabean meal to increase its protein level. The autumn grass was cut daily and fed indoors. The additional feeds were fed on top of the standard silage in individual feeding boxes and the standard silage was fed ad libitum to cows on all treatments. The cows were fed concentrates at 6 kg/day in two feeds on all treatments. The digestibility of the standard grass silage (754 g DMD/kg) was higher than planned and was only slightly less than that of the high quality supplementary silages (783 g DMD/kg). Feeding the U and W silages did not increase total forage intake but did increase milk yield by 1.7 - 1.9 kg/day compared with silage S alone. Milk fat and protein concentration tended to be reduced on the diets containing U and W silages, consequently yield of fat and protein were not significantly increased compared with silage S. Forage intake was increased by 8% (0.8 kg DM/day) when silage S was supplemented with autumn grass and milk yield was increased by 1.5 kg/day without affecting milk composition. Intake of silage was reduced by 37% by feeding grass. Feeding the pressed pulp supplement (P) increased intake of forage (+1.1 kg DM/day), increased milk yield by 2.7 kg/day and also improved milk protein concentration and yield (+121 g/day). Cows gained in liveweight to a similar extent on all diets. It was concluded that feeding pressed pulp with a good quality grass silage had the greatest effect on forage intake and milk production whereas feeding high quality grass silages or autumn grass had a smaller effect. Larger increases in intake and milk production would be expected from these feeds if the standard grass silage was of lower digestibility (~700 g DMD/kg), similar to average quality first cut silage.European Union Structural Funds (EAGGF

STAT5 in Cancer and Immunity

Signal transducers and activators of transcription 5 (STAT5a and STAT5b) are highly homologous proteins that are encoded by 2 separate genes and are activated by Janus-activated kinases (JAK) downstream of cytokine receptors. STAT5 proteins are activated by a wide variety of hematopoietic and nonhematopoietic cytokines and growth factors, all of which use the JAK-STAT signalling pathway as their main mode of signal transduction. STAT5 proteins critically regulate vital cellular functions such as proliferation, differentiation, and survival. The physiological importance of STAT5 proteins is underscored by the plethora of primary human tumors that have aberrant constitutive activation of these proteins, which significantly contributes to tumor cell survival and malignant progression of disease. STAT5 plays an important role in the maintenance of normal immune function and homeostasis, both of which are regulated by specific members of IL-2 family of cytokines, which share a common gamma chain (γc) in their receptor complex. STAT5 critically mediates the biological actions of members of the γc family of cytokines in the immune system. Essentially, STAT5 plays a critical role in the function and development of Tregs, and consistently activated STAT5 is associated with a suppression in antitumor immunity and an increase in proliferation, invasion, and survival of tumor cells. Thus, therapeutic targeting of STAT5 is promising in cancer

An Airborne Gamma-Ray Spectrometry Survey of Nuclear Sites in Belgium

No abstract available

Maize silage for milk production - Part 2: Effect of concentrate quality and quantity fed withmaize silage based forages on milk production

End of Project ReportIn some of the studies outlined in Part 1 of this report, mixed forages containing grass silage and a high proportion (60%) of maize silages varying in maturity and starch content were supplemented with concentrates at different levels to compare the response in milk production with a maize silage based forage and with good quality grass silage as the sole forage. The most suitable type of energy ingredient in the concentrate, i.e. high starch or low starch, high fibre ingredients, as supplements to maize silage based forages or grass silage was investigated. A range of levels of crude protein in the concentrate were examined in one study to determine the optimum level of crude protein in the supplement for maize silage based forages compared with grass silage.European Union Structural Funds (FEOGA

The evaluation of environmental, agronomic and economic implications of high and low input dairy systems.

End of Project ReportThis report marks the end of the first phase of a long term systems trial on phosphorus. The objective of the work was to define the minimum soil P necessary to ensure optimum production in terms of milk. If phosphorus applications are minimised, the potential damage to the environment is minimised. Three herds (21 cows each) were managed on three separate farmlets. The objective was to have each herd graze on land with it’s own soil P level. The target soil P levels required for herds 1, 2 and 3, were Indices 1, 2 and 3, respectively. At the end of this phase of the work these soil P targets were achieved. These were achieved by using no P fertiliser on treatment 1, application of maintenance P on treatment 2 (14kg p/ha) and 28 kg P/ha on treatment 3. In the course of the four years, grass growth, silage yields, milk yields and composition, cow weights and body scores were recorded. Soil phosphorus levels changed slowly. It took between 20 and 40 kg P/ha to move Morgan’s P by one unit. Silage yields and grazing sward yields were not affected by phosphatic fertiliser treatments. The P status in silage was significantly reduced in the low P treatments in three out of the four years. This resulted in lower P levels in the slurry in the low P treatments. In the fourth year P status in the grazing swards was consistently reduced in the low P treatment. Milk yields and composition were not influenced by P treatment. There was some evidence that cow weight and body score of cows were adversely effected in the low P treatments towards the end of the trial. In the next phase of the work, phosphorus will be applied to all three treatments at similar rates, i.e. maintenance dressings of P will be applied to cows grazing on soils with Indices 1, 2 and 3, respectively. It is concluded at the end of this phase that there may be some scope for modifications to the index system as is currently recommended by Teagasc. It will be in 2001 before the extent of changes that can be made will be quantified and implemented.European Union Structural Funding (EAGGF

Genetic variation among lambs in peripheral IgE activity against the larval stages of <i>Teladorsagia circumcincta</i>

IgA and IgE activity against Teladorsagia circumcincta was investigated in a flock of Texel lambs following natural, mixed nematode infection among lambs. The distribution of IgA activity was similar to a gamma distribution whereas IgE activity was different. Box-Cox analysis demonstrated that X0.25 was a suitable transformation to normalise IgE responses. The transformed IgE activity was under moderate to strong genetic control. Nine different allergens were identified by proteomic analysis. Tropomyosin was selected for further analysis. IgE activity against tropomyosin was moderately heritable and associated with decreased egg counts and with reduced body weight at the time of sampling

Adding value to milk by increasing its protein and CLA contents

End of project reportThe mid-summer milk protein study was undertaken on 34 commercial dairy farms in 2005 to evaluate the influence of dietary and management variables on milk protein content in mid-season. Data on grass composition, genetic merit of the herds and milk protein content were collected and analysed by multiple regression. Both calving date and genetic merit for milk protein content were significantly associated with milk protein content and were used as adjustment factors when evaluating the association between measures of grass quality and milk protein content. Milk protein content was associated with grass OMD (P = 0.04) and NDF content (P = 0.02) but not with CP content (P = 0.80). It is concluded that herds calving earlier, with a greater genetic merit for milk protein content and consuming better quality pasture would have greater milk protein contents in mid-season

Endocrine resistance in hormone receptor positive breast cancer–from mechanism to therapy

The importance and role of the estrogen receptor (ER) pathway has been well-documented in both breast cancer (BC) development and progression. The treatment of choice in women with metastatic breast cancer (MBC) is classically divided into a variety of endocrine therapies, 3 of the most common being: selective estrogen receptor modulators (SERM), aromatase inhibitors (AI) and selective estrogen receptor down-regulators (SERD). In a proportion of patients, resistance develops to endocrine therapy due to a sophisticated and at times redundant interference, at the molecular level between the ER and growth factor. The progression to endocrine resistance is considered to be a gradual, step-wise process. Several mechanisms have been proposed but thus far none of them can be defined as the complete explanation behind the phenomenon of endocrine resistance. Although multiple cellular, molecular and immune mechanisms have been and are being extensively studied, their individual roles are often poorly understood. In this review, we summarize current progress in our understanding of ER biology and the molecular mechanisms that predispose and determine endocrine resistance in breast cancer patients

Evaluation and Refinement of the French Protein System (PDI) under Irish Conditions

End of Project ReportThe CP and DM degradability of grazed grass (between April and October, inclusive) and grass silage samples (differing in cut number and treatment) was determined using the in situ technique and the results obtained were used to calculate the PDIE and PDIN values. The degradability data on 12 concentrate ingredients from a previous study (Woods, 2000) were used to estimate PDIE and PDIN values for these feedstuffs. The mean PDIE and PDIN values determined for grass were 81 g/kg and 127 g/kg DM, respectively and for grass silage were 60 g/kg and 94 g/kg DM. Regression analysis resulted in equations to predict the PDIN of samples of grazed grass (PDIN = 3.8 + 0.628 CP) (R²= 0.999) and grass silage (PDIN = 5.9 + 0.605 CP) (R²= 0.997), and the PDIE of grazed grass (PDIE = 181.4 - 0.104 NDF - 0.195 ash - 0.047 OMD) (R²= 0.987) and grass silage (PDIE = 27.7 + 0.083 DMD - 0.147 CP) (R²= 0.812). The PDIE and PDIN values of 11 of the 12 concentrate ingredients were similar to those used in the French Tables but the maize distillers’ grains in this study and those used in France would appear to be quite different products. The response to PDIE and PDIN in the diet of lactating cows was evaluated and the effect of better balancing the PDIE and PDIN supply on the efficiency of N utilisation was assessed. Twenty autumn calving cows were blocked in a complete Latin Square design and assigned to four different diets varying in PDIN and PDIE content. Each of the four treatments consisted of a concentrate, maize silage and grass silage in the proportions 37:38:25 on a DM basis. There were 4 periods of 4-week duration each. Diet A contained 92 g/kg DM of PDIE and 116 g/kg DM of PDIN. Diet B contained 103 g/kg DM of PDIE and 122 g/kg DM of PDIN. Diet C and D over supplied PDIN at 137 g/kg and 153 g/kg, respectively relative to PDIE at 111 g/kg DM. Dry matter intake increased significantly with the excess dietary PDIN relative to PDIE but there were no significant differences in milk yield and composition. Decreasing the supply of PDIE in the diet (i.e. diet A vs. B) resulted in no significant effect on milk or constituent yields but did significantly reduce the efficiency (kg milk / kg DMI) of milk production. There was also a significant reduction in the efficiency of milk produced per kg DMI with increasing dietary concentrations of PDIN and increasing PDIN: PDIE balance (B>C>D). Increasing the dietary PDIN from 122 to 153 g/kg DMI increased urine N (+54%), faecal N (+11%) and plasma urea concentrations (+75%). The results indicate that the optimum concentration of dietary PDI is approximately 103 g/kg DM for cows producing about 35 kg of milk per day. A better balance between PDIE and PDIN supply improves the efficiency of conversion of DM to milk and dietary protein

The Importance of Different On-Farm Feeding and Management Practices on Milk Protein Concentration and Yield

End of Project ReportThe objective of this project was to identify the most important factors which influence milk protein concentrations and yields on farms. Data collected on approximately 300 DairyMis farms were subjected to statistical evaluation by regression analysis, analysis of variance and factor analysis. The range in protein concentrations was 12% of the mean value compared to a variation in protein yield of 86% of the mean. The range in milk yield was 90% of the mean value. Initially data from 1995 were analysed. The regression model used only accounted for 4% of the variation between farms in milk protein concentration but for over 97% of the variation in milk protein yield. Milk protein yield was highly correlated with milk yield. Confining the analysis to Spring-calving herds only in 1995 (n=128) gave similar results but including genetic data in the regression model, for those spring-calving herds for which it was available (n = 36), explained approximately 25% of the variation in protein concentration. Analysis of variance on the spring-calving herd data (for 1994, 1995 and 1996) divided into quartiles on the basis of protein concentration indicated that higher protein concentration was associated with later calving, a higher proportion of milk produced on pasture and lower milk yield per cow. Factor analysis on all herds in 1994, 1995 and 1996 indicated that higher protein concentration was associated with Spring-calving herds, larger herds and with grass based milk production. These three factors accounted for 8% of the observed variation in milk protein concentration