Milk Yield In Dairy Cows Research Articles

Investigation of the effect of pegbovigrastim on some periparturient immune disorders and performance in Mexican dairy herds

This study analyzed the efficacy of pegbovigrastim (Imrestor, Elanco Animal Health, Greenfield, IN) on some health and production parameters in lactating dairy cows. Primiparous and multiparous Holsteins from 17 Mexican dairy herds (n = 10,238) were included in this study, which was conducted in 2015. Treated cows (n = 5,025) received Imrestor approximately 7 d before expected calving and again within 24 h after calving; control cows (n = 5,213) did not receive a placebo. Clinical mastitis (MAS; 0 to 30 DIM), retained placenta (RP), and clinical metritis (MET; 0 to 21 DIM) occurrences were recorded, as well as the number of medication days, medical treatments needed, and the number of days that milk was discarded due to medication administered for disease. Milk yield was measured from calving until 120 d in milk. Imrestor reduced the incidence of MAS by 25%, and the odds ratio of having mastitis in the first 30 d in milk was 35% greater for control cows than for Imrestor cows. Imrestor treatment reduced the number of medical treatments required for MAS by 6%, and less milk was discarded due to medication for MAS as a result of the Imrestor treatment. The incidence of RP was reduced by 4.15% with Imrestor and the odds of cows having RP were 4.6% greater for control than Imrestor treatments, but they did not differ. The MET incidence was increased by 17.1% with Imrestor. The use of Imrestor around parturition increased by 5.8% the odds of inseminating cows during the first 100 d after calving. Imrestor-treated multiparous cows with MAS produced 2.1 kg/d more milk than control cows with MAS during the first 30 d of their lactation. Imrestor-treated multiparous cows with MET produced 2.3 kg/d more milk than MET control cows during the first 120 d of their lactation. We conclude that Imrestor can help the dairy cow cope with immune periparturient disorders and can increase the milk yield of dairy cows due to a healthier transition, despite a reported increase in the incidence of MET.

Reproductive behavior of crossbred dairy cows grazing an intensive silvopastoral system under tropical dry forest conditions

ABSTRACT It is widely accepted that selection for high milk yield in dairy cows has negatively affected their reproductive performance. After calving, dairy cows experience a nutritional imbalance due to an asynchrony in the occurrence of the lactation and dry matter intake peaks. In the tropics, this situation is exacerbated due to poor quality and/ or availability of the diet. A study was carried out to describe the nutritional and reproductive behavior of two-to-four parturition crossbred cows (Gyr (Bos indicus) x Holstein (Bos taurus)) divided in two groups according to their calving to first service interval (CFSI): Group 1: ≤50 days CFSI, n=7; Group 2: ≥50 days CFSI, n=8. Animals were grazing in an intensive silvopastoral system (ISS) based on Leucaena leucocephala and Cynodon plectostachyus and also received protein, energy and mineral supplementation. Dry matter (DMI) and nutrient intake were individually estimated and correlations between reproductive and nutritional parameters were performed. Additionally, serum progesterone concentration was monitored. Group 2 had greater forage and total DMI and milk production than Group 1 (P<0.05). Hence, Group 2 had greater nutrient intake from forages than Group 1 (P<0.05). Group 1 had a positive nutritional balance and an optimum reproductive performance compared to Group 2, which had a negative energy balance and lengthier days with open intervals (P<0.05). It was corroborated that protein and energy are required in adequate levels, to ensure that uterus undergoes involution correctly and ovarian activity starts soon in the postpartum period.

Agentes causadores de mastite e relações entre a CCS com a produção e com a composição do leite em vacas leiteiras

Este estudo teve por objetivo avaliar o efeito da prevalência de patógenos causadores de mastite e da contagem de células somáticas (CCS) sobre a produção e composição do leite. Amostras de leite de 1163 vacas da raça Holandesa com 30.97±10.22 kg·d-1 de produção de leite foram coletadas e avaliadas. Staphylococcus spp. foi o patógeno mais prevalente. No geral, o aumento da CCS reduziu a produção de leite e a concentração de lactose e aumentou a concentração de proteína. Coliformes tiveram uma relação diferente entre CCS e teor de proteína no leite. A relação entre CCS e concentração de lactose foi diferente para S. aureus e Streptococcus spp. Lactose e proteína bruta são os componentes do leite mais sensíveis à variação da CCS e esta relação é dependente da presença do patógeno.

Effect of the inoculation of sugarcane silage with and on feeding behavior and milk yield of dairy cows

Effect of the inoculation of sugarcane silage with and on feeding behavior and milk yield of dairy cows

Feeding values of conventional diets and their effects on the performances of dairy cows in Central Myanmar

The conventional diets have been fed to dairy cows since many years ago in Myanmar, however there is a little scientific information regarding the use of those diets as feed. Therefore, this study was conducted to evaluate the feeding values of conventional diets and their effects on the performances of dairy cows in Central Myanmar. Nine cross-bred Holstein Friesian cows (460±22kg) with the 12th week of lactation were randomly allocated to one of three treatment groups with three replicates in a completely randomized design. The three treatments were Diet-ST (common diet from Sin Tel, Tatar U Township), Diet-MN (common diet from Myay Ngu, Tatar U Township) and Diet-AM (common diet from Amarapura Township). Cows were fed treatments for 60 days. The roughage to concentrate ratios ranged from 53:47 to 72:28 and the nutritive values were significantly different (p<0.05) each other. The highest nutrient intakes were observed in dairy cows fed on Diet-MN, however the nutrient digestibility were not different (p>0.05) except the CP and ether extract digestibility (CPD and EED). The nitrogen utilization was highest in dairy cows fed on Diet-ST and the lowest value was observed in the dairy cows fed on Diet-AM. Although the milk compositions were not different (p>0.05), the average milk yield of dairy cows offered the Diet-MN was significantly higher (p<0.05) than those of dairy cows fed on other diets. The highest total feed cost (p<0.05) was found in Diet-AM and the lowest value (p<0.05) was in Diet-MN. According to these findings, it was concluded that the highest feeding value was observed in Diet-MN and its effect on the performances of dairy cows was also greater than others. Moreover, it would be suggested that better bean residues and sesame residues could be used as fibre sources in the diets of dairy cows.

Effect of leucaena forage and silage substitution in concentrates on digestibility, nitrogen utilization and milk yield in dairy cows

This experiment was conducted to determine the effect of feeding leucaena forage and silage substitution in concentrate on the performances of dairy cows. Nine cross-bred Holstein Friesian cows (410±12kg) in the 12th week of lactation were randomly allocated to one of three treatment groups with three replicates/treatments in a completely randomized design. The three treatments were control diet without substitution of leucaena forage and silage (DLFS0), diet with substitution of leucaena forage 10% (DLF10) and diet with substitution of leucaena silage 10% (DLS10). Cows were fed treatments for 60 days. Although nutrient intakes were not significantly different (p>0.05) each other, digestibility of DLFS0 was significantly higher (p<0.05) than others. Conversely, nitrogen utilization and average milk yield of cows offered DLFS0 were significantly lower (p<0.05) than those of cows fed on DLF10 and DLS10. The highest feed cost (p<0.05) per kg of milk was found in DLFS0 and the lowest cost was observed in DLF10. Therefore, although the leucana forage and silage could be substitute up to 10% of concentrates without adverse effects on the performances of dairy cows, the substitution of leucaena forage gave the better performances than that of leucaena silage.

The Effect of Thermal Environment on Daily Milk Yield of Dairy Cows

Abstract The primary objective of this research was to evaluate the impact of environmental air temperatures on the milk production of dairy cows. Therefore, the experiment was carried out at the height of summer (from 15th of June to 15th of September) in three small family dairy farms and one commercial dairy farm. In total, 51 dairy cows from the black-white breed were subjected to the study. The season of research was divided into three periods: the period before the hot season, the period of the hot season and the period after the hot season. In each period there were three test days selected that were used for recording the air temperature inside and outside the barns and cow’s daily milk yield. Unvaried associations between the test day milk yield of cows and independent environmental and cow factors were done using the linear mixed model for repeated measurements. The statistical model showed that the farm management system and the hot season of the year had significant influence on daily milk yield per cow at the level of p<0.001. The test day per periods of the season when milk control was performed and the average test day environmental temperature showed statistically significant influence on daily milk yield per cow at level p<0.01. The present results revealed that environmental air temperatures contributes to considerable loss in the milk production of dairy cows.

The Effect of the Season on the Behavior and Milk Yield of the Czech Fleckvieh Cows

The aim of this study was to evaluate the seasonal behavior and milk yield of dairy cows of Czech Fleckvieh cattle. The subject of the monitoring was one section (housed in one quarter of barn) with 103 free cubicle beds with an average of 95 lactating dairy cows of Czech Fleckvieh cattle. In the seasons (spring, summer, autumn, winter) temperature (°C), relative humidity (%) and temperature-humidity index (THI) were monitored. Furthermore, behavioral signs were also observed (a total of 4,940 observations): dairy cows were either lying down (3,432 observations) or standing up (1,508 observations). In the conditions that dairy cows were standing up in the cubicle, up to 585 observations were proved. If dairy cows were standing up outside of the cubicle (923 observations), they were either lying on the left side (1,924 observations) or right side (1,508). Significant seasonal influence was found out (p < 0.05) on the number of dairy cows standing up (a maximum of 410 observations in the spring, a minimum of 342 observations in the summer) and then the number of cows lying both on the left (a maximum of 519 observations in the autumn and a minimum of 444 observations in the spring) and on the right side (a maximum of 415 observations in the winter, a minimum of 320 observations in the autumn). The seasonal influence was no significant (p > 0.05) in the remaining behavioral signs. With regard to milk yield, a significant seasonal influence was proved. The highest milk yield was reached with dairy cows in spring (29.27 kg of milk) and the lowest in the autumn (24.58 kg of milk). No significant differences of milk yield were detected between behavioral signs (p > 0.05). The maximum difference of milk yield was found out up to 1.39 kg between dairy cows lying down on the left side (28.35 kg) and the dairy cows standing up in a cubicle (26.96 kg) in the winter but even this difference was not statistically significant (p > 0.05).

Effect of ground corn cobs as a fiber source in total mixed ration on feed intake, milk yield and milk composition in tropical lactating crossbred Holstein cows.

The aim of this study was to evaluate the effect of ground corn cobs (GCC) as a sole fiber source in total mixed ration (TMR) on feed intake, milk yield and milk composition in tropical lactating crossbred Holstein cows. Four multiparous crossbreds Holstein Friesian dairy cows with an initial body weight (BW) of 415.5 ± 26.20 kg were used in a 4 × 4 Latin square design. The dietary treatments of TMR contained a roughage-to-concentrate ratio of 40:60. The roughage source was used at different ratios of GCC to rice straw (RS) at 100:0, 82.5:17.5, 67.5:32.5, and 50:50 for TMR1 to TMR4, respectively. The results revealed significant improvements in intake of dry matter, protein, neutral detergent fiber (NDF) and metabolizable energy (ME) for TMR1 and TMR2 (P < 0.05), while the digestibility of nutrients was not altered by the treatments (P ≥ 0.05). Ground corn cobs was used for up to 100% of the total roughage without affecting milk production. Moreover, ruminal pH, temperature, ammonia-nitrogen (NH3—N) and volatile fatty acid (VFA) concentrations were not impacted by the treatments (P > 0.05). However, milk yield was significantly different among the GCC:RS ratios (P < 0.05) and was the highest in TMR1 and TMR2 (13.1 kg/d), while the milk compositions were not changed (P > 0.05). The results imply that using GCC as a whole roughage source significantly improved nutrients intake and milk yield in dairy cows raised in tropical areas.

Effect of substituting dry corn with rehydrated ensiled corn on dairy cow milk yield and nutrient digestibility

The purpose of the present study was to evaluate the effect of substituting dry corn with rehydrated ensiled (90days) corn (REC) in dairy cow diets on the nutrient intake, total tract apparent digestibility, and milk yield and composition. Twelve Holstein cows, with an average of 550 (±30 SD)kg of body weight and 220 (±40 SD) days in milk (DIM), were allocated in three 4×4 contemporary Latin squares, organized in 4 periods composed of 14days for dietary adaptation and 7days for sample and data collection. Cows were fed diets formulated to be isoenergetic (6.489MJNEL/kg DM; dry matter) and isoproteic (150g CP/kg DM). Ensiled sugar cane (460g of DM/kg) was used as forage, and concentrated feed had four substitution levels (0, 33, 66 and 100%) of dry corn by REC. Increased inclusion of REC in substitution of dry corn caused increase of intake of DM, crude protein (CP) and non-fiber carbohydrates (NFC). On the other hand, intake of NDF decreased quadratically with increasing inclusion of REC. The total tract apparent digestibility of DM, OM, CP, ether extract, starch and NFC were linearly increased by 5.4–8% in diets with total substitution of dry corn with REC. Increased inclusion of REC in the diet also increased linearly milk and 3.5% fat-corrected milk yield, and fat, protein, lactose and total solids yield. In conclusion, the substitution of dry corn with REC increases milk production (by 2.1L/cow/day) and apparent total digestibility of starch (by 8 percentage points) in late-lactation dairy cows.

Effect of Complete Feed Silage Made from Agricultural Waste on Milk Yield and Quality of Dairy Cows

The problem facing dairy cow producers in tropical area is the low availability of proper nutrition, especially during the dry season. One solution to overcome this problem is to utilize technology of Complete Feed (CF) silage using ensiled several local abundant ingredients from agricultural wastes. This study aimed to find a formulation of CF silage from agricultural wastes as forage substitution for dairy cows to increase yield and quality of the milk. The study was conducted on dairy farms in Enrekang District, South Sulawesi of Indonesia. The formulations of CF silage used in the study were tested both in vitro and in vivo and compared with the farmer's practices that using elephant grass plus rice bran. A total of 20 Holstein Friesian dairy cows in 4-5 months lactation with a lactation period of 3rd-5th were used for in vivo study. The treatments were Elephant Grass + Rice Bran (EG-RB), Elephant Grass + Concentrate (EG-CON), Complete Feed Silage made from straws (CF-S) and complete feed silage made from straws and vegetable wastes (CF-VW). The results of this study showed that the dry matter intake and milk yield of dairy cow were higher in EG-CON, CF-S and CF-VW compared to EG-RB and were not different among EG-CON, CF-S and CF-VW. The crude protein, lactose, calcium and phosphorus of the milk were higher in the EG-CON, CF-S and CF-VW than EG-RB and were not different among EG-CON, CF-S and CF-VW. Fat content, density and pH of the milk were not different among treatments. In conclusion, in order to maintain and to improve the yield and quality of milk in dairy cows, the agriculture wastes, such as straws and vegetable wastes can be used as the basal feed of dairy cows for fodder substitution in the form of CF silage.

Effect of Hoof Trimming on Milk Yield in Dairy Cows with Foot Disease

Backround: Milk is produced at the cost of other metabolic processes in the body and high milk yield has been associated with lameness and claw lesions. Lameness has also been associated with a decrease in milk yield. In the past, claw disorders and lameness in dairy cattle have been an increasing problem of the modern dairy industry. Hoof trimming is performed to prevent hoof lesions and improve gait by correction and maintenance of the hoof symmetry and shape. Lameness caused by hoof disorders can be treated by correct hoof trimming. The aim of this study was to test the hypothesis that one-time claw trimming affect the milk production in dairy cattle with hoof disorders on commercial dairy farms.Materials, Methods &amp; Results: Milk yield level was examined before and after claw trimming in dairy cattle. Eighteen Holstein dairy cows were examined on a commercial dairy farm. Calving number, calving time, lactation number, lactation stage, culling date and milk yield in liters were detected from farm recording system. All cows were visual signs of claw disorders or lameness. Their hooves had not been were trimmed for several years. Trimming technique included leveling the 2 claws, aiming for symmetric bulbs. The axial and abaxial walls were both intended to be parts of the bearing surface and the 2 claws were trimmed flat and balanced with each other. The caudal two-thirds of the axial sole of both claws were sloped toward the interdigital area. All of the cows checked for hoof diseases. The period of observation spanned 45 d, starting day of claw trimming. The observation period was the lactation when the claw trimming was performed. Milk yield was performed one day before and 10, 30, and 45 days after hoof trimming. Cows that were in the mid to late lactation period were selected for the study. The mean days in milk for the group was 221.8 (150-272 days) and the mean number of calvings was 2.8 times (range: 2-5 times) before trimming.Discussion: The shape of the lactation curve is influenced by herd factors such as management and nutrition and individual factors like genetics, parity, and disease. Discrepancies in the literature with regard to the effect of lameness and claw lesions on milk yield are partly the result of these complex influences. Daily milk production of cows in the current study averaged 21 L/d, so milk weight represented approximately 3% of a cow’s body weight per milking. In this study cows were 2 to 5th lactation. Most hoof diseases are accrued around the time of calving. Hoof diseases is becomed visible on the bearing surface of the sole after 2 to 3 months such as white-line disease, sole ulcer, and hemorrhages. We assessed milk yield as the one time claw trimming performed, so any possible healing effect of claw trimming could have led to an underestimation of any negative effects of bad claw health on milk production. Cows with painful claw lesions eat less, are more reluctant to move, and might consequently produce less milk than cows without claw lesions. The significant associations between most claw disorders and increased yield in this study do not prove direct relationships. At claw trimming, the average lactation stage in first parity was 148 DIM; 25% of the cows were before 74 DIM and 25% were later than 226 DIM. After the claw trimming between days 10-30 and 10-45 were determined differences in milk yield (P &lt; 0.05; P &lt; 0.01). In conclusion, this study showed that one time hoof trimming during the lactation period changed the milk yield of the dairy cows with hoof diseases.

Effect of replacing organic grass-clover silage from primary growth with regrowth on feed intake and milk yield of dairy cows

Under Norwegian conditions, diets based on primary growth (PG) silage typically increase milk yield compared to silage prepared from the regrowth (RG). Organic PG, dominated by immature grasses, is often high in energy and low in crude protein (CP), whereas the opposite is the case for organic RG harvests, dominated by clover. Here, we tested the hypotheses that increasing proportions of RG will reduce the total supply of metabolizable energy, but increase the CP intake, and that there is a dietary optimal mix of PG and RG to meet requirements for optimal milk production. Sixteen Norwegian Red cows were used in an experiment designed with four balanced 4 × 4 Latin squares with 21-day periods to evaluate the effect of incremental replacement of PG with RG on feed intake, nutrient digestion, and milk production. Silages were prepared from PG and RG of an organically managed grassland. Treatments comprised silages fed ad libitum with RG replacing PG in ratios of 0, 0.33, 0.67, and 1 on dry matter (DM) basis. Additionally, concentrate was offered with 8 kg for pluriparous and 7 kg for primiparous cows. The PG had higher content metabolizable energy (ME), potentially degradable neutral detergent fiber (NDF), and water-soluble carbohydrates, while RG contained more CP and indigestible NDF. The already mentioned characteristics led to higher intakes of DM, organic matter, NDF, and ME and lower intakes of CP and indigestible NDF with increasing proportions of PG in the diet. Milk yield tended to be higher when PG and RG were offered as a mixture than when fed alone. The milk fat concentration decreased linearly with increasing proportions of RG proportion, while protein concentration was unaffected by diet. This led to a similar production of energy-corrected milk among cows fed diets containing PG while cows fed pure RG diet produced 0.9 kg less daily. Silage energy concentration and energy intake influenced milk production more than CP supply.

Digestibility of NDF and its effect on the level of rumen fermentation of carbohydrates

DOI: 10.15414/afz.2015.18.04.110–113 Received 14. July 2015 ǀ Accepted 12. October 2015 ǀ Available online 7. December 2015 The objective of this study, was to determinate the effects of digestibility of NDF of TMR on rumen fermentation characteristics and nutrient digestion, dairy cows were fed total mixed ration (TMR). We are measured NDF digestibility of TMR using in situ methods.Digestibility of NDF of TMR in our experiment range 26.8 to 48.2%. Digestibility of NDF of TMR did not alter VFA production but had effects on A/P ratio and production of acetate and propionate. Our results indicate that TMR with more dNDF may provide more favourable condition for nutrient digestion both in the rumen and in the total tract of dairy cows. Keywords : rumen, fermentation, NDF, volatile fatty acids, digestibility of NDF References ALLEN, M. S., BRADFORD, B. J. and OBA, M. (2009) BOARD-INVITED REVIEW: The hepatic oxidation theory of the control of feed intake and its application to ruminants. In J. Anim. Sci., vol. 87, no. 10, pp. 3317–3334. doi:http://dx.doi.org/10.2527/jas.2009-1779 BEEVER, D. E. and MOULD, F. L. (2000) Forage evaluation for efficient ruminant livestock production. In: D. I. Givens et al. (eds.) Forage Evaluation in Ruminant Nutrition. Wallington: CAB International. HOFFMAN, P.C. and SHAVER, R.D. (2009) UW-Feed Grain Evaluation System Marshfield Soil and Forage Analysis Laboratory. [Online] Available at: http://www.uwex.edu/ces/dairynutrition/documents/ WisconsinFGES.pdf. [Accessed? 2015-06-04]. HUTJENS, M. F. (2002) Is your TMR as good as it can be? In Hoard´s Dairyman, vol. 147, no. 18, pp. 698. CHUMPAWADEE, S. and PIMPA, O. (2009) Effect of fodder tree as fiber sources in total mixed ration on feed intake, nutrient digestibility, chewing behaviour and ruminal fermentation in beef cattle. In J. Anim. And Vet. Adv, vol. 8, no. 7, pp. 1279:1284. doi: http://dx.doi.org/2009.1279.1284 KOLVER, E. S. and DE VETH, M. J. (2002) Prediction of ruminal pH from pasture based diets. In J. Dairy Sci., vol. 85, no. 5, pp. 1255–1266. doi:http://dx.doi.org/10.3168/jds.S0022-0302 (02)74190-8 LINN, J.G. et al. (1989) Feeding the dairy herd. Madison: North Central Regional Extension. LOPEZ, S., J. DIJKSTRA, and FRANCE, J. (2000) Prediction of energy supply in ruminants, with emphasis on forages. In: D. I. Givens, E. Owens, R. F. E., Axford, and H. M. Omed, (eds.) Forage Evaluation in Ruminant Nutrition. Wallingford: CAB International, pp. 63-94. NRC (2001) Nutrient requirements of dairy cattle: Nutrient requirements of domestic animals. 7th revised edition. Washington: National Reserach Council. OBA, M. and ALLEN, M. S. (1999) Evaluation of the importance of the digestibility of neutral detergent fiber from forage: effects on dry matter intake and milk yield of dairy cows. In J. Dairy Sci., vol. 82, no. 3, pp. 589-596. doi:http://dx.doi.org/10.3168/jds.S0022-0302(99)75271-9 OBA, M. and ALLEN, M. S. (2000) Effects of brown midrib 3 mutation in corn silage on productivity of dairy cows fed two concentrations of dietary neutral detergent fiber: 3. Digestibility and microbial efficiency. In J. Dairy Sci., vol. 83, no. 6, pp. 1342–1349. doi: http://dx.doi.org/10.3168/jds.S0022-0302(00)75001-6 ORSKOV, E.R. and MCDONALD, I. (1979) The estimation of protein degradability in the rumen from incubation measurements weighed according to rate of passage. In J. Agric. Sci., vol. 92, no. 3, pp. 499-503. doi:http://dx.doi.org/10.1017/S0021859600063048 VARGA G.A. (2006) In vivo digestibility of forage. In: Proc. Tri-State dairy nutrition conference, Fort Wayne. Columbus: The Ohio State University, pp 95-106. VOELKER LINTON., J. A. and ALLEN, M. S. (2009) Nutrient demand interacts with forage family to affect N digestion and utilization responses in dairy cows. In J. Dairy Sci., vol. 92, no. 4, pp.1594-1602. doi:http://dx.doi.org/10.3168/jds.2008-1327

Effect of a phase I Coxiella burnetii inactivated vaccine on body temperature and milk yield in dairy cows

Q fever is a zoonotic disease caused by Coxiella burnetii. The pathogen is prevalent in ruminants (goats, sheep, cows), which are the main sources of human infection. In the cattle industry around the world, animal (15 to 20%) and herd (38 to 72%) level prevalences of C. burnetii are high. Vaccination of ruminants against Q fever is considered important to prevent spreading of the disease and risk of infection in humans. However, published information on side effects of the Q fever vaccination under field conditions is limited for cows. The objective of this study was to investigate the effect of the phase I C. burnetii inactivated vaccine Coxevac on body temperature and milk yield in dairy cows. In 2 experiments, a total of 508 cows were randomly divided into 2 groups to determine the effect of first vaccination on body temperature and milk yield. The C. burnetii serostatus of all cows was tested before vaccination with an indirect ELISA. The first experiment took place in the teaching and research barn of the Clinic of Animal Reproduction at the Freie Universität Berlin. Temperature was measured vaginally in 10 cows in a crossover design. The second experiment was conducted on a commercial dairy farm. Milk yield of 498 cows was measured 1 wk before and 1 wk after vaccination. In a subset of 41 cows, temperature was measured rectally. In both experiments, body temperature increased significantly after vaccination (1.0±0.9°C and 0.7±0.8°C). A significant difference was also found in body temperature between vaccinated and control cows. Thirty percent of the vaccinated animals in experiment 1 showed reversible swelling at the injection site as a reaction to the vaccination. The results indicate that vaccination against Q fever causes a transient increase of body temperature that peaks in the first 12 to 24h and declines after that. In experiment 2, vaccinated cows (26.8±0.39kg/d) produced significantly less milk than did control cows (28.2±0.44kg/d) 7d after first vaccination. The cumulative milk loss after first vaccination was influenced by an interaction between C. burnetii serostatus and average milk yield 7d before first vaccination. This was considered as part of the physiological immune response. Three out of 10 vaccinated animals in experiment 1 showed painful swelling of the skin at the injection site, which had a maximum size of 14.0×14.0×1.1cm. In conclusion, a transient increase of body temperature and a decrease in milk yield is prevalent after Coxevac vaccination.

In vivo inhibition followed by exogenous supplementation demonstrates galactopoietic effects of prolactin on mammary tissue and milk production in dairy cows

It has been previously shown that the long-term inhibition of milking-induced prolactin (PRL) release by quinagolide (QN), a dopamine agonist, reduces milk yield in dairy cows. To further demonstrate that PRL is galactopoietic in cows, we performed a short-term experiment that used PRL injections to restore the release of PRL at milking in QN-treated cows. Nine Holstein cows were assigned to treatments during three 5-d periods in a 3×3 Latin square design: 1) QN: twice-daily i.m. injections of 1mg of QN; 2) QN-PRL: twice-daily i.m. injections of 1mg of QN and twice-daily (at milking time) i.v. injections of PRL (2µg/kg body weight); and 3) control: twice-daily injections of the vehicles. Mammary epithelial cells (MEC) were purified from milk so that their viability could be assessed, and mammary biopsies were harvested for immunohistological analyses of cell proliferation using PCNA and STAT5 staining. In both milk-purified MEC and mammary tissue, the mRNA levels of milk proteins and BAX were determined using real-time reverse-transcription PCR. Daily QN injections reduced milking-induced PRL release. The area under the PRL curve was similar in the control and PRL injection treatments, but the shape was different. The QN treatment decreased milk, lactose, protein, and casein production. Injections of PRL did not restore milk yield but tended to increase milk protein yield. In mammary tissue, the percentage of STAT5-positive cells was reduced during QN but not during QN-PRL in comparison with the control treatment. The percentage of PCNA-positive cells was greater during QN-PRL injections than during the control or QN treatment and tended to be lower during QN than during the control treatment. In milk-purified MEC, κ-casein and α-lactalbumin mRNA levels were lower during QN than during the control treatment, but during QN-PRL, they were not different from the control treatment. In mammary tissue, the BAX mRNA level was lower during QN-PRL than during QN. The number of MEC exfoliated into milk was increased by QN injections but tended to be decreased by PRL injections. Injections of PRL also increased the viability of MEC harvested from milk. Although PRL injections at milking could not reverse the effect of QN treatment on milk production, their effects on cell survival and exfoliation and on gene expression suggest that the effect of QN treatment on the mammary gland is due to QN’s inhibition of PRL secretion.

Extruded soybean meal increased feed intake and milk production in dairy cows

The objective of this study was to assess the effects of 2 extruded soybean meals (ESBM) processed at 2 extruder temperatures, 149°C (LTM) and 171°C (HTM), on performance, nutrient digestibility, milk fatty acid and plasma amino acid profiles, and rumen fermentation in lactating dairy cows. Nine multiparous Holstein cows were included in a replicated 3×3 Latin square design experiment with three 28-d periods. The control diet contained 13% solvent-extracted soybean meal (SSBM; 53.5% crude protein with 74.1% ruminal degradability and 1.8% fat), which was replaced with equivalent amount (dry matter basis) of LTM (46.8%, 59.8%, and 10.0%) or HTM (46.9%, 41.1%, and 10.9%, respectively) ESBM in the 2 experimental diets (LTM and HTM, respectively). The diets met or exceeded the nutrient requirements of the cows for net energy of lactation and metabolizable protein. The 2 ESBM diets increased dry matter intake and milk yield compared with SSBM. Feed efficiency and milk composition were not affected by treatment. Milk protein yield tended to be increased by ESBM compared with SSBM. Milk urea N and urinary urea N excretions were increased by the ESBM diets compared with SSBM. Concentration of fatty acids with chain length of up to C17 and total saturated fatty acids in milk fat were generally decreased and that of C18 and total mono- and polyunsaturated fatty acids was increased by the ESBM diets compared with SSBM. Blood plasma concentrations of His, Leu, and Val were increased by HTM compared with LTM and SSBM. Plasma concentration of Met was decreased, whereas that of carnosine was increased by the ESBM diets. Treatments had no effect on rumen fermentation, but the proportion of Fibrobacter spp. in whole ruminal contents was increased by HTM compared with SSBM and LTM. Overall, data from this crossover experiment suggest that substituting SSBM with ESBM in the diet has a positive effect on feed intake and milk yield in dairy cows.

Effect of oral mineral and energy supplementation on blood mineral concentrations, energetic and inflammatory profile, and milk yield in dairy cows affected with dystocia

The objectives of this study were to determine the effect of mineral/energy supplementation of dairy cows with dystocia on blood mineral concentrations, energetic and inflammatory profiles, and milk yield. Multiparous Holstein cows with dystocia were randomly assigned into two groups, (1) treated with a mineral/energy supplement (DME, n = 18) and (2) not treated (DNT, n = 22). A group of cows with normal parturition were randomly selected and were left untreated (NNT, n = 25). Cows in DME received an oral drench of 110 g of calcium and 400 g of propionate as calcium propionate plus 110 g potassium chloride and 150 g of magnesium sulfate administered within 6 h of calving and again 3 days post-partum.Compared to cows with a normal parturition, dystocic cows had decreased plasma calcium concentrations, increased plasma haptoglobin, decreased milk yield at 1 day post-partum, and tended to have increased rectal temperatures from 1 to 12 days post-partum. Compared with cows in DNT, those in DME had decreased plasma calcium concentrations and increased plasma magnesium concentrations 2 and 3 days post-partum, and a tendency for an increase in rectal temperature from 1 to 12 days post-partum. Dystocia is detrimental to calcium homeostasis post-partum, but mineral/energy supplementation as undertaken in this study is not recommended for use in cows with dystocia.

Effect of organic sources of minerals on fat-corrected milk yield of dairy cows in confinement

This study evaluated the effects of organic and inorganic sources of minerals in diets for mid-lactation dairy cows on milk yield and composition, intake and total apparent digestibility of dry matter and nutrients, blood parameters, microbial protein synthesis, and energy and protein balances. Twenty Holstein cows averaging 146.83±67.34 days in milk and weighing 625.30±80.37 kg were used. The experimental design was a crossover. Diets were composed of corn silage (50%), ground grain corn, and soybean meal, differing with regard to the sources of trace minerals, plus an organic and inorganic mix. The organic mineral source increased milk fat and fat-corrected milk yield without changing milk yield, intake, or total apparent digestibility. Blood parameters, microbial protein synthesis, and energy and protein balances were not affected by the sources of minerals. Organic sources of minerals improve milk fat yield without affecting other parameters.

Effects of Mycotoxin Sequestering Agents Added Into Feed on Health, Reproduction and Milk Yield of Dairy Cattle

Effects of mycotoxin sequestering agents in feed on health, reproduction and milk yield of dairy cattle were studied in a 5-month long experiment on 300 dairy cows divided into two groups and six subgroups. The experiment was conducted in adding a mycotoxin sequestering agent based on 1,3 and 1,6 β-glucans to standard cattle nutrition (TMR), which was regularly tested for content of important mycotoxins, in order to gain knowledge about possible positive effect of this agent on the health of dairy cattle and about possible avoidance of negative effects of mycotoxins on dairy cattle due to their structural elimination caused by the agent. The experiment’s setting and conditions during it were in all aspects common and comparable within the European Union, the experiment’s results should be therefore seen as relevant. Health, pregnancy rate and milk yield were carefully monitored during the experiment. Indicators of state of health (occurrence of mastitis and somatic cell count in milk) did not show any significant differences between test and control groups of dairy cows. The average milk yield of dairy cows which were fed the agent enriched feed (30.2 kg a day) was slightly lower in comparison to control groups (31 kg a day, both results with P &lt; 0.001), however, fat content of milk of test groups’ cows (4.02%) was considerably higher than that of control groups’ cows (3.79%). The average pregnancy rate of cows which were fed the agent enriched feed also manifested considerable increase in percentage and stability (from 42.95% of control groups’ cows to 62.25% of test groups’ cows, the standard deviation decreased from 21.1% to 14.4% which means smaller differences among pregnancy rate of test groups’ cows, hence higher stability), this increase manifested even long after the cows had been fed regular feed again.