Days For Cows Research Articles

Productive response of dual-purpose cows supplemented with chelate minerals and calcium salts

Objective: To evaluate milk production, body condition and ethological behavior of grazing cows supplemented with chelated minerals and calcium salts, in dry tropical conditions. Design/methodology/approach: Two treatments were evaluated, T1 = Base feeding (grazing + 4 kg of concentrated feed cow-1 day-1 (CF); T2 = CF + 300 g cow-1 day-1 of nucleus (chelated minerals + calcium salts) (N). Milk production data were evaluated during 32 days in four periods of seven days, the body condition at the beginning, 15 and 30 days after the evaluation, and the ethological behavior of the cows. Results: In cows supplemented with nucelus, milk production increased 19.9% (P ≤ 0.05); body condition improved 0.5 units, there was no difference in grazing time (P>0.05) and rumination time was longer (P ≤ 0.05). Limitations on study/implications: The response to reproductive variables was not assessed in this study/reproductive activity is likely to improve in response to improved body condition. Findings/conclusions: By supplementing dual-purpose cows in the first third of lactation with chelated minerals and calcium salts, milk production increases, and body condition and rumination time improve.

Economic analysis of high-oleic soybeans in dairy rations

We evaluate the potential economic impact of using high-oleic soybeans (HOS) in dairy rations based on a synthesis of results from 5 prior feeding trials. Milk Income Less Feed Costs (MILFC) per cow per day is calculated based on assumed increases in milkfat production and increased cost of rations including HOS. Impacts of changes in MILFC are evaluated for herds with different numbers of milking cows, and the total volume of HOS required to support different proportions of US dairy cows is calculated. A dynamic supply chain model assesses the potential market impacts of increases in butterfat supply. The increase in milkfat from the substitution of 5% of ration dry matter with whole HOS (1.4 kg cow-1 day-1) has the potential to increase MILFC by up to $0.27 cow-1 day-1, or an increase the average value of milk by $0.29/45.4 kg for a cow producing 41 kg /day. Changes in MILFC are highly correlated with the price of butter but were positive for butter prices observed from January 2014 to September 2020. HOS impacts on MILFC suggest the potential for increases in farm profitability of $33,000 per year for a dairy feeding 500 milking cows. Scaled-up use of HOS by US dairy farmers would increase butterfat supplies and lower the butterfat price to a small extent, but these aggregated effects do not offset the positive impacts of MILFC at the farm level.

The climate and its implications for milk production in the Brazilian cerrado

Objective. To analyze the climate in the last thirty years in the Northwest of Minas and its impacts on dairy production. Materials and Methods. The database of the National Institute of Meteorology was used during the period from 1985 to 2017 in the cities of Unaí, Paracatu, Arinos and Formoso/MG. For each month and year, the average minimum temperature (Tmin), maximum temperature (Tmax), relative humidity (RH), Temperature and Humidity Index (THI), Wet-bulbe Globe Temperature Index (WBGT), estimate of the decrease in milk production (DMP) and DMP on critical days (DMPc) were calculated. Results. The results were evaluated using the lm function of R, and the t test to test the null hypothesis that the regression coefficient was equal to zero with a significance level of 5%. An increase in Tmax and Tmim values by 0.6-0.9°C respectively was observed. The THI and WBGT values in the municipalities show states of danger and emergency. The DMP obtained were 2.8 kg cow-1 day-1 (Paracatu and Formoso), 3.2 kg cow-1 day-1 in Unaí and between 3.7 and 4.6 kg cow-1 day-1 in Arinos. Conclusions. It is verified that the thermal condition in the studied cities is outside the considered thermoneutral zone, being necessary primary and secondary environmental modifications to guarantee the welfare of the animals and satisfactory livestock indexes.

​​Qualitative Analysis of Apple Pomace based Maize Silage for Animal Feeding

Background: Himachal Pradesh is one of the important apple producing state in India and a substantial quantity of apple fruit is utilized in processing for the preparation of juice and the left-over apple pomace remains a pollutant owing to the un-hygienic nature of apple pomace and its quick bio-degradability. Only a small fraction of apple pomace is traditionally being utilized in animal feeding due to the rapid spoilage of the wet pomace. The utilization of apple pomace in animal feeding remains a challenge and thus an attempt was made to ensile the maize through incorporation of apple pomace. Methods: The study was conducted to evaluate the nutritive value of maize silage incorporated with different levels of apple pomace and to study the effect of feeding silage on milk performance of crossbred cows. In the experiment apple pomace was incorporated in maize silage at 10, 20 and 30 per cent level. Result: On studying the proximate composition of different silage it was found that silage (T3) containing 80 per cent maize, 10 per cent apple pomace and 10 per cent mulberry leaves showed promising results. In T3 the proximate principles viz. dry matter, crude protein, crude fibre, ether extract, neutral detergent fibre acid detergent fibre, total ash, acid insoluble ash and pH were in ideal range and was at par with the silage formed by ensiling of sole maize crop. In the animal feeding trial, on feeding of apple pomace based maize silage 10.21 per cent higher milk yield was recorded with significantly higher milk fat, SNF and proteins. The net return on feeding of apple pomace based maize silage to crossbred cows was ₹ 149.00 which was higher than the control group (₹143.00 cow-1 day-1).

Dairy herd production aspects of family farms in Western Amazon, Brazil

This study aimed to evaluate the production parameters of herds in 100 dairy family farms in the mesoregion of the Acre Valley, in Western Amazon, Brazil. To this end, the farms were divided into two levels of milk production. Data were collected from March to June 2016, using a 248-question semi-structured form and on-site observations. The information was recorded in SPSS® spreadsheets. Dairy farmers were divided into two clusters known as "high production cluster" (1,755.65 L ha-1 yr-1) and "low production cluster" (492.75 L ha-1 yr-1), using the K-means non-hierarchical method. Descriptive statistics was used and, with the aid of the multivariate cluster analysis, cattle ranchers were divided into the two clusters (high and low production). The results showed that the high-production cluster had larger total milk production (L milk cow-1 day-1) and family income within smaller areas and using less workforce. The farmers in this group also used more ear tags for cattle identification and more technologies such as electric fence and artificial insemination at a fixed time. We concluded that family farms should improve their management and receive technical assistance to strengthen their weaknesses in dairy-cow health and reproduction systems. Moreover, milk yield in these dairy farms should be improved to increase profitability of farmers.

Milk Fatty-Acid Profile after Feeding Increasing Doses of a Mixture of Soybean and Linseed Oils to Pasture Dairy Cows

The goal was to determine the effect of growing intake of a mixture (75:25) of soybean (SoOi) and linseed (LiOi) oils on milk production and composition and milk fatty-acid (MF-A) profile in grazing dairy cows. Twenty-four Holstein cows were assigned to 4 treatments in a completely randomized design with three weeks of adaptation to oil doses and one week of experimental measurements. On a dry matter (DM) basis, cows were fed pasture (63%), energy concentrate (37%) and the SO-LO oil mixture at zero (Tr0%), 2% (Tr2%), 4% (Tr4%) and 6% (Tr6%) of total DM intake equivalent to 0, 0.36, 0.72 and 1.08 kg/cow/day of the oil mixture. The oil mixture was manually mixed-up to the concentrate (7.04 kg DM cow/day) and supplied by halves during each milking time without refusals. Pasture (P = 0.49) and total DM intakes (P = 0.31) were similar between treatments averaging 11.27 and 18.85 kg DM cow-1 day-1 respectively. Milk output (22.71 kg/cow/day) was not affected (P = 0.46). Milk fat content reduced linearly (P < 0.05) from 3.20 (Tr0%) to 2.67 g 100 g-1 (Tr6%) without effects (P = 0.73) on fat or fat corrected milk (4%FCM) yields. Milk protein concentration (P < 0.56) or yields (P < 0.11 were not affected. Lactose contents tended (P < 0.08) to be higher in oil supplemented cows and milk urea nitrogen was not affected (P = 0.14). The basal (Tr0%) concentration (g /100 g MF-A) of totaly hypercholesterolemic MF-A (C12:0, C14:0 and C16:0) of milk averaged 38.93 and decreased linearly (P < 0.0001) with oil intake to 37.81 (Tr2%), 31.59 (Tr4%) and 29.18 (Tr6%). Levels of elaidic (trans-9 C18:1) and trans-10 C18:1 MF-A resulted low-slung in the basal (Tr0%) milk (0.21 and 0.20 g/100g MF-A, respectively) but increased linearly (P < 0.0001) after oil intake reaching the maximum values at Tr6% (0.73 and 2.23 g/100g MF-A, respectively). Milk concentration (g/100g MF-A) of vaccenic acid (trans-11 C18:1, VA) averaged 3.63 in Tr0% and increased linearly (P < 0.0001) with oil intake reaching 4.97, 7.05 and 8.38 in Tr2%, Tr4% and Tr6%, respectively. Basal concentration of rumenic acid (cis-9. trans-11 C18:2, RA) was 2.28 g/100g MF-A and increased linearly (P < 0.0001) with increased oil dose resulting in maximal plateau in Tr4% (3.88) and Tr6% (3.89). The basal atherogenic index (AI) of milk was 1.87 and linearly decreased (P < 0.01) to 1.64 (Tr2%), 1.18 (Tr4%) and 0.95 (T6%) after oil intake. The basal Ω6/Ω3 ratio (3.57) was no different (P > 0.05) from T2% (3.37) but was upper (P < 0.05) in Tr4% (4.41) and Tr6% (4.63) remaining under the recommended value of 5:1. Taken together the results suggest that feeding a blend (75:25; SoOi:LiOi) of SiOi an LiOi oils at 4% of total DM intake to pasture dairy cows maximize the milk RA content with a concomitant decrease in the hypercholesterolemic MF-A of milk maintaining a beneficial for health Ω6/Ω3 ratio with low levels of the detrimental trans-9 C18:1 and trans-10 C18:1.

Effects of Area Specific Mineral Mixture (ASMM) Supplementation on Production and Reproductive Parameters of Crossbred and Desi Cows: A Field Study

A field study was conducted to evaluate the effects of supplementation of area specific mineral mixture (ASMM) on the production and reproductive performance of cows. 16 animals of both crossbred and desi cows each were evaluated for production and reproduction performances. In all treatment groups (n=8), ASMM was supplemented @ 50 g cow-1 day-1 and @ 30 g cow-1 day-1 to crossbred and desi cows respectively. The control groups (n=8) of each experiment were without ASMM supplementation. In case of productive performance, milk production and milk composition parameters were studied for a period of 90 days of lactation where as dissolution of common reproductive disorders were screened for reproductive performance. Average daily milk yield in the crossbred cows supplemented with ASMM on 90th day and 120th day were 7.72 ± 0.19 L cow-1 and 7.52 ± 0.12 L cow-1 in contrast to 5.96 ± 0.14 L cow-1 and 5.63 ± 0.21 L cow-1 in the control group. Similarly average daily milk yield in the desi cows supplemented with ASMM on 90th day and 120th day were 4.17 ± 0.09 L cow-1 and 3.70 ± 0.08 L cow-1 in contrast to 3.06 ± 0.03 L cow-1 and 2.92 ± 0.04 L cow-1 in the control group. No significant supplemental effects on the milk composition parameters in all the groups were found. First postpartum estrus and number of AI per conception were lesser but conception rates were higher in both crossbred and desi treatment groups compared to respective control groups. It can be concluded that continuous supplementation of area specific mineral mixture enhanced the productive and reproductive efficiency of both crossbred and desi cows.

Productive and nutritional aspects of forages oats and barley alone and consociated to vetch in high Andean conditions

Forage grasses, such as oats and barley are the most common and cheap source of nutrients for ruminants in the high Andean region. Therefore, information about productivity and chemical composition of these forages are important in the high Andean region. Results indicate that forage oats cultivated at an altitude between 4200 and 4400 meters above sea level produced 30.0 t ha-1 of fresh matter (FM) or 5.0 t ha-1 of dry matter (DM) and 0.7 t ha-1 of crude protein (CP). The crude protein (CP) of oats allows covering the maintenance, pregnancy, or lactation requirements. For the case of barley, the productivity was 35.3 t ha-1 of fresh matter (FM) or 9.4 t ha-1 of dry matter (DM) and 0.8 t ha-1 of crude protein (CP) allowing a milk production of 8 kg cow-1 day-1. Regarding associations, the association of oat variety Tayko and vetch in a ratio of 75:25 performed better than other associations, resulting in a production of 58.5 t ha-1 of FM or 16.3 t ha-1 of DM and 0.76 t ha-1 of CP. The association of oat variety Mantaro 15 and vetch in a ratio of 50:50 (7.43% CP) enables milk production of 5.5 kg cow-1 day-1. Forage oats and barley are good sources of energy for ruminants due to the neutral detergent fiber concentration (46.70 and 51.76% respectively).

Improving Concentration of Healthy Fatty Acids in Milk, Cheese and Yogurt by Adding a Blend of Soybean and Fish Oils to the Ration of Confined Dairy Cows

Compared to pasture based sistems, milk produced in confined dairy systems is characterized by a high saturated fat (SF) content with a lower concentration of healthy fatty acids (FA) such as vaccenic (VA, trans-11C18:1), conjugated linoleic cid (cis-9, trans-11 C18:2, CLA), α-linolenic (cis-9, cis-12, cis-15C18: 3), eicosapentaenoic (EPA, C20:5) and docosahexaenoic (DHA, C22:6) whose presence in milk and dairy products can be increased by feeding polyunsaturated FA (PUFA). The aim of the study was to determine the differences in milk composition and FA profile between a regular (Reg) milk (Reg-Milk), a Reg-Dambo type cheese (Reg-DCh) and a Reg yogurt (Reg-Yog) with that obtained after including a blend (7:1) of soybean (SO) and fish (FO) oils in the total mixed ration (TMR) of lactating dairy cows. The experiment was carried out at the Talar Farm located at Laguna del Sauce, Maldonado Department, Punta del Este, Uruguay Republic during a period of 30 experimental days using a single production batch of 29 Holstein cows. Within this batch, one group of 8 cows (1.88 ± 0.99 calves) in early lactation (135 ± 19 days postpartum) was selected to individually measure milk yield and composition. During the first 7 days of the experiment, cows were fed a TMR without oil-blend inclusion to obtain the Reg-Milk, Reg-DCh and Reg-Yog. From the 8th day onwards, the oil blend was added to the TMR at 4% DM (1.0 kg oil blend cow-1 day-1) and after 23 days of feeding, the modified milk (Mod-Milk) was analyzed and collected to elaborate the modified Dambo-type cheese (Mod-DCh) and Mod-yogurt (Mod-Yog). Milk yield was recorded daily in the selected 8 cows and milk composition was determined over two consecutive days prior to the start of blend-oil supply (Reg-Milk) and at the end of oil supplementation (Mod-Milk) on days 29th and 30th. Milk-tank samples of Reg-Mi and Mod-Mi were also collected and analyzed for chemical composition and milk FA profile. Cheese and yogurt were assayed for its FA profile. Differences in milk yield and composition and in the FA profile before and after oil-feeding were stated using the Student T-test for paired observations. Milk production (kg·cow-1·day-1) slightly (-6.7%) decreased (P -1 g leading to a lower (P -1·day-1) of fat corrected milk (4%FCM) from 32.83 (before) to 29.63 after oil. Milk protein content (g 100 g-1) increased (P -1·day-1) (P -1 in Mod-Mi as it was observed (P -1). Yield of NFS tended (P -1·day-1after oil supply. Content of atherogenic FA (C12:0 to C16:0) was significantly (P -1 (Mod-Mi) with a concomitant decrease (P -1 FA) of elaidic (trans-9 C18:1) and trans-10 C18:1 FA was low in Reg-Mi (0.22 and 0.34 respectively) but tended (P -1 FA) of VA resulted higher (+110%, P -1 FA) increased (P -1) of α-linolenic were higher (P cis-9 C18:1) content (g 100 g-1) remained unchanged (P < 0.504) averaging 21.99 in Reg-Mi and 22.86 in Mod-Mi. Composition of FA of the Mod-DCh was highly correlated (R2 = 0.999) with FA profile from its original Mod-Mi. A serving of the M-DCh (30 g) theoretically involved a 12.1% reduction in total fat consumption with 16.9% less in SF intake compared to the Reg-Ch. A serving of the M-DCh could putatively increase total CLA consumption by 72.7% compared to the Reg-DCh. Compared to Reg-Yo, a portion (178 g) of the Mod-Yo could increase (69.4%) total CLA intake. The nutritional value of milk fat was improved by feeding a blend of PUFA oils to confined dairy cows and the consumption of the mofified dairy products obtained could promote a lower intake of the potentially atherogenic saturated FA and some increase in healthy FA ingestion.

Feeding Protected Lysine and Methionine Modifies Milk Protein Profile in Grazing Dairy Cows

The experiment was designed to determine the effect of protected lysine (Lys) and methionine (Met) supply on milk protein profile in grazing dairy cows specifically in the caseins (CNs) and α-lactalbumin fractions. Twelve multiparous mid lactation Holstein cows producing 24 (±4.76) kg of milk were assigned to one of two treatments (six cows per treatment) during an experimental period of 21 days. In the control (C) group, cows grazed a Pennisetum clandestinum pasture and were supplemented with a commercial concentrate according to milk production. In the Met-Lys treatment, cows received the same ration supplemented with protected Lys and Met. Milk yield and composition and milk protein profile were measured at the start and the end (21st day) of the experimental period. The Tricine-SDS-PAGE and the Gel-Quant Express Analysis (Invitrogen) software were used to determine milk protein composition. Statistical analysis was performed using the SAS’s PROC MIXED procedure through a mixed model that included the animal as a random effect and the treatments as a fixed effect adjusted by covariables. Milk production averaged 23.7 (±2.0) kg cow-1 day-1 without differences between treatments (P P -1 day-1) compared to C (24.2 kg cow-1 day-1). Milk protein content (g/kg) did not differ (C = 30.4; Met-Lys = 31.1) and lactose content tended (P P β-CN also increased (P < 0.05) after protected aminoacid supply (C = 9.58; Met-Lys = 10.35). It can be concluded that milk protein composition was improved by protected Lys-Met supply without altering other compositional parameters of milk composition. Milk nutritional quality and its potential yield for cheese-making were positively enhanced.

Evaluación productiva y económica de un sistema silvopastoril intensivo en bovinos doble propósito en Michoacán, México

Se evaluó el comportamiento productivo de bovinos doble propósito en un sistema silvopastoril intensivo (SSPi) en Apatzingán, Michoacán. La actividad se llevó a cabo mediante seguimiento técnico-económico. Asimismo, se monitorearon variables productivas y económicas (consumo de forraje, producción de leche, peso, ingresos y egresos) de 60 vacas de la raza Gyr analizadas mediante estadística descriptiva y presupuestos por actividad. La carga animal empleada fue de 2.06 UA ha-1 y la producción de leche obtenida fue 9.15 kg vaca-1 día-1. El manejo de vacas Gyr en un SSPi favorece la producción de leche y carne y el ingreso económico a la unidad de producción (UP).

Effect of daily herbage allowance restriction on pasture characteristics and milk production by grazing dairy cows in spring

The cumulative effects of daily herbage allowance (DHA) restriction on pasture characteristics and the sustainability of pasture-based dairy systems were evaluated. Sixty-four dairy cows were randomly assigned to one of two grazing treatments (20 and 30 kg DM cow-1 day-1). Milk yield and pre- and post-grazing herbage mass were recorded for every grazing event. Botanical and chemical compositions of the pasture were evaluated. Low DHA increased the stocking rate by 0.7 cows ha-1 and consequently increased grazing efficiency from 41 to 47%. Daily herbage allowance restriction did not affect pasture characteristics or milk production per cow, but DHA restriction increased milk production per hectare (+27%). The results suggest that restriction on daily herbage allowance ensures a higher level of herbage utilization and milk output per ha than high DHA, without affecting pasture characteristics. Therefore, DHA might be a useful grazing management tool for improving the profitability and sustainability of grazing-based dairy systems.

External validation of the GrazeIn model of pasture dry matter intake and milk yield prediction for cows managed at different calving dates and stocking rates

The aim was to evaluate the prediction accuracy of pasture dry matter intake (PDMI) and milk yield (MY) predicted by the GrazeIn model using a database representing 124 PDMI measurements at paddock level and 2232 MY measurements at cow level. External validation of the model was conducted using data collected from a trial carried out with Holstein-Friesian cows (n=72) while grazed 28 paddocks and were managed in a 2×2 factorial design by considering two calving dates (CD), with different number of days in milk (DIM), early (E, 29 DIM) vs. middle (M, 167 DIM), and two stocking rates (SR), medium (M, 3.9 cows ha-1) vs. high (H, 4.8 cows ha-1), under a rotational grazing system. Cows were randomly assigned to four grazing scenarios (EM, EH, MM and MH). The mean observed PDMI of the total database was 14.2 kg DM cow-1 day-1 while GrazeIn predicted a mean PDMI for the database of 13.8 kg DM cow-1 day-1. The mean bias was −0.4 kg DM cow-1 day-1. GrazeIn predicted PDMI for the total database with a relative prediction error (RPE) of 10.0% at paddock level. The mean observed MY of the database was 23.2 kg cow-1 day-1 while GrazeIn predicted a MY for the database of 23.1 kg cow-1 day-1. The mean bias was –0.1 kg cow-1 day-1. GrazeIn predicted MY for the total database with a mean RPE of 17.3% at cow level. For the scenarios investigated, GrazeIn predicted PDMI and MY with a low level of error which made it a suitable tool for decision support systems.

Effect of essential oil supplement on milk yield and composition of lactating dairy cows

Essential oils (EO), an important group of plant extracts, which are concentrated extracts of aromatic oily liquids from various plant materials obtained by steam distillation. Plant-derived EO is a useful means to improve efficiency of nutrient utilization in ruminants and reduce the impact of their production on the environment. In recent years, more research has been directed toward evaluating the potential of EO to improve performance in dairy cows but according to the results the effect of EO on milk production is not consistent. Therefore, the study evaluated the effects of supplementing a mixture of EO (oregano, thyme, citrus, cinnamon, ginger, curcuma, pepper and an organic carrier) in the diet of lactating Holstein Friesian dairy cows (n=46) in late lactation on the intake, milk yield and composition in a dairy farm experiment. The average DIM at the start of the experiment was 156 days. Experimental treatments consisted of a mixture of EO (2 g cow-1 day-1) inclusion in a total mixed ration. There was a 3-week long preliminary and a 7-week long experimental period in the trial. Milk production was recorded every day. Chemical analyses were made from the morning milked samples once a week. Supplementation of dairy cows with mixture of EO significantly (P&amp;lt;0.05) increased the dry matter intake (control: 26.9±1.49 kg DM day-1 vs. experimental: 27.3±0.95 kg DM day-1) but had no effect on milk production (control: 38.3±4.99 kg vs. experimental: 37.9±4.93 kg) and milk composition (fat, protein, lactose). Results show that an intake of 2 g cow-1 day-1 mixture of EO may increase the feed intake but does not influence milk yield and composition in late lactation.

Estimation of prevalence and incidence of subclinical mastitis in a large population of Brazilian dairy herds.

The objectives of this study were to estimate the prevalence and incidence of subclinical mastitis (SM) in a large population of Brazilian dairy herds and to describe how these indices changed over time. A data set comprising individual cow somatic cell counts (SCC) from 18,316 test days (TD) of 1,809 herds that participated in a Dairy Herd Improvement Association (DHIA) program between January 2011 and May 2015 was available for analysis. Only tests that had ≥10 lactating cows and that were performed at 30 ± 10-d intervals were used for analysis. The final data set included 8,285 TD from 517 herds located in 5 regions of the country. Prevalence (%) of SM was defined as the number of cows with SCC ≥200,000 cells/mL divided by the total number of tested cows on a given TD. The incidence of SM was defined as the number of cows whose SCC increased from <200,000 to ≥200,000 cells/mL over 2 consecutive TD divided by the sum of each cow's days at risk during this interval, expressed as new cases per cow month at risk. Prevalence and incidence of SM were compared among years, regions, herd size categories, and frequency of DHIA testing during the study period. The overall mean prevalence and incidence of SM including all tests performed during the study period was 46.4% and 0.17 new cases per cow month at risk, respectively. The prevalence of SM varied little from 2011 to 2015, and an increasing trend was observed over the years. Prevalence was lower in herds that performed ≥60 DHIA tests during the study period than in those that performed fewer tests and was not different among regions or herd size categories. Incidence of SM varied little over the years and was not different among the regions studied. Prevalence and incidence of SM in the 517 herds studied were high and did not improve over the years. These trends were observed across all herd size categories and regions studied. Producers who had more DHIA tests performed per herd during the study period had lower prevalence of SM. Results of this study highlight the need to establish large-scale milk quality programs in Brazil.

Milk Yield and Composition and Pasture Ruminal Digestion in Grazing Dairy Cows Receiving Three Levels of Energy Concentrate Supplementation

The objective of the experiment was to determine the effect of feeding three levels (T3.5, T7.0 and T10.5) of energy concentrate (3.5, 7.0 and 10.5 kg cow-1 day-1) on total dry matter (DM) and energy intakes, milk yield and composition, nutritional value of milk and rumen pasture neutral detergent fiber (NDF) digestion in grazing dairy cows. Twenty-one multiparous Holstein cows in early lactation (70.2 ± 13 days postpartum) producing 37.1 (±4.7) kg of milk were assigned to a 3 treatments (7 cows/treatment) × 3 periods Latin square design. Parameters of ruminal environment and pasture NDF degradation were obtained using 3 additional cows of the same breed fitted with rumen cannulae. On a wet basis, concentrate was composed by corn grain (68%), soybean meal (22%), wheat bran (8%) and a vitamin-mineral nucleus with monensin. Pasture (Medicago sativa, sp) was used in a rotational grazing system with an herbage allowance of 30 kg DM cow-1 d-1. Yield (kg cow-1 d-1) of fat corrected milk (4% FCM) resulted higher (p p p p p p p p

Characteristics of cattle breeders and dairy production in the southeastern and northeastern mesoregions of Pará state, Brazil

The objective of this study was to characterize the dairy production systems of the southeastern and northeastern mesoregions of Pará state. A total of 112 questionnaires were administered on rural properties with dairy cow milk production in the municipalities of Ulianópolis and Irituia from April to May 2013. The activity was conducted mainly by men between 36 and 70 years of age. The education level was low, with 67% of the cattle breeders having incomplete basic education and 20.5% being illiterate. Regarding herd feeding, only 19.6% of the breeders used energy supplements, and 13.39% used roughage supplements. Sanitation control was performed by 99.1% of the breeders, with vaccines against foot and mouth disease and brucellosis being the most common vaccines because they are mandatory. Milking was performed manually on 98.2% of the properties, and pre-dipping and post-dipping techniques were used on only 2.7% and 3.6% of the properties, respectively. Regarding management, 84.8% of the breeders did not perform financial planning, and 99.1% did not have a defined chart of accounts and cost centres and were unaware of their production costs. Average herd productivity was 4.34 L cow-1 day-1, with average production varying between 30 L day-1 in units with fewer than 10 lactating cows and 355 L day-1 in those with over 55 cows. Age and education level were shown to hinder the access to knowledge and technological innovations in products, processes and management.

Monensina sódica sobre vacas em fase inicial de lactação: produção de leite e peso vivo

Avaliou-se o efeito do fornecimento de monensina sódica no desempenho de vacas leiteiras em fase inicial de lactação, cuja alimentação, em sua dieta total no cocho, compôs-se em 81,4% de silagem de milho e 18,6% de concentrado, em que se fez uso de maior proporção de silagem de milho de que concentrado. Foram utilizadas 14 vacas multíparas 7/8 Holandês, aos 20±10 dias pós-parto aproximadamente, com média de 22±0,5kg vaca-1 dia-1 de leite, em delineamento de blocos casualizados, adotando-se o esquema de parcelas subdivididas no tempo, em modelo de medidas repetidas. Os tratamentos nas parcelas foram diferenciados pela presença (200mg animal-1dia-1) ou ausência da monensina na ração e, nas subparcelas, pelos diferentes períodos de avaliação. Não se observaram diferenças no consumo em matéria seca da dieta, conversão alimentar, produção de leite in natura e corrigida e peso vivo nas médias diárias de cada período. No entanto, a produção de sólidos totais foi superior para os tratamentos com o ionóforo, sinalizando que a administração da monensina sódica para vacas no início de lactação modifica o rendimento em produção de leite.

Fatty acid intake and rumen fatty acid composition is affected by pre-grazing herbage mass and daily herbage allowance in Holstein dairy cows

The objective of this study was to investigate the effect of level of pre-grazing herbage mass (HM) and daily herbage allowance (DHA) on the fatty acid (FA) intake and composition of ruminal content of grazing dairy cows. Four rumen fistulated Holstein-Friesian dairy cows were allocated to either a high or low HM (1700 vs 2600 kg DM ha-1) and within herbage mass treatment further allocated to a high or low DHA (20 vs 16 kg of DM cow-1 day-1) in a 4 × 4 Latin square design. Total FA intake and linolenic acid (LNA) intake was higher for cows on high DHA (p&lt;0.05). Ruminal oleic acid, linoleic and LNA were not affected by treatments. Ruminal stearic acid (C18:0) and vaccenic acid (VA) concentrations were higher at low HM (43.6 and 14.8 g/100 gof FA respectively; p&lt;0.01) compared to high HM (42.0 and 12.5 g/100 gof FA respectively for C18:0 and VA). Cows grazing high DHA had higher ruminal concentration of VA (15.3 g/100 gof FA; p&lt;0.01) than low DHA (12.1 g/100 gof FA). Regarding milk FA composition, only some of the milk FA varied across treatments, being the VA and LNA concentrations higher at low HM (p&lt;0.05). These data suggest that low HM and high DHA, at least within the range studied here, promotes the accumulation of ruminal VA which could be available for subsequent conversion within the mammary gland to the human health promoting c9,t11 isomer of conjugated linoleic acid.

Comportamento ingestivo de vacas leiteiras em pastagem de azevém alimentadas com diferentes fontes proteicas

Estudou-se o efeito da substituição do farelo de soja da ração por pastejo controlado de trevo-branco (Trifolium repens L.) sobre o comportamento ingestivo de vacas da raça Holandesa em pastejo de azevém (Lolium multiflorumLam.). Utilizaram-se dois grupos de animais, com média de 20 vacas agrupadas por produção, período de lactação e peso corporal, em delineamento experimental em blocos ao acaso. Um grupo recebeu, diariamente, 3kg de suplemento energético e teve acesso controlado à pastagem de trevo-branco por aproximadamente duas horas e meia (TB); o outro recebeu o mesmo suplemento, adicionado de quantidade de proteína equivalente ao consumo diário no tratamento anterior via trevo, na forma de farelo de soja (FS). Para a avaliação de comportamento, procedeu-se à observação e ao registro do ritmo de atividade dos animais, no período de pastejo em azevém durante dois dias consecutivos, quinzenalmente. Observou-se maior tempo de pastejo em minutos (min), 212,00 versus 194,24min dia-1, e frequência de bocados (bocado), 67,78 versus 64,09 bocado min-1, entre os animais do tratamento FS, em relação ao TB. Não houve diferença no consumo de azevém entre os tratamentos, com valores de 3,65 e 4,11kg vaca-1 dia-1de matéria seca para TB e FS, respectivamente, o que sugere adequada adaptação dos animais às duas situações estudadas.