Kg Of Milk Yield Research Articles

A randomized controlled trial to study the effect of supplemental premilking stimulation on milking performance, teat tissue condition, udder health, and well-being in dairy cows

The objectives of this study were to evaluate the effect of supplemental premilking stimulation, provided after manual stimulation, by means of high-frequency pulsation without reduction of the vacuum in the pulsation chamber on milking performance, teat tissue condition, udder health, and well-being in dairy cows. In a randomized controlled trial, Holstein cows (n = 491) from 1 commercial dairy farm with a thrice-per-day milking schedule were assigned to treatment and control groups over a 64-d period. Treatments consisted of a maximum of 20 s of pulsation stimulation at a pulsation rate of 100 (SPS100) or 300 (SPS300) cycles per minute and a pulsation ratio of 25:75, which were applied after completion of manual premilking stimulation upon milking unit attachment. Cows in the control group (CON) received only traditional premilking stimulation by manual forestripping for 6 s, and wiping. Milking characteristics were measured with on-farm milk flow meters. Milking machine-induced short-term (swelling at teat base, firmness at teat end, and teat discoloration) and long-term (teat-end callosity) changes to the teat tissue were assessed manually and visually. Composite milk samples were analyzed for somatic cell counts. Cow hind-leg activity was assessed with 3-dimensional accelerometers. Fecal 11,17-dioxoandrostanes (11,17-DOAs; a group of cortisol metabolites) were determined on wk 4 and 8 to assess the well-being of the cows. Generalized linear mixed models were used to study the effect of treatments on the outcome variables milk yield/milking and milking unit-on time. We observed no meaningful differences among groups for milk yield or milking unit-on time. Least squares means and their 95% confidence intervals (95% CI) for cows in the SPS100, SPS300, and CON groups were 13.9 (13.3-14.5), 14.0 (13.4-14.6), and 13.9 (13.3-14.6) kg for milk yield and 218 (212-224), 218 (211-224), and 218 (212-224) s for milking unit-on time, respectively. Compared with cows in the CON group, the odds (95% CI) of short-term changes were 1.30 (0.95-1.78) for the SPS100 group and 1.50 (1.10-2.05) for the SPS300 group. The odds of long-term changes were 0.94 (0.67-1.34) for cows in the SPS100 group and 0.71 (0.49-1.04) for cows in the SPS300 group. We observed no differences in SCC. In reference to the CON group, the hazard ratio (95% CI) in SPS100 and SPS300, respectively, were 0.35 (0.13-0.98) and 1.22 (0.57-2.64) for clinical mastitis, and 0.34 (0.12-0.95) and 1.28 (0.60-2.73) for culling. The least squares means (95% CI) of hind-leg activity during milking were 8.3 (6.5-10.5), 10.6 (8.1-13.7), and 9.1 (7.2-11.6) movements per milking for the SPS100, SPS300, and CON groups, respectively. The least squares means (95% CI) of fecal 11,17-DOAs concentration (ng/g) at the first and second test days, respectively, were 31.1 (28.1-34.2) and 22.3 (19.2-25.4) for the SPS100 group, 26.4 (23.4-29.4) and 25.2 (22.0-28.4) for the SPS300 group, and 24.8 (21.8-27.9) and 25.0 (21.7-28.3) for the CON group. We conclude that applying supplemental stimulation after manual stimulation through the high-frequency pulsation system tested here did not impart additional benefits to the milk harvesting process, teat tissue condition, somatic cell count, or the well-being of the animals.

PSV-10 Evaluation of the effect of probiotic feed additives in the diet to improve dairy production and quality measures

Abstract There is limited information regarding the effectiveness of probiotic feed additives in the diet of lactating dairy cows. This study aimed to determine the effect that Fastrack probiotic had on the yield and milk quality measures of lactating dairy cows. To accomplish this goal, lactating Holstein cows (n = 80) were equally divided into two treatment groups: one supplemented with a probiotic (PRO) and one that did not receive the probiotic supplement (CON). The cows remained in their treatment groups for the duration of the 120-d study and were given ad libitum access to a total mixed ration consisting of 35% corn silage, 30% rolled corn, 10.5% soybean meal, 23% DDGS, and 1.5% mineral supplement. Cows on the PRO treatment were given 1 kg of DDGS once a day at milking that had the probiotic mixed in while the CON treatment were given 1 kg of the same DDGS that did not have the probiotic included. Preliminary results of this study show a decrease in individual treatment records for cows on the PRO treatment and an increase of 2 kg of milk yield per day.

Feed preference in lactating dairy cows for different pellet formulations

Two taste preference experiments were conducted with the same 8 multiparous lactating Jersey cattle (100 ± 7.1 DIM, 30.5 ± 4 0.06 kg of milk yield, 18.8 ± 2.52 kg of DMI in experiment 1; and 215 ± 7.1 DIM, 27.6 ± 3.98 kg of milk yield, 19.6 ± 3.03 kg of DMI in experiment 2). In experiment 1, 4 pellets were formulated and manufactured into 4.0-mm pellets. These were as follows: 45.7% alfalfa meal, 45.7% corn grain, and 8.57% wheat middlings (ALFC); 72.3% corn grain, 18.5% wheat middlings, and 9.25% dried distillers grains and solubles (ENG); a pellet containing 100% dehydrated alfalfa meal (DALF); and a pellet containing a mixture of concentrate ingredients (GMIX; 43.1% corn grain, 26.3% dried distillers grains and solubles, 13.8% wheat middlings, 7.10% dry molasses, 3.18% soybean meal, 0.93% corn oil, and 5.6% minor constituents). Cows were offered 0.50 kg of pellets in a randomized arrangement within the feed bunk. Feed preference was ranked from 1 to 4 with 1 being the most preferred and 4 the least. The resulting preference rankings were averaged (± SE) resulting in a highest (closest to 1) to lowest (furthest from 1) ranking as follows of ALFC (1.38 ± 0.164), ENG (2.13 ± 0.327), GMIX (2.88 ± 0.375), and DALF (3.13 ± 0.350). The probabilities of first choice were 70.6 ± 0.55% ALFC, 16.5 ± 0.46% ENG, 5.50 ± 0.475% DALF, and 7.48 ± 0.455% GMIX. A Z-test was conducted to determine the percentage a treatment would be chosen first differed from the value of no preference at 25%; ALFC and DALF differed from the mean value, whereas no difference was observed for ENG and GMIX. The most preferred pellet (ALFC) was used in a second study and compared against 3 other treatments in which different flavoring agents were added. In this study, 4 pellets were manufactured with ALFC: 45.7% alfalfa meal, 45.7% corn grain, 6.76% wheat middlings, and 1.81% oregano leaf (ALFCO); 45.7% alfalfa meal, 45.7% corn grain, 8.22% wheat middlings, 0.10% melon flavoring, and 0.25% BitterOff (ALFCM); and 45.7% alfalfa meal, 45.7% corn grain, 8.47% wheat middlings, and 0.10% licorice flavoring (ALFCL). The resulting preference rankings were averaged resulting in a highest to lowest ranking as follows: ALFC (1.25 ± 0.164), ALFCO (2.38 ± 0.263), ALFCM (2.63 ± 0.375), and ALFCL (3.25 ± 0.164). The probabilities of first choice were 81.9 ± 0.65% ALFC, 8.49 ± 0.46% ALFCO, 6.50 ± 0.481% ALFCM, and 3.12 ± 0.491% ALFCL. Of the pellet choices, ALFC and ALFCL differed from the mean value of no choice, whereas no difference was observed for ALFCO and ALFCM. Mixtures of corn grain and dehydrated alfalfa meal bound by wheat middlings may serve as a feeding strategy that is preferred by the animals and may be an effective reward to cows entering an automated milk system, and we were unable to improve preference by adding flavoring agents.

Lactational performance, enteric methane emission, and nutrient utilization of dairy cows supplemented with botanicals

The objective of this study was to evaluate lactational performance, enteric gas emissions, ruminal fermentation, nutrient use efficiency, milk fatty acid profile, and energy and inflammatory markers in blood of peak-lactation dairy cows fed diets supplemented with Capsicum oleoresin or a combination of Capsicum oleoresin and clove oil. A 10-wk randomized complete block design experiment was conducted with 18 primiparous and 30 multiparous Holstein cows. Cows were blocked based on parity, days in milk, and milk yield (MY), and randomly assigned to 1 of 3 treatments (16 cows/treatment): (1) basal diet (CON); (2) basal diet supplemented with 300 mg/cow per day of Capsicum oleoresin (CAP); and (3) basal diet supplemented with 300 mg/cow per day of a combination of Capsicum oleoresin and clove oil (CAPCO). Premixes containing ground corn (CON), CAP, or CAPCO were mixed daily with the basal diet at 0.8% of dry matter intake (DMI). Supplementation of the diet with CAP or CAPCO did not affect DMI, MY, milk components, and feed efficiency of the cows. Body weight (BW) was increased during the last 2 wk of the experiment by CAP and CAPCO, compared with CON. The botanicals improved BW gain (0.85 and 0.66 kg/d for CAP and CAPCO, respectively, compared with -0.01 kg/d for CON) and CAP enhanced the efficiency of energy utilization, compared with CON (94.5% vs. 78.4%, respectively). Daily CH4 emission was not affected by treatments, but CH4 emission yield (per kg of DMI) and intensity (per kg of MY) were decreased by up to 11% by CAPCO supplementation, compared with CON and CAP. A treatment × parity interaction indicated that the CH4 mitigation effect was pronounced in primiparous but not in multiparous cows. Ruminal molar proportion of propionate was decreased by botanicals, compared with CON. Concentrations of trans-10 C18:1 and total trans fatty acids in milk fat were decreased by CAP and tended to be decreased by CAPCO, compared with CON. Total-tract apparent digestibility of nutrients was not affected by treatments, except for a tendency for decreased starch digestibility in cows supplemented with botanicals. Blood concentrations of β-hydroxybutyrate, total fatty acids, and insulin were not affected by botanicals. Blood haptoglobin concentration was increased by CAP in multiparous but not in primiparous cows. Lactational performance of peak-lactation dairy cows was not affected by the botanicals in this study, but they appeared to improve efficiency of energy utilization and partitioned energy toward BW gain. In addition, CH4 yield and intensity were decreased in primiparous cows fed CAPCO, suggesting a potential positive environmental effect of the combination of Capsicum oleoresin and clove oil supplementation.

PSV-2 Difference in Sire Pta Evaluated By Taiwan Dhi and the Original Countries

Abstract Taiwan is located in a region with a tropical/subtropical oceanic climate characterized by high temperatures and humidity, which significantly affects the milk production, health, and reproduction of dairy cows. Most dairy herds in Taiwan have utilized semen of superior foreign sires from countries in temperate climate, mainly from USA and Canada. However, the performance of daughters in Taiwan of those foreign sires may differ from those in temperate countries. Therefore, the objective of this study was to evaluate the performance of foreign sire semen in Taiwan's dairy herds, and to compare the PTAs of those sires in both Taiwan and their original countries. Data and pedigree from the Dairy Herd Improvement program (DHI) were collected between 2009 and 2021. In total, 108,348 lactation records from 54,269 cows and 76,024 animals in the pedigree were obtained from 120 herds. Traits to evaluate include milk yield (MY), milk fat percentage (MF%), milk fat yield (MFY), milk protein percentage (MP%), and milk protein yield (MPY) standardized to 305d-2X yield. The herd-year-season and lactation were considered as fixed effects in the model with additive genetic effect and permanent environmental effect as random effects. In addition, an extra fixed effect, physical situation of lactation (PSL), was included to account for abnormal physiology or subclinical mastitis in those dairy cows. The ASReml program was used to estimate the variance and covariance components as well as heritability and correlation with multiple-trait animal models. Not only the accuracy of predicted transmitting ability (PTATW) ≥ 75% of those superior foreign sires using DHI data and their PTAs obtained from the original countries (PTAInt) were compared, but also the rank correlation between PTATW and PTAInt was also calculated. The results indicated that only when the accuracy of PTATW increased to 90%, a moderate correlation was observed. Moreover, PTATW and PTAInt of all the sires with an accuracy of PTATW ≥ 75% were tracked to the lactation performance of their daughters in Taiwan using regression analysis. The results showed that selecting sires with an increase of 1 kg in PTATW and in PTAInt would increase the average production of their daughters in Taiwan's dairy herds by 1.620 kg and 0.213 kg in milk yield, 1.328 kg and 1.201 kg in fat yield, and 1.493 kg and 0.550 kg in protein yield, respectively. Therefore, selecting offspring through PTATW of sires is much more efficient, and increasing the number of daughters for each sire and their DHI records would improve the accuracy of PTATW prediction and ranking, making it an important indicator for selecting progeny in Taiwan dairy herds.

Increasing palmitic acid and reducing stearic acid content of supplemental fatty acid blends improves production performance of mid-lactation dairy cows

We determined the effects of altering the ratio of palmitic (C16:0) and stearic (C18:0) acids in supplemental fatty acid (FA) blends on production responses of mid-lactation dairy cows. Twenty-four multiparous Holstein cows (mean ± standard deviation; 47.1 ± 5.8 kg of milk yield, 109 ± 23 DIM) were randomly assigned to treatment sequences in a replicated 4 × 4 Latin square design with 21-d periods. Treatments were a control diet not supplemented with FA (CON), and 3 diets incorporating 1.5% of dry matter (DM) FA supplement blends containing 30% C16:0 + 50% C18:0, 50% C16:0 + 30% C18:0, and 80% C16:0 + 10% C18:0. Additionally, the FA blends were balanced to contain 10% of oleic acid (cis-9 C18:1). The FA blends replaced soyhulls in the CON diet. Diets were formulated to contain (% of DM) 31.0% neutral detergent fiber, 27.0% starch, and 16.9% crude protein. The statistical model included the random effect of cow within square and the fixed effects of period, treatment, and their interaction. Preplanned contrasts included CON versus overall effect of FA supplementation and the linear and quadratic effects of increasing C16:0 in FA blends. Overall FA treatment had no effect on dry matter intake (DMI), but increasing C16:0 linearly increased DMI. Compared with CON, overall FA treatment increased yields of milk, 3.5% of fat-corrected milk, energy-corrected milk, and milk fat but did not affect milk protein yield. Increasing C16:0 linearly increased milk fat yield and tended to linearly increase the yields of 3.5% of fat-corrected milk and energy-corrected milk. Fatty acid supplementation decreased the yield of de novo milk FA but increased yields of mixed and preformed milk FA compared with CON. Increasing C16:0 in FA treatments did not affect the yield of de novo milk FA, linearly increased the yield of mixed, and decreased the yield of preformed milk FA. In summary, feeding FA supplements containing C16:0 and C18:0 increased milk production responses with no effect on DMI compared with a control diet. Mid-lactation cows producing ∼40 to 50 kg/d milk yield responded best to increasing supplemental C16:0 in FA supplements, demonstrating that FA supplements higher in C16:0 and limited in C18:0 improves production responses.

Lactational performance, rumen fermentation, nutrient use efficiency, enteric methane emissions, and manure greenhouse gas-emitting potential in dairy cows fed a blend of essential oils

The objective of this experiment was to investigate the effects of an essential oil (EO) blend on lactational performance, rumen fermentation, nutrient utilization, blood variables, enteric methane emissions and manure greenhouse gas-emitting potential in dairy cows. A randomized complete block design experiment was conducted with 26 primiparous and 22 multiparous Holstein cows. A 2-wk covariate and a 2-wk adaptation periods preceded a 10-wk experimental period used for data and sample collection. Treatments were: (1) basal diet supplemented with placebo (CON); and (2) basal diet supplemented with a blend of EO containing eugenol and geranyl acetate as main compounds. Supplementation with EO did not affect dry matter intake, milk and energy-corrected milk yields, and feed efficiency of cows, compared with CON. Milk fat and lactose concentrations were increased, and milk total solids (TS) concentration and milk fat yield tended to be increased by EO. Multiparous cows supplemented with EO tended to have slightly decreased dry matter and crude protein digestibility compared with CON multiparous cows. There was a tendency for increased ruminal pH by EO, whereas other rumen fermentation variables did not differ between treatments. Daily methane emission was not affected by EO supplementation, but methane emission intensity per kg of milk fat was decreased by 8.5% by EO. Methane emission intensity per kg of milk lactose and milk TS were decreased and methane emission intensity per kg of milk yield tended to be decreased by up to 10% in EO multiparous cows, but not in primiparous cows. The greenhouse gas-emitting potential of manure was not affected by EO supplementation. Compared with CON, fecal nitrogen excretion was increased by EO supplementation in multiparous, but not in primiparous cows, and milk nitrogen secretion (as a % of nitrogen intake) tended to be increased in EO supplemented cows. Blood variables were not affected by EO supplementation in the current study. Overall, dietary supplementation of EO did not affect lactational performance of the cows, although milk fat and lactose concentrations were increased. Most enteric methane emission metrics were not affected, but EO decreased methane intensity per kg of milk fat by 8.5%, compared with the control.

A short-term comparison of wheat straw and poplar wood chips used as litter in tiestalls on hygiene, milk, and behavior of lactating dairy cows

A short-term study was conducted to compare the effect of using poplar wood chips (PWC) instead of wheat straw (WS) litter in dairy cows. A total of 38 lactating Holstein cows (204 ± 119 days in milk, 26.9 ± 6.5 kg of milk yield [MY]) were housed in a tiestall farm for a 10-d trial including 5 d of adaptation followed by 5 sampling days (from d 5 to 10). Cows were divided into 2 homogeneous groups: one group was bedded with WS, and the second with PWC. Both litter materials were provided in the amount of 7 kg/stall per d. Each group was composed of 3 subgroups of 6 or 7 cows; the subgroups were physically separated along the feeding line by wooden boards. During the sampling days, fecal composition, used litter composition, and bacterial count (Clostridium spp., Salmonella spp., Escherichia coli, Lactobacillus, and total bacterial count) were analyzed by subgroup twice a day. On d 1 and from d 5 to 10, udder hygiene score and cow cleanliness score were also evaluated individually twice a day. Meanwhile MY, milk hygiene (total bacterial count [TBC], coliform bacterial count [CBC], and spore-forming unit [SFU]) and quality were measured and analyzed from 9 animals per group. Moreover, individual animal behavior (body position and behavioral traits) and subgroup dry matter intake were measured on d 9 and 10. Fecal dry matter did not differ between groups, PWC had the lowest used litter moisture and N content favoring the highest clean cow frequency, but also gave rise to the greatest used litter microbial contamination. The MY, milk quality, TBC, SFU, and CBC were similar. The lying behavior frequency was similar between groups. However, the PWC group showed the lowest sleeping frequency, the highest frequency of other behaviors (including discomfort signs), and the lowest dry matter intake. However, despite this apparent reduction in cow comfort, no biologically important differences were observed in this short-term study between cows on PWC and WS in milk production or hygiene.

A randomized controlled trial to study the effects of an automated premilking stimulation system on milking performance, teat tissue condition, and udder health in Holstein dairy cows

The objectives were to examine the effect of an automated premilking stimulation (APS) by means of a high pulsation frequency (300 cycles/min) without a reduction of the vacuum in the pulsation chamber or claw piece on (1) milking performance, (2) teat tissue condition, and (3) udder health in dairy cows. In a randomized controlled field study, Holstein cows (n = 427) from 1 commercial dairy farm with a milking schedule of 3 times per day were assigned to treatment and control groups over a 90-d period. Treatments consisted of a maximum of 80 s (APS80) or 99 s (APS99) of mechanical stimulation at a pulsation rate of 300 pulses per minute and a ratio of 25:75 (no reduction of the pulsation chamber or milking vacuum). Cows in the control group (CON) received traditional premilking stimulation by means of manual forestripping for 8 s. Milking characteristics were documented with on-farm milk meters. Short- and long-term changes in teat tissue condition induced by machine milking were assessed visually on a weekly basis. Composite milk samples were analyzed once per month to determine somatic cell count. Generalized linear mixed models were used to study the effect of the treatment on the outcome variables. We observed no meaningful differences in milk yield or milking unit-on time. Least squares means and their 95% confidence intervals (95% CI) for cows in the APS80, APS99, and CON groups were 13.5 (13.1-14.0), 13.2 (12.8-13.7), and 13.2 (12.8-13.7) kg for milk yield and 222 (213-231), 219 (210-228), and 223 (214-232) s for milking unit-on time, respectively. The effect of treatment on bimodality was modified by milk yield such that the odds of bimodality increased in the treatment groups with increasing milk yield. Compared with cows in the CON group, the odds ratios (95% CI) of bimodality were 1.08 (0.62-1.89) in the APS80 group and 0.89 (0.55-1.42) in the APS99 group at a milk yield of 11 kg and 2.0 (1.24-3.22) in the APS80 group and 2.08 (1.29-3.35) in the APS99 group at a milk yield of 16 kg. We observed differences in short- and long-term changes in teat tissue condition between the treatment and control groups. Compared with cows in the CON group, the odds (95% CI) of short-term changes were 1.87 (1.35-2.58) for the APS80 group and 1.49 (1.08-2.07) for the APS99 group, and the odds of long-term changes were 1.52 (1.24-1.85) for cows in the APS80 group and 1.59 (1.31-1.94) for cows in the APS99 group. The least squares means (95% CI) for somatic cell counts (log10-transformed) were 4.74 (4.68-4.81) for the APS80 group, 4.77 (4.71-4.83) for the APS99 group, and 4.79 (4.73-4.86) for the CON group. We conclude that the APS system tested here had no negative effects on milk yield or milking unit-on time. However, differences in bimodality and teat tissue condition suggest that the APS system did not provide sufficient stimulation to facilitate a gentle milk harvest and adversely affects teat tissue condition.

Implementation of Feed Efficiency in Iranian Holstein Breeding Program.

This study aimed to evaluate the economic impact of improving feed efficiency on breeding objectives for Iranian Holsteins. Production and economic data from seven dairy herds were used to estimate the economic values of different traits, and a meta-analysis was conducted to analyze the genetic relationships between feed efficiency and other traits. Economic weights were calculated for various traits, with mean values per cow and per year across herds estimated at USD 0.34/kg for milk yield, USD 6.93/kg for fat yield, USD 5.53/kg for protein yield, USD -1.68/kg for dry matter intake, USD -1.70/kg for residual feed intake, USD 0.47/month for productive life, and USD -2.71/day for days open. The Iranian selection index was revised to improve feed efficiency, and the feed efficiency sub-index (FE$) introduced by the Holstein Association of the United States of America was adopted to reflect Iran's economic and production systems. However, there were discrepancies between Iranian and US genetic coefficients in the sub-index, which could be attributed to differences in genetic and phenotypic parameters, as well as the economic value of each trait. More accurate estimates of economic values for each trait in FE$ could be obtained by collecting dry matter intake from Iranian herds and conducting genetic evaluations for residual feed intake.

An insight into population structure and genetic progress of Argentinean Holstein cattle.

The objective of the present study was to investigate the most critical issues associated with the limited genetic progress evidenced in the Argentinean Holstein ("Holando Argentino") breed in the last 20 years (only 26% of the phenotypic trend in milk yield was due to genetics). The study comprised the analysis of population structure, realized genetic selection differentials, genetic progress and partition of genetic trends by sex and country of origin from 1936 to 2019 (1,045,582 records; 24,680 sires and 619,322 dams in the pedigree). Average inbreeding steadily increased in the last 15 generations (ΔF=0.6%, which translates to Ne=75). Partition of genetic trends revealed that local genetics made a negligible contribution to genetic progress, which for most traits was highly dependent on imported genetics (>80%). Mean generation intervals were fairly constant until 2009 (8-9 years for males and 5-6 years for females, respectively) and then decreased, especially in the paths of sires of bulls and dams of bulls (to 5 and 4 years, respectively) mostly due to the influence of imported sires. The reduction in generation intervals was counterbalanced by a marked deterioration of realized selection differentials, particularly in the path of sires of bulls that nevertheless made the largest contribution to genetic progress. In the last 20 years, realized selection differentials in this path went from 533.6 to 170.8kg for milk yield and from 16.7 to 13.3kg for protein yield (1.7-0.5 and 1.6-1.3 standard deviation units, respectively). Among all considered traits (milk yield, fat yield, protein yield, stature, final score and daughter pregnancy rate) in the analysed period, annual genetic gain was negative for milk yield, fairly constant for composition and conformation traits, and positive only in the case of daughter pregnancy rate. Considered together, these results suggest that limited genetic progress is due to the absence of a sound breeding programme that includes genomic selection and a carefully defined selection objective, together with the absence of stronger regulations in germplasm importation; however, other factors such as potential genetics by environment interactions cannot be ruled out.

Examining feed preference of different pellet formulations for application to automated milking systems

Feed is often offered to a cow in the milking unit of an automated milking system. This offering provides nutrients but also acts as a reward to the cow for entering the unit. To complement the partial total mixed ration and to enable handling, flow, and delivery within this mechanized system, this offering is usually a mix of feeds that are combined and manufactured into a feed pellet. The objective of this experiment was to compare 4 different pelleting formulation strategies and measure the effects of feed preference in lactating Jersey cattle. To test the objective, a taste preference experiment was conducted with 8 multiparous lactating Jersey cattle (289 ± 25.3 d in milk, 26.0 ± 2.45 kg of milk yield, 19.36 ± 1.29 kg of dry matter intake). Four formulation strategies were tested including (1) a pellet containing feeds commonly included in the concentrate mixture of a total mixed ration, including 43.1% corn grain, 26.3% dried distillers grains, 3.18% soybean meal, and 5.6% vitamin and mineral premix (CMIX), (2) a pellet of dry corn gluten feed (CGF), (3) a pellet including feedstuffs that are considered to be highly palatable (53.2% wheat middling, 15.7% dried corn distillers grains and solubles, 15.2% cane molasses, and 1.81% oregano (FLVR), and (4) a high-energy pellet (ENG) consisting of 61% corn grain and 26.2% wheat middlings. Cows were offered 0.50 kg of each in a randomized arrangement within the feed bunk for 1 h or until the feed was fully consumed. According to the procedure, cows were offered all 4 treatments for the first 4 d, then the most preferred feed for each cow was removed, and the remaining 3 feeds were offered for 3 d. The process was repeated for the last 2 d. Feed preference was ranked from 1 to 4 with 1 being the most preferred and 4 the least. The resulting preference ranking was CGF (1.25 ± 0.463), FLVR (2.5 ± 0.926), CMIX (2.88 ± 0.835), and ENG (3.13 ± 0.991). These results were subsequently examined utilizing the Plackett-Luce analysis to examine the probability animals would choose a given pellet first based on the current data set. The analysis determined probabilities of first choice as 78.6 ± 0.601% CGF, 9.38 ± 0.438% FLVR, 4.94 ± 0.453% ENG, and 7.11 ± 0.439% CMIX. A Z-test was also conducted to determine if the percentage a treatment will be chosen first differed from the mean value of no preference at 25%. Corn gluten feed and ENG differed from the mean value while no difference was observed for FLVR and CMIX. Results suggest that animals exhibit a high degree of preference for CGF pellets and that this preference is greater than pellets containing other feed ingredients. Alternatively, cows appeared to exhibit the lowest preference for a high-energy pellet containing mostly corn and wheat middlings.

Development of feeding and reproduction technology in dairy cattle breeding based on the use of digital technologies.

A study on the study of the qualitative assessment of the behavior of dairy cattle according to the VAS system (visual analog scale) was conducted in the LLP "Agrofirme "AKAS", located in the West Kazakhstan region of the Republic of Kazakhstan. According to research, it follows that different seasons of time affect the conditions of detention in different ways. So, for the maintenance of cows in the summer, the distance of avoidance at the feeding site according to test 1 and 2 is within 3 meters, whereas in spring and autumn it was 2 meters. The difference between the reference norm and the household ration has been determined, from which it follows that the feeding ration of the farm corresponds to the norm of 12 kg of milk yield per head per day. The vitamin and mineral premix developed by us includes vitamins, minerals, including macro-microelements. The premix also includes components in the following ratio: phosphorus (P) - 5% of monocalcium phosphate, vitamin A - 1.2% of rovimix A 1000, vitamin D3 - 0.64% of rovimix D3, vitamin E - 16% of rovimix E-50, manganese (Mn) - 22.2%, copper (Cu) - 9%, zinc (Zn) - 19%, iodine (I) - 0.28%, selenium (Se) - 7.65 and cobalt (Co) - 0.14%, and feed chalk - 5% and chickpea flour - 13.89% are used as fillers as a source of calcium (Ca).. The average daily milk yield at the beginning of the experiment in both study groups was in the range of 10.6-10.8 kg. At the end of the experiment, the average daily milk yield in animals receiving premix exceeded their peers from the control group by 1.4 kg or 1.6%. According to the chemical composition of milk, the indicators of fat, protein and lactose were higher in the cows of the experimental group compared with the peers of the control group (for fat - 3.92>3.37, for protein - 3.32>3.23, for lactose - 4.16>4.01).

Productive and reproductive qualities of animals of the Ukrainian black and spotted dairy breed in breeding farms of the western region of Ukraine

Productive and reproductive qualities of animals of the Ukrainian black and spotted dairy breed in breeding farms of the western region of Ukraine

Heat stress develops with increased total-tract gut permeability, and dietary organic acid and pure botanical supplementation partly restores lactation performance in Holstein dairy cows.

To evaluate the effects of heat stress (HS) conditions and dietary organic acid and pure botanical (OA/PB) supplementation on gut permeability and milk production, we enrolled 46 multiparous Holstein cows [208 ± 4.65 dry matter intake (DMI; mean ± SD), 3.0 ± 0.42 lactation, 122 ± 4.92 d pregnant, and 39.2 ± 0.26 kg of milk yield] in a study with a completely randomized design. Cows were assigned to 1 of 4 groups: thermoneutral conditions (TN-Con, n = 12), HS conditions (HS-Con, n = 12), thermoneutral conditions pair-fed to HS-Con (TN-PF, n = 12), or HS supplemented with OA/PB [75 mg/kg of body weight (BW); 25% citric acid, 16.7% sorbic acid, 1.7% thymol, 1.0% vanillin, and 55.6% triglyceride; HS-OAPB, n = 10]. Supplements were delivered twice daily by top-dress; all cows not supplemented with OA/PB received an equivalent amount of the triglyceride used for microencapsulation of the OA/PB supplement as a top-dress. Cows were maintained in thermoneutrality [temperature-humidity index (THI) = 68] during a 7-d acclimation and covariate period. Thereafter, cows remained in thermoneutral conditions or were moved to HS conditions (THI: diurnal change 74 to 82) for 14 d. Cows were milked twice daily. Clinical assessments and BW were recorded, blood was sampled, and gastrointestinal permeability measurements were repeatedly evaluated. The mixed model included fixed effects of treatment, time, and their interaction. Rectal and skin temperatures and respiration rates were greater in HS-Con and HS-OAPB relative to TN-Con. Dry matter intake, water intake, and yields of energy-corrected milk (ECM), protein, and lactose were lower in HS-Con relative to HS-OAPB. Nitrogen efficiency was improved in HS-OAPB relative to HS-Con. Compared with TN-Con and TN-PF, milk yield and ECM were lower in HS-Con cows. Total-tract gastrointestinal permeability measured at d 3 of treatment was greater in HS-Con relative to TN-Con or TN-PF. Plasma total fatty acid concentrations were reduced, whereas insulin concentrations were increased in HS-Con relative to TN-PF. We conclude that exposure to a heat-stress environment increases total-tract gastrointestinal permeability. This study highlights important mechanisms that might account for milk production losses caused by heat stress, independent of changes in DMI. Our observations also suggest that dietary supplementation of OA/PB is a means to partly restore ECM production and improve nitrogen efficiency in dairy cattle experiencing heat stress.

Dairy cow and calf behavior and productivity when maintained together on a pasture-based system.

We determined the impact of maintaining pasture-based dairy cows and calves together over 100 days on cow milk production, cow and calf behavior, and calf liveweight and carcass quality. Six Holstein-Friesian cows and their male calves were monitored for 106±8.6 days. Cows were temporarily separated twice a day for milking with calves remaining in the paddock. Cow and calf behaviors were recorded via scan sampling at 6 different timepoints, for the first 7 days and twice a week thereafter. Calves were weighed weekly and immediately processed for meat quality and rumen development analysis at 106±8.6 days. Daily cow milk yields were collected from enrollment until 109±8.6 days (3 days post-weaning). The average daily gain of calves was 1.4±0.73 kg/d, with an average carcass dressing percentage of 59%. Calves had the greatest frequency of observed close proximity to cow and suckling in the first two weeks and decreased with experiment duration. During separation for milking, cow vocalizations and attempts to return to their calf decreased over time. Reticulorumen weight was on target for calf age, but as a proportion of total stomach weight was lower than industry averages of calves the same age due to the larger abomasum. Cows produced an average of 12±7.6 kg of milk yield per day over the 3-days before the calves were weaned and increased to mean of 31±8.3 kg/d the 3 days after weaning, indicating a consumption of close to 20 kg per calf per day. The impact of a pasture-based cow-calf rearing system on cow and calf behavior and the potential for high levels of calf liveweight gain when provided ad-libitum milk and feed were determined. Further research is required to determine the practicality of replicating such systems with large herds and impact on reared calves post-weaning.

Молочная продуктивность коров с разными формами наследования удоя и жирномолочности

In the course of the research conducted at Agro-Soyuz LLC (Kabardino-Balkarian Republic, Chegemsky district), the goal was to study the productivity of 69 first-calf cows of the Gomitinsky black-andwhite breed, the daughters of three breeding bulls, depending on the forms of inheritance or the leading breeding characteristics of dairy productivity (milk yield, fat content), for the definitions of which were used by a new methodology, which is a modified version of the methodology widely used in breeding work with dairy cattle.As a result of determining the forms of inheritance of milk yield in experimental first-calf cows, it was found that the largest share among them fell on animals with milk yield due to such a form of inheritance as regression of the mother (44.9%), the smallest share – on first-calf cows with milk yield due to the dominance of the father (7.3%). When determining the forms of inheritance of fat milk, the same trend was observed as when determining the forms of inheritance of milk yield, that is, among 659 first-heifer cows, the most animals were from the mother regression group (42%), and the least were animals from the father dominance group (4,4%). The established difference between groups of first-calf cows with different forms of inheritance of the breeding trait turned out to be quite significant and reached, in some cases, 2368 kg in milk yield per lactation (p>0,999), 0,32% in fat content (p>0,99).

Evaluating the effects of high-oil rapeseed cake or natural additives on methane emissions and performance of dairy cows

We evaluated the potential of feeding high-oil rapeseed cake or natural additives as rumen modifiers on enteric methane (CH4) emissions, nutrient utilization, performance, and milk fatty acid (FA) profile of dairy cows. Eight Nordic Red dairy cows averaging (mean ± SD) 81 ± 21 d in milk and 41.0 ± 1.9 kg of milk yield at the beginning of the study were randomly assigned to a replicated 4 × 4 Latin square design with 21-d periods. Treatments comprised grass silage-based diets (45:55 forage to concentrate ratio on dry matter basis) including (1) control containing 19.3% rapeseed meal (CON), (2) CON with full replacement of rapeseed meal with rapeseed cake (RSC), (3) supplementation of CON with 50 g/d of yeast hydrolysate product plus coniferous resin acid-based compound (YHR), and (4) supplementation of CON with 20 g/d of combination of garlic-citrus extract and essential oils in a pellet (GCE). Apparent total-tract digestibility was measured using total collection of feces, and CH4 emissions were measured in respiratory chambers on 4 consecutive days. Data collected during d 17 and 21 in each period were used for ANOVA analysis using a mixed model. Treatments did not affect dry matter intake (DMI), whereas feeding RSC increased crude protein and ether extract digestibility compared with the other diets. Emissions of CH4 per day, per kilogram of DMI, and per kilogram of energy-corrected milk, and gross energy intake were lower for RSC compared with other diets. We found no effect of YHR on daily CH4 emissions, whereas CH4 yield (g of CH4/kg of DMI or as percentage of gross energy intake) decreased with GCE compared with CON. Treatments did not influence energy balance. Further, RSC reduced the proportion of N intake excreted in feces, and YHR improved N balance compared with CON diet. Feeding RSC resulted in greatest yields of milk and energy-corrected milk, and feed efficiency. Relative to the CON diet, RSC decreased saturated FA by 10% in milk fat by increasing cis-monounsaturated FA but also increased the proportion of trans FA. Proportion of odd- and branched-chain FA increased with GCE and YHR compared with CON. We conclude that replacing rapeseed meal by rapeseed cake decreased CH4 emissions, whereas YHR or GCE had no effect on CH4 emissions in this study.

Influence of live weight on milk productivity and longevity of economic use of cows

The purpose of the research was to study the influence of the live weight of first-calf heifers on the subsequent milk productivity and productive longevity of high-blood Holstein animals. Research has shown that live weight influence on dairy productivity and productive longevity of cows. From cows with genotype 1/4S+1/4A+1/2RWH with a live weight of 580–600 kg for the first lactation 750 kg more milk was produced than from cows with the live weight 480–500 kg at the first calving. With an increase of the part of Holstein breed blood the differences in milk productivity between cows with different live weight during the first lactation have been increased. First-calf heifers with genotype 1/8S+1/8A+3/4RWH with the live weight of 580–600 kg outperformed their herdmates with the live weight 480–500 kg in milk yield by 1761 kg (P ≥ 0,999), and cows of genotype 1/16S+1/16A+7/8RWH by 2271 kg of milk (P ≥ 0,999). Indicators of productive economic use had certain differences. Thus, cows with the genotype 1/4S+1/4A+1/2RWH with the live weight of 540–560 kg had the highest longevity of economic use – 43,29 months and a lifetime productivity – 24942 kg of milk. In crossbred cows with genotype 1/8S+1/8A+3/4RWH the longevity of economic use and lifetime productivity were higher in cows with the live weight of 580–600 kg, the indicators were 24,73 months and 18294 kg of milk, respectively, in cows with genotype 1/16S+1/16A+7/8RWH the highest longevity of economic use 24,96 months was in cows with the live weight of 560–580 kg, and lifetime productivity – 18131 kg in cows with the live weight 580–600 kg.

Effects of organic acids in total mixed ration and feeding frequency on productive performance of dairy cows

This study aimed to evaluate the effects of organic acid (OA; Mold-Zap, Alltech, Nicholasville, KY) inclusion in the total mixed ration (TMR) and feeding frequency of TMR for lactating dairy cows on intake, total-tract apparent digestibility, sorting index, feeding behavior, ruminal fermentation, milk yield and composition, nitrogen balance, and serum metabolites. Twenty-four lactating Holstein cows, 4 with rumen cannulas, with (mean ± standard error) 247 ± 22.2 d in milk, 672 ± 14.6 kg of body weight, and 31.1 ± 1.09 kg of milk yield at the beginning of the experiment were used. The cows were distributed in a balanced and contemporary 4 × 4 Latin square experimental design and randomly assigned in a 2 × 2 factorial arrangement to evaluate OA [0 (OA-) or 0.5 (OA+) L of Mold-Zap/tonne of TMR on a natural matter basis] and feeding frequency of TMR offered once a day (1×) or twice a day (2×). Each experimental period lasted 21 d, with 14 d for acclimation and 7 d for data collection. The treatments were tested for TMR, in which its temperature was recorded every 2 h through a 24-h period in each experimental period. Organic acid-treated TMR showed a lower temperature during the 24-h period compared with nontreated TMR. The OA and feeding frequency had no effect on intake and total-tract apparent digestibility of dry matter and nutrients, aside from a tendency to increase neutral detergent fiber digestibility in cows fed 2×. Also, cows fed 1× tended to select more particles between 19 and 8 mm and refused particles smaller than 4 mm, whereas cows fed OA tended to select more particles smaller than 4 mm. Cows fed OA had greater milk yield and milk protein and lactose yields, but tended to have higher 3.5% fat-corrected milk yield. Neither treatment influenced ruminal and serum variables nor milk fat yield and milk production efficiency. Cows fed OA spent less time idling and tended to have lower rumination time, and tended to have higher time spent drinking water and eating, whereas animals fed 1× spent more time drinking water. Under the conditions of this experiment, we conclude that it was possible to reduce the feeding frequency of TMR, without negative effects on dairy cow performance. However, the use of OA resulted in higher milk yield and mitigated TMR temperature rise regardless of feeding frequency. The effect of external factors such as collective stimulation of intake and stage of lactation on feeding frequency effect must be surveyed in further research.