Lactation Number Research Articles

288 Effects of increasing water concentrations of oregano essential oil supplementation for lactating sows

Abstract The use of essential oils as a supplement for sows has gained attention in recent years to potentially improve sow and litter performance. Sows (n = 182; avg. lactation length = 19.8 d) were blocked by parity, genetics, estimated farrowing date, and randomly allotted to one of four treatments when entering the farrowing barn. Treatments included: control, 0 mL, (CON, n = 46), 31 mL (L-OEO, n = 45), 47 mL (M-OEO, n = 46), or 63 mL (H-OEO, n = 45) of oregano oil (OEO; Ecodiar Liquid, Nutrinae, Palo Alto, CA) per liter of dosing water with medicators set at 1:128 dilution. Sows were fed a corn-soybean meal-DDGS based lactation diet that met or exceeded NRC (2012) requirements. Sow body weight (BW) was recorded upon entry, 2 d post-farrowing, and weaning. Sow backfat depth (BF) and loin muscle depth (LD) ultrasound measurements, body condition score (BCS), and Knauer sow caliper measurements were collected upon entry and weaning. Sow average daily feed intake (ADFI) was recorded daily 1-wk post-farrowing, then weekly until weaning. Sow water intake was recorded daily (DWI). Individual piglet BW were recorded d 1, d 7, and weaning. Data were analyzed using Proc Mixed procedure in SAS 9.4 with treatment and rep as fixed effects, parity class (P1, P2/P3, P4+) as a covariate, and individual sow as a random effect. Lactation length and number of piglets weaned were used as covariates for weaning data. Linear, quadratic, and cubic contrasts were analyzed among treatments. Litter scouring and medication rates were analyzed using chi-square analysis in the Proc Freq procedure in SAS 9.4. Differences were considered significant at P ≤ 0.05 and trend at 0.05 < P ≤ 0.10. Week 3 lactation sow ADFI increased for L-OEO and H-OEO treatments but decreased for M-OEO compared with CON sows (CON: 7.29 kg/d, L-OEO: 7.60 kg/d, M-OEO: 7.03 kg/d, H-OEO: 7.55 kg/d; cubic; P = 0.0427). No differences were observed among treatments in overall lactation ADFI, DWI, changes in BF, LD, BCS, and piglet and litter growth performance. Sow BW change tended to decline and then increased as OEO increased in the water (CON: -8.79 kg, L-OEO: -6.36 kg, M-OEO: -8.03 kg, H-OEO: -10.52 kg; quadratic, P = 0.0640). There was a cubic tendency for OEO supplementation to reduce loss of caliper measurement (CON: -1.91, L-OEO: -0.98, M-OEO: -1.68, H-OEO: -1.00; P = 0.0598). Percentage of piglets treated with medications for various health issues decreased in the H-OEO supplemented group compared with the L-OEO and M-OEO supplemented groups, with CON group being intermediate and not different (CON: 7.01%, L-OEO: 9.35%, M-OEO: 9.91%, H-OEO: 4.15%; P = 0.0322). Overall, there were no significant impacts of OEO supplementation on sow and litter performance in this study. Future research is needed to determine the effectiveness of OEO in health-challenged sows and litters and the long-term effects of OEO on piglets post-weaning.

A scoping review on associations between paratuberculosis and productivity in cattle.

Paratuberculosis (PTB), or Johne's disease, is a disease with worldwide distribution caused by Mycobacterium avium subsp. paratuberculosis (MAP) that leads to chronic enteritis, primarily in ruminants. Even subclinical infection significantly reduces the animals' performance, and consequences of the disease lead to high economic losses for the cattle industry. To estimate the economic burden of bovine PTB and to evaluate the benefits of a potential control program, accurate estimates of the production effects associated with the disease are required. Therefore, the aim of this scoping review was to provide a comprehensive overview of associations between MAP infection and production parameters in cattle. The studies were collected from three electronic databases. Of the total 1,605 identified studies, 1,432 did not meet the set criteria in the title and abstract screening and a further 106 were excluded during full-text review. Finally, data on 34 different production parameters were extracted from 67 publications. Results show that the magnitude of reported performance losses varies depending on several factors, such as the type of diagnostic test applied, disease status or number of lactations. Studies reported a reduction in milk yield, changes in milk quality (e.g., higher somatic cell count, lower amount of produced milk fat and protein), reduced fertility (e.g., prolonged calving interval and service period, higher abortion rate and calving difficulties), reduced weaning weight, slaughter weight and slaughter value, or a higher risk for mastitis. Results from the studies included in our review show a median decrease of milk yield per infected cow of -452 kg/lactation for raw and -405 kg/lactation for modeled data. Similarly, the amount of produced milk protein fell by a median of -14.41 kg/lactation for modeled data and the amount of produced milk fat by a median of -13.13 kg/lactation. The reviewed studies revealed a prolonged calving interval by around 30 days and a 1.5 to 3 times higher likeliness of culling per lactation in PTB positive animals. Results from this scoping review provide evidence-based inputs for the development of economic models aiming at the estimation of the costs and benefits associated with different disease control scenarios for PTB.

Lifetime milk production of Holstein cattle in the humid tropics compared to Holstein-Gyr and Holstein-Brahman crosses.

Crossbred cattle are commonly used for milk production in the tropics, combining the potential benefits of pure breeds with the heterosis effects of the offspring. However, no comprehensive assessment of lifetime productivity for crossbred versus purebred cattle in low-altitude tropical environments has been carried out. The present study compares the lifetime productivity of purebred Holstein (HO, n = 17,269), Gyr (GY4, n = 435), and Brahman (BR4, n = 622) with crossbreds Gyr × Holstein (GY × HO, n = 5521) and Brahman×Holstein (BR × HO, n = 5429) cows from dairy farms located in low and medium altitude tropical regions in Costa Rica. The production traits of interest were age at first calving (AFC), days open (DO), milk production per lactation (TMP), lactation length (LLEN), age at culling (ACUL), and number of lactations (NLAC). Estimates of heterosis were also calculated. The AFC for GY × HO crosses (33-34 months) was not significantly different (p > .05) from HO (33.8 months). For BR × HO crosses, a significant (p < .05) decrease in AFC (BR3HO1 35.6 months, BR2HO2 34.5 months, and BR1H03 33.3 months) was observed as the fraction of HO breed increased. Estimates of heterosis for AFC were favourable for both crosses, of a magnitude close to 3%. The DO for F1 crosses (GY2HO2 94 days; BR2HO2 96 days) was significantly (p < .05) lower than HO (123 days). Estimates of heterosis for DO were also favourable and above 15% for both crosses. The TMP and LLEN were higher for HO (TMP = 5003 kg; LLEN = 324 days) compared with GY × HO (TMP = 4428 to 4773 kg; LLEN = 298 to 312 days) and BR × HO (TMP = 3950 to 4761 kg; LLEN = 273 to 313 days) crosses. Heterosis for TMP was favourable but low for both crosses, with a magnitude below 3.0%. The NLAC for HO (4.6 lactations) was significantly (p < .05) lower than F1 (GY2HO2, 5.8 lactations; BR2HO2, 5.4 lactations). Heterosis for NLAC was above 6.0% for both crosses. Overall, estimates of lifetime income over feed costs per cow on average were USD 2637 (30.3%) and USD 734 (8.4%) higher in F1 GY × HO and BR × HO, respectively, compared to HO. In conclusion, crossbred animals, specifically those with Gyr and Brahman genetics, extend the productive lifespan, increasing economic returns.

Influence of thermal heat load accumulation on daily rumination time of lactating Holstein cows in a zone with temperate climate

In the future, conflicts between animal welfare and climate change will gradually intensify. In the present study, we investigated the daily rumination time (RT) of lactating Holstein-Friesian cows in a zone with temperate climate and the effects of heat load duration and heat load intensity. Responses of individual cows to heat load were assessed, adjusting for milk yield, lactation number, days in milk as well as reproductive status and season. A total of 27,149 data points from 183 cows in a naturally ventilated barn in Brandenburg, Germany, were collected from June 2015 to May 2017. Ambient temperature and relative humidity were recorded at eight positions inside the barn every 5 min, and the temperature-humidity index (THI) was calculated. Based on THI, the degree of heat load was determined, using critical thresholds of THI = 68, 72, and 80. Daily RT was measured with a microphone-based sensor system (collar) on the cow's neck. The analysis models included autocorrelations in time series as well as individual cow-related effects. With each 5 min exposure to contemporaneous heat load, a decrease of approximately 1.17 min d−1 in RT per cow from non-heat stress to heat stress conditions by exceeding THI ≥68 (p < 0.01). This effect was intensified by exceeding the critical THI thresholds of 68 and 72.As heat load duration and intensity increased, daily RT decreased in comparison to daily RT under non-stress conditions. High-yielding (>38.4 kg milk/day) cows were more influenced in rumination time than low-yielding (≤28.8 kg milk/day) cows. With moderate contemporaneous heat load, RT decreased by 0.14 min d−1 per 5 min in high-yielding cows compared to low-yielding cows under moderate heat load. A decrease of 0.1 min d−1 was found in daily RT of mid-yielding cows. However, the delayed effects of heat load (one to three days after the heat stress event) were associated with days in milk and reproduction status. When the heat load duration lasted for several days, the responses were less pronounced than the impacts of contemporaneous heat load (when the heat stress event lasted for one day). Delayed mild heat load resulted in an increase in RT by 0.13 min d−1 in lactating cows ≤60 DIM. This was also found with delayed moderate heat load. Lactating cows ≤60 DIM showed a rise of 0.09 min d−1 in RT. RT also showed interactions with reproduction status of cows under delayed moderate heat stress. Lactating cows with ≤180 days of pregnancy showed an increase of 0.61 min d−1 in RT. Similarly, cows with >180 days of pregnancy had 0.64 min d−1 more RT compared to non-pregnant cows. Further analysis with higher temporal resolution of RT than data accumulation in 24-h blocks as well as the assessment of the correlation between feed composition, intake and rumination will elucidate the influence of heat load on daily RT.

A Temporal Study on Incidence of Bovine Mastitis in Haryana, India

Mastitis affects dairy animal’s productivity and causes financial losses for dairy farmers in India and across the world. In this study, a total of 52,494 quarter milk samples from 14,381 bovines were screened for the primary microorganisms causing mastitis in Hisar and adjoining districts of Haryana and their antibiotic sensitivity patterns were analyzed. The cultural positivity from subclinical form of mastitis was observed as 86.32% and 87.73% from cows and buffaloes, respectively while that from clinical mastitis was 87.36% and 87.57%. The major Gram positive bacterial pathogens associated with mastitis in the entire study period were found as Staphylococcus species with an average incidence rate of 45.53% and 44.1% from cows and buffaloes, respectively. The Streptococcus species were found to be 33.76% and 29.94% of total isolates. Escherichia coli were the most predominant Gram negative bacteria isolated (17.37% and 13.85%), thereafter Klebsiella spp. (5.54% and 5.19%) from both cows and buffaloes. A significant proportion of clinical cases of mastitis were chronic in nature from both the species of bovines. The incidence of mastitis with respect to different lactation number and lactation months was found as significant. The highest incidences of mastitis was observed in the first lactation among buffaloes (20.69%), while the maximum incidences were observed in second and third lactation in cows with 16.59% and 16.99%, respectively. However, in both the species maximum occurrence of mastitis was observed during the first lactational month. The antibiotic sensitivity patterns of most of the isolates had shown higher sensitivity towards enrofloxacin and gentamicin, while the penicillin had shown least sensitivity. The knowledge regarding the mastitis causing pathogens and their sensitivity pattern in Hisar and adjoining districts of Haryana enables the veterinarians to adopt for the proper treatment protocols and dairy farmers to assure optimal health, welfare and productivity of bovines in the State, in turn reducing antimicrobial resistance.

Genetic investigations on backfat thickness and body condition score in German Holstein cattle.

Up to now, little has been known about backfat thickness (BFT) in dairy cattle. The objective of this study was to investigate the lactation curve and genetic parameters for BFT as well as its relationship with body condition score (BCS) and milk yield (MKG). For this purpose, a dataset was analysed including phenotypic observations of 1929 German Holstein cows for BFT, BCS and MKG recorded on a single research dairy farm between September 2005 and December 2022. Additionally, pedigree and genomic information was available. Lactation curves were predicted and genetic parameters were estimated for all traits in first to third lactation using univariate random regression models. For BCS, lactation curves had nadirs at 94 DIM, 101 DIM and 107 DIM in first, second and third lactation. By contrast, trajectories of BFT showed lowest values later in lactation at 129 DIM, 117 DIM and 120 DIM in lactation numbers 1 to 3, respectively. Although lactation curves of BCS and BFT had similar shapes, the traits showed distinct sequence of curves for lactation number 2 and 3. Cows in third lactation had highest BCS, whereas highest BFT values were found for second parity animals. Average heritabilities were 0.315 ± 0.052, 0.297 ± 0.048 and 0.332 ± 0.061 for BCS in lactation number 1 to 3, respectively. Compared to that, BFT had considerably higher heritability in all lactation numbers with estimates ranging between 0.357 ± 0.028 and 0.424 ± 0.034. Pearson correlation coefficients between estimated breeding values for the 3 traits were negative between MKG with both BCS (r = -0.245 to -0.322) and BFT (r = -0.163 to -0.301). Correlation between traits BCS and BFT was positive and consistently high (r = 0.719 to 0.738). Overall, the results of this study suggest that BFT and BCS show genetic differences in dairy cattle, which might be due to differences in depletion and accumulation of body reserves measured by BFT and BCS. Therefore, routine recording of BFT on practical dairy farms could provide valuable information beyond BCS measurements and might be useful, for example, to better assess the nutritional status of cows.

INFLUENCE OF SUPPLEMENTATION OF FALLEN APPLE ON THE PERFORMANCE OF LACTATING COWS

The present study was conducted to evaluate the influence of supplementation of feeding fallen apple on the performance of lactating cows. Eighteen multiparous dairy cows (2-4 lactation number) were divided into three groups based on the average milk yield. The animals in the group-1(6 cows, average milk yield of 7.34 kg per day,control group- C) where fed maize fodder, concentrate mixture as per the requirement, while the animals in the group-2(6 cows, average milk yield of 7.35 kg per day, Apple fed group, T1) were fed maize fodder, concentrate mixture as per the requirement and chopped fresh fallen apple 4 kg per animal per day, while the animals in the group-3 (6 cows, average milk yield of 7.37 kg per day, Urea treated apple fed group, T2) where fed maize fodder, concentrate mixture as per the requirement and 4% urea treated fallen apple 500g per animal per day. The milk yield in lactating cows of C, T1 and T2 were comparable and did not vary significantly. There were no significant differences in the haematological parameters of C, T1 and T2 groups. Dry matter intake (DMI) was similar among the three groups. Average fortnightly body weight were not statistically significant among the three experimental groups. It was observed that apparent digestibility coefficients (%) of dry matter, organic matter, ether extract, neutral detergent fibre and acid detergent fibre were comparable among the three groups. The milk yield, dry matter intake, fortnightly body weight changes, digestibility of the nutrients were also not statistically significant among the threegroups. Hence, it is concluded that the supplementation of fallen apple and urea treated apple on the lactating cows did not affect significantly the intake and digestibility of nutrients as well as milk production and its composition.

Mechanisms by which feeding synthetic zeolite A and dietary cation-anion difference diets affect mineral metabolism in multiparous Holstein cows: Part I

The periparturient period is characterized by the increased demand for calcium (Ca) in dairy cows. This has resulted in the utilization of several different prepartal nutritional strategies to prevent hypocalcemia postpartum. The objective of our study was to determine the effects of feeding synthetic zeolite A (XZ), a negative dietary cation-anion difference (DCAD) diet, or a positive DCAD diet (CON) during the close-up period on peripartal mineral dynamics and hormones involved in calcium metabolism. To this end, one hundred and 21 multiparous Holstein cows, blocked by lactation number and expected due date were enrolled at 254 d of gestation and randomly assigned to 1 of 3 prepartum diets: CON (+190 mEq/kg; n = 40), -DCAD (-65 mEq/kg; n = 41), or a diet supplemented with sodium aluminum silicate (XZ; +278 mEq/kg, fed at 3.3% DM, targeting 500 g/day; n = 40; Protekta Inc.). Blood, urine, and saliva samples were collected from enrollment until parturition, with data analyzed and presented beginning 14 d before parturition (D-14) until parturition (D0), and on D1, D2, D3, D6, D9, D12, D15, D18, D21, D35, and D49 postpartum to assess mineral and hormone dynamics. Total fecal collections were performed in a subset of 8 cows per treatment group to assess fecal mineral loss. Data was analyzed as a randomized complete block design in SAS. Cows fed XZ and -DCAD had higher blood Ca concentrations compared with CON fed cows, with XZ fed cows exhibiting the highest blood Ca concentrations pre and postpartum. Cows fed XZ had decreased blood and salivary phosphorous (P), increased fecal water extractable phosphate (WEP), and the highest blood calcium concentrations pre and postpartum. Parathyroid hormone (PTH) was unaffected by diet but was increased at parturition in all treatments. Serotonin concentrations were increased in -DCAD and XZ fed cows compared with CON during the prepartum period. Our data indicate that XZ's improvement in blood Ca concentrations pre and postpartum most likely is regulated by a dietary P restriction. Taken together, these data suggest that XZ and -DCAD diets improve postpartum calcium metabolism, however, they appear to work through different mechanisms.

Mechanisms by which feeding synthetic zeolite A and dietary cation-anion difference diets affect feed intake, energy metabolism, and milk performance: Part II

The objectives of this study were to assess the effects of feeding 2 different diets, a low dietary cation-anion difference (DCAD) or a diet with synthetic zeolite A to multiparous Holstein cows during the close-up period on DMI and energy metabolism, as well as evaluate colostrum and milk production. A hundred and 21 multiparous Holstein cows, blocked by lactation number and expected parturition date were enrolled at 254 d of gestation and randomly assigned to 1 of 3 dietary treatments: control (CON; +190 mEq/kg; n = 40), negative DCAD (DCAD, -65 mEq/kg; n = 41; Ultra Chlor; Vita Plus, Lake Mills, WI, USA), or a diet containing sodium aluminum silicate zeolite (XZ; +278 mEq/kg, fed at 3.3% DM, targeting 500 g/day; n = 40; X-Zelit, Protekta Inc., Lucknow, ON, Canada/Vilofoss, Graasten, Denmark). Prepartum DMI was measured daily using Insentec Roughage Intake Control (RIC) gates (RIC System, Holofarm Group, Netherlands). All cows received the same postpartum diet. Blood and urine samples were collected daily beginning 14 d before parturition (D-14) until parturition (D0), and on 1, 2, 3, 6, 9, 12, 15, 18, 21, 35, and 49 d postpartum. Colostrum collected within 6 h of parturition, weighed, and based on samples Brix value, IgG concentrations, and nutrient composition were analyzed. Prepartum, cows fed XZ diet had decreased DMI (11.70 ± 0.26, 13.88 ± 0.26, and 13.45 ± 0.25 kg/d for XZ, CON, and DCAD respectively) and lower rumination (487 ± 8.1, 531 ± 8.3, and 527 ± 8.5 min for XZ, CON, and DCAD respectively) compared with CON and DCAD fed cows. However, rumination was not different postpartum due to treatment. No prepartum or postpartum differences were observed for glucose or BHB concentrations in blood between dietary treatments. Colostrum collected from cows fed XZ had the highest IgG concentrations (91.10 ± 2.63, 78.00 ± 2.63, and 78.90 ± 2.63 mg/mL for XZ, CON, and DCAD, respectively), but yield did not differ between dietary treatments. Additionally, cows in their third or greater lactation fed XZ had the highest milk production (51.0 ± 1.1 kg) during the first 49 d in milk. This study demonstrates that despite a decrease in DMI and rumination in cows fed XZ prepartum, blood BHB concentrations were not altered. Additionally, cows fed XZ had higher colostral IgG concentrations and 3+ lactation cows fed XZ produced the most milk. These data suggest that feeding XZ prepartum may improve colostrum quality and improve milk yield in mature cows, and does not impact energy metabolism.

ОЦЕНКА ПЛЕМЕННОЙ ЦЕННОСТИ КОРОВ СИММЕНТАЛЬСКОЙ ПОРОДЫ ПО ПОЖИЗНЕННОЙ ПРОДУКТИВНОСТИ В ЗАВИСИМОСТИ ОТ ВОЗРАСТА ВЫБЫТИЯ И ПРОИСХОЖДЕНИЯ

The purpose of research is to study the variability of genetic assessments of cows of different origins for traits of lifelong milk production when varying the age of retirement in the population of Simmental cattle in Russia. The analyzed database included breeding cows of the Simmental breed that were retired in the pe¬riod 2001–2020; the total number of livestock was 47,868 head. Calculation of the breeding value of productive longevity was carried out using the BLUPF90 program based on the BLUP Animal Model methodology. The share of Simmental cows of foreign selection that were eliminated after the 1st and 2nd lactations was 61.2 %, and those lactating longer than 6 lactations was only 4.0 %, while cows of Russian selection were 12.3 % less eliminated during the first two lactation and are able to produce longer. Phenotypic values of lifetime productivity in Simmental cows for an equal number of lactations are significantly higher in animals of foreign selection: from 824 kg of milk when leaving after the 1st lactation to 4,210 kg when leaving after the 10th lactation, from 35.3 to 188.5 kg by lifetime amount of fat and from 27.3 to 190.9 kg by lifetime amount of protein, respectively. The maximum estimates of breeding value for the lifetime productivity of a cow of fo¬reign selection reach +115.7 kg of milk fat and +91.3 kg of milk protein for a productive life by the 7th lactation.In cows of Russian selection, the predicted maximum breeding value estimates are achieved by the 9th lactation with indicators of +111.0 kg of milk fat and +88.4 kg of milk protein during the period of productive use. Lifetime milk productivity is significantly higher in Simmental cows of imported origin (by +824...+4210 kg), as well as estimates of breeding value (by +27.5...+35.9 kg), however, domestic Simmentals had a longer use period – on average for 2 lactations.

Genetic association between fat-to-protein ratio and traits of economic interest in early lactation Holstein cows in Brazil.

The aims of this study were to estimate the genetic parameters for fat-to-protein ratio (F:P) within the first 90days of lactation and to examine their genetic associations with daily milk yield (MY), somatic cell score (SCS), and calving interval between the first and second calving (IFSC) and between the second and third calving (ISTC) during the first three lactations of Holstein cows. We utilized 200,626 production-related data officially recorded from 77,436 cows milked two or three times a day from 2012 to 2022, sourced from the Holstein Cattle Breeders Association of Paraná State, Brazil. The (co)variance components were estimated using animal models, adopting the restricted maximum likelihood (REML) method with single-trait analysis (for heritability and repeatability) and two-trait analysis (for genetic and phenotypic correlations), per lactation. Regardless of lactation number, heritability estimates were relatively low, ranging from 0.08 ± 0.005 to 0.10 ± 0.003 for F:P; 0.08 ± 0.01 to 0.18 ± 0.005 for MY; 0.04 ± 0.01 to 0.07 ± 0.004 for SCS; and 0.03 ± 0.01 for both IFSC and ISTC. Repeatability estimates within the same lactation were low for F:P (ranging from 0.17 ± 0.002 to 0.19 ± 0.03), high for MY (between 0.50 ± 0.003 and 0.53 ± 0.002), and moderate to high for SCS (between 0.39 ± 0.003 and 0.44 ± 0.004). Genetic correlations between F:P and MY ranged from -0.26 ± 0.03 to -0.15 ± 0.02; F:P and SCS, from -0.06 ± 0.03 to -0.03 ± 0.08; F:P and IFSC, 0.31 ± 0.01; F:P and ISTC, 0.20 ± 0.01; MY and IFSC, 0.24 ± 0.05; and MY and ISTC, 0.13 ± 0.08. The fat-to-protein ratio during early lactation showed low genetic variability, regardless of lactation number. Furthermore, it was genetically correlated with MY, IFSC, and ISTC, although there is an antagonistic and unfavorable correlation between traits that can limit genetic progress.

Does Keeping Cows for More Lactations Affect the Composition and Technological Properties of the Milk?

This study investigated differences in the raw milk composition and technological properties between cows with different numbers of lactations. In total, 12 commercial herds were visited within a period of 12 weeks. On each farm, milk samples from five young cows (lactations 1-2) and five older cows (lactation ≥ 3) were collected. For each farm, milk samples from the young cows and the older cows, respectively, were pooled. The pooled milk samples were analyzed for gross composition and technological properties. Using principal component analysis (PCA) to assess the overall variation in milk quality attributes and the potential clustering of milk from young cows and older cows, respectively, an effect of breed, but no clear effect of lactation number, was observed. In contrast, one-way ANOVA showed higher plasmin activity (p = 0.002) in pooled milk from the older cows, whereas plasminogen-derived activity (p = 0.001) and total proteolysis (p = 0.029) were higher in milk from the young cows. Likewise, orthogonal projections to latent structure discriminant analysis (OPLS-DA) showed higher plasmin activity in milk from older cows, whereas younger cows had higher plasminogen-related activity and higher total proteolysis. To conclude, except for plasmin and plasminogen-related activities, there were no major differences in the composition and technological properties between milk from older cows and young cows.

Influence of production level, number, and stage of lactation on milk quality in compost barn systems.

This study evaluated the influence of milk production, number of lactations, and days in milk (DIM) on the quality and composition of milk from dairy cows housed in a compost barn (CB) system. The study was carried out using a six-year database, counting 31,268 observations from 2,037 cows of European breeds. Multiparous cows showed higher fat and protein production. Lactose showed high levels for primiparous and the initial stage of lactation (4.65%) and was negatively influenced by somatic cell count (SCC). Milk urea nitrogen was higher (14.01%) from 106 to 205 days in milk, and the other components were higher at >305 days. Therefore, the solids content was higher in the first and second lactations due to the high contents of lactose, fat, and milk protein, but lactose was reduced over lactations. In contrast, high DIM increased SCC and concentrated solids due to lower milk production. The effect of milk production, stage, and lactation order on the composition and milk quality of herds housed in CB showed the same pattern as in other production systems.

Marcadores metabólicos e produção de leite de vacas da raça Holandesa submetidas a diferentes protocolos de aplicação de cianocobalamina e butafosfan no pós-parto recente

Abstract The objective of this study was to evaluate the effects of different protocols combining cyanocobalamin and butaphosphan on metabolic markers and milk production by Holstein cows postpartum. We used 154 multiparous cows housed in a free-stall system and divided into five groups, using the number of lactations and the probable date of calving as randomization criteria. The animals received intramuscular applications of a 100 mg/mL butaphosphan and 0.05 mg/mL cyanocobalamin combination. The treatment was delivered in a volume of 1 mL for every 20 Kg of body weight on varying treatment days as follows: treatment 1 (T1), on delivery day (day 0) (n=36); T2, days 0 and 3 (n = 31); T3: days 0 and 7 (n = 30); T4: days 0, 3 and 7 (n = 28). The control group (CG) received saline solution on days 0, 3 and 7 (n = 29). Blood samples were collected for metabolite evaluation on days 0, 7, 21 and 30. Milk production was recorded once a week for up to 98 lactation days. T4 elicited higher average milk production (25.87±0.34 kg/day; P &lt; 0.001) than all other groups. Administering butaphosphan and cyanocobalamin on days 0, 3 and 7 postpartum increased milk production and improved energy and liver metabolism in the animals.

Comparison of sheep and goat colostrum fatty acids contents

The quality and content of colostrum is a very important factor for the health of the offspring. Colostrum is the first food that ensures the growth and development of offspring and their immunity against diseases. Colostrum composition is affected by many factors such as calving season, number of lactations, length of dry period, maternal diseases, age and breed. The animal material of the research consisted of Awassi sheep and Saanen goats raised in Adana province, where Mediterranean conditions prevail, and these animals were kept in semi-intensive conditions. In the study, fatty acids of sheep and goat colostrums were determined by gas chromatography device. As a result of the analysis, 26 fatty acids were detected in Awasi sheep and 27 fatty acids in Saanen goats. Erucic acid was not detected in Awasi sheep colostrum. The colostrum fatty acids with the highest percentage in both breeds wre oleic acid (Awassi sheep: 36.32%, Saanen goat: 25.68%) and palmitic acid (Awassi sheep: 28.15%, Saanen goat: 29.20%) was determined as. ∑SFA rates were found to be higher in Saanen goat colostrum, and ∑MUFA and ∑PUFA rates were found to be higher in Awassi sheep.

Supplementing a Bacillus-based direct-fed microbial improves feed efficiency in lactating dairy cows.

This experiment was conducted to evaluate the effects of feeding a Bacillus-based direct-fed microbial (DFM) on performance and nutrient digestibility of lactating dairy cows. Seventy-six lactating (42 ± 6 days in milk[DIM]) Holstein-Friesian primiparous and multiparous cows were enrolled to a 16-wk experiment. Cows were blocked by lactation number and DIM and within blocks, assigned to 1 of the 2 treatments: 1) basal partial-mixed ration (PMR) without DFM addition (n = 38; CON) or 2) basal PMR with the addition of 3g/head/d of a DFM containing B. licheniformis 809 and B. subtilis 810 (n = 38; BOVACILLUS, Chr. Hansen A/S, Hørsholm, Denmark; DFM). The DFM was mixed in a protein-based pellet, whereas the CON group was fed the same pellet without DFM (0.6kg/cow/d). The PMR contained (dry matter [DM] basis) 50% of forage and 48% of a concentrate feed based on corn meal, soybean meal, wheat meal, wheat middlings, and a mineral-vitamin premix, with the remaining part of the diet being represented by the pellet used as a carrier for the treatments (CON and DFM). Dry matter intake (DMI), milk yield, and production efficiency were recorded daily, whereas milk protein and fat concentrations were recorded using electronic milk meters. An additional milk sample was collected every second week of the study for milk composition. On week 15 of the study, fecal samples were collected from each cow for apparent nutrient digestibility calculation. All data were analyzed using the MIXED procedure of SAS (version 9.4; SAS Inst. Inc., Cary, NC). No treatment effects were observed on cow final body weight, daily DMI, milk yield, energy-corrected milk (ECM), ECM efficiency, milk composition (yield or content), and somatic cell count (SCC) (P ≥ 0.12). However, cows fed DFM had a greater feed and N efficiency (P ≤ 0.03) compared to cows fed CON. Moreover, DM digestibility tended to be greater for DFM-fed cows when compared to CON (P = 0.10), whereas no further nutrient digestibility differences were observed (P ≥ 0.24). In summary, supplementing a DFM containing Bacillus licheniformis and B. subtilis benefited feed efficiency of lactating dairy cows fed a PMR, while also tending to improve the digestibility of DM.

Genetic analysis of first lactation and lifetime performancetraits in composite Vrindavani cattle: important considerations for higher milk production.

The present study was aimed to evaluate the influence ofnon-genetic factors on several first lactation and lifetime performance traits and elucidate their genetic parameters in an organized Vrindavani cattle population.Data on eight first-lactation and thirteen lifetime traits were collected on 2400 cows with pedigree records that werereared during33-year period (1989-2021). The first-lactation traits included age at first calving (AFC), total milk yield (FTMY), standard milk yield (FSMY305), peak yield (FPY), lactation length (FLL), dry period (FDP), service period (FSP) and calving interval (FCI). Whereas, the lifetime traits mainly included total lifetime milk yield (TLMY), total standard milk yield (TSMY), number of lactations completed (NL), total lactation length (TLL), herd life (HL), productive life (PL), average milk yield per day of herd life (TLMY/HL), average milk yield per day of productive life (TLMY/PL), average milk yield per day of productive life (TLMY/TLL). Other lifetime production traits included average service period (ASP), average dry period (ADP), average calving interval (ACI) and unproductive days (UD).The heritability estimates of first-lactation traits ranged between 0.026 and 0.228and were found to be low for AFC (0.180 ± 0.042), FCI (0.191 ± 0.125), FSMY305 (0.145 ± 0.061), FTMY (0.165 ± 0.048), FDP (0.052 ± 0.049) and FSP (0.026 ± 0.033); however, FLL (0.229 ± 0.044) and FPY (0.202 ± 0.046) showed moderate heritability. Positive phenotypic correlation (p < 0.001) was revealed among FTMY, TLMY, TLL, HL and PL. The AFC produced a significant effect (p < 0.05) on several traits i,e, TLL, TLMY/HL, FSMY305, FPY, TLMY, HL and TLMY/PL.Lower AFC was associated with higher TLMY, TLL and TLMY/HL; while FSMY305, FPY, HL and TLMY/PL were higher in heifers that calved late in their life. The results revealed that AFCmay be optimized with first lactation and lifetime traits for this population.

The Effect of Conventional Semen, Sexed-Semen, and Embryo Transfer on Pregnancy Rate in Holstein Dairy Cows

In this study, it was aimed to detect the effects of conventional semen, sexed-semen and embryo transfer on pregnancy rates in Holstein dairy cows. In the study, a total of 139 healthy cows with the serum progesterone &amp;gt; 8 ng/ml were used as animal material. Estrus synchronization protocol was applied and cows were divided into three different groups as conventional semen group (G1, n=46), sexed semen group (G2, n=47), and embryo transfer group (G3, n=46) considering age, body condition score, lactation number, and body weight. Cows in G1 and G2 were inseminated with conventional semen and sexed-semen, respectively. Embryo transfer was performed to cows in Group 3 (n=46) 7th day after estrus. The embryos were transferred to recipients as freshly. Pregnancy examinations for the cows were conducted on the 30th and 60th days of gestation. The statistical analysis of the obtained results was performed. Pregnancy rates were detected as %50, %46,8 and %69,56 in G1, G2, and G3 respectively on 30th day. On 60th day, however, pregnancy rates were %45.60, %42.55 and %67.39 in G1, G2, and G3 respectively due to embryonic losses. The pregnancy rate was significantly higher in the embryo transfer group (G3) compared to the conventional semen (G1) and sexed-semen (G2) group (p&amp;lt;0.05) on both 30th and 60th days. There was no significant difference between G1 and G2 (p&amp;gt;0.05). Findings led to the conclusion that higher serum progesterone level may increase pregnancy rate in cattle. In addition, it is evident that embryo transfer has the potential for widespread use in the field of veterinary medicine in terms of genetic progress.

CHARACTERISTICS THE OFFSPRING OF SIRES BY LONGEVITY TRAITS OF THE HERD FOR BREEDING UKRAINIAN BLACK-AND-WHITE DAIRY BREED

Based on studies of the offspring of sires in a herd for breeding the Ukrainian Black-and-White dairy breed (UBWD), a significant influence of their heredity on the variability of longevity traits has been established. According to the duration of productive use, the variability between extreme options was 1061 days, and in terms of the number of lactations used during life, it was ‑ 2.7, with high reliability for both traits (P &lt; 0.001). The variability of longevity traits did not depend on the origin of the sires, among whom there are purebred Holsteins and bulls of domestic selection of Ukrainian Black-and-White dairy breed of different genotypes and lines. It was found that the quantity of days of productive use and the number of used lactations during the life of cows of different origins are positively correlated with indicators of productive longevity ‑ lifetime milk yield and milk fat, and milk yield per day of productive use. Variability in lifetime milk yield varied widely, from 14934 (daughters of the sire Katka 5218, Metta line, UBWD), to 33031 kg (daughters of the sire Marcellus 136057831, line P. F. A. Chief, Holstein breed), with a high reliable difference between them, which amounted to 18097 kg (P &lt; 0.001). The milk fat content of the daughters of the assessed sires also differed in significant, at a reliable level, variability within the range of 3.72–3.85% with a difference between the extreme options of 0.13% (P &lt; 0.001). Similar variability in sire offspring, regardless of origin, was observed in lifetime milk fat yield, with variation ranging from 570.5–1197.9 kg, with the highest indicator in daughters of Holstein bull Caprice 401393 and the lowest in daughters of domestic sire Katka 5218.

Reproductive Longevity of the Russian Black Pied Cattle Depending on Period Length between Calving

The article deals with the indicators of reproductive longevity of the Russian black pied cattle depending on the period length between calving. The research object is the data of the electronic database of OAO “Zarya” of the Vologda Oblast. We divided animals of the study sample into four groups depending on the duration of the calving interval. We have studied indicators of productive longevity and reproductive qualities of cows. We have calculated underproduction with an increase in the duration of the calving interval. The highest number of completed lactations (3.4) and a fairly high lifetime milk yield of 25.6 kg are established in group II (calving interval is 366–425 days). This animal group has the highest milk productivity per day of life (10.5 kg), as well as a higher number of live calves (4.26 heads). Lower indicators of lifetime productivity, calf yield and reproductive qualities are obtained in group I (up to 365 days).