Heifers In Group Research Articles

Problems with Congestive Heart Failure and Lameness That Have Increased in Grain-Fed Steers and Heifers

Grain-fed steers and heifers have increasing problems with both lameness and congestive heart failure. Congestive heart failure used to be limited to cattle raised at high altitudes. It is now occurring at much lower elevations. An inspection of hearts at the slaughter plant indicated that some groups of grain-fed steers and heifers had abnormally swollen hearts in 34% of the animals. Congestive heart failure may also increase death losses in the late stages of the feeding program. Lameness has also increased to 8% of grain-fed steers and heifers arriving at U.S. slaughter plants. Twenty years ago, observations by the author indicated that lameness in fed cattle arriving at the slaughter plant was almost zero. There has also been an increasing occurrence of abnormal hoof structure and poor leg conformation. Genetic selection for rapid growth and a large ribeye may be associated with the increase in both of these problems. Lameness and heart problems severely compromise animal welfare.

Characterization of Cellular Immune System at Different Ages in Water Buffalo (Bubalus bubalis)

In recent years, there has been an increased interest in understanding the immune system of the water buffalo due to the increased economic impact of this species. The study aimed to perform an in-depth evaluation of lymphoid and myeloid cells in water buffalo of different ages. We assess three multicolor panels of antibodies to evaluate by flow cytometry the percentage of the CD3+ CD4+, CD8+, and γδ T lymphocytes; CD79+ and CD21+ B lymphocytes; monocytes and cM, intM, and ncMsubsets; NK cells, granulocytes, and peripheral blood mononuclear cell (PBMC). Seventy-eight animals from three different farms were divided into three groups by age (26 in each group): 80-100 days old calves, 16-18 months old heifers, and 4-6 years old cows. Significant differences by Kruskal-Wallis test were found between age groups in the percentage of CD4+, CD8+, γδ T lymphocytes, NK cells (P=0.0001), total monocytes (P=0.0008), granulocytes (P=0.0358) and PBMC (P=0.0056). Between the farms, the adult animals showed differences in the percentage ofCD3+ (P=0.0152), CD4+ (P=0.0047), CD8+ (P=0.0019), CD4:CD8 ratio (P=0.0033) and γδ (P=0.0013) T lymphocytes; CD21+ B lymphocytes (P=0.0007);total monocytes (P=0.0100), cM and ncM subsets (P=0.0320;P=0.0252), granulocytes (P=0.0030) and PBMC (P=0.0120). The calves showed significant differences in CD79+ and CD21+ B lymphocytes (P=0.0141; P=0.0049), total monocytes (P=0.0010), cM, intM and ncM subsets (P=0.0335; P=0.0499; P=0.0065). The heifers group in CD21+ B subset (P=0.0439).In summary, this study provides the composition of lymphoid and myeloid cells in this species for the first time, highlighting large differences between age groups and between different herds.

PSVI-24 Gene expression profiles of granulosa and peripheral white blood cells from fertile and sub-fertile beef heifers

Abstract Beef heifer fertility issues contribute to a major economic loss in the cow-calf production industry. Therefore, identifying beef heifers with superior genetic potential for improved fertility would increase profitability. This study aimed to identify differences in the transcriptome profiles from granulosa and peripheral white blood cells (pWBCs) of beef heifers with varying reproductive potential. For this, Angus-Simmental crossbred heifers were subjected to an estrus synchronization and fixed-time artificial insemination (AI) protocol (7-D CO-Synch + CIDR) followed by exposure for 60-d to a fertile bull. Depending on the presence or absence of conceptus 120 d post-AI, heifers were classified as fertile (pregnant by AI) or sub-fertile (non-pregnant by AI or bull-breeding). Pregnancies were terminated, and all animals in both groups (fertile, n = 8; and sub-fertile, n = 5) were cycling when the blood and ovaries were collected from each heifer. Total RNA was extracted from the pWBCs and granulosa cells and subjected to library preparation and sequencing on the Nova-Seq platform. The read counts were obtained after data quality control using FastQC v0.11.9 and MultiQC v1.12 and alignment to the Ensemble’s ARS UCD1.2 Bos taurus genome reference using STAR aligner v2.7.5. The filtered data were subjected to differential expression analysis using DESeq2. We identified 1,061 and 72 significantly differentially expressed genes (DEGs) with P-values ≤ 0.05 and absolute (log2 fold change) ≥ 0.5 from pWBC and granulosa, respectively. Notably, 12 targets including 9 protein coding genes (PLCL1, DNER, GNAS, CDH3, PER1, ITGA2B, CXCL12, ENSBTAG00000048613, ENSBTAG00000051519), bta-mir-2887-1, 5-8S-rRNA and U5 were found as DEGs in both the tissues. Based on a differential co-expression analysis using PCIT, we identified GNAS and DNER as hub genes in pWBC and the granulosa cells of the sub-fertile heifer group. The 12 shared genes were over-represented for pathways such as NF kappa B and chemokine signaling, regulation of actin cytoskeleton, and platelet activation. Some of the identified genes have been previously associated with fertility, while others are novel. A detailed understanding of the underlying biological mechanisms of the top genes and a follow-up study with a larger sample size at different time points could validate the candidates identified in this study for their role as potential therapeutic targets.

52 Differences in body composition measurements for developing Angus heifers

Abstract The profitability of beef cow-calf operations relies on the reproductive ability of females to calve at 2 yr of age and provide a calf each subsequent year for her lifetime. The management of replacement heifers could affect her ability to conceive early, calve, and rebreed. Common management practices use heifer body weight (BW) (and body condition score (BCS) as indicators of puberty onset but do not indicate body composition and fat deposition. The objective of this study was to use ultrasound measurements of carcass traits to compare the effect of different diet management practices on muscle development and fat deposition of post-weaning heifers. The heifers placed on a higher energy diet are expected to have greater mean carcass trait measurements than the lower energy diet heifers. A total of 124 purebred Angus heifers from the Iowa State University McNay Memorial Research and Demonstration Farm were used for this study. Two diets were administered in this study. One group of heifers (G1; n = 61) was developed on a low-energy roughage diet to reach a target BW of 55% of mature BW at the time of breeding. The second group (G2; n = 63) was developed on a grain diet to reach the target BW of 65% mature BW at breeding. Body weight and ultrasound measurements for backfat (BFAT), ribeye area (REA), and intramuscular fat (IMF) were collected over three time points (0-d, 55-d, and 123-d) during the study to quantify the development of body composition characteristics. The initial measurements were collected 1 wk post-weaning. Significant mean differences between the two groups were observed for BW, BFAT, and REA at 55-d (P = 0.027, P = 0.008, and P < 0.0001, respectively), and 123-d (P < 0.001). The mean differences for BW, BFAT, and REA at 123-d between G1 and G2 were 30.98 kg, 0.10 cm, and 7.81 cm2, respectively No significant difference was found between the groups for IMF measurements at 55-d (P = 0.927) or 123-d (P = 0.169). This suggests IMF is not significantly influenced by diet during the early, post-weaning heifer developmental stage. Although further research is needed, the results from this study suggest the development of weight, BFAT, and REA in early post-weaning beef heifers is influenced by the energy concentration of the diet.

Use of domestic biological drugs in reproduction of cattle

purpose of the work was to analyze the use of domestic biodrugs in the reproduction of cattle. In the scientifi c and economic experiment, three groups of dry cows (control, 1st and 2nd experimental) were formed according to the principle of analog groups, taking into account the clinical and physiological condition, age and live weight. In the 2nd series of the experiment, 3 groups of newborn heifers were formed in accordance with the groups of dams. The work scientifi cally substantiates and experimentally proves the eff ectiveness of using complex immunomodulatory biodrugs consisting of two main active components (yeast cells and vitamins) Salus-PE and Bovistim-K, in the technology of cow reproduction and calf rearing. It has been established that the use of biodrugs in late pregnant cows improved the course of the calving and postpartum periods, increased milk productivity and colostrum quality, forms stable colostral immunity in newborn calves, reduced the risks of respiratory and gastrointestinal diseases in young animals, contributing to better live weight gains. The tested complex immunomodulatory biodrugs activate hematopoiesis, compensatory mechanisms of the body, the population of immune cells in the blood, increased protein metabolism, the expression profi le of cellular and humoral factors of non-specifi c resistance. The use of the developed biodrugs during decornuation stimulated tissue regeneration, accelerated the process of scab formation, normalized the level of γ-globulins, activated the synthesis of α- and β-globulins, oxidation-reduction processes and metabolism, which ensured an increase in the immune status of the body of calves in the neonatal period. The economic effi ciency of using the biodrugs Salus-PE and Bovistim-K in the technology of cow reproduction in the 1st and 2nd experimental groups based on 1 ruble of additional costs was 2.63 and 4.50 rubles, and in the technology of raising calves 6.85 and 11.20 rubles, respectively.

Growth response of post weaned F1 Friesian × Borena (Bos taurus × Bos indicus) crossbred growing heifers fed on wheat straw-based densified complete feed block.

This experiment was designed to investigate the effect of feeding wheat-straw based densified complete feed block (DCFB) on daily weight gain, feed intake, digestibility and feed conversion rate in growing heifer calves. Eight weaned F1 Frisian*Borena (Bos taurus × Bos indicus) crossbred calves (92.5 ± 27.5kg body weight) and 5 months of age were randomly distributed into four groups, each with two animals evaluated under 4 × 4 double Latin Square Design for 240 days. The control treatment was natural pasture hay (NPH) and concentrate mix (CM) fed conventionally in a way that covers 50:50% requirements on dry matter (DM) bases and DCFB prepared by mixing wheat straw (WS) to concentrates mixture in the ratio of 50:50 (T2), 40:60 (T3) and 30:70 (T4), respectively. Each heifer group was fed on each diet for 60 days. At the end of each period the last 7 days were used to collect feed and feacal samples. However, the heifers were weighed each 15 days to estimate daily growth performances. It was found that significant (P < 0.05) differences among groups in average daily gain, feed conversion rate, feed intake and digestibility. The densification of WS and feeding in the form of feed block generally improved feed DM and nutrient intake and digestibility. The increase in the proportion of CM in the DCFBs also increased the DM and nutrient intake and digestibility. Heifer growth rate was higher (P < 0.05) in T1, T3 and T4 diets than T2 groups. Feed conversion ratio was higher (P < 0.05) both in T3 and T4 compared to T1 and T2. The total cost of production per each gram body weight gained was recorded higher (P < 0.05) for calves in the T2 group compared to calves in T1, T3 and T4. In conclusion, maintaining post weaned F1 heifer calves on DCFB composed of wheat straw and a commercial calf's concentrate based diet in the ratio of 40 to 60 would both biologically and economically feasible.

Prophylactic treatment with PEGylated bovine IFNλ3 effectively bridges the gap in vaccine-induced immunity against FMD in cattle.

Foot-and-mouth disease (FMD) is a vesicular disease of cloven-hoofed animals with devastating economic implications. The current FMD vaccine, routinely used in enzootic countries, requires at least 7 days to induce protection. However, FMD vaccination is typically not recommended for use in non-enzootic areas, underscoring the need to develop new fast-acting therapies for FMD control during outbreaks. Interferons (IFNs) are among the immune system's first line of defense against viral infections. Bovine type III IFN delivered by a replication defective adenovirus (Ad) vector has effectively blocked FMD in cattle. However, the limited duration of protection-usually only 1-3 days post-treatment (dpt)-diminishes its utility as a field therapeutic. Here, we test whether polyethylene glycosylation (PEGylation) of recombinant bovine IFNλ3 (PEGboIFNλ3) can extend the duration of IFN-induced prevention of FMDV infection in both vaccinated and unvaccinated cattle. We treated groups of heifers with PEGboIFNλ3 alone or in combination with an adenovirus-based FMD O1Manisa vaccine (Adt-O1M) at either 3 or 5 days prior to challenge with homologous wild type FMDV. We found that pre-treatment with PEGboIFNλ3 was highly effective at preventing clinical FMD when administered at either time point, with or without co-administration of Adt-O1M vaccine. PEGboIFNλ3 protein was detectable systemically for >10 days and antiviral activity for 4 days following administration. Furthermore, in combination with Adt-O1M vaccine, we observed a strong induction of FMDV-specific IFNγ+ T cell response, demonstrating its adjuvanticity when co-administered with a vaccine. Our results demonstrate the promise of this modified IFN as a pre-exposure prophylactic therapy for use in emergency outbreak scenarios.

Clinical and experimental substantiation of the use of reduced concentrations of FSH during superovulation in highly productive cows

The purpose of the studies was to substantiate the use of reduced concentrations of follicle-stimulating hormone to induce superovulation in highly productive cows and heifers. The research was carried out in one of the farms in the Leningrad region. After analyzing breeding cards and based on ultrasound visualization of the reproductive organs, promising animal embryo donors were selected - cows after the first calving and heifers that had reached physiological maturity, Holstein breed. According to the principle of analogues, groups of experimental animals Ⅰ and Ⅱ were formed, which included cows, and groups Ⅲ and Ⅳ, which included heifers, eight and six animals each, respectively. To induce multiple ovulation, hormonal treatment regimens were used, presented in Table 1. Hormonal treatment regimens were compiled in accordance with methodological recommendations on the procedure and conditions for applying the method of cattle embryo transplantation, as well as in accordance with the results of previously conducted studies and analysis of literary sources. As a result of the studies, it was established that all experimental animals responded equally to the hormonal regimen recommended by the manufacturer of exogenous gonadotropins and the experimental regimen, with a reduced concentration of the latter. It was revealed that there were no significant differences in the number of corpora lutea in the groups of cows and heifers when using a standard scheme for stimulating polyovulation and with a reduced content of follicle-stimulating hormone. There was also no difference between the experimental groups of cows and heifers in the number of embryos obtained. Analyzing the data obtained, we can conclude that it is advisable to use reduced concentrations of pituitary gonadotropins to stimulate multiple ovulation in highly productive cows and heifers.

Methods of artificial regulation of estrous cycle of Aberdeen Angus breeding stock

The research aim is to study the efficiency of using the OvSynch and Co-Synch schemes with subsequent resynchronization on beef cows and heifers of the Aberdeen Angus breed. The hormonal state of animals and the biochemical blood serum parameters were chosen as factors determining reproductive function. The purpose is to study the efficiency of applying the OvSynch and Co-Synch synchronization protocols on cows and heifers of the Aberdeen Angus breed depending on the hormonal state of the inseminated animals and the biochemical blood serum parameters. The rate of fertilization in cows inseminated according to the OvSynch protocol was determined to be 5.0 to 8.5 % higher during the first stage of insemination and 5.5 % higher during the second stage of insemination. In the group of heifers, the best fertilization results were obtained while using the Co-Synch protocol (59.3 %). Giving cows a second injection of GnRH, on day 9 of the OvSynch protocol, 16 hours before insemination, provided an average rate of fertilization of 52.3 %, which is 3.4 % higher compared to the 14-hour interval between GnRH injection and insemination. The concentration of steroid and gonadotropic hormones, including cortisol, estradiol, FSH and LH, in experimental animals during insemination corresponded to the estrus phase. The results of biochemical blood tests indicate a number of metabolic inconsistencies in the animal body. Changes in the biochemical blood serum parameters in animals that did not become pregnant followed the same patterns as in those that became pregnant. However, the level of increase or decrease in parameters was less pronounced. The results obtained can be used in arranging artificial insemination in breeding and commercial agricultural organizations engaged in beef cattle breeding, as well as in teaching process of zootechnical and veterinary disciplines in agricultural higher educational institutions of the Republic of Belarus.

Influence of genetic factors on productive traits of firstcalf heifers

The objects for the research were Holsteinized fi rst-calf heifers-daughters of sires with blood of 90 % or more of Holstein breed. In order to carry out the research three groups of first-calf heifers per 30 heads in each were formed. The 1st group included daughters of the sire Privelezh, the 2nd group included the daughters of the sire Alt Pilsner, and the 3rd group included the daughters of the sire Alt Tyson. The infl uence of sires on the productive traits of Holsteinized fi rst-calf heifers of Black-and-White breed was assessed under the conditions of the Petrovsky Agricultural Production Complex in the Bashmakovsky district of Penza region. It was revealed as a result of the research that the highest milk yield for 305 days of lactation was shown by the daughters of the sire Privelezh, which amounted to 9398 kg of milk and had a statistically signifi cant diff erence with the daughters of the sire Alt Pilsner – 3657 kg (Р &gt; 0,999) and with the daughters of the sire Alt Tyson – 3542 kg (Р &gt; 0,999). In terms of qualitative traits of milk productivity, the highest indicators were for fi rst-calf heifers of the 2nd and 3rd groups. For example, in terms of the mass fraction of fat the difference between cows of the 2nd and 1st groups was 0,16 abs.% (Р &gt; 0,95). Diff erences were revealed between the 1st and 2nd groups by 0,04 abs.% (Р &gt; 0,999). At the same time, due to higher milk yields animals of the 1st group exceeded their herdmates of the 2nd group in the yield of milk fat and protein by 127,92 kg (Р &gt; 0,95) and 111,67 kg (Р &gt; 0,999); 3rd group by 128,90 kg (Р &gt; 0,999) and 109,08 kg (Р &gt; 0,999), respectively. First-calf heifers of the 3rd group had the highest live weight (568,7 kg), the diff erence with their herdmates of the 1st group was 57,2 kg (Р &gt; 0,999). Animals of the 2nd group exceeded the first group by 53,0 kg (Р &gt; 0,999). The greatest variability in milk yield over 305 days of lactation was characterized by the 3rd group of cows (Cv=19,83 %) vice versa 17,45 and 18,92 % in the 1st and 2nd groups. First-calf heifers of the 1st group were distinguished by the greatest effi ciency and usefulness, although no significant differences were found between the groups. For example, per 1 kg of live weight, the Biological efficiency of a cow coefficient was 445,45 and the Cow biological f usefulness coefficient was 306,23.

Effects of Pasturella Multocida B:2 and its immunogens (LPS and OMP) on reproductive hormones in Nili-Ravi Buffaloes.

Livestock is a fundamental part of the agriculture industry in Pakistan and contributes more than 11.53% to GDP. Among livestock species, the buffaloes are regarded as the black gold of Pakistan. Being the highest milk producers globally, Nili-Ravi buffaloes are the most famous ones. Buffaloes are affected by many endemic diseases, and "Hemorrhagic septicemia" (HS) is one of them. This study was designed to ascertain the effects of experimental exposure ofP. multocida B:2 (oral) and its immunogens, i.e., LPS (oral and intravenous) and OMP (oral and subcutaneous) on reproductive hormonal profiles in Nili-Ravi buffaloes. Repeated serum samples were collected from the jugular vein of experimental animals for 21 days (0, 02, 04, 08, 12, 16, 20, 24, 36, 48, 72, 120, 168, 216, 264, 360, 456 and 504 hours). Hormonal assays to determine the serum concentrations of Gonadotropin-releasing hormone (GnRH), Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), Estrogen (E2) and progesterone (P4) were performed using (MyBioSource) commercial Elisa kits. The hormonal profile of all treatment groups of the buffalo heifers exhibited significant (P<0.05) variations as compared to the control group (G-1). These results indicate suppression in Nili-Ravi buffaloes' reproductive hormonal profile on exposure to P. multocida B:2 and its immunogens. This influence warrants that exposure to H.S may be a possible reason for delayed puberty and poor reproduction performance in Nili-Ravi buffaloes.

Баланс азота у ремонтных телок при разных схемах выпойки цельного молока в раннем возрасте

In a study conducted on replacement heifers (111–116 days), nitrogen balance was studied when different whole milk feeding schemes were used at their early age. According to the results of the experiment, it was found that that a decrease in the milk norm established on the farm of 375 liters did not subsequently lead to significant changes in the nitrogen balance and the dynamics of growth and development of replacement heifers. At the same time, the greatest efficiency of using nitrogen taken with feed was noted in the experimental group of heifers that received 345 liters of whole milk. With an additional reduction in milk drinking rates to 285 liters, an increase in the average daily feed consumption was detected in the experimental animals.

Efficiency of tissue biostimulant application in growing heifers

The materials of research on the effectiveness of tissue biostimulant application in the technology of breeding replacement heifers are presented. The experiment was conducted in the conditions of the Altai Territory on four groups of heifers of the Priobsky type of the Black-and-White breed with a live weight of 51.3 ± 1.48 kg at the age of 1 month. Each group had ten heads. The experiment lasted for 18 months. Animals of the control group were injected subcutaneously with physiological solution every month: from the 1st to the 5th month – at a dose of 3.0 ml/head, from the 6th to the 11th month – 6 ml/head, from the 12th to the 15th month – 12.0 ml/head and from the 16th to the 18th month – 15.0 ml/head. Injections of tissue biostimulant were given to the heifers of the experimental groups according to the following schemes: in the 1st experimental group – from the 1st to the 5th month – at a dose of 2.0 ml/head, from the 6th to the 11th month – 4 ml/head, from the 12th to the 15th month – 8.0 ml/head and from the 16th to the 18th month – 10.0 ml/head; in the 2nd experimental group – from the 1st to the 5th month – at a dose of 3.0 ml/head, from the 6th to the 11th month – 6 ml/head, from the 12th to the 15th month – 12.0 ml/head and from the 16th to the 18th month – 15.0 ml/head; in the 3rd experimental group – from 1st to 5th month – at a dose of 4.0 ml/head, from the 6th to the 11th month – 8.0 ml/head, from the 12th to the 15th month – 16.0 ml/head, from the 16th to the 18th month – 20.0 ml/head. Biostimulant is made of slaughter house tankage and by-products of the antler deer. The scheme of its application, used in the 2nd experimental group of animals, was the most effective and contributed to the increase in body weight in repair heifers up to 14% (p ˂ 0.001), average daily gain – up to 33% (p &lt; 0.001), absolute gain – up to 23% (p ˂ 0.001) and relative gain – up to 2% (p &lt; 0.05).

THE STUDY OF THE INSECTICIDAL EFFECTIVENESS OF CYFLUTHRIN WHEN CATTLE ARE AFFECTED BY CAUSATIVE AGENTS OF ECTOPARASITES

The article presents data on the determination of the insecticidal effectiveness of cyfluthrin for the damage of cattle caused by ectoparasites. Insecticidal efficiency was determined on groups of cattle of different sex and age groups. The research was carried out during the period of maximum intensity of infestation by ectoparasites. Counting of insects on the body of animals was carried out before their treatment, as well as on the 2nd, 7th, 15th and 30th day.&#x0D; According to the obtained data, in cows treated with a preparation based on cyfluthrin, the extent of bovicolosis invasion decreased already on the 2nd day and amounted to 23.3%, in the group of heifers of parous age, on the 2nd day after treatment, the extent of invasion was 22.2%, in the group of young animals, they noted a decrease in the extent of bovicolosis infestation on the 2nd day after treatment - 77.8%. The extent of invasion due to siphunculatosis in the group of cows treated with the drug on the 2nd day was 20.0%, in the group of heifers of mating age - 22.2%, in the group of young calves - 88.9%.&#x0D; The rate of extensibility for the treatment of groups of cows, heifers of mating age, as well as young animals on the 30th day of the experiment was 90.0, 91.5, and 91.1%, respectively. In cows treated with cyfluthrin, the intensity of invasion due to bovicolosis decreased already on the 2nd day and amounted to 43±3.1 exps/100 m2 of the skin of the animal’s body, in the group of heifers of mating age, the intensity of invasion was 46±2.1 exps/100 m2, in the group of young animals – 32±3.3 copies/100 m2. Intensity efficiency for processing groups of cows, heifers of mating age, as well as young animals on the 30th day of the experiment was 87.5%, 84.3% and 90.7%, respectively. The conducted set of studies established that when determining the effectiveness of cyfluthrin against bovicolosis and syfunculatosis, the intensity of treatment of groups of cows infested with hair-eaters on the 30th day of the experiment was 87.5%, among heifers of mating age, as well as young animals - 84.3 and 90.7 % respectively. The intensity efficiency indicator for the treatment of groups of cows, heifers of mating age, as well as young animals infested with lice, on the 30th day of the experiment was 87.0, 91.8 and 84.5%, respectively.&#x0D; Therefore, in vivo experiments, cyfluthrin showed high levels of insecticidal efficiency against causative agents of ectoparasites of cattle (sifunculat and bovicol).

PSXII-24 Examining Relationships Between Residual Feed Intake Classification, Enteric Emissions, and Apparent Total Tract Digestibility in Late Gestation Beef Heifers

Abstract Improving feed efficiency on forage-based systems can be an important tool for beef producers to reduce their environmental footprint. The objective of this project is to assess the relationship between traditional residual feed intake (RFI) efficiency classification, enteric gas emissions, and apparent total tract nutrient digestibility in late gestation beef heifers. Pregnant Angus crossbred heifers in late gestation (n = 72, BW = 576 ± 45.8 kg) were blocked by expected calving date and randomly assigned to pen groups. Heifers had ad libitum access to a common haylage-based diet formulated to meet nutritional requirements for the last eight weeks of gestation. Individual feed intake and behavior data were recorded daily using Insentec feeding stations (Insentec B.V., Marknesse, The Netherlands). Groups of heifers were rotated through pens with access to GreenFeed trailers (C-Lock Inc., Rapid City, SD, USA) to measure enteric gas emissions of methane (CH4), carbon dioxide (CO2), and oxygen (O2). To determine individual apparent total tract digestibility, fecal samples were collected from each heifer every 9 h over three days, mixed, dried at 65 °C for 96 h, and analyzed for nutrient values (A&amp;L Canada Laboratories, London, ON, Canada). Nutrient digestibility was determined for each heifer using acid-insoluble ash (AIA) and undigestible neutral detergent fiber (uNDF) as internal markers. Heifer RFI was determined using predicted DM intake as a regression of midpoint BW and ADG, and heifers were classified by RFI quartile group. Data were analyzed using PROC GLIMMIX in SAS, with efficiency quartile group as the fixed effect and pen as a random effect, comparisons between quartile groups were assessed with a Tukey test. Heifers classified as efficient (lowest RFI) had decreased DMI (8.2 vs 10.7 ± 0.21 kg/d, P &amp;lt; 0.01), less bunk visits (43 vs 64 ± 5 visits/day, P &amp;lt; 0.01) and greater time per visit (4.8 vs 3.0 ± 0.53 min/visit, P = 0.05). Efficient heifers also had reduced CH4 (219 vs 245 ± 6.2 g/d, P = 0.03) and CO2 (7,517 vs 8,074 ± 165.9 g/d, P = 0.01) emissions compared with inefficient (greatest RFI) heifers. However, apparent total tract digestibility of organic matter, crude protein, NDF, ADF, starch, and sugar using AIA (P &amp;gt; 0.08) or uNDF (P &amp;gt; 0.06) as internal markers were not correlated with heifer efficiency. These data indicate that more efficient heifers in late gestation consume less feed and have reduced enteric emissions, despite no differences in apparent total tract digestibility.

Combined single-step evaluation of functional longevity of dairy cows including correlated traits

BackgroundFor years, multiple trait genetic evaluations have been used to increase the accuracy of estimated breeding values (EBV) using information from correlated traits. In France, accurate approximations of multiple trait evaluations were implemented for traits that are described by different models by combining the results of univariate best linear unbiased prediction (BLUP) evaluations. Functional longevity (FL) is the trait that has most benefited from this approach. Currently, with many single-step (SS) evaluations, only univariate FL evaluations can be run. The aim of this study was to implement a “combined” SS (CSS) evaluation that extends the “combined” BLUP evaluation to obtain more accurate genomic (G) EBV for FL when information from five correlated traits (somatic cell score, clinical mastitis, conception rate for heifers and cows, and udder depth) is added.ResultsGEBV obtained from univariate SS (USS) evaluations and from a CSS evaluation were compared. The correlations between these GEBV showed the benefits of including information from correlated traits. Indeed, a CSS evaluation run without any performances on FL showed that the indirect information from correlated traits to evaluate FL was substantial. USS and CSS evaluations that mimic SS evaluations with data available in 2016 were compared. For each evaluation separately, the GEBV were sorted and then split into 10 consecutive groups (deciles). Survival curves were calculated for each group, based on the observed productive life of these cows as known in 2021. Regardless of their genotyping status, the worst group of heifers based on their GEBV in 2016 was well identified in the CSS evaluation and they had a substantially shorter herd life, while those in the best heifer group had a longer herd life. The gaps between groups were more important for the genotyped than the ungenotyped heifers, which indicates better prediction of future survival.ConclusionsA CSS evaluation is an efficient tool to improve FL. It allows a proper combination of information on functional traits that influence culling. In contrast, because of the strong selection intensity on young bulls for functional traits, the benefit of such a “combined” evaluation of functional traits is more modest for these males.

Influence of premix for dairy cattle on milk productivity and milk quality of simmental breed cows

The paper shows the results of testing a new premix developed by scientists of the North Kazakhstan University named after M. Kozybayev. The aim of the study was to determine the effectiveness of the new premix compared to the manufactured P-60-1. For this purpose, 3 groups of heifers of 10 heads were formed (1 – control, 2 group – diet with premix PSVM-1, 3 group – PSVM-2). The inclusion in the concentrate part of the silage-hay-hay rations of heifers instead of the premix P-60-1 produced by the feed industry, the premixes PSVM-1 and PSVM-2 developed by us allowed us to increase the concentration in the dry matter of the cobalt rations to 0,49 mg, copper – to 8,60–8,67 mg, zinc – to 30,4–30,6 mg, manganese – up to 44–45 mg, vitamin A – up to 3250–3300 м.е. and vitamin D – up to 1289–1276 м.е. The milk yield of the experimental groups of animals at a probability level of p&lt;0,05 exceeded the control by 1,5 kg per day. The content of milk fat in the colostrum of cows of group 3 increased (6,18±0,18% versus 5,13±0,16 in the control) and vitamins A and D, which is very important for the normalization of metabolism in the body of a newborn calf at a probability level of p&lt;0,001. Enriching the diet of animals with vitamin and mineral complex allowed the heifers of the experimental groups to get more growth live weight from 72 to 140 g in the third group per day at p&lt;0,001.

Optimization of Age at Maturity in Surti Buffalo Heifers with Dietary Supplementation of Bypass Protein and Bypass Fat

Surti buffaloes heifers reared under ideal feeding and managemental practices achieve puberty, sexual maturity and first calving at the optimum desired age and body weight. In growing heifers during first parity, requirement of high plane of nutrition is obvious to meet the demands of body growth of dam, growth of fetus, and galactopoetic functions. This study was aimed to find out the effect of feeding bypass protein and bypass fat right from the age of puberty up to the age of first successful conception, i.e. maturity in Surti buffalo heifers. Sixteen Surti buffalo heifers were allotted in four equal groups (n=4 in each group), viz., Control (T-1) fed basal diet following ICAR nutrient requirements, T-2 basal diet + 30 % protein of concentrate mixture replaced with formaldehyde treated guar meal (FTGM), T-3 basal diet + 100 gm bypass fat (BF), and T-4 basal diet + 30 % protein of concentrate mixture replaced with FTGM + 100 gm of BF. All the treatment diets were isonitrogenous. The results revealed that there was beneficial effect of feeding by pass protein and bypass fat along with routine feeding management on growth of heifers in terms of the body wt. gain and reduced age at first conception (maturity) and thereby age at first calving (AFC). AFC reduced to 37.25, 37.87 and 33.37 months, respectively, in T2, T3 and T4 groups respectively; compared to 43.75 months in Control group. Further, the net benefit over control, in the group of heifers fed with FTGM alone and FTGM plus BF groups were 22.90 % and 16.40 % respectively.

Udder Volume and Teat Size of Friesian Holstein Dairy Cows from Post-Weaning Calves to Pregnant Heifers

This study aimed to evaluate the development of udder volume, teat circumference and teat length of Holstein Friesian (HF) dairy cows from post-weaning calves to pregnant heifers. The materials used in this study were 60 heifers. The research was conducted by observational method. The groupings of heifers were 1st group (heifer age 4-8 months), 2nd group (heifer age 9-12 months), 3th group (heifer age ≥ 13 months but not yet pregnant), 4th group (gestational age 1-3 months), 5th group (gestational age 4-6 months), 6th group (gestational age 7-9 months). The parameters were udder volume, teat circumference, teat length, heifer age and gestational age. Data analysis used t-test to examine differences in udder volume and teat size between groups of heifers. Linear regression analysis was used to find the relationship between udder volume and teat size with heifer age and gestational age. The results showed that the udder volume, teat circumference, and teat length showed significant differences (P<0.05) between the heifer groups. The 6th group was significantly higher (P<0.05) than the other groups, namely udder volume of 8149.57 cm3, teat circumference of 6.97 cm and teat length of 6.01 cm. There was a significant relationship between udder volume (Y) and heifer age (X), namely Y = -297.204 + 100.801X (R2 = 0.823). While the udder volume (Y) with gestational age (X) has the equation Y = 993.711 + 889.841X (R2 = 0.772). It can be concluded that the increasing heifer age and gestational age, the volume of udder and teat size will increase.

Examination of the haematological profile of pregnant Polish Holstein-Friesian black-and-white cattle in the early stage.

Cattle health and welfare are monitored via the analysis of the haematological profile, and it shows cattle's ability to adapt to changing environmental conditions, pregnancy and lactation; profile changes also indicate reproductive disorders. The literature lacks reports of the examination of the haematological profile in cows up to the 50th day of pregnancy (dop). Therefore, this research examined that in cows up to this pregnancy stage. A total of 101 Polish Holstein-Friesian black-and-white cows were divided into groups. The control groups consisted of non-pregnant heifers (group C00) and non-pregnant cows (group C0), and the experimental groups were pregnant heifers (group T1 at dop ≤ 28 and group T2 at dop ≥ 29-dop < 45) and pregnant cows (group T3 at dop ≥ 29-dop ≤ 50). In addition, the T3 group was divided into cows pregnant for up 45 dop and cows between 45 and 50 dop. Blood samples were collected in March and April 2021 from each animal and analysed. A transrectal ultrasound examination was performed to detect and confirm pregnancy. Statistically significant differences (P ≤ 0.01) between the group of cows at dop < 45 dop and those at dop ≥ 45-dop ≤ 50 dop were noted in granulocyte percentage (GRA%), white and red blood cell counts (WBC/RBC), platelets (PLT), platelet distribution width (PDW), haematocrit (HCT) and lymphocyte percentage (LYM%). No statistically significant differences were found in the mean corpuscular haemoglobin, monocytes (MON), monocyte percentage (MON%), mean platelet volume (MPV), thrombocrit or red blood cell distribution width (RDW). Similar statistically significant differences (P ≤ 0.01) emerged between the groups of heifers in PLT, GRA, RBC, lymphocytes, LYM% and HCT, and no significant differences were found between MPV, MON, MON% or RDW. Examining the haematological profile in high-yielding cattle is vital in maintaining herd profitability and high reproduction, which depend on the quick diagnosis of disorders facilitated by haematology. This study analysed the haematology profile of dairy cattle at dop ≤ 50 for the first time, indicating changes in lymphocyte levels, which suggests that the animals experienced direct stress during the study.