Increased Milk Yield Research Articles

Boswellia sacra resin as a phytogenic feed supplement to enhance ruminal fermentation, milk yield, and metabolic energy status of early lactating goats

Boswellia sacra resin (BS) is well known for its antimicrobial, antioxidant, and anti-inflammatory properties and hence could be used as an efficient dietary feed additive for ruminants during the transition period. This study was conducted to determine the effects of BS by characterizing the ruminal fermentation, nutrient digestibility, milk production, and energy status of early lactating goats fed different levels of BS. A total of 21 late pregnant Nubian goats (initial body weight 26.3 ± 3.9 kg) were stratified using a completely randomized design to the following three dietary treatments (n = 7 does/treatment): control (without supplementation of BS) and BS treatments; low BS and high BS received 2 and 4 g BS/day/animal, respectively. The treatments were started 2 weeks before parturition and continued till 7 weeks postpartum. Constituents with high biological activity (e.g., bisabolene, limonene, α-pinene, and α- and β-amyrins) were the most abundant components found in experimental BS. Linear reductions (P < 0.01) in acetate molar proportions consistent with linear increases (P < 0.01) in propionate molar proportions and linear (P = 0.01) decreases in total short-chain fatty acids (SCFAS) concentrations by BS treatments. The branched-chain volatile fatty acids were quadratically decreased (P < 0.05) by BS supplementation compared with the control. Supplementation of BS resulted in linear decreases (P < 0.01) in blood plasma glucose, nonesterified free fatty acid, and β-hydroxybutyrate concentrations compared with control. Treatment of BS resulted in linear increases (P < 0.05) in milk yield, energy-corrected milk, net energy for lactation, and feed efficiency without causing adverse effects on nutrient digestibility or dry matter intake compared with control. Goats fed BS had linear reduction (P = 0.04) in milk somatic cell count values compared with control. These results suggested that BS could be used as a novel promising natural dietary feed additive to support the transition of goats from late pregnancy to lactation.

Uneven milking intervals are adequate to achieve the benefits of increased milking frequency in early lactation

Increasing milking frequency (MF) increases milk yield (MY) and farm profit, and optimal milking intervals (MI) prevent milk production decline. The objective of this experiment was to compare the MY effect of even and uneven 4 times daily (4×) MI in early lactation under increased MF. Fourteen multiparous and 6 primiparous cows were milked using unilateral frequent milking, with right udder halves milked 4× and left udder halves milked 2 times daily (2×) for 20 d in early lactation starting on d 5 postpartum. Ten (7 multiparous and 3 primiparous) cows were allocated evenly based on parity and assigned to either the even or the uneven MI groups distinguished by intervals of 9:3:9:3 h or 6:6:6:6 h. The left and right udder halves were milked at 0100 and 1300 h. The right udder glands were additionally milked at 0400 and 1600 h for the uneven MI group and at 0700 and 1900 h for the even MI group. Milk from each udder half was weighed and sampled for components on the final day of treatment and at 60, 120, 180, 240, and 300 d in milk. The overall effect of 4× milking on the right udder halves was a 5.96 ± 0.70 kg/d increase in MY on d 21 of unilateral frequent milking compared with the 2× udder halves. This elevated MY continued through 300 d in milk and averaged 1.56 ± 0.70 kg/d. Increased MF in early lactation increased the udder half difference in total yield throughout a 300-d lactation by 508 kg for milk, 25 kg for milk fat, and 15 kg for milk protein. Increased MF in early lactation increased milk component yields, but there were no differences between MI groups. The lack of treatment difference may be beneficial to farmers. The ability to achieve the same increased MY effect with uneven MI may optimize labor efficiency because early-lactation cows could be milked at the beginning and end of milking sessions. Farmers would not have to add additional milking sessions to achieve the enhanced MY response regardless of normal milking session length.

Effects of rumen-protected methionine supplementation on the performance of high production dairy cows in the tropics

Increasing methionine availability in dairy cow diets during the first third of lactation may enhance their performance and health. The aim of this study was to determine the effect of supplementing rumen-protected methionine (Smartamine® M, SM) in a lactation diet with protein and energy levels calculated according to the literature. Seventy-six multiparous Holstein cows (39.1 ± 6.8 kg of milk/d and 65 ± 28 DIM) were assigned to 1 of 2 dietary treatments (38/treatment) according to a randomized complete block design with a 2-wk (covariate) and 10-wk experimental period. Treatments were a basal diet (CON; 3.77 Lys:1Met); and CON + 23 g SM (2.97 Lys:1 Met). Individual milk samples were taken every 2 weeks to determine milk composition. Blood was collected from 24 cows on d+30 d to measure plasma AA levels. Body weight and body condition score (BCS) were measured at the beginning and the end of the experiment. The SM diet promoted higher milk yield (41.7 vs. 40.1 kg/d; P = 0.03). Energy-corrected milk yield (41.0 vs. 38.0 kg/d), milk protein yield (1.30 vs. 1.18 kg/d), milk protein (3.14% vs. 2.97%) and casein (2.39% vs. 2.28%) were also different (P < 0.01) as well as milk fat yield (1.42 vs. 1.29 kg/d; P = 0.02). A trend (P = 0.06) for higher milk fat % (3.41% vs. 3.21%) was observed. Both diets resulted in similar body weight, but CON-fed cows tended (P = 0.08) to have higher BCS. Higher plasma methionine levels were determined with SM compared with CON (29.6 vs. 18.4 μM; P < 0.01), but lysine and histidine were not different. Dietary supplementation of RPM improved productive performance by increasing milk yield and milk components yields, suggesting better dietary AA utilization when Met levels are adjusted in Lys-adequate lactation diets.

Associations between feed efficiency and aspects of lactation curves in primiparous Holstein dairy cattle

Genetic selection for improved feed efficiency in dairy cattle has received renewed attention over the last decade to address the needs of a growing global population. As milk yield is a critical component of feed efficiency metrics in dairy animals, our objective was to evaluate the associations between feed efficiency in primiparous Holstein cattle and parameters of a mathematical model describing individual lactation curves. The Dijkstra lactation curve model was fit to individual lactation records from 34 Holstein heifers with previously estimated measures of feed efficiency. We found that the optimal fit of the Dijkstra model was achieved using daily milk yield records up to 21 d in milk to capture the rise to peak milk yield and using monthly dairy herd improvement records for the remainder of lactation to accurately characterize lactation persistency. In the period of lactation before peak milk yield, improved feed efficiency was associated with a faster increase in daily milk yield over a shorter period of time at the expense of increased mobilization of body reserves; this serves to reinforce the concept that dairy cattle are primarily capital breeders versus income breeders. Feed efficiency in the period following peak lactation, as measured by gross feed efficiency, return over feed costs, and net energy efficiency of lactation, was positively associated with higher peak milk yield. The findings in early lactation suggest that estimates of feed efficiency could be improved by evaluating feed efficiency relative to conception, rather than parturition and lactation, to better account for the energy stored and released from body reserves in capital breeding.

Effect of Chlorophytum borivilianum supplementation on milk production, composition and fatty acid profile in crossbred cows during hot-humid season.

The present investigation was carried out to test the efficacy of Chlorophytum borivilianum (CB) supplementation on milk production, composition, and fatty acid profile in crossbred (KF) cows. Eighteen crossbred cows were selected randomly from the institute herd and divided as control (n = 6), treatment 1 (T1, n = 6) and treatment 2 (T2, n = 6) based on body weight (av. 410.45, 424.47, 414.45 kg) and milk yield (av. 15.17, 15.80, 15.95 kg/d), respectively. The CB was supplemented at low dose at a dose rate of 40 mg/kg BW/day (T1) and high dose at a dose rate of 80 mg/kg BW/day (T2) during hot-humid (HH) season. The parameters like milk yield, dry matter intake (DMI), and body weight were recorded and milk composition viz., milk fat, solid not fat (SNF), protein, and fatty acid profile, somatic cell count (SCC), and plasminogen were estimated. Temperature humidity index (THI) was calculated to assess the level of heat stress on animals during hot-humid (HH) season. Body weight of crossbred cows did not vary between the groups during HH season. C. borivilianum supplementation in higher dose (80 mg/kg BW/day) increased DMI (per 100 kg BW) (p < 0.01) in T2 group KF cows in comparison to T1 and control group. The supplementation of CB in high dose increased milk yield, milk fat, protein, plasminogen and decreased SCC in comparison to low dose and control. Further, ratio of saturated to unsaturated fatty acids (SFAs:UFAs) was significantly reduced (p < 0.01) due to CB supplementation at higher dose in comparison to lower dose. It was concluded that supplementation of C. borivilianum at a dose rate of 80 mg/kg BW/day was found effective to augment milk production. The reduced saturated fatty acid, milk SCC, and the increase in unsaturated fatty acid content of milk, milk plasminogen suggest that its supplementation could be used in improving the mammary health and quality of milk production in dairy animals.

Influence of Cane Molasses Inclusion to Dairy Cow Diets during the Transition Period on Rumen Epithelial Development.

Simple SummaryThe rumen epithelium of dairy cattle undergoes a transformation in response to dietary and physiological changes. Rumen papillae development and adaptation from a typical dry cow diet to a lactating diet can require a substantial amount of time, subsequently limiting the amount of volatile fatty acids (VFA) absorbed from the rumen during early lactation. Infusions of butyrate into the rumen of sheep stimulates cellular proliferation of rumen epithelial tissue, which may prove beneficial for ruminal papillae development in dairy cows during the dry period. However, no studies have investigated mechanisms associated with rumen epithelial adaptation in periparturient dairy cattle. Our hypothesis was that supplementation with cane molasses containing 34% sucrose during the prepartum period would stimulate ruminal butyrate production and ultimately promote ruminal papillae development and absorption rate, thus increasing dry matter intake (DMI) and milk production during the postpartum period. Results from these experiments indicate that diets containing cane molasses during a 60 day dry period can positively influence transition cow performance. The objective of this study was to evaluate the addition of cane molasses during a 60 day dry period on performance and metabolism of Holstein cows during prepartum and postpartum periods. For experiment 1, 26 primiparous and 28 multiparous cows were used. Upon freshening, all cows were offered a common lactation diet. For experiment 2, six multiparous cows fitted with rumen cannulas were used to measure performance and metabolism, following the same protocol as experiment 1. Ruminal propionate increased by 10% during both prepartum and postpartum periods; however, papillae area was greater for cows not fed molasses, and volatile fatty acids (VFA) absorption from the rumen was not increased, resulting in similar glucagon-like-peptide-2 receptor (GLP-2R) density. The improved dry matter intake, when molasses was added into prepartum diets, translated into increased milk yield and energy-corrected milk (ECM) in Experiment 1 only for multiparous cows. For experiment 2, the improvement on milk performance was also observed, where cows fed molasses had 18.5% greater ECM production. Feeding molasses during a 60 day dry period positively influenced transition cow performance, and it was not accompanied by changes in rumen morphometrics; however, this indicates enhanced adaptation by the rumen epithelium based on similar capabilities for VFA absorption.

Plasma albumin-to-globulin ratio before dry-off as a possible index of inflammatory status and performance in the subsequent lactation in dairy cows

The dry-off of dairy cows represents an important phase of the lactation cycle, influencing the outcome of the next lactation. Among the physiological changes, the severity of the inflammatory response can vary after the dry-off, and this response might have consequences on cow adaptation in the transition period. The plasma protein profile is a diagnostic tool widely used in humans and animals to assess the inflammatory status and predict the outcome of severe diseases. The albumin-to-globulin ratio (AG) can represent a simple and useful proxy for the inflammatory condition. In this study, we investigated the relationship between AG before dry-off and inflammation, metabolic profile, and performance of 75 Holstein dairy cows. Blood samples were collected from -62 (7 d before dry-off) to 28 d relative to calving (DFC) to measure metabolic profile biomarkers, inflammatory variables, and liver function. Daily milk yield in the first month of lactation was recorded. Milk composition, body condition score, fertility, and health status were also assessed. The AG calculated 1 wk before dry-off (-62 DFC) was used to retrospectively group cows into tertiles (1.06 ± 0.09 for HI, 0.88 ± 0.04 for IN, and 0.72 ± 0.08 for LO). Data were subjected to ANOVA using the PROC MIXED program in SAS software. Differences among groups observed at -62 DFC were almost maintained throughout the period of interest, but AG peaked before calving. According to the level of acute-phase proteins (haptoglobin, ceruloplasmin, albumin, cholesterol, retinol-binding protein), bilirubin, and paraoxonase, a generally overall lower inflammatory condition was found in HI and IN than in the LO group immediately after the dry-off but also after calving. The HI cows had greater milk yield than LO cows, but no differences were observed in milk composition. The somatic cell count reflected the AG ratio trend, with higher values in LO than IN and HI either before dry-off or after calving. Fertility was better in HI cows, with fewer days open and services per pregnancy than IN and LO cows. Overall, cows with high AG before dry-off showed an improved adaptation to the new lactation, as demonstrated by a reduced systemic inflammatory response and increased milk yield than cows with low AG. In conclusion, the AG ratio before dry-off might represent a rapid and useful proxy to evaluate the innate immune status and likely the ability to adapt while switching from the late lactation to the nonlactating phase and during the transition period with emphasis on early lactation.

Genetic Polymorphism in Prolactin Gene and its Effect on Test Day Milk Production Traits in Sahiwal Cattle

Background: The selection of genetically superior animals at an early stage of life, the molecular markers are used along with traditional selection. The study was carried out to identify the genetic polymorphism in the exon3 region of the Prolactin and enumerate its effect on milk production performance in Sahiwal cattle. Prolactin plays an imperative regulatory role in mammary gland development, milk emission and lactogenesis. Analysed the sequence of this gene to explore whether mutations in this sequence and it could be accountable for quantitative variations in milk production and its composition traits.Methods: Total DNA was isolated from the blood samples of 98 pedigreed Sahiwal population. Using PCR-RFLP method and direct sequencing, noticed a single-nucleotide polymorphism in exon3 region of the Prolactin gene in 156bp and also the effect of non- genetic factors on each trait was assessed by least-squares analysis for non-orthogonal data by a fixed model.Result: PCR-RFLP was done with RsaI restriction endonuclease for the identification of different genotypes. The frequency of G and A alleles of the Prolactin gene was evaluated as 0.575 and 0.425, whereas the frequencies of GG, GA and AA genotypes for the Prolactin gene were 0.45, 0.25 and 0.30, respectively. SNP (G55A) conferred an increase in test-day milk yield around 321.5g, in test day fat yield around 13.9g and in test day SNF yield increase was 19.4g, respectively. High correlation was perceived from test day (TD2) onwards between test day traits and lactation milk yield indicating that selection based on identified SNP in TD2 increased test day milk yield, fat yield and SNF yield by 1.1472 kg, 29.6gm and 45.4gm, respectively.

Selection and Breeding of Dairy Cattle in Western Siberia

The main objective of stock breeding is to raise highly productive animals, improve existing ones and create new types and breeds of livestock. The main focus of dairy cattle breeding is on increasing milk yield, fat and protein content in milk; preserving fertility and productive longevity; and developing high adaptive properties of suitability for modern industrial technologies. Selection and breeding of black-and-white and red steppe breeds of cattle is aimed at improving the breeding and productive qualities of the animals. These breeds are traditionally raised in Western Siberia. Breeding to improve the economic and productive features of black-and-white and red steppe breeds of cattle led to the creation of new zonal types, including the Priobsky, Kulunda and Siberian zonal types, which are characterized by relatively high dairy productivity. This study showed that the Siberian type of heifers had the maximum milk yield – 6389 kg, which was 1239 kg and 828 kg more than the Kulunda and Priobsky types, respectively. The same tendency was observed for the third lactation. Animals with a dry period of less than 40 days had lower milk yields than those with a longer period. In terms of the amount of milk and the weight fraction of fat and protein in the milk, the animals exceeded the standard for the parental breed. The duration of pregnancy among the studied animals was within the physiological norm – 276.1-280.8 days. The research results may be of interest to agricultural students and specialists involved in selection issues.&#x0D; Keywords: reproduction, breed, milk productivity

Development and study of the effectiveness of a biologically active drug in the diet of sows

Many researchers note the need to improve feed additives and the search for new promising drugs for the intensification of the pig industry. We have developed a biologically active complex drug Microlact. It is used by animals as a means aimed at correcting the disturbed metabolism of sows associated with pregnancy and lactation, to activate the growth and development of piglets as well as their viability. The purpose of the work was to develop and study the effectiveness of the biologically active drug in the diet of lactating sows. The use of the drug led to the improvement of biochemical parameters of blood of pregnant sows, indicating the activation of metabolic processes in their body, which provided the increase in milk yield of sows, average daily weight gain of piglets and their livability. The live weight of piglets for weaning increased by 8,0% (P &lt; 0,01), the livability of suckling piglets increased to 93,1%, which is a consequence of improving the quality of colostrum and milk, and consequently the positive effect of the biologically active drug containing an optimal complex of minerals, vitamin E in the composition of malt sprouts, essential amino acids and organic form of selenium. More nutritious colostrum and milk contributed to the better development of the piglets’ body and resistance to adverse factors. Immunoglobulins have been obtained by piglets with colostrum and milk increase their resistance and contribute to higher livability. The increase in the weight of suckling pigs has a positive effect on the further development and growth of animals on fattening. Thus, the administration of the biologically active drug Microlact to sows during pregnancy leads to the activation of metabolic processes, which can only be provided by a high level of functioning of the organs and systems of the body.

Productive and Reproductive Performance of Syrian Shami Cows

The objectives of this study were to characteristic productive and reproductive traits of native Shami cows in Syria and to study the effect of nongenetic factors on their productive and reproductive traits. In this study, 2654 records were collected on 605 cows from 1980 to 2010 of Deir al-Hajar station in Syria. Data were analysed using the General Liner Model (XLSTATE. 2019). The least squares means for age at first calving (AFC), calving interval (CI), total milk yield (TMY), daily milk yield (DMY), lactation period (LP) and dry period (DP) were 30.9±0.16 months, 454±0.16 days, 1503±0.16 kg, 9.1±0.16 kg, 163±0.16 days and 292±34 days, respectively. The results showed that year of birth had a significant (p < 0.01) effect on age at first calving. While season of birth haven’t significant effect on (AFC). Also, results showed that year of calving and parity had a significant (p < 0.01) effect on all studied traits. Season of calving had significant (p < 0.01) effect on all studied traits except for dry period. Improve management conditions and genetic improvement for Syrian native Shami cows could be improve reproductive performance that leads to increase milk yield and number of calvings of their cows.

Effects of dietary 25-hydroxyvitamin D3 on the lactation performance, blood metabolites, antioxidant and immune function in dairy cows

The objective of this study was to evaluate the effects of 25-hydroxyvitamin D3 on the lactation performance, blood metabolites, and antioxidant and immune function in dairy cows. Thirty-six mid-lactation Holstein dairy cows were blocked according to day in milk, milk yield and somatic cell counts (SCC) and were randomly assigned to 3 treatments. Treatments were a basal diet plus 0 mg, 1 mg or 3 mg 25-hydroxyvitamin D3 per cow per day throughout a 9-week trial period. Cows were milked three times daily, and dry matter intake and milk yield were measured daily. Milk components were sampled at days 0, 21, 42 and 63 for milk fat, protein, lactose and SCC analysis. Blood was sampled for blood metabolites, parameters of antioxidant and immune function at days 0, 21, 42 and 63. Dairy cows fed 25-hydroxyvitamin D3 showed linear increases (P < 0.05) in milk yield, energy-corrected milk, milk protein and lactose yield and a decrease in somatic cell counts in milk (P < 0.01). Feeding dietary 25-hydroxyvitamin D3 linearly increased serum total Ca, P, 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 and had no negative effect on blood biochemical parameters and markers of fat mobilization. Additionally, dietary 25-hydroxyvitamin D3 linearly increased (P < 0.05) total antioxidant capacity, total superoxide dismutase, glutathione peroxidase, immunoglobulin A and immunoglobulin G and linearly decreased (P < 0.05) malondialdehyde and tumor necrosis factor-α. In summary, dietary supplementation with 25-hydroxyvitamin D3 increased milk yield and decreased SCC, improved serum minerals, 25-hydroxyvitamin D3 levels, and antioxidant and immune function of dairy cows.

DISINFECTANTS FOR SANITARY TREATMENT OF THE SKIN OF THE ELDER OF LACTING COWS

The article highlights the relevance of udder hygiene, sources of milk contamination with microflora, udder treatment requirements, sanitary condition control of the teats skin of cow udders, as well as a list of udder treatment products authorized in Ukraine.&#x0D; Proper preparation of udder teats for milking, namely: treatment with special detergents and disinfectants, compliance with the correct milking procedure significantly reduce the risk of cows with mastitis and increase milk yield. The content of microorganisms in milk shows the hygiene of milking cows, animal health, and the presence of pathogenic and technologically dangerous microorganisms.&#x0D; Bacterial contamination of milk is significantly increased due to udder diseases in cows. This increases the bacterial contamination of milk with pathogenic microbes, and the milk becomes unfit for consumption and processing (milk from cows with mastitis must be disposed of) milking procedure significantly reduce the risk of mastitis in cows and increase milk yield.&#x0D; It is necessary to prevent the penetration of microbes into the teat duct for prophylactic mastitis measures Special products should be used to treat the udder after milking. These products have certain requirements, the main of which are: the ability to quickly destroy bacteria; to keep the skin of the teats in good condition; to protect the teat between milking; easy to wash off before milking to eliminate the risk of getting into the milk.

Effects of ground, steam-flaked, and super-conditioned corn grain on production performance and total-tract digestibility in dairy cows

This study aimed to evaluate the effects of feeding ground, steam-flaked, or super-conditioned corn on production performance, rumen fermentation, nutrient digestibility, and milk fatty acid (FA) profile of lactating dairy cows. Twenty-four lactating Holstein cows (130 ± 12 d in milk) in a completely randomized block design experiment were assigned to 1 of 3 treatments that contained 31% of one of the following corn types: (1) ground corn; (2) steam-flaked corn; and (3) super-conditioned corn. Actual milk yield was greater in the super-conditioned corn diet than in the steam-flaked and ground corn diets. Dry matter intake, 3.5% fat-corrected milk and energy-corrected milk remained unaffected by treatments; however, milk fat concentration decreased in the super-conditioned corn diet compared with the ground and steam-flaked corn diets. The molar proportion of ruminal acetate decreased in the super-conditioned corn diet compared with the ground and steam-flaked corn diets, whereas the molar proportion of propionate spiked in the super-conditioned corn diet. Ruminal pH dropped in cows fed super-conditioned corn compared with the other 2 diets. A similar pattern was observed for ruminal NH3-N and acetate-to-propionate ratio. Total-tract starch digestibility increased the most in the super-conditioned corn diet followed by the steam-flaked and ground corn diets (96.8, 95.1, and 92.5%, respectively). The neutral detergent fiber digestibility declined in cows fed the super-conditioned corn diet as opposed to other diets (~3.9%). The concentrations of 16:0 and mixed-FA in milk fat dropped in the super-conditioned corn-based diet compared with the ground corn diet. Milk trans-10 18:1 FA increased, whereas trans-11 18:1 FA decreased in cows fed the super-conditioned diet. We concluded that super-conditioned corn has the potential to increase milk yield and starch digestibility in lactating dairy cows; however, reduced milk fat output caused by altering ruminal pH and ruminal FA biohydrogenation pathways may not be desirable in certain markets. Future research is warranted to investigate how super-conditioned corn affects feed efficiency.

СОВРЕМЕННЫЕ АСПЕКТЫ КОРМЛЕНИЯ МОЛОЧНЫХ КОРОВ

Research on the study of differentiated feeding of cows was carried out in the conditions of OOO “Krasnoe Sormovo” of Krasnoarmeyskiy district of Chuvash Republic. For the experiment, one control and experimental groups of cows were formed, each containing 150 heads. The control animals remained on the farm ration. The cows of the experimental group were fed with differentiated diets according to their productivity and physiological state. The first experimental group consisted of cows with a daily milk yield of 25 kg and more, the second - from 18 to 25 kg, the third - below 18 kg. The diets of dry cows were also revised: we proposed dividing the drying-off period into two stages: far-off dry period (from 8 to 3 weeks before calving) and close up dry period (from 3 weeks before calving). The principal feature of feeding in the experimental groups was that the rations were balanced directly in terms of crude protein and energy. The share of basic or bulk feed was 50% in the structure of the ration. The amount of concentrated feed was calculated taking into account the eatability of the main feed. Maintaining of balanced feeding was achieved through constant monitoring of the diet for quality parametres of milk, body condition and feces consistency. The research focused on a comparative assessment of milk productivity of cows in the control and experimental groups. Analysis of productive parametres of the cows showed a significant increase of milk yield of experimental animals for 305 days by 472 kg, an increase of daily milk yield by 1.8 kg per head. The results obtained indicate that the application of differentiated feeding of cows is advisable, as it contributes to an increase of their milk productivity. Therefore, we recommend using this strategy in feeding of dairy cows.

Effect of protein level and methionine supplementation on dairy cows during the transition period

Cows experience a significant negative protein balance during the first 30 d of lactation. Given the functional effects of AA on health, especially in challenging periods such as calving, higher levels of protein and specific AA in the diet may act to improve health and feed intake. The response of dairy cows to 3 protein supplementation strategies during the transition period and through the first 45 d in milk was evaluated. The final data set had 39 Holstein cows blocked based on parity (primiparous vs. multiparous) and expected calving and randomly assigned within each block to one of 3 dietary treatments: low protein (LP), high protein (HP), or high protein plus rumen-protected methionine (HPM). Treatments were offered from d -18 ± 5 to 45 d relative to parturition. Pre- and postpartum diets were formulated for high metabolizable protein (MP) supply from soybean meal, and HP and HPM provided higher MP balance than LP. Preplanned contrasts were LP versus HP+HPM and HP versus HPM. Significance was declared at P ≤ 0.05 and trends at 0.05 <P ≤ 0.10. Cows fed HP and HPM had greater fry matter intake (DMI) prepartum than LP (+2 kg/d), and there was a trend for greater DMI with HPM than with HP (+1.6 kg/d). Body weight and condition score before and after calving did not differ among treatments. High protein (HP and HPM) tended to increase milk yield during the first 45 d of lactation (+1.75 kg/d), increased milk lactose content and urea-N in milk and plasma, tended to increase blood BHB 14 d postpartum, and tended to reduce milk/DMI compared with LP. Blood concentrations of calcium at calving and of glucose, and nonesterified fatty acids pre- and postpartum did not differ. High protein induced lower concentration of plasma IL-1 at calving and lowered blood lymphocytes 21 d postpartum, suggestive of a reduced inflammatory status compared with LP. The concentrations of IL-10, tumor necrosis factor alpha, and other hemogram variables did not differ among treatments. Addition of rumen-protected methionine to the HP diet did not alter milk yield but increased fat and total solids concentrations. The rumen-protected methionine had no effect on blood metabolites and immunity markers, with the exception of increased pre-partum insulin concentrations. The data indicate that dairy cows around calving respond positively to an increase in the supply of MP and to rumen-protected methionine supplementation of the HP diet by increasing intake and improving immune status.

Effects of harvest date and grass species on silage cell wall components and lactation performance of dairy cows

This study evaluated the effect of harvest date and forage species on the concentration of hydroxycinnamic acids in silage and its relationship to dairy cow performance. Tall fescue and timothy were harvested at a regular date on June 27 and July 8, respectively, or at a late date on July 8 and 25, respectively, in the first regrowth. Forage was treated with a salt-based additive and ensiled in hard-pressed round bales. Forty-seven lactating dairy cows were used in a block design. Cows received 1 of 4 treatments: (1) tall fescue harvested at regular date (RTF), (2) timothy harvested at regular date (RTI), (3) tall fescue harvested at late date (LTF), and (4) timothy harvested at late date (LTI). Diets were formulated to have the same forage-to-concentrate ratio (46:54 on a dry matter basis). Harvesting at late date increased fiber components, but only for timothy, where LTI contained greater neutral detergent fiber, acid detergent fiber, and acid detergent lignin concentrations than the other silages. Concentrations of hydroxycinnamic acids were affected by forage species, where concentrations of esterified ferulic acid and p-coumaric acid were greater for tall fescue silages than for timothy silages. Cows fed the RTI diet showed the greatest intakes of dry matter, organic matter, and crude protein. Feeding diets containing timothy silages increased milk yield and energy-corrected milk yield compared with tall fescue diets when averaged over harvest dates. Cows fed the RTI diet had greater milk protein yield than cows fed the RTF and LTF diets, and milk lactose yield was greater for cows fed diets containing timothy silage compared with tall fescue silage when averaged over harvest dates. Cows fed the LTF diet showed greater urinary N excretion compared with the LTI diet, but RTI showed the lowest urinary N and urea N excretions when calculated as percent of N intake. Cows fed diets containing timothy silage excreted more uric acid than cows fed tall fescue diets. Allantoin excretion was greater for cows eating the RTI and LTI diets compared with cows eating the RTF diet. Cows fed the RTI diet had a greater estimated microbial N flow and a greater excretion of hippuric acid than the RTF and LTF groups. In conclusion, besides the effect of harvest date on increasing the fiber components of timothy, concentrations of hydroxycinnamic acids were mainly affected by forage species; consequently, milk production was only affected by forage species. This indicates that hydroxycinnamic acids, such as ferulic acid, which cross-links to glucuronoarabinoxylans, was a major factor regulating milk production of cows fed tall fescue- and timothy silage-based diets, where lower hydroxycinnamic acid concentrations were responsible for greater milk yield.

Dairy goats productivity using the probiotic preparation “Plantarum” in the diet

The influence of the experimental probiotic “Plantarum” on the productive and some exterior-constitutional features of dairy Saanen breed goats was studied. The preparation was developed in the microbiology laboratory of milk and dairy products of the department “Siberian Research Institute for Cheese Making” of the Federal State Budgetary Scientific Institution “Federal Altai Scientific Center of Agrobiotechnology” (FSBSI FASCA). The composition of the preparation includes pure cultures of probiotic strains of lactobacilli and propionic acid bacteria from the “Siberian collection of microorganisms”. The probiotic preparation in liquid form was introduced into concentrated feed (oats). The positive effect of the use of the probiotic “Plantarum” on the average daily milk yield of the experimental groups of fully developed (assessed by the exterior) pregnant female goats was established. A significant increase in milk yield was observed in the second and third groups by 1.66% (p < 0.05) and 3.27% (p < 0.05), respectively. With an increase in the average daily milk yield, the main physical and chemical parameters of milk (mass fraction of fat, mass fraction of protein) of the experimental groups did not decrease. There was a tendency to improve the safety of young animals in the second and third groups with an increase in the probiotic dose. At this stage of the work, the optimal dose with the maximum positive effect of introducing the probiotic preparation into the diet of experimental animals (0.8 ml/kg of body weight per day) was established. In this connection, it is necessary to conduct an additional experiment with an increase in the dose of probiotic administration when feeding it to experimental animals.

Influence of the age of cows on the dynamics of dairy efficiency depending on a breeding line

The article suggests that one of the most widespread dairy breeds in the world is the Holstein breed; and the black-mottled breed in the Russian Federation. This breed has been improving during the past four decades by interbreeding it with the best one, the Holstein breed. A large set of the Holsteinized black-mottled livestock of the high thoroughbred cows of the Holstein breed has been produced. The aim of the work is to study the effect of age on the dynamics of dairy efficiency of the Holsteinized cows depending on the breeding line. At present, the dairy herd of the farm actually consists of cows of three breeding lines, Reflection Sovering 198998, Vis Back Ideal 1013415, Montvik Chieftain 95679. The rest breeds are not developing due to the absence of breeding valuable breeding bulls. It was found that the Reflection Sovering breeding line 198998 has that the highest milk yield during the sixth lactation, and then there is a decrease in milk yield. The article considers that the milk yield changes with age, starting from the first lactation, increasing during the second lactation and then it is gradually decreasing in productivity to the fifth one. The regularity of the increase in milk yield of mature cows during the third and fourth lactation is not confirmed of the dairy cows of this breeding line. It can be explained by the intensity of herb replacement, when it accumulates a significant amount of nutrients in the body. That is why, they can be used during the first and the second lactations without restoring nutrients in further. Dairy cows of the Vis Back Ideal 1013415 breeding line have a gradual increase in milk yield, starting from the first to the fourth lactation, by 52, 292, 300 kg or by 0.5; 2.8% and 2.8%, respectively. Further, there is a decrease in dairy efficiency. At reaching physiological maturity they have a natural increase in dairy efficiency. The same tendency is observed with cows of the Montvik Chieftein 95679 breeding line.

The relationship between the duration of the service period and the milk yield of the Holsteinized black-mottled breed

The article says that all over the world, dairy livestock is used for dairy production. They use such breeds as a black-mottled breed, Holstein, Dutch ones. Breeding livestock differs in economically useful qualities depending on the climatic and ecological-forage conditions of the breeding zone, and the gene pool of breed resources. The widespread and long-term use of the Holsteinisation, along with a positive effect, i.e., an increase in milk yield, revealed problems associated with a decrease in the reproductive functions of the livestock. The aim of the work is to study the milk yield of the Holsteinized black-mottled breed of the Ural type depending on the duration of the service period. The article notes a significant percentage of dairy cows with a service period of more than 200 days and 121-160 days. Dairy cows with a service period of up to 120 days turned out to be 32%, taking into account the presence of dairy cows with optimal insemination period of only 19%. This indicates a decrease in reproductive functions in the Holsteinized black-mottled breed of the Ural type. The change in milk yield per three lactation depending on the duration of the service period is mainly determined by the individual characteristics of dairy cows and but not on the service period. Dairy cows with a service period of 103 days have the highest milk yield indicators. Dairy cows of other groups with other duration of the service periods had milk yield by 209 - 656 kg, or 1.96 - 6.15% less. The difference was not reliable due to the significant variation in milk yield within the groups. The duration of the service period does not affect the quality indicators of milk. The optimal duration of the service period for livestock breeding, namely the Holsteinized black- mottled breed of the Ural type is considered to be 81-120 days. An increase in the duration of the service period does not lead to an increase in milk yield, but affects the duration of productive longevity of dairy cows.