Cow Rations Research Articles

Effect of Diet on CPFAs Used as Markers in Milk for the Detection of Silage in the Ration of Dairy Cows

In hay milk production, fermented feed, like silage, is forbidden. This study aims to reveal the presence of silages made from maize or grass in the diet of dairy cows through the detection of cyclopropane fatty acids (CPFAs) in their milk. It also investigates how CPFAs in their milk declines when the diets of the cows are transitioned from one containing silage to one that does not include silage. CPFAs were quantified in silages collected on the farm, and the relationship between the dietary intake of CPFAs from silages and the marker concentration in milk was investigated. Except for one sample (below LOQ), CPFAs were never detected in hay milk, while they were found in 98% and 85% of milk samples obtained from cows whose diet included maize or grass silage as the only fermented component, respectively. CPFAs were found to still be detectable in milk 56 days after the removal of maize silage from the diet, while they were no longer detectable about three weeks after removing grass silage from the ration. A quantitative positive relationship was detected between CPFAs content in the milk and the dietary intake of CPFAs from silages. CPFAs can be regarded as reliable markers to detect the occurrence of silages in the ration, but it is more effective for maize than for grass silage.

Influence of lemongrass and oregano essential oils and their combination on in vitro ruminal fermentation and greenhouse gas emissions in total mixed ration for dairy cows

Ruminants play a crucial role in the food chain, but are also considered contributors of greenhouse gas (GHG) emissions . Essential oils (EOs) are emerging as natural feed additives in ruminants’ nutrition to enhance animal health, performance and reduce environmental footprint. Among EOs, lemongrass (Cymbopogon winterianus) and oregano (Origanum vulgare) EOs (LEO and OEO) have attracted attention as modulators of ruminal fermentations, but their role needs to be clarified. The experiment was designed using a randomised setup to assess the effects of LEO and OEO on in vitro ruminal fermentation and GHGs, using total mixed ration (TMR) as substrate (incubation time 24h). Experimental treatments included (doses as % of TMR on DM basis): 1) control only TMR (0% EOs) 2) 0.07% LEO 3) 0.07% OEO 4) 0.035% LEO + 0.035% OEO 5) 0.07% LEO + 0.07% OEO. Each treatment was repeated three times in two experimental runs. Only EO combinations reduced total gas (−9%, p=0.001). All EOs decreased CO2 emissions by −5 to −12% with no significant differences between treatments (p<0.001), although anti-methanogenic effects were not observed (p=0.192). Volatile fatty acids were slightly affected only by EOs blend at the highest dose, resulting in a reduction of propionate (−1.3%, p=0.02), an increase in acetate:propionate (+0.16%, p=0.04) and isovalerate (+0.7%, p=0.03). LEO reduced pH (−0.6%, p=0.004), while OEO increased oxidation capacity (+4.2%, p=0.004), but both parameters remained within physiological ranges. Canonical discriminant analysis confirmed distinct EOs effects, highlighting their potential as natural additives for improving ruminal fermentation and mitigating ruminant environmental footprint.

Impact of Low Inclusion Rate of Olive Cake in Dairy Cow Rations on Uterine Health and Fertility Indices During Early Lactation.

Olive cake was incorporated at a low inclusion rate (3.7%) into the rations of dairy cows through partial substitution of maize, and its effects on milk production, general health, and fertility traits were investigated. Multiparous purebred Holstein dairy cows (n = 148) were divided into two groups: a treated group (n = 86) and a control group (n = 62). The control ration (group C) was modified by replacing 1 kg of maize with an equal quantity of olive cake (group T). The experiment lasted from 60 days prepartum to 150 days postpartum. Electronic aids were utilized to quantify daily milk yield and detect estrus expression, while clinical and uterine examinations were performed weekly. Blood samples, uterine epithelial cells, and endometrial tissue samples were collected from a subgroup of healthy animals in both groups at specific time points. Blood samples were examined to determine the β-hydroxybutyric acid (BHBA), acute phase proteins (haptoglobin [Hpt] and serum amyloid A [SAA]), progesterone, and pregnancy-associated glycoproteins concentrations. Uterine epithelial cells were assessed for polymorphonuclear neutrophil (PMN) counts, and the expression of nine genes encoding inflammatory cytokines and immune system activation was analyzed in uterine biopsy tissue. No significant differences (p > 0.05) were observed between groups in milk yield, general morbidity, clinical endometritis, or conception rates. However, animals in group T came to estrus approximately 6 days earlier (p = 0.013) than those in group C; progesterone concentrations on day 7 of the subsequent cycle tended (p = 0.07) to be higher in group T. On day 21, BHBA concentrations were higher in group C than in group T (p < 0.05). Throughout the experiment, Hpt levels in group T were consistently lower (p < 0.001), while SAA was lower on day 7 compared to group C. From days 21 to 42 postpartum, there was a significant reduction in PMN numbers (group C p = 0.02; group T p < 0.0001), with a tendency for a greater reduction rate in group T (p = 0.08). Among the genes studied, a significant difference was revealed in the expression of the ILA1 gene, with strong correlations of gene expression in group C and weak to moderate correlations in group T. In conclusion, under the conditions of this experiment, the inclusion of olive cake into dairy cows' rations did not affect milk production but improved certain health and fertility parameters, making olive cake a suitable alternative feedstuff for high-producing animals.

Factors affecting the occurrence of cyclopropane fatty acids in grass silage

Haymilk and haymilk products meet the consumers expectations about traditional and sustainable dairy farming and have gained increasing interest in some parts of Europe. In haymilk production, among other restrictions, fermented feed is not allowed in the ration of cows. Recently, advancements in analytical methods applicable to dairy products have emerged, enabling the detection of silage utilization in animal diets. Notably, cyclopropane fatty acids (CPFAs), such as dihydrosterculic acid (DHSA) (cis 9,10-methylene octadecanoic acid) and lactobacillic acid (LBA) (cis-11,12-methylene octadecanoic acid), have been identified as biomarkers capable of distinguishing between Grana Padano and Parmigiano Reggiano cheeses. Silage is permitted in the production of the former but prohibited for the latter. Consequently, these biomarkers allow authentication by confirming the absence of silage in the animals' diet. CPFAs are known to be produced by some microorganisms during fermentation in silage production, thus they are expected to occur only in milk of animals fed silage. Most of the previous studies in this area referred to lowland areas, where the fermented part of the dairy cows' diet typically consists of maize silage. However, in the mountainous areas of the Alps (Europe) the diet often includes on-farm produced grass silage, which only recently came to the attention of research concerning the authentication of dairy products based on a silage-free diet. In this work, grass silage was produced under controlled conditions to test the formation of CPFAs depending on the growth cycle (cut), fermentation temperature and the use of fermentation starters. In addition, 69 silage samples of several farms were collected and studied to investigate the relationship between silage quality and the CPFAs content under on-farm conditions in the local practice. The concentration of CPFAs were found to be differently affected by the temperature, depending on the cut, whilst the starter only marginally affected CPFAs. A positive relationship between acetic acid and CPFAs was observed both in laboratory-produced silages and in on-farm collected grass and maize silages. These results provide a first insight into the presence of CPFAs in grass silage and its association with fermentation parameters adding new helpful information in using CPFAs as markers to authenticate milk from a silage-free diet.

Simulation and Optimization of Available Local Feed Resources for Dairy Cattle in Burkina Faso

The poor quality of natural pastures in the dry season does not make it possible to meet dairy cows’ requirements for milk production in Burkina Faso and in most West African countries. Therefore, it is urgent to find an alternative by developing a full diet from locally available ingredients. The objective was to determine a diet for dairy cattle based on locally available ingredients in the peri-urban area of Ouagadougou. A progressive methodology was used. Thus, a survey was conducted ontoonton 30 dairy farms. This survey was followed by chemical analysis, for which the most dominant forage and concentrate ingredients were selected. Secondly, the recording of milk and on-farm ingredient use was also carried out using Op-Ration software (Op-Ration version V3.4.5.0) in order to compare and determine the most suitable diets. The data from the survey were subjected to descriptive statistics using SPSS version 20. Those from chemical analysis, milk recording, and ingredient assessment on the farm were subjected to a statistical method using the software Minitab version.18.1.0.0 setup. The results showed two dominant forage species, Sorghum (84.85%) and Pennisetum pedicellatum (90.91%), and two dominant concentrates, corn bran (32%) and cottonseed meal (26%), used by dairy farmers. From these ingredients and simulating the requirements of 400 kgPV0.75 of lactating cows, a diet assessment was carried out at early, middle, and end lactation. The results showed that at the beginning of lactation, the diet consisted of 6.73 kg of forage and 6.59 kg of concentrate for 13.5 L as the main objective of milk production. The diet for mid-lactation was 8 kg of forage and 6.5 kg of concentrate for 15.5 L per day and 5.7 kg of forage and 3.8 kg of concentrate for the end of lactation. The results of this study show that it is possible to manufacture a complete ration for dairy cows at different stages of lactation from locally available forages and concentrates in the peri-urban area of Ouagadougou. This type of method could be applied to other regions from local forages and concentrates for milk production.

Study of the Effects of Alfalfa Bioactive Substances and Polysaccharides on the Lactation Performance and Immune Function of Dairy Cows

Background: The aim of this study was to investigate the effects of alfalfa polysaccharides on the lactation performance and immune function of dairy cows. Methods: A total of 84 healthy Holstein cows were selected and randomly divided into 7 groups, including the control Group A0, the alfalfa polysaccharide groups (AP1, AP2, AP3) and the alfalfa extract groups (AE1, AE2, AE3). Each group had three replicates and each replicate had four cows. The daily rations of the dairy cows in the AP group and the AE group were supplemented with alfalfa polysaccharide powder and alfalfa extract at concentrations of 1, 2 and 3 kg/t, those in the A0 group served as a control. Result: (1) the milk production of dairy cows in the AE groups was extremely significantly greater (p less than 0.01) than that in A0 group and AP groups. The milk protein content of cows in the AP2 and AE2 groups was significantly greater (P less than 0.05) than that in the A0 group (2) The interleukin-2 (IL-2) levels in the serum of cows in the AP2, AP3, AE2 and AE3 groups were greater than those in the A0 and AP1 groups and the IgM antibody levels in the AP group and the AE group were extremely significantly greater than those in the A0 and AP1 groups (P less than 0.01). The IgA antibody level in the serum of dairy cows in the AP2, AP3, AE2 and AE3 groups was significantly (P less than 0.01) greater than that in the A0, AP1 and AE1 groups. In summary, the alfalfa extract improved both the lactation performance and immunity of dairy cows, indicating comprehensive effects. Alfalfa polysaccharides at a concentration of 2 kg/t improved the immunity of dairy cows.

Long-term effects of transition milk feeding on feed intake, growth performance, feeding behavior, and oxidative status of Holstein calves

This study investigated the long-term effects of feeding 5-d transition milk (TRANS) compared with milk replacer (MR) on parameters, including intake, growth, feeding behavior and oxidative stress. Fifty Holstein calves (30 females and 20 males) were fed either 12 L/day TRANS or MR for the first 5 d after an initial colostrum feeding of 3.5 L. Thereafter, all calves were fed with 12 L of MR/d (140 g/L) and were gradually weaned starting in wk 8 until wk 14. Throughout the 14 wk the calves had unrestricted access to concentrate (up to 9.8 kg/calf/day), hay, and water. After weaning all heifers were fed a total mixed ration for young cows. Oxidative status was assessed in blood samples from birth to first insemination. Parameters assessed included the ferric reducing ability of plasma (FRAP) for antioxidant capacity and the concentration of reactive oxygen metabolites by the dROM (detection of reactive oxygen metabolites) assay. In addition, the activity of glutathione peroxidase (GSH-Px), oxidative damage in the form of lipid peroxidation as thiobarbituric acid reactive substances (TBARS) and as advanced oxidation protein products (AOPP) were measured. An oxidative stress index (OSi) was calculated: dROM/FRAP x 100. Total protein (TP) concentration was also quantified via the Bradford assay. The only significant difference in feeding behavior between the 2 treatment groups was a higher concentrate intake by the TRANS calves during the weaning phase. Body weight and ADG did not differ significantly between the TRANS and MR groups. TRANS calves showed a trend for fewer cases of health disorders. Markers of oxidative status, including TBARS, AOPP, GSHPx, FRAP and ROM, showed no treatment effects but varied significantly over time. Of note, the oxidative stress index as ratio between pro- and antioxidants in both groups peaked during weaning and then returned to baseline, suggesting an effective response to this transition phase Overall, the results indicate that feeding TRANS during the first 5 d of life had no long-term effect on the parameters studied as compared with MR feeding under the present rearing conditions. These results provide insight into the changes of oxidative status with age and confirm that the relatively high milk feeding level, slow and late weaning enables calves to adapt well to solely solid feed.

Changes in the quality indicators of cows› milk depending on feeding the feed additive in different doses

Relevance. The quality of milk depends on the season, the breed of animals, the state of metabolism, the features of feeding technology and maintenance, and the feed additives fed. The doses of their feeding can affect the composition of milk. Methods. The content of mass fractions of fat, protein, lactose, its acidity, as well as the content of urea, acetone, and beta-hydroxybutyric acid in milk were determined.Results. The introduction of an experimental feed additive into the feeding rations of dairy cows had an impact on the change in the values of the indicators studied in milk. Moreover, not all the studied indicators changed under the influence of feeding this supplement. So, if we correlate the results obtained with changes in control, then, according to the authors, it is correct to talk about its significant effect on the change in the value of the mass fraction of protein in milk and the values of milk acidity: feeding in the diet of a feed additive at a dose of 1.0 kg and 1.5 kg leads to a significant increase in the mass fraction of protein in milk by 0.18% (p ˂ 0.01) and 0.15% (p ˂ 0.01), respectively, as well as a significant shift in the active acidity of milk to the alkaline side by 1.56% (p ˂ 0.001) and 0.78% (p ˂ 0.05), respectively.

Increasing the milk yield in cows on corn silage and concentrates enriched with feed additive with biologically active substances

The purpose of the work was to investigate the characteristics of increasing the milk yield in cows on corn silage and concentrates enriched with a feed additive with biologically active substances. The research work was carried out at the educational and experimental farm of the Federal State Budgetary Educational Institution of Higher Education “Northern Trans-Ural State Agricultural University” on cows of Black-and-White breed with a milk yield of 6000–7000 kg per lactation. The cows of the control group received a farm ration consisting of 1.5–2.0 kg of brome hay, 25–27 kg of corn silage, 10–12 kg of grain mixture; the animals of the experimental group received the same feeds, but additionally a feed additive with biologically active substances. It was found that the inclusion of a feed additive with biologically active substances in the ration of cows during the fi rst 100 days of lactation helped to eliminate the deficiency of individual nutritional elements in the ration, reduced the consumption of concentrated feed and protein. It was found that enrichment of the concentrate-silage ration with the feed additive in the amount of 60 g/head/day allowed to obtain 472 kg of milk or 8.06 % more per lactation than without its use. Consumption of the feed additive with biologically active substances by cows of the experimental group led to diff erences in the digestibility coeffi cients of nutrients. Thus, the animals of the experimental group had higher digestibility coeffi cients of dry matter by 2.67 abs.%, organic matter by 2.91 abs.%, crude fi ber by 0.60 abs.% and nitrogen-free extractive substances by 3.75 abs.%, and the digestibility coeffi cient of crude protein and crude fat on the contrary was lower by 0.36 and 2.55 abs.%, respectively. Economic indicators of milk production were significantly higher in cows of the experimental group receiving the feed additive with biologically active substances.

Effect of Postbiotic Supplementation on Nutrient Digestibility and Milk Yield during the Transition Period in Dairy Cows.

The metabolites secreted by probiotics or released after their lysis are called postbiotics. They provide physiological benefits to the host, preventing the colonisation of pathogens by improving the intestinal environment for beneficial commensal bacteria, which reduces the incidence of digestive disorders and improves the immune system. The aim of this work was to evaluate the addition of postbiotics to dairy cow rations during the transition period on nutrient digestibility, composition, and milk yield. The effects of two postbiotics were evaluated in twelve Friesian cows from 30 days before calving to two months of lactation. The animals were randomly allocated to two treatment groups: control (CT) and supplemented with postbiotics (PC and PR). Feeding was ad libitum with 60/40 of forage/concentrate ratio on dry matter basis. Daily feed intake and milk production were recorded individually throughout the study. Two digestibility balances were performed, one before parturition and one after parturition. Colostrum was sampled at first milking and milk was sampled weekly. Data were analysed using a mixed mode in R software 4.4.1. The results suggest that postbiotic supplementation in late gestation and early lactation increase the voluntary intake of dry matter, especially in the PR treatment, with higher apparent total tract digestibility of dry matter, organic matter and neutral detergent fibre. Both treatments including postbiotics induced an increase in colostral immunoglobulin concentration. Milk production of cows receiving the PC treatment was the highest, with high fat and protein yields and a higher persistence of the production curve throughout the lactation.

Evaluation of the realization of the genetic potential of cows of Jersey breed

An urgent issue in cattle breeding is the evaluation of the genetic potential of cattle. By monitoring the livestock, breeders have the opportunity to identify animals with various traits necessary in agriculture. Important traits include milk yield in cows and high levels of fat and protein content in milk. This type of animal evaluation helps to produce of young animals with increased milk productivity potential, which leads to increased profi ts in this industry. The main purpose of the research was to evaluate the implementation of the genetic potential of cows of Jersey breed housed at the enterprise LLC SKhP Novomarkovskoye in the Kantemirovsky district of the Voronezh region. During the research have been received results characterizing the milk productivity of the experimental cows. Thus, milk yield for the fi rst lactation was 6370 kg, and for the second it was 5780 kg, which was a high productivity indicator for cows of Jersey breed. The milk yield for 305 days of the fi rst lactation was 5765 kg, and in the second it was 5665 kg, which meets the international standard for assessing milk productivity. The mass fraction of fat in the milk under study was at the level of 5.63 %, which indicated a high fat content compared to other breeds of cows. Cows of Jersey breed are distinguished by the production of milk with a high fat content. The yield of milk fat in cows of Jersey breed was 324.5 kg. Milk with a high fat content usually contains more vitamins, such as A, D and E, they are fat-soluble and are better absorbed if consumed together with dairy products with a high fat content. It can be concluded on base of the data obtained that the choice of breeding animals with high genetic potential is important. At the same time, a properly selected and balanced ration for cows and housing animals under favorable conditions ensures the maximum realization of their genetic potential.

Aplication of Sweet Maize Whole Plant Silage (Zea mays saccharata Sturt) and Gliricia sepium for Feed of Dairy Cattle

The low productivity of smallholder dairy cattle in Indonesia is due to limited capital and feed management. Limited land ownership, resulting in feeding from low-quality natural grasses and agricultural waste, limits milk production. Farmers rely on expensive commercial concentrate feed to improve feed quality. Efforts to improve productivity and milk quality on smallholder farms include utilizing low-cost, high-nutrient forages. Legume forages have the potential to replace commercial concentrates in dairy cow rations because they contain high crude protein (CP) and can increase livestock productivity. Using legumes as a substitute for commercial concentrates can reduce milk production costs by up to 20%. In Indonesia, the most widely cultivated legume crop is Gliricidia. Harapan Makmur Farmer Group is one of the few dairy cattle groups established in Padang City in 2011. The problem of the dairy cattle business is the high feed price, some of which comes from commercial feed. The activity method uses counseling, discussion, and the practice of making sweet corn silage mixed with Gliricidia. These activities concluded that farmers were utilizing forage from legumes to substitute commercial concentrates, and they were skilled in processing corn straw waste from sweet corn cultivation and Gliricidia into silage.

Evaluation of the effectiveness of the influence of the feed product Vinassa on milk productivity and rumen indicators of cows during the period of increasing the milk yield

By-products of processing of various industries in the agro-industrial complex with an optimal level of their introduction into the ration of farm animals make it possible to increase the productivity of farm animals by optimizing ruminal digestion. The purpose of the research was to assess the eff ectiveness of the infl uence of the feed product Vinassa on milk productivity and rumen indicators of cows during the period of increasing the milk yield. In order to conduct the experiment lactating fresh cows were selected during the period of increasing the milk yield (n=45), which were divided into three groups of 15 heads in each according to the method of pair-analogs. The introduction of diff erent levels of sugar processing products and domestically produced yeast production into the ration of cows in the 1st experimental group in the amount of 500 g/head/day and in the 2nd experimental group 1000 g/head/day has been examined in the work. The introduction of the feed product Vinassa in the amount of 1000 g/head/day as part of a totally mixed ration contributed to the optimization of rumen pH. The level of volatile fatty acids increased in the rumen contents of cows of the 2nd experimental group by 2.27 mmol/l, and the concentration of ammonia decreased by 4.48 mg% compared to the control group. Improving indicators of ruminal contents contributed to the growth and development of bacteria and ciliates. Thus, in cows of the 2nd experimental group the number of dry matter of ciliates was higher by 0.7 g/100 ml of dry matter of rumen contents. It was found during the experiment that optimization of ruminal digestion leads to increased milk productivity. Thus, in cows of the 2nd experimental group during the period of increasing the milk yield, the increase in the gross milk yield of milk with 4 % fat content for the period of increasing the milk yield was found to increase by 7.1 % and the increase in the gross yield of milk fat by 7.1 % (p &lt; 0.05).

Optimization of Sodium-Potassium Ratio in Cow Diets

In the conditions of the Nakhchivan Autonomous Republic, research has been carried out on the prevention of metabolic disorders and optimization of the sodium-potassium ratio in the feed ration of cows. The diets were identical in composition and nutritional value, but the ratio of sodium and potassium in the groups was different due to different amounts of table salt. During the stall period of the experiment, the ratio of sodium and potassium in group I was 0.36, in group II — 0.43, and in group III — 0.48. It should be noted that this attitude in groups II and III contributed to a greater consumption of roughage and succulent feed than in the control group. During the grazing period, cows of all groups also received the same rations. However, the ratio of sodium and potassium in them was different. Thus, in group II it was 0.32, in group III — 0.41 versus 0.24 in the control. In group I for 1 feed units sodium accounted for 5.7 g, in II — 7.6 and III — 10.0 g. Cows of groups II and III consumed more grass on pasture by 4.8 and 9.6%, and green fertilizer by 3.2 and 7.6% compared to control. The amount of grass eaten on pasture was determined using the reverse calculation method. On average, per lactation in groups II and III there was 1.4 and 3.0 g more sodium per feed unit, respectively, than in group I. The nutritional value of the diets corresponded to the needs and level of productivity of the animals. Thus, optimizing the sodium-potassium ratio in the diets of highly productive cows by increasing the rate of sodium chloride by 40% in the stall and by 100% in the grazing periods with excess potassium in the diets ensures improved mineral metabolism, increases the use of nutrients and increases milk yield by 4%. Fat content by 8,8% on average per lactation.

Features of the accumulation of pollutants in plant feed and their translocation into the milk of cows

One of the sources of toxic substances entering the human body may be a valuable food product as milk. The intensity of exposure of ecotoxicants to milk of cows is determined by a number of factors, among which the main one is feed. The purpose of the research was to study the characteristics of the accumulation of heavy metals and radionuclides in plant feed, and their translocation from rations of cows into milk. The research was carried out in agricultural enterprises of the Shchuchansky district of the Kurgan region. In order to obtain the most complete information about the degree of contamination of the studied objects, the area was divided into fi ve zones taking into account the geographical location such as northern (Peschanskoye village), southern (Sukhoborskoye village), western (Beloyarskoye village), eastern (Petrovskoye village) and central (Chumlyak village) zone. The content of heavy metals in the feed and milk of cows was determined such as copper, zinc, cadmium, lead and radionuclides such as strontium-90 and cesium-137. The features of the accumulation of heavy metals and radionuclides depending on the type of feed as well as the dependence of the concentration of toxic substances in the ration on their amount in feed have been established. Regression equations have been calculated to predict changes in the concentration of heavy metals and radionuclides in the daily ration depending on their content in feed. The coeffi cients of translocation of heavy metals and radionuclides from the ration into the milk of cows during the stall and pasture periods were determined, which showed the absence of a connection between the presence of ecotoxicants in feed and milk. The maximum degree of contamination of rations was observed in the northern zone. The dependence of the concentration of toxic substances in the ration on their amount in feed has been established. No relation was found between the content of heavy metals and radionuclides in the rations and milk of cows. As the toxicity of the ration increased, the transfer coeffi cient of ecotoxicants decreased. During the pasture period, the transition coeffi cient was higher than during the stall period. The obtained research results would make it possible to regulate the intake of toxic elements into livestock products by selecting the components of the ration.

The use of improved premix recipes in rations of cattle

Complete balanced feeding of farm animals cannot be organized without the use of various balancing additives, in particular premixes. It is important to note that the greatest eff ect from the use of premixes is observed when their recipes are developed taking into account specifi c feeding and housing conditions. The purpose of this work was to study the eff ectiveness of using improved premix recipes based on an analysis of the actual nutritional value of feed in the rations of lactating cows and calves. During the research, two experiments were carried out. The experiments were carried out at the Staraya Chigla livestock complex in the Anninsky district of the Voronezh region. In the experiment on cows, 20 animals were selected, which were divided into two groups (control and experimental) of 10 heads in each using the method of analogue pairs. In an experiment to study the eff ectiveness of the premix in feeding of young animals, two groups of calves of 12 heads in each were similarly formed. Animals of the control groups received farm rations with the premix developed without taking into account the analysis of the nutritional value of the rations. In the experimental groups, cows and calves received new and improved premixes developed based on these specific feeding conditions. The use of the premix with an improved recipe in the rations of cows made it possible to increase the average daily milk yield by 5,61 %, the fat content by 0,05 abs.% and the protein content in milk by 0,15 abs.%. At the same time, there was an increase in the level of digestibility of dry matter by 1,25 abs.%, organic matter by 1,07 abs.%, crude protein by 1,56 abs.%, crude fat by 1,63 abs.%, crude fi ber by 1,08 abs.%, nitrogen-free extractive substances by 1,87 abs.%. Calculation of feed intake for the synthesis of 1 kg of milk showed that they were lower in the experimental group by 0,31 MJ of net lactation energy and 2,97 g of digestible protein. Positive results were also obtained in experiments on calves. The use of the premix developed on the basis of the actual nutritional value of feed and rations, made it possible to increase the live weight of heifers at 12 months of age by 5,04 %, the average daily gain in live weight during the experimental period by 5,74 %, the relative gain by 1,91 abs.%.

PSIV-A-5 Effect of roughage inclusion in limit-fed cow rations on behavior, cow hygiene, and manure scores

Abstract The objective was to determine the effects of roughage inclusion in isocaloric total mixed rations (TMR) fed to drylot housed cow-calf pairs on behavior, manure score, and hygiene score. Spring-born Simmental x Angus cows (n = 72) and their calves were stratified by calf age, sex, and body weight (BW) and assigned to 12 pens with 6 pairs to pen. Pens were randomly assigned to one of two treatments: moderate roughage inclusion (40%) TMR targeting DMI of 1.7% of BW (LimitTMR) or high roughage inclusion (60%) TMR targeting DMI of 2.1% of BW (BulkyTMR). Concrete bunks (4.7 m; 0.8 m/cow). Cow-calf pairs were housed in concrete dry lots with open-front buildings. Buildings were bedded with straw once a week. Cow and calf behavior (standing, lying, at bunk, and eating bedding) was observed hourly from 1 h before feeding until 6 h post-feeding. Behavior assessments were done on 2 consecutive days (before new bedding and after new bedding) each week for 5 wk. Hygiene and manure scoring was conducted on d 40 and 75 by 2 trained evaluators. Hygiene was scored on a 1-4 scale; 1 – no manure, 4 confluent plaque of manure. Cow hygiene was evaluated on the lower leg, udder, and upper leg and flank. Manure from each pen was scored on a 1-5 scale; 1 – very liquid consistency, 5 – firm fecal balls. Data were analyzed using the MIXED procedure of SAS 9.4. On day prior to new bedding, there was a treatment × time interaction (P &amp;lt; 0.01) for cows at bunk. More cows on BulkyTMR were at the bunk at h 2, 3, 4, and 5 post-feeding. On day after new bedding, there was also a treatment × time interaction (P &amp;lt; 0.01) for cows at bunk. More cows on LimitTMR were at the bunk before feeding; however, more cows on BulkyTMR were at bunk at h 2 and 3 post-feeding. On both evaluation days there was a treatment × time interaction (P ≤ 0.05) for calves at bunk. More calves on BulkyTMR were at the bunk at h 1 and 2 post-feeding. Cows fed the LimitTMR had dirtier (P ≤ 0.02) lower leg (1.5 vs 1.2) and upper leg/flank (1.4 vs 1.1) hygiene scores on d 40 than cows fed the BulkyTMR; however, there were no treatment differences (P ≥ 0.31) on d 75. There were no treatment differences (P ≥ 0.26) for manure scores on d 40 or d 75. In conclusion, a bulkier TMR with more roughage inclusion resulted in more time at the bunk for cows and calves and cleaner hygiene scores for cows, but roughage inclusion did not affect manure scores.

Feed costs and indicators of reproductive capacity of high-yielding cows at different levels of Bypass soybeans in rations

The article presents the results of a scientific and economic experiment to study the influence of different levels of Bypass soybeans in the diets of high-yielding cows on feed costs per kilogram of milk and reproductive functions of cows. Provision of the rations of the experimental cows with an unequal amount of the difficult-to-dissolve fraction of crude protein, at the expense of Bypass soybeans, affected their consumption of bulk feed. The experimental cows consumed 4.1–4.8 kg from the specified 5 kg of alfalfa hay, 20.8–24.6 kg from 25 kg of corn silage, and 8.4–9.7 kg from 10 kg of alfalfa hay. The consumed feed provided cows with crude protein at the level of 16.0–16.5 % of the dry matter, its poorly soluble fraction at the level of 27.3 % of the crude protein in the 1st control group, 31.1 % in the 2nd experimental group, 35.2 % – in the 3rd experimental group and 40.0 % – in the 4th experimental group. The sugar-starch-protein ratio was normal and ranged from 2.20 to 2.28 : 1 with a norm of 2.1 : 1. The micronutrient rations were balanced due to micronutrients of organic origin. On the basis of the obtained data, it was proved that the lowest feed consumption per 1 kg of milk was observed in cows of the 4th experimental group, which were fed rations with 2 kg of Bypass soybeans, where the level of insoluble protein was 40 % of crude protein and these consumptions were 6.5 MJ against 7.4 MJ in the 1st control group. Cows of the 4th experimental group also had the best insemination and service period indicators. The duration of the service period in the experimental groups was less in percentage compared to the animals of the 1st control group by: 15.0 in the 2nd; 25.6 in the 3rd and 32.9 in the 4th. Partial and complete replacement in the diets of cows of the 2nd, 3rd and 4th experimental groups of soybean meal with Vypass soybeans at the level of 1.0; 1.7 and 2 kg of compound feed concentrate in the first 100 days of lactation has a positive effect on the physiological state, stimulates appetite and provides normal conditions for fertilization and embryo development.

Dry period length affects rumen adaptation in dairy cattle precalving and during the first weeks after calving

Omitting or shortening the dry period may result in a fairly constant ration throughout the transition period of dairy cows, reducing the need for adaptation of cow metabolism and rumen function to a new lactation. The objective of this study was to determine the effect of dry period length on rumen adaptation and cow metabolic state during the transition period. Twelve pregnant, rumen-cannulated Holstein Friesian dairy cows at the end of their first lactation were assigned to one of 3 treatments: a conventional (60 d), short (30 d) or no dry period (0 d). At dry-off, cows received a dry cow ration until calving. Lactating cows received a lactation ration. Cows were monitored from 8 wk before calving until 8 wk after calving for milk yield and dry matter intake (DMI). Rumen biopsies were taken from 3 locations in the rumen at 60, 40 and 10 d before calving and 3, 7, 14, 28 and 56 d after calving to assess papillae dimensions. Blood was sampled weekly from 3 wk before until 8 wk after calving, and liver biopsies were taken at wk -2, wk 2 and wk 4 relative to calving. Prepartum, DMI and milk yield were greater for cows with a short or no dry period, compared with cows with a conventional dry period. Postpartum, DMI was greater for cows with a short dry period compared with cows with a conventional dry period. Plasma glucose concentration was greater for cows without a dry period, compared with the other dry period lengths postpartum. Plasma concentrations of nonesterified fatty acids and β-hydroxybutyrate, and liver triglyceride content, did not differ among dry period. Rumen papillae differed in size based on biopsy location, but there was no interaction between biopsy location and the effect of dry period length. Rumen papillae surface area for cows managed for a 30 d or 60 d dry period decreased toward calving. At 40 d prepartum, papillae surface area was greater for short and no dry period treatment compared with a conventional dry period. At 10 d prepartum, papillae surface area was greater for the no dry period treatment compared with both other treatments, and this difference was still present 3 d postpartum. Cows managed for a short dry period showed faster increase in papillae dimensions after calving compared with cows managed for a conventional dry period. From d 28 onwards, no differences in papillae surface area were observed. The faster rumen adaptation postpartum may be related to the increased DMI during the first weeks postpartum for cows managed for a short dry period. However, this did not result in improved metabolic status or milk yield. The results from the present study demonstrate that the dietary changes related to a conventional dry period length affected rumen papillae development, not only prepartum but also early postpartum. Further optimization of dry period length as well as dietary composition throughout the transition period may support cows in their adaptation to a new lactation.

Evaluation of Partial Replacement of Barley Grain with Heated Potato Processing By-products in the Diet of Dairy Cows Using an In vitro Gas Production Technique

Background: The increasing urban population requires more dairy product (meat and milk) production; therefore, using agricultural sector by-products as animal feedstuffs has found double importance.&#x0D; Objective: The effects of replacing barley grain with heated potato slices (HPS) and French fries waste (FFW) in iso-energetic total mixed dairy cow rations on cumulative gas production and in vitro DM degradability were evaluated using in vitro techniques.&#x0D; Methods: Seven experimental dairy cow total mixed rations (TMR) were formulated based on partial replacing barley grain with HPS or FFW, including Control: a diet containing 16% (DM basis) barley grain as one of the main sources of non-forage carbohydrates; 5 HPS: a diet containing 11% barley grain and 5% HPS; 10 HPS: a diet containing 6% barley grain and 10% HPS; 15 HPS: a diet containing 1% barley grain and 15% HPS; 5 FFW: a diet containing 11% barley grain and 5% FFW; 10 FFW: a diet containing 6% barley grain and 10% FFW; 15 FFW: a diet containing 1% barley grain and 15% FFW. Two in vitro gas production approaches were conducted separately to measure the production of gas volumes and dry matter (DM) degradability at 2, 4, 6, 12, 24, 36, and 48 hours of incubation.&#x0D; Results: After 48 h of incubation, the gas production volume varied between 174 and 197 ml/g DM, with the highest value observed with control and the lowest value with FFW treatments (P &lt; 0.05). Also, the gas production rate for the insoluble fraction varied from 0.031 to 0.054 ml/h and was higher for HPS treatments than for control and FFW treatments (P &lt; 0.05). After 48 h of incubation, DM degradability was significantly lower for the control than other treatments. DM effective degradability, with a passage rate of 0.05 h−1, found to be higher for FFW and HPS treatments compared with the control. Moreover, the rate of the B fraction degradation was significantly lower for the control (0.14 % h−1) than for treatments.&#x0D; Conclusion: The heated potato processing by-products could be replaced with barley grain by 15% in the diet of dairy cows without having negative effects on ruminal fermentation.