Milk Yield Research Articles

Addition of the By-Pass Fat into Diet of Awasi Sheep on Milk Composition

By-pass fat is an important source of essential fatty acids for ruminants. It affects yield rather than maintenance requirements. This study was carried out to investigate the effect of adding by-pass fat into diet of dairy sheep on milk components. The study was carried out in a private dairy sheep farm in Konya. For this purpose, 99 Awassi sheep were used after 1 month of the birth during the fresh lactation period. The sheep were randomly divided into 2 groups, the control (C) group (n=54) was fed with total mixed ration (TMR) twice a day, the by-pass fat (BF) group (n=45) was fed with TMR twice a day and 30 g/day of commercial Ca-soap palm oil by-pass fat was given individually during milking. The trial last 15 days with 11 days of adaptation and 4 days of sample collection. The animals in the experimental group consumed 30 g/day of Ca-soap by-pass fat individually during morning milking. The animals were milked for once with an automatic milking system and the lambs were suckled for once by creep. Milk yields of the animals were recorded automatically during the sample collection period, also 50 ml milk samples were taken from each animal at the milking times on the 2nd and 3rd days, and milk fat, non-fat dry matter, protein, lactose, density, freezing point, and somatic cell counts were determined. Fat, non fatty dry matter, density, protein, lactose and somatic cell were respectively; 4.50±0.14 and 5.65±0.17%, 10.86±0.07 and 11.16±0.12%, 34.66±0.45 and 34.33±0.64%, 5.42±0.06 and 5.70±0.10%, 4.49±0.01 and 4.47±0.01%, 121.556±16987 and 171.222±28348 in the C and BF groups, Among milk components, while fat, nonfat dry matter and protein were higher in BF group than C group (p<0.05), density, lactose and somatic cell were similar between groups (p>0.05). It can be concluded that the even though addition of 30 g of Ca soap by-pass fat significantly improved milk fat, non-fat dry matter and protein in dairy sheep fed with TMR at the level of maintenance and yield.

Effects of Oregano on Lactation Performance, Nutrient Digestibility, Ruminal Fermentation Parameters, and Methane Emissions in Dairy Cows: A Meta-Analysis

Growing concerns regarding antibiotic use in livestock, due to antibiotic resistance and potential human transmission, have led to increased interest in herbs and their derivatives, including essential oils, which possess antimicrobial properties that may enhance overall productivity and serve as a strategy for methane mitigation. The objective of this meta-analysis was to investigate the effects of adding oregano to the diet in different forms (essential oils, plant materials, or leaves) on the dry matter intake (DMI), milk yield (MY), milk components, nutrient digestibility, ruminal fermentation parameters, and methane (CH4) emissions of dairy cows. A literature search was conducted to identify papers published from 2000 to 2023. Effect size for all outcomes was reported as a standardized means difference (SMD) and raw means difference with 95% confidence intervals. Heterogeneity was determined using the Q test and I2 statistic. The results of the meta-analysis indicated that adding oregano had no effect on DMI (SMD = 0.081; p = 0.507) and MY (SMD = 0.060; p = 0.665). Milk fat percentage, milk protein percentage, and milk lactose percentage were not affected by oregano. The addition of oregano to the diet significantly decreased dry matter digestibility (SMD = −0.502; p = 0.013), crude protein digestibility (SMD = −0.374; p = 0.040), and neutral detergent fiber digestibility (SMD = −0.505; p = 0.014). Ruminal pH (SMD = −0.122; p = 0.411), total volatile fatty acids concentration (SMD = −0.038; p = 0.798), acetate (SMD = −0.046; p = 0.757), propionate (SMD = 0.007; p = 0.960), and butyrate (SMD = 0.037; p = 0.801) proportion were not affected by oregano. The addition of oregano to the diet tended to decrease CH4/DMI (SMD = −0.275; p = 0.095) but did not affect CH4 production (SMD = −0.156; p = 0.282). Heterogeneity (Q and I2) was non-significant for all parameters. We conclude that the inclusion of oregano in various forms (essential oils, plant materials, or leaves) in the diet of dairy cows reduces nutrient digestibility but does not significantly affect DMI, MY, milk components, ruminal fermentation parameters, or CH4 production. Future research should focus on optimizing the dosage of oregano (both EOs and plant materials) and exploring the impact of its form on lactation, nutrient digestibility, ruminal fermentation, and CH4 emissions in dairy cows.

Different sources of alfalfa hay alter the composition of rumen microbiota in mid-lactation Holstein cows without affecting production performance.

Alfalfa hay is a commonly used and important feed ingredient in dairy production. To better expand the alfalfa supply market, it is of great significance to explore the impact of alfalfa hay from different sources on dairy cow production performance. This study compared the effects of imported alfalfa hay from America (AAH) and Spain (SAH) on lactation performance and rumen microbiota of cows. Three hundred and sixty healthy mid-lactation Holstein cows with similar body weight, milk yield, and parity were randomly divided into two groups fed diets based on AAH or SAH for a 70-day experimental period. Each group was composed of four pens, with 45 cows in each pen. Daily records were kept for MY per cow and dry matter intake per pen. Twelve randomly selected cows per group were sampled to collect milk, feces, rumen fluid, and blood. The findings revealed no significant differences between the two groups in terms of production performance, nutrient apparent digestibility, serum biochemical indices, or rumen fermentation parameters. However, rumen microbial composition differed significantly between the two groups of cows based on β-diversity. On the genus level, the relative abundance of Prevotella, Succinivibrionaceae_UCG-002 increased while that of NK4A214_group, Ruminococcus, norank_f_F082 and Lachnospiraceae_NK3A20_group decreased in the SAH group compared with AAH group. There was no significant correlation between these core differential bacteria and the molar proportions of acetate and propionate, the concentration of total volatile fatty acids, and milk yield. In conclusion, the feeding effects of SAH were similar to those of AAH. These findings provided a reference for the application of alfalfa hay from different sources and for the improvement of the economic benefit of dairy farms.

Effect of a Bacillus subtilis-based direct-fed microbial, on milk yield, milk components, feed intake and plasma hormones and metabolites in lactating Holstein cows

To investigate the effects of a Bacillus-based direct-fed microbial on milk production and related factors, a study was conducted on Holstein cows (n = 28) starting at 90 ± 11 DIM. The cows were divided into two dietary groups: a control group (CON) that received a total mixed ration (TMR), and a Bacillus-fed group (DFM) that received the same TMR along with a Bacillus subtilis product containing two strains (747 and 1781) in equal amounts. The study lasted for 25 wk and included both primiparous and multiparous cows. The cows were housed in a free-stall barn and were provided with ad libitum TMR, which was fed twice a day. Their daily meals and dry matter intake (DMI) were recorded during wk 1–4 and wk 19–25 using electronic feeders. Milk samples were collected weekly during morning and evening milkings and analyzed for milk fat, protein, lactose, and milk urea nitrogen (MUN). Blood samples were also collected weekly and analyzed for plasma glucose, insulin, cholesterol, insulin-like growth factor 1 (IGF1), and progesterone concentrations. Additionally, rumen fluid samples were collected and evaluated for various species of bacteria. One of the key findings was that daily 4 % fat-corrected milk production (FCM) was influenced by the interaction between treatment (DFM vs. CON) and parity (primiparous vs. multiparous), with multiparous DFM cows producing 11 % more FCM compared to CON. The DFM cows also had a higher milk fat percentage (4.41 % vs. 4.02 %) and MUN concentrations were 1.0 mg/dL higher in the DFM group. In terms of blood metabolites and hormones, multiparous DFM cows had lower plasma cholesterol, glucose, and insulin concentrations compared to CON multiparous cows. However, there were no significant differences between the groups in terms of plasma IGF1 concentrations, insulin-to-glucose ratios, and luteal phase plasma progesterone concentrations. The analysis of rumen fluid samples revealed that the abundance of Ruminococcus albus and Fibrobacter succinogenes group I was greater in the DFM cows compared to CON cows. Furthermore, during the periods when feed intake was measured, the DFM cows had a 9 % reduction in feed intake and a 14 % improvement in feed efficiency (FCM per DMI) compared to CON cows. In conclusion, the two-strain Bacillus product used in this study (Certillus) showed potential as an effective direct-fed microbial. It was found to increase feed efficiency and milk production by altering the composition of ruminal microbiota and metabolism in the cows.

Impact of Heat Stress on Milk Yield, Milk Fat-to-Protein Ratio, and Conception Rate in Thai-Holstein Dairy Cattle: A Phenotypic and Genetic Perspective.

Heat stress severely affects dairy cattle production and reproduction performances in tropical regions. Genetic selection to maintain adequate yield and reproductive performance while enhancing their ability to withstand heat is essential for improving the genetics of dairy cows. Therefore, in this study, we aimed to estimate genetic parameters affecting production and reproduction performances under heat stress conditions in dairy cattle and to investigate the threshold point of heat stress for milk yield (MY), milk fat-to-protein ratio (FPR), and conception rate (CR) in Thai-Holstein dairy cattle. The data included 168,124 records related to MY and milk FPR and 21,278 records of CR in Thai-Holstein dairy cattle, covering the period from 1990 to 2007. A multiple-trait threshold-linear random regression model based on a Bayesian approach via Gibbs sampling was used to estimate variance components, genetic parameters (heritability values, and genetic correlations), and decline rates for each studied trait. The threshold point of heat stress was identified as a temperature and humidity index (THI) of 76. At THI76, a decline was observed in the MY, milk FPR, and CR of Thai dairy cattle. The heritability estimates for MY, milk FPR and CR were 0.347 ± 0.032, 0.293 ± 0.021, and 0.032 ± 0.001, respectively. The genetic correlation between MY and milk FPR and MY and CR were -0.24 and -0.53, respectively, whereas those between milk FPR and heat tolerance as well as between CR and heat tolerance were -0.48 and -0.49, respectively. In addition, the decline rates in MY, milk FPR, and CR were found to be associated with a high percentage of Holstein genetics. In conclusion, the results obtained in this study reveal that the simultaneous consideration of the MY, milk FPR, CR, and heat tolerance traits of Thai-Holstein dairy cattle is possible. In addition, developing a genetic model that incorporates THI is essential for sustainably addressing heat stress problems.

Effects of Methionine on Milk Performance and Milk Constituents of Lactating Donkeys.

This study investigated the effects of adding methionine (Met) in milk production and the milk and blood metabolites of lactating donkeys. Eighteen healthy multiparous donkeys in early-stage lactation were selected for this study. The donkeys were randomly divided into three groups and fed diets with different levels of Met: control group (C, Met 0 g/d), Met group I (M1, Met 5 g/d), and Met group II (M2, Met 15 g/d). The total duration of the experiment was 5 weeks. Donkey milk and blood samples were collected at the end of the experiment. The milk yield and composition, milk, and serum metabolites were analyzed. The results showed that the addition of 5 g of Met significantly increased milk yield as well as the milk composition contents of protein, fat, lactoferrin, polyunsaturated fatty acid (PFA), solids, and solids-not-fat (SNF) (p < 0.05). Significant differences in metabolites were detected among the different samples of milk (p < 0.05). The addition of Met increased the levels of milk metabolites, such as myristic acid, d-glutamine, l-aspartic acid, and LPS 16:0. A total of 753 metabolites were detected in the serum, including 17 differential metabolites between C and M1 and 48 differential metabolites between C and M2. The levels of serum metabolites, such as l-ascorbate, inositol, and l-lysine, were up-regulated by the addition of Met (p < 0.05). The above results indicated that Met increased donkey milk production and milk composition yield and improved milk metabolites by regulating serum metabolites. These results provide a foundation for improving the nutritional needs of lactating donkeys and the nutritional regulation of donkey milk synthesis.

Beta-Glucans Improve the Mammary Innate Immune Response to Endotoxin Challenge in Dairy Ewes.

This study evaluated short-term immune responses of dairy ewes supplemented with barley β-glucan (BG) following an intramammary Escherichia coli lipopolysaccharide (LPS) challenge. In the adaptation period, 36 ewes were fed an alfalfa hay diet ad libitum and barley grain cv. Hispanic (3.8% BG). Then, ewes were assigned into three experimental groups: (1) Control (CON), the same previous diet (13.3 g BG/d); (2) high β-glucans barley (HBG), new barley (cv. Annapurna) containing 10% BG (35 g BG/d); (3) intraperitoneally injected (INP) with a 1.4% BG solution dose (2 g BG/ewe). At d 9, all ewes were infused with an E. coli LPS or saline solution in each udder half. After the challenge, rectal temperature (RT), milk yield and composition, somatic cell count (SCC), and plasma interleukins (IL-1α and IL-1β) were monitored daily. The INP treatment revealed a transitory increase in RT and decreased milk yield by 38%. Milk fat, protein, and SCC increased in LPS-treated udders but not by BG treatment. The IL-1α plasma concentration was similar among groups but INP ewes showed a lower IL-1β concentration suggesting a lower inflammatory response. The BG administration appears more effective intraperitoneally than orally, which needs additional study.

Performance of Holstein dairy cows fed a diet supplemented with rosemary and ginger essential oils: milk production, milk fatty acid, and ruminal fermentation

Abstract The study determined the impact of Rosmarinus officinalis and/or Zingiberene officinalis essential oil (EO) on milk yield, composition, milk fatty acids profile, blood biochemicals, and rumen fermentation in dairy cows. Twenty-eight Holstein lactating cows were distributed into four groups using a completely randomized block design in a 70-d experiment. The control diet consisted of 13 kg of concentrate and 40 kg of fresh berseem clover per head per day, without supplementation. In the other treatments, the control diet was supplemented with 10 mL of EO per head per day, using either ginger EO (GEO treatment), rosemary (REO treatment) EO or a blend of both at a 1:1 v/v ratio (BEO treatment). Supplementation did not affect intake, milk production, or composition. Omega-n3 and omega-n5 were increased with REO (p &lt; 0.05) compared to the control. Both REO and BEO decreased (p = 0.003) serum globulin and increased (p &lt; 0.005) albumin to globulin ratio, high-density lipoprotein cholesterol, and total lipid. Serum total antioxidant capacity was increased (p ˂ 0.001) with the supplementation, without affecting glucose, total protein, albumin, serum cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase, aspartate aminotransferase, and urea concentrations. In conclusion, supplementing Holstein dairy cows with GEO and/ or REO increased the level of omega-3 and omega-5 fatty acids while reduced saturated fatty acids in milk, without affecting feed intake, milk production or milk composition.

Assessment of Husbandry Practices, Production and Reproductive Performance of Indigenous Cattle in Urban and Peri -urban Areas of Gambella City, Ethiopia

The objective of the present study was to characterize cattle husbandry practices, production and reproductive performance of cattle in the urban and peri-urban areas of Gambella city. Sample of respondents from each selected kebele were selected randomly using simple random sampling technique. A total of 133 household (70 from urban and 63 from peri-urban) were selected for questionnaire interview. Data was analyzed using SPPS version 23 software. The overall mean of the respondents revealed that, the management system practiced was semi-intensive (87.2%), extensive system (12.8%) and there was no intensive management system practiced. the overall mean daily milk yield was 1.58± 0.017 Littre/cow/day. The overall mean daily milk yield analysis of variance was significantly (P&amp;lt;0.05) difference among urban and peri-urban areas. The current result also indicated that, the overall average lactation length was and 10.59± 0.15 months, and was not significantly (P&amp;gt;0.05) affected by the study areas. The overall average age at first services, age at first calving and calving interval was 46.31±0.33, 51.51±0.54, and 19.01±0.11 months respectively. In Addition, disease prevalence, poor animal health service delivery, grazing land and feed shortage were among the major constraints affecting production and productivity in the study areas. In conclusion, Age at first services, age at first calving and calving interval of indigenous cow was low compared to some of the indigenous breed in other regions, animal health and health services delivery are the problems affecting cattle productivity. Hence, all concerned stakeholders need to take urgent interventions in order to improve production and productivity of cattle.

Nitidine Chloride Alleviates Hypoxic Stress via PINK1-Parkin-Mediated Mitophagy in the Mammary Epithelial Cells of Milk Buffalo.

Hypoxia in the mammary gland epithelial cells of milk buffalo (BMECs) can affect milk yield and composition, and it can even cause metabolic diseases. Nitidine chloride (NC) is a natural alkaloid with antioxidant properties that can scavenge excessive reactive oxygen species (ROS). However, the effect of NC on the hypoxic injury of BMECs and its molecular mechanisms are still unknown. Here, an immunofluorescence assay, transmission electron microscopy (TEM), and flow cytometry, combined with untargeted metabolomics, were used to investigate the protective effect of NC on hypoxic stress injury in BMECs. It was found that NC can significantly reduce cell activity (p < 0.05) and inhibit cellular oxidative stress (p < 0.05) and cell apoptosis (p < 0.05). A significant decrease in mitophagy mediated by the PINK1-Parkin pathway was observed after NC pretreatment (p < 0.05). In addition, a metabolic pathway enrichment analysis demonstrated that the mechanisms of NC against hypoxic stress may be related to the downregulation of pathways involving aminoacyl tRNA biosynthesis; arginine and proline metabolism; glycine, serine, and threonine metabolism; phenylalanine, tyrosine, and tryptophan biosynthesis; and phenylalanine metabolism. Thus, NC has a protective effect on hypoxic mitochondria, and it can regulate amino acid metabolism in response to hypoxic stress. The present study provides a reference for the application of nitidine chloride to regulate the mammary lactation function of milk buffalo.

Effects of rumen-protected methionine and lysine on antioxidant status and lactationperformance in crossbred dairy cattle during transition

Dairy cows undergoing the transition phase often face nutritional challenges, impacting their antioxidant status and lactational performance. To address these challenges, the incorporation of rumen-protected methionine and lysine in the diet has emerged as a strategic intervention.Twelve crossbred cows inthe transition period were randomly divided into two groups of six animals. The control group and treatment group were fed with a standard diet (ICAR, 2013) while the treatment group was supplemented with rumen-protected methionine and lysine. Throughout the trial period, all the animals were subjected to consistent management and feeding conditions.Glutathione peroxide(GPx)levels exhibited a statistically significant difference between groups, with the treatment consistently showing higher GPx levels, indicating an improvement in antioxidant capacity, where it helps regulate systemic oxidative stress.The recorded milk yield data was utilized to compute the daily milk production for each individual for the experimental period. Milk yield remained unaffected, but the treatment group consistently exhibited higher milk yield, suggesting positive influences on postpartum lactation performance. Keywords: Rumen-protectedmethionine, rumen-protectedlysine,transition period, antioxidant status

Effects of pre- and postpartum dietary fat sources (soybean oil versus linseed oil) on lactation performance and blood metabolites in transition dairy cows

This study investigated the effects of supplementation with two calcium salt fatty acid sources (soybean oil (CaSO) and linseed oil (CaLN)) before and after parturition on lactation performance and blood metabolite profiles in dairy cows. A study was conducted with twenty-four multiparous Holstein cows (parity = 3.12 ± 0.9 and Backfat thickness = 21.77 ± 1.98) that were divided into a 2 × 2 factorial design 21 days before expected calving. The aim was to investigate the interplay between prepartum (CaSO or CaLN, at 2 % of dry matter) and postpartum (at 1.4 % of dry matter) fat supplementation on lactation performance and blood metabolite profiles. Initially, cows were grouped according to the source of prepartum fat (either CaSO or CaLN, with 12 cows in each group). Postpartum, these groups were further subdivided according to whether the fat source was administered continuously (LN-LN, SO-SO) or alternately (LN-SO, SO-LN) over a 28-day period. This resulted in four different treatment groups, each with six cows. The fat supplements contained 84 % fat and 9 % Ca. No statistically significant differences were found in dry matter intake (DMI), colostrum yield or most concentrations of blood metabolites (insulin, cholesterol, glucose, triglycerides, total protein, albumin, β-hydroxybutyric acid (BHB), non-esterified fatty acids (NEFA), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and urea-N). However, cows fed CaSO prepartum had a significantly higher plasma concentration of insulin-like growth factor-1 (IGF-1) than cows fed CaLN. Cows fed CaSO had higher backfat thickness (BFT) from day −21–0 than those fed CaLN (P = 0.05). Notably, cows in the SO-SO group lost the most weight, while cows in the SO-LN group lost the least, especially on days 21 and 28 postpartum (P = 0.05). Switching from soybean oil prepartum to linseed oil postpartum (SO-LN) significantly increased milk production in the first 28 days of lactation compared to other diets. In addition, the fat content in milk was influenced by the type of fat supplementation prepartum, with cows receiving CaSO having a lower milk fat percentage than those receiving CaLN (P < 0.05). The results on blood parameters suggest potential benefits of the SO-LN diet for postpartum cows, as emphasized by stable BHB concentrations and the highest IGF-1 concentrations, especially without the elevated BHB concentrations typically associated with the SO-SO diet. The blood concentrations of total protein, urea-N, triglycerides and NEFA were not affected by the treatments. Also, the dietary change did not adversely affect liver function, as shown by unchanged AST and ALT concentrations. Therefore, the results suggest that a dietary intervention involving the administration of soybean oil prepartum and switching to linseed oil postpartum (SO-LN strategy) has the potential to improve milk yield during the early lactation period.

Camel Milk Yield and Composition and its Adjuvant Potential Impacts on Health of Consumers: A Review

Dromedaries can be integrated efficiently into an extensive and intensive management milk production systems for producing milk. Camel milk has specific nutritional values that alleviate certain diseases. The camel milk can be produced under harsh and intensive management conditions. Camel milk was given to human and experimental animal species under normal and dysfunction conditions as hyperglycemic, hyperlipidemic and hepatitis. The articles concerning management conditions of producing camel milk and its specific nutritive values were used for writing the manuscript and they were collected from google scholar, ScienceDirect, PubMed databases. The results indicated that camels species were significantly produced milk either under harsh or intensive management conditions. The constituents of chemical camel milk were differed among species, stage of lactation, and management systems. The nutritional values of camel milk were explored as antihyperglycemic, antihyperlipidemic, anti-cancer, and others. The possible biological candidates in camel milk include lactoglobulins, lactoferrin, and lysozyme. It could be concluded that camel milk has a potential nutritional therapy, where it is effected on blood glucose values, liver and kidney functions.

Some Yield and Growth Traits of Anatolian Buffaloes and the Effects of First Calving Age and Calving Interval on These Traits

Numerous in-depth studies have described the fertility traits, growth performance and milk yield traits of dairy animals, which are considered indicators of welfare, but there are limited studies examining these traits within the framework of cause-effect relationships, especially in buffaloes. The aim of this study was to determine the changes in some milk, growth and fertility traits of Anatolian buffaloes over the years in some dairy farms where the Buffalo Breeding Project in Public Conditions was implemented in Samsun province and, to investigate the effects of first calving age (FCA) and calving interval (CI) on milk and growth traits. The study was conducted in 27 buffalo farms (3295 buffalo cows and 3317 buffalo calves) located in Bafra district, the region with the highest buffalo population in Samsun province, Türkiye. The data was taken from records previously kept within the scope of the relevant project. The data such as growth characteristics [birth weight (BW), 6th and 12th-mo live weight (LW) values of calves born between 2013-2020] and lactation traits of cows [lactation milk yield (LMY) and lactation duration (LD)] and FCA and CI values were analyzed by analysis of variance. The effect of years on LMY of buffalo cows was found to be significant, and significant positive changes were determined from year to year. In addition, the BW, 6th-mo, and 12th-mo LW values of calves also varied from year to year. As the FCA value of buffaloes increased, the BW, 6th-mo, and 12th-mo LW values of calves and LMY of cows increased. Similarly, CI values affected the BW values of calves (P&lt;0.01), and LMY and LD values increased in parallel with the increase in CI values. Consequently, determining the lactation and growth traits of buffaloes could benefit developing herd management practices that would optimize these performance indicators.

Strategies of positive deviants in fodder conservation among smallholder dairy farming systems in highlands and midlands of Kenya.

Fodder scarcity and low quality affect the productivity of dairy cattle in Kenya yet only few smallholder dairy farmers show positive deviance in fodder conservation. Information on the strategies of such positive deviant (PD) farmers is scanty. The objective of this study was to determine strategies that distinguish PDs from peers (non-PDs) in fodder conservation among smallholder dairy farmers in highlands and midlands of Kenya. A cross-sectional survey was conducted among farms producing and conserving fodder in Tharaka Nithi County. Multistage sampling procedures was used; purposive sampling of the Sub-counties and locations, random selection of villages and proportional selection of 246 farms through snowball chain referral. Data were collected on demographic, socio-economic, farm characteristics and fodder conservation. Farms were categorized as PDs (n = 24) or non-PDs (n = 97). The PDs conserved fodder adequate to last dry season (about 3 months) and had milk yield 15kg/cow/day and above, while non-PDs do not qualify for both criteria. Chi-square and T-test were used to analyze categorical and continuous variables respectively. Logit regression was used to examine independent variables that influence probability of PDs. Farmers with high school and tertiary education who accessed extension services were PDs while non-PDs had non-formal and primary education and access extension less. Farms conserving hay and silage dominated PDs. Land in hectare (ha) and herd sizes in Tropical Livestock Unit (TLU) distinguished PDs (1.7ha and 9.0 TLU) from non-PDs (0.7ha and 3.3 TLU). The strategies that distinguished PDs from non-PDs were allocating land to fodder production, high milk yield kg/cow/day, large herd size and access to extension services. Increasing access to extension and resources (land) raised chances of PDs in fodder conservation. Knowledge of PDs strategies is important for fodder conservation, improve productivity and inform direction of future research.

Validation of a Remote Sampling Sensor for Measuring Urine Volume and Nitrogen Concentration in Grazing Dairy Cattle.

The purpose of this research was to validate a urine sensor (Lincoln University PEETER V2.0, Canterbury, New Zealand) that records the time and volume of urination events for dairy cows in addition to collecting a proportional urine sample from all urination events. Sixteen multiparous Holstein × Jersey mid-lactating cows (101 ± 5 days in milk, 498 ± 24.2 kg body weight, 26.2 ± 3.07 kg/d milk yield; mean ± standard deviation) were allocated herbage diets ranging in protein and sodium content to generate a range of urine volumes and urine nitrogen (UN) concentrations. Total collection of individual urination events occurred during a 72-h measurement period where PEETER V2.0 sensors were attached to cows. A mixed model ANOVA using lme4 package (version 1.1-35.5) in R (version 4.3.3) were used to compare the means. The average urine event size was 2.65 ± 1.1 L for total collection by observers and 2.68 ± 1.1 L as recorded by the sensor (mean ± standard deviation; p = 0.730). The urine nitrogen concentration was 5.76 ± 1.2 g N/L for samples collected by observers and 5.85 ± 1.3 g N/L for the samples collected by the sensor (p = 0.583). The calculated UN excretion was 156 ± 45.1 g/day for direct measurements and 162 ± 40.0 g/day for the sensor (p = 0.539. Contrasts with simultaneously measured data were undertaken using Lin's Concordance Correlation Coefficient (CCC) and a Pearson correlation coefficient (r). Correlations between the actual values and sensor values were strong, with little to moderate variability in the urine volume (CCC = 0.936, r = 0.937; n = 222), UN concentration (CCC = 0.840, r = 0.837, n = 48) and total UN excretion (CCC = 0.827, r = 0.836, n = 24). Considering the findings, the PEETER V2.0 urine sensor has the potential to reliably measure urine volumes and UN concentrations for estimations of the UN excretion of dairy cattle under grazing systems.

Genetic assessment of productive and reproductive traits in Friesian, native, and crossbred cattle in Egypt

This study utilized a dataset comprising 3023 lactation records for Friesian cows, 596 records for Native cows (Baladi), and 1189 records for Crossbred cows spanning from 1994 to 2015. The objective was to estimate and assess genetic and phenotypic parameters and breeding values for 305-day milk yield (305-DMY), lactation period (LP), calving interval (CI), and days open (DO) within the Egyptian dairy context. The motivation for this research stemmed from the need to understand the genetic potential of different cattle genotypes in Egypt and identify opportunities for enhancing dairy production. Data were analyzed using the linear mixed model least squares and maximum likelihood (LSMLMW) and multiple-trait derivative-free restricted maximum likelihood (MTDFREML) programs. The analytical model included fixed effects such as season and year of calving, parity, and genotype groups, while random effects included animal and error. Unadjusted means for 305-DMY, LP, CI, and DO were calculated for each genotype group. Genotype groups significantly impacted all studied traits. Heritability estimates varied across genotype groups, with higher estimates observed in Crossbred (0.32, 0.26, 0.25, 0.23) and Native cows (0.26, 0.28, 0.28) compared to Friesian cows (0.24, 0.22, 0.16, 0.17) for productive and reproductive traits, respectively. Genetic correlations among traits ranged from 0.10 to 0.86 for the three genotype groups, while corresponding phenotypic correlations were generally small to moderate and positive. Regarding breeding values, the accuracy estimates suggested that both sires and cows could contribute to genetic improvement. This indicates the potential for enhancing dairy production through selective breeding strategies.

Productive performance and milk composition of dairy ewes supplemented with corn silage (Zea mays L.), sunflower (Helianthus annuus) silage and their mixture.

The work reported in the Research Communication investigated in vitro rumen gas kinetics and fermentation profile as well as in vivo performance of lactating ewes fed corn silage (CS), sunflower silage (SFS) and their 50 : 50 mixture (CS-SFS). For the in vivo experiment, nine early-lactation Suffolk × Texel ewes were grouped in a replicated 3 × 3 Latin square design of three 21-d periods. Treatments were based on ad libitum CS, SFS, and CS-SFS supplemented with concentrate at 48 g/kg LW0.75. In vitro results showed that the CS had the highest dry matter degraded substrate and microbial crude protein production followed by CS-SFS. The in vivo data showed that animals fed on CS had higher digestibility of dry matter and organic matter than CS-SFS, while SFS were intermediate. Nitrogen (N) intake, fecal N excretion, and urine N excretion were similar between groups, however, milk N excretion was lower in SFS than CS. Milk yield was higher for CS and CS-SFS than SFS group, however, SFS-fed ewes had higher milk fat content than either CS or CS-SFS (all differences reported here were significant, P < 0.05 or better). Overall, CS-SFS could be used as dietary roughage for dairy ewes without deleterious effects on nutrient intake, N-balance and milk yield whilst potentially offering a more sustainable alternative to CS.

Effects of fibrolytic and amylolytic compound enzyme preparation on rumen fermentation, serum parameters and production performance in primiparous early-lactation dairy cows.

This research communication reports the effects of a compound enzyme preparation consisting of fibrolytic (cellulase 3500 CU/g, xylanase 2000 XU/g, β-glucanase 17 500 GU/g) and amylolytic (amylase 37 000 AU/g) enzymes on nutrient intake, rumen fermentation, serum parameters and production performance in primiparous early-lactation (47 ± 2 d) dairy cows. Twenty Holstein-Friesian cows in similar body condition scores were randomly divided into control (CON, n = 10) and experimental (EXP, n = 10) groups in a completely randomized single-factor design. CON was fed a basal total mixed ration diet and EXP was dietary supplemented with compound enzyme preparation at 70 g/cow/d. The experiment lasted 4 weeks, with 3 weeks for adaptation and then 1 week for measurement. Enzyme supplementation significantly increased diet non-fibrous carbohydrates (NFC) content as well as dry matter intake (DMI) and NFC intake (P < 0.05). EXP had increased ruminal butyrate and isobutyrate percentages (P < 0.01) but decreased propionate and valerate percentages (P < 0.05), as well as increased serum alkaline phosphatase activity and albumin concentration (P ≤ 0.01). Additionally, EXP had increased milk yield (0.97 kg/d), 4% fat corrected milk yield and energy corrected milk yield, as well as milk fat and protein yield (P < 0.01). In conclusion, dietary supplementation with a fibrolytic and amylolytic compound enzyme preparation increased diet NFC content, DMI and NFC intake, affected rumen fermentation by increasing butyrate proportion at the expense of propionate, and enhanced milk performance in primiparous early-lactation dairy cows.

The Impact of Negative Energy Balance in Holstein-Friesian Cows on the Blood Concentrations of Interleukin-6 and Plasminogen.

Background/Objectives: The negative energy balance activaties of spontaneous lipolysis. This may promotes inflammation within the adipose tissue. The aim of the study was to explain the development of inflammation during increased lactogenesis. It was hypothesized that lipolysis contributes synthesis of interleukin-6 and plasminogen. Methods: The study was in production conditions carried out using Holstein-Friesian cows. The period studied covered time of early lactation. Results: Up to the peak of lactation, milk yield strongly influenced the rate of loss of body condition. This had an impact on with the intensity of the release of the fatty acids. In both cases this relationships strengthened to the peak of production. Oobserved tendencies towards a decrease in the concentration of glucose and an increase in that of leptin. Loss of the body condition and the release of NEFA were were influencing to affect the blood concentrations of interleukin-6 and plasminogen. We have shown that IL-6 has a relatively strong correlation with the NEFA. They correlate with IL-6 independently of EB influence. This may suggest independent associations between these variables, which could potentially be applied in practice. Conclusions: The NEFA release in the long term can increase the inflammatory response within adipose tissue and can intensify the release of interleukin-6 and plasminogen. It is likely that in the initial stage of lactogenesis, the inflammatory process developing within adipose tissue is physiologically justified. Our results can provide background to this little-described area of research.