Crossbred Holstein Friesian Research Articles

"Assay of BLf using Sandwich ELISA and its Comparative Study of Holstein-Friesian Crossbred and Sahiwal with Poda Thurpu Cow Milk"

"Assay of BLf using Sandwich ELISA and its Comparative Study of Holstein-Friesian Crossbred and Sahiwal with Poda Thurpu Cow Milk"

High resolution melt curve analysis identifies a novel SNP (G21A) in butyrophilin gene having significant association with milk production traits in Holstein Friesian crossbreds of Kerala

Butyrophilin (BTN1A1) gene is located in the neighborhood of a quantitative trait loci for milk production in bovine autosome 23. We verified the genetic variability of exon-3 in BTN1A1 and its association with milk production traits in Holstein Friesian crossbreds of Kerala. Genomic DNA was isolated and 94 bp fragment enclosing exon-3 was amplified by primers designed using PRIMER 3 based on reference sequence (GenBank NC_037350). Pooled amplicons were sequenced by Sanger’s method and a novel single nucleotide polymorphism due to a transversion of guanine to adenine at position 21 of amplicon (G21A) leading to amino acid change arginine to glutamine was detected. The study population was genotyped by high-resolution melt curve analysis and revealed two genotypes with frequencies GG/0.84 and GA/0.14. The allele G was found to be the major one (G/0.93 and A/0.07). Moreover, association analysis of G21A with milk production traits was done using the General linear model-Analysis of Variance considering herd, season, and parity as non-genetic factors and milk production trait as a dependent variable. In analysis, animals with GA genotype were found to be having significantly higher (p ≤ 0.01) 305 day milk (GG:2720.74 ± 122.92 kg; GA:3250.20 ± 183.24 kg), fat (GG:106.55 ± 4.32 kg; GA:126.30 ± 13.35 kg), and SNF yield (GG: 211.52 ± 9.20 kg; GA: 246.90 ± 13.70 kg). However, GG (7.80 ± 0.04) genotype has significantly higher (p ≤ 0.05) SNF percent than GA (7.65 ± 0.07). Butyrophilin gene polymorphism G21A can be suggested as a molecular marker for future breeding programmes of cattle.

Subclinical ketosis: Prevalence and risk factor analysis in early lactation dairy cattle of Thrissur district

Present study was conducted in Kerala Veterinary and Animal Sciences University farms, various organized and unorganised farms and individual households in Thrissur district during the period of May 2021 to April 2022 with the objectives of estimation of prevalence of subclinical ketosis (SCK) by screening dairy cows on 14th and 28th day post-partum. Multiparous cows with a blood beta-hydroxy butyrate (BHB) value ≥ 1.2 mmol/L without any overt clinical signs were considered as positive for SCK. One hundred and fourteen animals from second to seventh lactation were screened for SCK. Prevalence of SCK was 23.7 per cent on 14th day and 14.04 per cent on 28th day with a total prevalence of 27.2 per cent. Occurrence of SCK was highest in animals in second lactation (54.8 per cent) with more occurrence in crossbred Holstein Friesian cows. Maximum number of positive cases were observed in dairy cows of age between four to six years (54.8 per cent). Body condition score of diseased animals were higher than normal animals. Prevalence was highest in animals calved between months of July to September and 58.1 per cent of affected animals had male calf. Concurrent abnormalities during transition period were also assessed based on clinical examination and farm records.

Risk factors associated with subclinical mastitis in dairy cows reared in district Ganderbal, Jammu and Kashmir

Subclinical mastitis is associated with certain risk factors such as age, lactation stage, milk production and parity. A cross sectional study including 135 cross bred Holstein Friesian dairy cows was undertaken from June 2017 to January 2019 in surrounding villages of district Ganderbal in order to identify major risk factors. The overall prevalence of SCM was 81.48%. The highest prevalence of subclinical mastitis associated with various risk factors was 48.1% (early lactation), 44.54% (5-7 years), 49.09% (>10 litres per day) and 30.90% (3rd parity) respectively. In intensive system of rearing, prevalence was 66.36% whereas in extensive 33.63% was found. In present study, single quarter was affected in 61.81% of SCM infections. In milking method, knuckling and stripping showed more incidence of SCM. In present study, moderate form of mastitis was more predominant (40.9%).

Evaluation of motility and morphology of frozen bull semen under different thawing methods used for artificial insemination in North Shewa zone, Ethiopia

The frozen bull semen straws were gathered from three specifically chosen locations in the North Shewa Zone, namely Baso, Chacha, and Debre-Birhan town, and the laboratory work was carried out at the Debre Birhan agricultural research center. The researchers wanted to see how different thawing methods affected the mass motility of frozen bull sperm. The thawing protocols used for mass motility evaluation were 37 °C for 30 s, 35 °C for 40 s, 40 °C for 40 s, body temperature using a hand for 15 s and body temperature using a hand for 30 s by using a water bath. The mass motility of the frozen bull semen was evaluated subjectively using a phase contrast microscope with 10x magnification. The frozen straws were taken from six bulls and two breeds (Holstein Friesian and 75% Holstein Friesian). Motility, morphology, and storage time length of frozen bull semen were analyzed using the general linear model of SAS (9.0). The mass motility of spermatozoa varied from 31 to 41.6 percent in different thawing protocols. Among the thawing protocols, 37°C/30 s (thawing at 37°c for 30 s) was found to have a better motility percentage, which was about 41.6 percent of the frozen bull semen being motile. The frozen sperm cell motility using the 37 °C for 30 s thawing protocol from the national artificial insemination center was 47%, Baso 46.6% and Chacha 39.6%. There was no significant difference (p > 0.05) in the percentage of mass motility of frozen bull spermatozoa between Holstein Friesian and 75% Holstein Friesian cross breeds. There was no significant difference (p > 0.05) in the mass motility and morphology of frozen bull spermatozoa at different storage time length (58–204 days). The current study indicated that the major problems with low semen mass motility were thawing protocols which were used by artificial insemination technicians. Finally, the study recommended that thawing at 37 °C for 30 s had better frozen bull semen mass motility than other methods, so, artificial insemination technicians should use this recommended thawing method to have better frozen bull semen mass motility when they are doing artificial insemination (AI).

Morphological and Morphometrical Studies on the Crossbred Cows under Temperate Climatic Condition of Kashmir Valley

Background: Kashmir Valley, one of the temperate regions of India, has experienced an exponential increase in the milk-production over the last decades. This may be mainly attributed to massive cross-breeding of ‘Local Cattle of Kashmir Valley’ with the world-class dairy breeds like Jersey and Holstein-Friesian (HF), popularly known as Jersey-Crossbreds (JCB) and Holstein-Friesian Crossbreds (HFCB), respectively. However, no specific guidelines on their breed characteristics is available, which is crucial for their establishment, recognition and management. Precise and standardized morphological details are a primary requisite for application of advanced technologies like automation, Internet of Things (IoT) and robotics. Therefore, the present study aimed to characterize the HFCB and JCB cows. Methods: Morphologic and morphometric traits of 600 and 447 cows respectively, reared in the Srinagar district of Kashmir, were studied in detatil as per the standard methods. The null-hypothesis set was that the two crossbreds do not differ from each other. Result: It was observed that two crossbreds differed significantly (p less than 0.05) with each other in respect of the morphological and morphometrical traits like body size and weight. The study generated a baseline data on these two crossbreds, which is critical not only for their recognition, welfare and scientific management, but shall also act as a reference for global researchers to assess the results of crossbreeding superior dairy breeds in improving the genetic-merit of other breeds worldwide.

Comparative effect of Volvariella volvacea-treated rice straw and purple corn stover fed at different levels on predicted methane production and milk fatty acid profiles in tropical dairy cows

The objective of this study was to determine the effect of different concentrations of rice straw (RS) and purple corn stover (PCS) treated with Volvariella volvacea fed in total mixed rations (TMR) on ruminal fermentation, blood metabolites, calculated methane (CH4) production, and milk fatty acid profile in mid-lactation crossbred Holstein Friesian cows. The experimental design was a 2 × 2 factorial arrangement of treatments in a 4 × 4 Latin square design. Factor A included roughage type (V. volvacea-treated RS and V. volvacea-treated PCS), and Factor B included roughage (R)-to-concentrate (C) ratio (R:C) (50:50 and 60:40). The four dietary treatment combinations were 1) RS with an R:C ratio of 50:50 (RS50); 2) RS with an R:C ratio of 60:40 (RS60); 3) PCS with an R:C ratio of 50:50 (PCS50); and 4) PCS with an R:C ratio of 60:40 (PCS60). Different roughage sources did not alter total tract digestibility of DM, OM, and NDF (P > 0.05), but PCS increased NDF digestibility by 4.6 percentage units and CP digestibility by 15.6 percentage units. Roughage types influenced rumen propionic acid (C3) concentration 4 h after feeding with PCA increasing higher C3 concentration compared to RS at both R:C ratios. There was no interaction between roughage types and the R:C ratio for CH4 emission calculated based on volatile fatty acid profiles. However, roughage type impacted CH4 emission. Calculated CH4 concentration was lower in PCS than RS. Changing the R:C ratio did not alter milk production, milk composition, or somatic cell count (SCC). Moreover, roughage type did not influence milk production and milk composition, except for SCC which was lower in PCS. Roughage type and the R:C ratio independently influenced milk fat arachidonic acid (C20:4n-6) concentration. Furthermore, the PCS group had higher conjugated linoleic acid (CLA) than the RS groups. The proportion of total C18:0 and cis-9 C18:1 in milk fat increased 10% with the feeding of PCS50 and PCS60. However, milk cis-9, trans-11 C18:2 increased by 61% in the PCS group (P < 0.01). In conclusion, PCS increased rumen C3 and milk fat CLA and arachidonic acid concentration and decreased CH4 production compared to the RS. The PCS treated with V. volvacea could be used for up to 60% of TMR for dairy cows.

Screening and Association of Polymorphism in Alpha-Lactalbumin Gene in Holstein Friesian Crossbred Cattle

Screening and Association of Polymorphism in Alpha-Lactalbumin Gene in Holstein Friesian Crossbred Cattle

Effect of parity on lactation traits in crossbred Holstein Friesian in Ethiopia

Effect of parity on lactation traits in crossbred Holstein Friesian in Ethiopia

Spatial surveillance and risk factor assessment of ixodid ticks in cattle population of Himachal Shivalik hill zone of North-Western Himalayas

ABSTRACT The present study aimed at assessing the epidemiology and associated risk factors of ixodid ticks from Shivalik hill zone of Himachal Pradesh, India. A total of 602 cattle of different age, breeds, and sex were screened for the occurrence of ixodid ticks from six districts from March, 2019 to February, 2020. The associated data were recorded for the risk factor assessment. The overall tick prevalence was recorded to be 66.4%. Three tick species were found prevalent viz., Rhipicephalus (Boophilus) microplus (68.4%), Rhipicephalus (Boophilus) annulatus (30.85%), and Hyalomma anatolicum anatolicum (0.74%). The highest prevalence was recorded during the monsoon season (74.9%) (OR: 1.25; 0.65–1.86) followed by summer (65.3%) and lowest in winter season (59.4%) (OR: 0.64; 0.26–0.79). Agewise, tick infestation was observed to be highest in age group >1 year (76.5%) (OR: 6.37; 3.32–12.21) followed by age group >6 months–1 year (38.8%) (OR: 9.09; 4.67–17.69) and the lowest in ≤6 months age (29.3%). The prevalence rate was found to be more in female cattle (71.6%) in comparison to males (23.4%). Breedwise, the highest tick infestation was observed in cross-bred Jersey (69.8%) (OR: 3.51; 1.59–7.76) followed by cross-bred Holstein Friesian (69.6%) (OR: 0.95; 0.51–1.75) and lowest in indigenous cattle (45.0%). The risk factors related to management practices revealed that the prevalence of ixodid ticks was significantly (P < 0.05) less when the animals were kept in pucca sheds with acaricide application done both on body and shed with reapplication in 3 months. The odds of tick infestation were high in cattle population in Solan (OR: 2.29; 1.05-5.02) and least in Hamirpur in comparison to Kangra region (reference district) when the regression analysis of the risk factors associated with tick prevalence was studied. The current study represents the first report determining the epidemiological status of ixodid ticks in Shivalik hill zone region and findings of the study would provide a basis for generating new and effective control strategies for management the management of ticks in cattle population of the region.

Influence of chitosan sources on intake, digestibility, rumen fermentation, and milk production in tropical lactating dairy cows.

The aim of study was to compare the influence of chitosan sources (commercial chitosan vs chitosan extract) on rumen fermentation, methane (CH4) emission, and milk production in tropical lactating dairy cows. Six lactating Holstein-Friesian crossbreeds (410 ± 5 kg, 120 ± 21 day-in-milk) were arranged in a 3 × 3 replicated Latin square design. In addition to control, a 2% chitosan extract supplement and a 2% commercial chitosan supplement of dry matter intake were the treatments. The results denoted that no significant differences on daily dry matter, nutrients, or estimated energy intake were noted when cows received different sources of chitosan. Nutrient digestibility was not influenced differently by extraction-based or commercial chitosan supplements. The pH, temperature, ammonia nitrogen, blood urea, and microbial count were similar among treatments. The different sources of chitosan supplements did not change the totals of volatile fatty acids, acetate, and butyrate; in contrast, different chitosan sources influenced (P<0.05) propionate content. The ruminal acetate to propionate ratio was markedly (P<0.05) reduced with chitosan supplement, but no change appeared between sources of chitosan. At 4 h after feeding, the methane estimation significantly decreased with the addition of chitosan supplementation (P<0.05) compared to the control group. The purine derivatives and microbial protein synthesis were not altered by the treatments. No significant differences existed on milk yield, milk composition, or milk urea nitrogen when cows received different sources of chitosan (P>0.05). In summary, supplementing extracted chitosan showed more potential than did the commercial chitosan for enhancing economic efficiency and recycling shrimp residues, therefore, reducing environmental waste.

Isolation and Characterization of Yeasts from Rumen Fluids for Potential Use as Additives in Ruminant Feeding.

Saccharomyces cerevisiae is a yeast strain often used to improve the feed quality of ruminants. However, S. cerevisiae has limited capacity to provide biomass when inoculated with carbon sources and a low ability to produce cellulase enzymes. Here, we hypothesized that yeast in the rumen produces a large amount of biomass and could release cellulase enzymes to break down fiber content. Therefore, the aim of this study was to screen, isolate and identify yeast from the rumen fluids of Holstein Friesian steers and measure the efficiency of biomass production and cellulase activity. A fermentation medium containing sugarcane molasses as a carbon source and urea as a nitrogen source was optimized. Two fistulated–crossbred Holstein Friesian steers averaging 350 ± 20 kg body weight were used to screen and isolate the ruminal yeast. Two experiments were designed: First, a 12 × 3 × 3 factorial was used in a completely randomized design to determine biomass and carboxymethyl cellulase activity. Factor A was the isolated yeast and S. cerevisiae. Factor B was sugarcane molasses (M) concentration. Factor C was urea (U) concentration. In the second experiment, potential yeasts were selected, identified, and analyzed for 7 × 4 factorial use in a completely randomized design. Factor A was the incubation times. Factor B was the isolated yeast strains, including codes H-Khon Kaen University (KKU) 20 (as P. kudriavzevii-KKU20), I-KKU20 (C. tropicalis-KKU20), and C-KKU20 (as Galactomyces sp.-KKU20). Isolation was imposed under aerobic conditions, resulting in a total of 11 different colonies. Two appearances of colonies including asymmetric colonies of isolated yeast (indicated as A, B, C, E, and J) and ovoid colonies (coded as D, F, G, H, I, and K) were noted. Isolated yeast from the rumen capable of providing a high amount of biomass when inoculant consisted of the molasses 15% + urea 3% (M15 + U3), molasses 25% + urea 1% (M25 + U1), molasses 25% + urea 3% (M25 + U3), and molasses 25% + urea 5% (M25 + U5) when compared to the other media solution (p < 0.01). In addition, 11 isolated biomass-producing yeasts were found in the media solution of M25 + U1. There were 4 isolates cellulase producing yeasts discovered in the media solution of M25 + U1 and M25 + U5 whereas molasses 5% + urea 1% (M5 + U1), molasses 5% + urea 3% (M5 + U3), molasses 5% + urea 5% (M5 + U5), molasses 15% + urea 1% (M15 + U1), molasses 15% + urea 3% (M5 + U3), and M25 + U3 were found with 2, 3, 1, 2, 1, and 2 isolates, respectively. Ruminal yeast strains H-KKU20, I-KKU20, and C-KKU20 were selected for their ability to produce biomass. Identification of isolates H-KKU20 and I-KKU20 revealed that those isolates belonged to Pichia kudriavzevii-KKU20 and Candida tropicalis-KKU20 while C-KKU20 was identified as Galactomyces sp.-KKU20. Two strains provided maximum cell growth: P. kudriavzevii-KKU20 (9.78 and 10.02 Log cell/mL) and C. tropicalis-KKU20 (9.53 and 9.6 Log cells/mL) at 60 and 72 h of incubation time, respectively. The highest ethanol production was observed in S. cerevisiae at 76.4, 77.8, 78.5, and 78.6 g/L at 36, 48, 60, and 72 h of incubation time, respectively (p < 0.01). The P. kudriavzevii-KKU20 yielded the least reducing sugar at about 30.6 and 29.8 g/L at 60 and 72 h of incubation time, respectively. The screening and isolation of yeasts from rumen fluids resulted in 11 different yeasts being obtained. The potential yeasts discovered in the rumen fluid of cattle were Pichia kudriavzevii-KKU20, Candida tropicalis-KKU20, and Galactomyces sp.-KKU20. P. kudriavzevii-KKU20 had higher results than the other yeasts in terms of biomass production, cellulase enzyme activity, and cell number.

English

English

Milk production and composition efficiency as influenced by feeding Pennisetum purpureum cv. Mahasarakham with Tiliacora triandra, Diels pellet supplementation.

Ruminal fermentation efficiency has been shown to be closely related with milk production in dairy cows. This investigation aimed at the utilization of sweet grass and bamboo grass pellet supplementation on ruminal fermentation, feed utilization efficiency, milk quantity, and quality in lactating dairy cows. Four lactating Holstein Friesian crossbreds were randomly assigned in a 2 × 2 factorial arrangement in a 4 × 4 Latin square design to determine the effect of roughage sources and bamboo grass (Tiliacora triandra, Diels) pellet (BP) supplementation on voluntary feed intake, digestibility of nutrients, fermentation characteristics of the rumen, and milk quantity and quality. Sweet grass (SG) (Pennisetum purpureum cv. Mahasarakham) and rice straw (RS) were fed as roughage sources as the first factor, while the second factor was supplementation levels of BP (0 and 150g/cow/day). The results revealed that SG (P < 0.01) and BP supplementation (P < 0.05) improved feed intake, digestibility of nutrients, especially roughage intake and digestibility of DM and NDF. Ruminal pH (P < 0.05), bacterial (P < 0.01), and fungal population (P < 0.01) were increased with SG feeding, enhancing the concentration of total VFAs (P < 0.01) and propionic acid (P < 0.01), while both SG and BP decreased methane production (P < 0.01). While milk yield (P < 0.01) and milk composition (P < 0.01), especially unsaturated fatty acids including those of conjugated linoleic acid (P < 0.001), were enhanced. Supplementation of BP containing bioactive compounds such as condensed tannins (CT) enhanced rumen bacterial population with increased total VFAs (P < 0.05) and propionic acid (P < 0.05) concentrations, while decreased methane production (P < 0.05). The findings of this study indicate that SG would be beneficial to improved rumen fermentation, feed utilization, and milk production of dairy cows, while bamboo grass pellet supplementation tended to additionally improve rumen fermentation and feed intake without negative effects on milk production.

Prediction of First Lactation 305-Day Milk Yield by Test Day Simple and Multiple Regression Models in Holstein Friesian Crossbred Cattle

Prediction of First Lactation 305-Day Milk Yield by Test Day Simple and Multiple Regression Models in Holstein Friesian Crossbred Cattle

Characterization of bovine MHC DRB3 diversity in global cattle breeds, with a focus on cattle in Myanmar

BackgroundMyanmar cattle populations predominantly consist of native cattle breeds (Pyer Sein and Shwe), characterized by their geographical location and coat color, and the Holstein-Friesian crossbreed, which is highly adapted to the harsh tropical climates of this region. Here, we analyzed the diversity and genetic structure of the BoLA-DRB3 gene, a genetic locus that has been linked to the immune response, in Myanmar cattle populations.MethodsBlood samples (n = 294) were taken from two native breeds (Pyer Sein, n = 163 and Shwe Ni, n = 69) and a cattle crossbreed (Holstein-Friesian, n = 62) distributed across six regions of Myanmar (Bago, n = 38; Sagaing, n = 77; Mandalay, n = 46; Magway, n = 46; Kayin, n = 43; Yangon, n = 44). In addition, a database that included 2428 BoLA-DRB3 genotypes from European (Angus, Hereford, Holstein, Shorthorn, Overo Negro, Overo Colorado, and Jersey), Zebuine (Nellore, Brahman and Gir), Asian Native from Japan and Philippine and Latin-American Creole breeds was also included. Furthermore, the information from the IPD–MHC database was also used in the present analysis. DNA was genotyped using the sequence-based typing method. DNA electropherograms were analyzed using the Assign 400ATF software.ResultsWe detected 71 distinct alleles, including three new variants for the BoLA-DRB3 gene. Venn analysis showed that 11 of these alleles were only detected in Myanmar native breeds and 26 were only shared with Asian native and/or Zebu groups. The number of alleles ranged from 33 in Holstein-Friesians to 58 in Pyer Seins, and the observed versus unbiased expected heterozygosity were higher than 0.84 in all the three the populations analyzed. The FST analysis showed a low level of genetic differentiation between the two Myanmar native breeds (FST = 0.003), and between these native breeds and the Holstein-Friesians (FST < 0.021). The average FST value for all the Myanmar Holstein-Friesian crossbred and Myanmar native populations was 0.0136 and 0.0121, respectively. Principal component analysis (PCA) and tree analysis showed that Myanmar native populations grouped in a narrow cluster that diverged clearly from the Holstein-Friesian populations. Furthermore, the BoLA-DRB3 allele frequencies suggested that while some Myanmar native populations from Bago, Mandalay and Yangon regions were more closely related to Zebu breeds (Gir and Brahman), populations from Kayin, Magway and Sagaing regions were more related to the Philippines native breeds. On the contrary, PCA showed that the Holstein-Friesian populations demonstrated a high degree of dispersion, which is likely the result of the different degrees of native admixture in these populations.ConclusionThis study is the first to report the genetic diversity of the BoLA-DRB3 gene in two native breeds and one exotic cattle crossbreed from Myanmar. The results obtained contribute to our understanding of the genetic diversity and distribution of BoLA-DRB3 gene alleles in Myanmar, and increases our knowledge of the worldwide variability of cattle BoLA-DRB3 genes, an important locus for immune response and protection against pathogens.

Comparison of daughter's performance of progeny tested sires with pedigree selected sires in Holstein Friesian crossbred cattle

The present study was conducted to compare the estimated breeding values of progeny tested sires and pedigree selected sires for test day milk yield of crossbred Holstein Friesian cattle. First lactation milk yield records (1,20,198) of 12,971 daughters sired by 267 sires were collected from INAPH database maintained by NDDB. Variance and covariance components for test-day milk yield (TDMY) were estimated by different random regression test day models (RRTDM), viz. Cubic B- Spline function, Quadratic B-Spline function, Legendre polynomial (LP) function and Wilmink function using Average Information Restricted Maximum Likelihood (AIREML). Considering various criteria for comparison of different orders of TDMs, LP of 6th order for TDMY was the best fitted model for further estimation of breeding values. The heritability estimates ranged from 0.15 to 0.39 for TDMY using Leg_2 model. The additive genetic correlations were higher than the phenotypic correlations among different TDs. The additive genetic correlations between test day yields varied from 0.73 to 0.99. The expected progeny difference (EPD) for TDMYcalculated based on dam’s yield for the top ten and bottom ten PS bulls was 2,662.5 kg; whereas, the actual progeny difference (APD) for these bulls was -28.47 kg. While, EPD for top 10 and bottom 10 PT bulls selected based on EBVs was 2,820.52 kg whereas the APD for PT bulls was 890.48 kg. The difference in expected and actual MY of progeny was higher in PS bulls as compared to PT bulls indicating that the pedigree information for EPDs had a poor association with APDs and sire superiority is not reflected in progeny’s actual performance. The rank correlation between ranks of all PS and PT bulls were very poor and non-significant. The bulls selected based on estimated breeding values will give faster genetic progress and decision to select replacement bulls based on breeding values instead of dam’s yield will have positive effect on genetic progress.

English

English

Systemic levels of iron, phosphorus, and total protein in normocyclic versus repeat breeder Holstein Friesian crossbred cows of Kesharbag, Chitwan, Nepal.

Background and Aim:In repeat breeding, a sexually mature cow fails to conceive even after three or more consecutive inseminations despite being without any clinically detectable reproductive anomalies. This is a major cause of economic loss in livestock farms, particularly in developing countries, where humans and livestock directly compete for food, and the mineral content of animal feed is rarely checked. This study investigated the association between systemic iron, phosphorus, and total protein and estrous cyclicity in crossbred Holstein Friesian cows.Materials and Methods:Blood samples were collected from 10 normal cyclic and 10 repeat breeder cows 12 h after the onset of estrus. Serum was separated, and iron, phosphorus, and total protein were quantified with spectrophotometry, using standard controls for all three measurement parameters (iron, phosphorus, and total protein).Results:Iron and phosphorus levels were significantly (p<0.05) lower in the repeat breeders group than in the normocyclic group, but no significant differences were found in total protein levels.Conclusion:Repeat breeding is associated with systemic iron and phosphorus levels but is independent of total protein level.

Modeling Lactation Curve for Test Day Milk Yields in Holstein Friesian Crossbred Cattle

Modeling Lactation Curve for Test Day Milk Yields in Holstein Friesian Crossbred Cattle