<div>Background: This study examines the impact of herd size on milk production in semi-arid regions, where productivity and efficiency are critical. Herd size (HS) is a key determinant of both milk yield and quality. 
&nbsp; 
Methods: Data from 88 farms in the Souss-Massa region, affiliated with the COPAG cooperative, were analyzed to assess Total milk yield (TMY), standardized 305-day milk yield (305-dMY), Standardized fat yield (MFY), Fat content (FC) and lactation duration (LD) in holstein cows. 
&nbsp; 
Result: The average values recorded were: 7052.19&plusmn;1849.68 kg for TMY, 324.92&plusmn;42.93 days for LD, 6596.66&plusmn;1624.99 kg for 305-dMY, 242.18&plusmn;62.36 kg for MFY and 3.70&plusmn;0.53% for FC. Large herds (HS&gt;150) showed significantly higher productivity (p&lt;0.001), averaging 7360.86 kg for TMY, 6894.98 kg for 305-dMY and 242.33 kg for MFY, though with slightly lower fat content (3.65%). Smaller herds (HS&le;30) yielded 6554.44 kg for TMY, 6095.92 kg for 305-dMY and 229.66 kg for MFY, but with higher FC (3.79%). Large farms benefit from modern management, automated health monitoring and optimized nutrition but face challenges such as higher stress, disease incidence and environmental concerns. These results highlight the need for balanced management strategies that enhance productivity while ensuring animal welfare and sustainability in semi-arid dairy farming.</div>

Impact of Herd Size on Milk Production in a Dairy Cattle Farm under Semi-arid Climate

<div>Background: In a herd going through improvement by selective breeding, bulls contribute more than half of the genetic gain due to higher selection intensity and wider coverage through AI. On the other side, meritorious sires might have a lower fertility due to various reasons which would render them less fit in their contribution to genetic improvement. Thus dairy buffalo breeders must find a delicate balance between production and reproduction superiority for selection of sires, for which an accurate assessment of genetic and non-genetic component of conception is essential.&nbsp; 
 
Methods: Present study was conducted on thirty five years data comprising of 5349 AI records on 1302 Murrah buffaloes using 86 bulls maintained and semen analysis of cryopreserved semen samples of 130 Murrah maintained at ICAR-National Dairy Research Institute Karnal were analyzed to study bull conception rate and sperm quality traits. Data were classified into four periods; four seasons of AI viz., Summer (April-June), rainy (July-September), autumn (October-November), winter (December-March); five parity (first, second, third, fourth, fifth and above) and five female AI number (1,2,3,4 and &sup3; 5 AI) to study the conception rate. Age at freezing (Years), period of freezing and season of freezing were analysed to observe their effects on semen quality traits. Mixed model analysis (SAS 9.3) and the analysis of variance were used to see the effects of various factors on conception rate as well as on semen quality parameters. 
 
Result: The analysis of variance revealed that period of AI and season of AI had significant (P&lt;0.05) effect on conception rate while parity and female AI number were not found to affect the conception rate of bulls. For seminal parameters, acrosome integrity and HOST were significantly affected by age at freezing. Season affected all the semen quality traits while the effect of period of freezing was found to be non-significant for all the traits. Over all autumn season was found to be most suitable with respect to better seminal parameters. Considering season of AI, rainy season (July-September) had the lowest conception rate. The overall conception rate (%) in the study was 38.43&plusmn;0.99; where Sires showed a wide variation for conception rate ranging from 20.00% to 60.46%. Concluding with the fact that there exists variation among bull fertility that can be utilized for not only herd conception rates but also be used as a criteria for bull selection and evaluation.</div>

Effects of Various Non-genetic Factors on Fertility Traits in Murrah Bulls in an Organized Herd

<div>Background: In Algeria, COVID-19 containment procedures 2020-2021 have put the livestock sector in a critical situation, particularly in the Saharan regions where animal feed is based on supplies from other regions. Indeed, a famine has threatened the herds, but the breeders have been able to save their animals by an unconventional diet. The knowledge of these nutritional measures and know-how makes it possibleto evaluate local products andto guide Algerian decision-makers towards a safer food strategy that is well adapted to the Sahara region. 
 
Methods: We used the &ldquo;12MO method&rdquo;, which is a retrospective survey based on the declarations of the breeders for the last twelve months. 12MO served as a basic tool for a systemic analysis conducted in 110 farms in different areas of Oued Souf (Sahara of Algeria). 
 
Result: The results highlighted changes in animal feed, under the impact of COVID-19 pandemic through unconventional feeding. 6 feeds were distinguished, including 4 crop residues (PoCR; PeCR; CCR ; TCR) and 2 by-products (PD By-P; PD By-P). During a year of containment, it was not only the interrelationship (agriculture/livestock) that has secured the feeding herds in the Saharan environment, but the breeder&rsquo;s solidarity has significantly contributed in that also.</div>

How Have Saharan Breeder Been Able to Secure Food for Their Herds During the Containment of COVID-19? Case of Oued Souf, Algeria

Information on culling pattern of animals helps in developing effective breeding plans for genetic improvement of the herd. Data on 292 reserved KF males out of 1740 male calves born, spread over a period of sixteen years from 1997 to 2012, were collected based on pedigree performance. The data were analysed using descriptive statistics considering the period of birth, season of birth, genetic group and age group. Study revealed increase in culling percentage with advancement in age. Culling in KF males for the different periods (1997-2000, P-1; 2001-2004, P-2; 2005-2008, P-3 and 2009-2012, P-4) were 75.93, 92.16, 64.44 and 28.26 percent, respectively. Maximum culling &nbsp;was observed in males born in summer season (76.12%) which could be due to inclement weather conditions exposure in young age and insufficient quality green leguminous fodder in subsequent months. Generally, upto the age of 3 years, culling in KF males were maximum in interbred and minimum in F1 but with advancing age, culling rate was found higher in F1 genetic group KF males where reproductive problems were the main causes. High culling rate in &lt;1.5 yrs age groups was observed due to poor growth (3.42%) while in adult bulls of above 1.5yrs of age, main reasons of culling was surplus (33.22%) followed by poor semen quality (10.27%), poor libido (7.53%), and poor semen freezability (4.45%). It can be concluded that culling pattern study can help in formulation of better management strategy to reduce the problems associated with culling and better economic return for the farm.&nbsp;

Culling pattern of Karan Fries (crossbred) males in an organised herd

<div>Background: Dairy farming has been emerging as an important commercial enterprise in India as milk is an essential commodity where majority of the population is vegetarian. Milk production plays an important role in the rural economy with particular focus on landless, marginal and small farmers who constitute core milk production system in the country. Therefore, the current study was aimed to analyse milk production across different herd sizes of buffaloes and crossbred cows in Middle Gujarat. 
 
Methods: This study is based on the primary data collected from the dairy farmers during the agricultural year 2018-19 by interviewing the respondents through a pre-tested structured schedule from 240 respondents spread over 24 villages of Anand, Kheda and Panchmahal districts of Middle Gujarat.&nbsp; 
 
Conclusion: The present investigation indicated that for increasing farmer&rsquo;s income and eventually livelihood, rearing of crossbred cows should be encouraged in the study area as they have edge over buffaloes in net returns. Break-even analysis indicated that crossbred cow owners were able to cover their total expenditure at a lower point than the buffalo owners due to the fact that the crossbred owners realized higher milk production as compared to buffalo owners.</div>

<div>An Economic Analysis of Milk Production Across Different Herd Sizes of Buffaloes and Crossbred Cows in Middle Gujarat</div>

<div>Background: Mastitis is the most common and economically important disease of dairy cattle. Subclinical mastitis is a more important form in India than clinical mastitis. Subclinical mastitis (SCM) detection done by periodic examination of the udder health by evaluation of milk at the herd level or the individual cow level by milk somatic cell count (SCC), followed by culture of random milk samples. The presented study was undertaken by survey and sampling of milk from lactating crossbred cattle of unorganized dairy farms and farmer&rsquo;s dairy of the peri-urban region of middle Indo-Gangetic Plains. The objective of the study was to monitor the status of SCM in crossbred cattle and associated changes in milk constitutes and oxidative stress in milk.&nbsp; 
 
Methods: A total of 147 lactating crossbred cattle were screened for SCM using the modified California Mastitis Test (CMT) using detergent based CMT reagent and compared with conventional CMT reagent, followed by SCC, milk constituents, bacterial isolation and antibiotic sensitivity testing (ABST). General information was collected in pre-tested questionnaire. The data obtained were statistically treated to evaluate significance of the study. 
 
Conclusion: The overall prevalence of subclinical mastitis in peri-urban cross-bred cattle was 36.74% which varied with parity and stage of milking. Prevalence of subclinical mastitis was highest (55.77%) in cross-bred cattle in mid-lactation and Parity 3-5. The mean SCC was significantly higher (7.21&plusmn;0.27) in subclinical mastitis compared to CMT negative (3.66&plusmn;0.06) milk sample. Somatic cell count was positively and significantly correlated with CMT reactions using conventional CMT reagent (rs= 0.86) as well as modified CMT reagent (rs=0.815) attempted using Spearman rank-order correlation coefficient. The mean values of milk pH, fat and lactic acid acidity increased significantly (P&le;0.01) in SCM compared to the milk of healthy cattle, except lactose which decreased significantly in SCM milk. The common contagious bacteria responsible for SCM isolate were coagulase-positive Staphylococcus spp. (64.82%) isolates from these SCM milk followed by Streptococcus spp. ABST test conducted on random CMT positive milk sample indicated that gentamicin as most sensitive, followed by enrofloxacin. The present finding indicates the suitability of enrofloxacin as the most useful antibiotic for the treatment of subclinical mastitis in cross-bred cattle of the peri-urban area of middle Indo-Gangetic plains.</div>

Status of Subclinical Mastitis in Crossbred Cattle of Peri-urban Unorganized Herd of Middle Indo-gangetic Plains

Background: Mucopolysaccharidosis type IIID is caused by a deficiency of N-acetylglucosamine-6-sulfatase enzyme, which increases heparan sulfate accumulation in lysosomes and generate cytoplasmic vacuolation in central nervous system and somatic tissues. Goats kids with this disorder exhibit delayed motor development, growth retardation and sudden death. This is a transition mutation of cytosine to thymine at nucleotide 322 of the genetic sequence. The objective of this study was to determine the allelic frequency of the glucosamine N-acetyl-6-sulfatase gene (GNS) that causes mucopolysaccharidosis type IIID (MPS IIID) in a population of Nubian goats in Colima, Mexico.&nbsp;&nbsp; 
 
Methods: Genomic DNA was isolated from blood samples of 158 Mexican Nubian goats. The 96 bp fragment of GNS gene including the nonsense mutation was PCR amplified. The PCR amplicon was subjected to RFLP using AluI restriction enzyme to identify polymorphism at nucleotide position 322 (C&gt;T). Genotypes were scored. Using Hardy-Weinberg equilibrium (HWE) testing we determined the population to be in genetic equilibrium. 
 
Result: Of the entire Nubian goat population genotyped, eight of which were MPS IIID carriers (1 male and 7 females). Observed allelic frequencies were 0.975 for the wild-type allele C and 0.025 for the mutant allele T. MPS IIID was first found in goats at the end of the last century, with considerable higher frequencies, but recent advances in diagnosis and marker-assisted selection against genetic diseases appear to have lowered MPS IIID mutation frequencies in North American Nubian goats. We identified for the first time the variant causing MPS IIID in Nubian goats in Mexico.

Detecting the Causal Mutation for Mucopolysaccharidosis IIID in a Nubian Goat Herd in Mexico

Background: Bovine mastitis poses a significant challenge for Algeria&rsquo;s dairy industry, impacting cattle health and productivity while threatening animal welfare and economic stability. The study aimed to determine the prevalence of bovine subclinical mastitis, identify the etiological pathogens and assess their susceptibility. The study included 65 dairy cows from seven small dairy farms. 
&nbsp; 
Methods: The California Mastitis Test was used to screen cows with subclinical mastitis and antibiotic susceptibility of the isolates was assessed using the disk diffusion method. 
&nbsp; 
Result: The prevalence of mastitis was 70.77% (46 / 65) and 35% (91/260) respectively. Coagulase-negative staphylococci (CNS) were the predominant strains at 54.84%, followed by Staphylococcus aureus at 20.97% and Escherichia coli at 11.29%. Antimicrobial susceptibility tests revealed a high level of multidrug resistance, affecting 81.48% of the strains tested. Escherichia coli demonstrated a high resistance to ampicillin, tetracycline and trimethoprim-sulfamethoxazole. Coagulase-negative staphylococci exhibited a notable resistance to streptomycin, penicillin G and tetracycline. Additionally, Staphylococcus aureus showed considerable resistance to penicillin G and tetracycline. Most strains tested in this study showed a high sensitivity to Kanamycin. The high prevalence of bovine mastitis and significant multidrug resistance highlight the urgent need for better management practices in the dairy industry. Effective monitoring and targeted treatments are essential for animal welfare and the economic viability of dairy farming in Algeria.

Subclinical Mastitis Prevalence and Antimicrobial Susceptibility Profile in Western Algerian Dairy Herds

<div style="text-align:justify">Background: The present investigation was carried out to study the &ldquo;productive and reproductive performance&rdquo; of Indigenous Milch Cows reared under Gaushalas. This study describes productive and reproductive performance of milch cows through onsite observation and interviews with structured questionnaires of 30 (no.) Gaushalas randomly selected from 10 districts of Haryana.&nbsp; 
 
Methods:&nbsp;The total 30 Gaushala in 10 districts of Haryana were studied, which were rearing more than 34,279 indigenous cows (mostly Hariana and Sahiwal cow). These Gaushalas were divided into three categories based on the total number of animals present in Gaushalas as small (100-500 animals), medium (501-1000 animals) and large size Gaushalas (&gt;1000 animals). To assess the productive performance of the milch cows, milk yield per day (MY/D), lactation length (LL) and lactation yield (LY) were utilized as indicator traits. In addition, age at first calving (AFC), service period (SP), number of services per conception (NSPC) and calving interval (CI) were considered as an indicator of the reproductive performance traits. 
 
Result: It was observed that the average milk yield per day and lactation yield in large size gaushala were significantly (P&lt;0.05) higher than the medium size Gaushalas and small size Gaushalas. Large Gaushalas had a significantly higher lactation length (P&lt;0.05) than small size Gaushala. The average service period, number of services per conception and calving interval in large size Gaushalas were significantly (P&lt;0.05) lower as compared to small size Gaushalas. From the above finding, it could be concluded that the productive and reproductive performance were better in large size Gaushalas.</div>

Productive and Reproductive Performance of Indigenous Milch Cows under Different Herd Structure of Gaushalas

<div>Background: Loss of genetic diversity is allied with adverse incidents such as inbreeding depression in fitness related traits, addiction of favorable alleles and enhances fluctuation on selection response. Therefore, the study aims to monitor population structure and avoid unfavorable effects of inbreeding for sustainable improvement in breeding programme. 
 
Methods: Pedigree information on 3449 animals born from 1955-2018 was analyzed. The effect on inbreeding on Age at first calving (AFC), Service period (SP), Daughter pregnancy rate (DPR), Calving interval (CI) and pregnancy rate was seen by regression analysis. 
 
Result: The pedigree completeness index (PCI) were found to be (%) 92.32, 80.26, 65.22, 49.43% and 32.54 respectively from first to fifth generations. The estimated average inbreeding rate was 2.30% and average genetic diversity loss was 2.64%. Study also revealed significant effect of inbreeding on (AFC, CI and SP) with slightly increasing trends. Hence, it is suggested that more precise pedigree recording and planned mating strategies should be adopted to avoid negative effect of inbreeding in future generation.&nbsp;</div>