Lactation Length Research Articles

The effect of placentation type, litter size, lactation and gestation length on cancer risk in mammals.

Reproduction is a central activity for all living organisms but is also associated with a diversity of costs that are detrimental for survival. Until recently, the cost of cancer as a selective force has been poorly considered. Considering 191 mammal species, we found cancer mortality was more likely to be detected in species having large, rather than low, litter sizes and long lactation lengths regardless of the placentation types. However, increasing litter size and gestation length are not per se associated with an enhanced cancer mortality risk. Contrary to basic theoretical expectations, the species with the highest cancer mortality were not those with the most invasive (i.e. haemochorial) placentation, but those with a moderately invasive (i.e. endotheliochorial) one. Overall, these results suggest that (i) high reproductive efforts favour oncogenic processes' dynamics, presumably because of trade-offs between allocation in reproduction effort and anti-cancer defences, (ii) cancer defence mechanisms in animals are most often adjusted to align reproductive lifespan, and (iii) malignant cells co-opt existing molecular and physiological pathways for placentation, but species with the most invasive placentation have also selected for potent barriers against lethal cancers. This work suggests that the logic of Peto's paradox seems to be applicable to other traits that promote tumorigenesis.

WPŁYW KRÓTSZEJ LUB DŁUŻSZEJ EKSPOZYCJI CIĘŻARNYCH NOREK NA SZTUCZNE DOŚWIETLANIE (NEOVISON VISON) NA ICH WSKAŹNIKI ROZRODU

The aim of this study was to analyze the influence of the length of the period of artificial lighting of mink on their reproductive performance. The experiment was carried out on a mink farm in West Pomerania, Poland. Reproduction data of 1068 one-year-old female mink of the silverblue strain were analyzed. All females were in selection classes 7 and 8 and were mated four times, first between the 1st and 10th of March. Females were illuminated during pregnancy with artificial light such that the light day was 17 hours per day. Females were divided into two groups – one group was illuminated from March 20 to April 17, and the other from March 20 to May 15. The following reproductive indices were analyzed in relation to the length of illumination: length of diapause and gestation, litter size, number of live-born and weaned young per litter, percentage of barren females, percentage of females dead during gestation and lactation, and average length of lactation in which females died. Artificially illuminated females were characterized by longer diapause, longer gestation, larger litters, but they had higher mortality of young during maternal nursing. It was also found that females with shorter lactation reared slightly more young, and were characterized by a lower percentage of barren females and females dying during pregnancy and lactation. The analysis conducted in this study confirmed the period of illumination of pregnant mink until April 17 is sufficient in terms of reproductive performance of the females.

Genetic analysis of milk production and lactation period in Holstein cows according to BTN1A1 Gene Polymorphism

The results showed that the Holstein BTN1A1gene has two alleles (A allele ) which is superior to the second allele (B allele )in the two values of the substitution effect and the average effect of the allele, and the homo genotype AA over the hetero genotype AB was successful in the breeding value of the two traits. It was also revealed through the new equations that the gene is responsible for the characteristic of milk production of the total output and the amount of 37725 Iraqi dinars of the full value of the milk price, and it also affects by ±7.24 days of the length of the milking season, which is estimated at 3583.8 Iraqi dinars. It is responsible for the inheritance of 70.09 kg of total milk production for 6.35 days/season length, reflecting the product's price value.The possibility of adopting the BTN1A1 gene within the selection programs to improve some productive traits, as well as the possibility of conducting a comparison between genes on the basis of the new equations, determining their contribution to the studied traits, and choosing the most influential gene to be an effective marker in the selection of quantitative traits. Keywords: Genetic analysis, Milk production, length of lactation, Holstein cows, BTN1A1 gene

Effect of Non Genetic Factors and Sire on Lactation Length in Frieswal Cattle

Lactation length is a very important trait of dairy animals directly affecting the milk yield. Shorter or extended lactation lengths are not desirable as it affects the milk yield. Therefore the study of factors affecting lactation length is of most important. The present study was conducted on data of 9094 lactations collected from 3425 Frieswal lactating cattle (Holstein Friesian x Sahiwal cattle) born to 239 sires maintained at Military Farm, Pimpri, Pune, Maharashtra from the year 1983 to 2018 to quantify effect of certain non genetic factors on lactation length. The normalized data were analyzed using PROC GLM procedure of SAS to study the effect of various genetic (sire) and non genetic (period, season and parity) factors on lactation length. The age at first calving was used as a covariate. The effect of period of calving was found to be highly significant ( less than 0.001) on lactation length. The season, parity and age at first calving were significantly affecting the lactation length. Parity two to six does not differ significantly in lactation length. Among the genetic factors effect of sire was significant on lactation length.

DIETARY DICALCIUM PHOSPHATE SUPPLEMENTATION ENHANCES PRODUCTIVE AND REPRODUCTIVE PERFORMANCES OF CROSSBRED AND LOCAL DAIRY COWS

This study was carried out to investigate the productive and reproductive performances following oral supplementation of dicalcium phosphate (DCP) in different crossbred and local dairy cows. A total of 64 dairy cows of different genetics were selected for the study. All the cows were divided into four different groups and each group consists of 16 cows, namely Local (L), Local ×Holstein Friesian (L×HF), Local × Sindhi (L×S) and Local ×Sahiwal (L×SA). Each group of dairy cows were again subdivided into two subgroups like control and DCP supplement group. We assessed the productive performances such as milk production and lactation length, as well as reproductive performances such as service per conception, post-partum heat period and calving intervals among different breeds of cows as well as in the matching DCP supplement group. The productive performance among the different groups of cows i.e. L×HF, L×S, L×SA and Local cows were found significantly (p<0.01) different. Interestingly, DCP supplement group showed a significant increase of productive performances compared with the control group. Likewise, reproductive performance such as service per conception in different crossbred and Local cows also decreased significantly (p<0.01) with DCP supplement group than the control. Contrarily, the post-partum heat period and calving intervals in different crossbred and Local cows were slightly lower in the DCP supplemented group than control that did not differ significantly. Therefore, the study reveals that L×HF crossbred were found to be better performer followed by L×SA, L×S and Local cows, and DCP supplementation improve all the parameters studied irrespective of genetic variation.

Genetic variation in promoter region of the bovine LAP3 gene associated with estimated breeding values of milk production traits and clinical mastitis in dairy cattle.

The purpose of this study was to identify genetic variants in the promoter and 5'UTR regions of bovine leucine amino peptidase three (LAP3) gene and analysed their associations with estimated breeding values (EBVs) of milk production traits and clinical mastitis in Sahiwal and Karan Fries cattle. Eleven SNPs were identified within the region under study of the LAP3 gene, including seven promoter variants (rs717156555: C>G, rs720373055: T>C, rs715189731: A>G, rs516876447: A>G, rs461857269: C>T, rs136548163: C>T, and rs720349928: G>A) and four 5'UTR variants (rs717884982: C>T, rs722359733: C>T, rs481631804: C>T and rs462932574: T>G). Out of them, 10 SNPs variants were found in both Sahiwal and Karan Fries cattle, with one SNP variant (rs481631804: C>T) being unique to Karan Fries cattle. Seven of these identified SNPs were chosen for association analyses. Individual SNP based association analysis revealed that two SNPs (rs720373055: T>C and rs720349928: G>A) were significantly associated with EBVs of lactation milk yield (LMY), 305-day milk yield (305dMY), and one significant association of SNP rs722359733: C>T with lactation length (LL) was observed. Haplotype based association analysis indicated that diplotypes are significantly associated with EBVs of LMY, 305dMY, and LL, individuals with H1H3 (CTACGCT/GCGTACG) being linked to higher lactation performance than other diplotypes. Further logistic regression analysis revealed that, animals with diplotype H1H3 was less susceptible to the incidence of clinical mastitis than other cows, as the odds ratio for the non-incidence of clinical mastitis was found to be low. Altogether, variations in the LAP3 gene promoter could be used as a genetic marker, most notably diplotype H1H3, may greatly benefit the simultaneous improvement of mastitis resistance and milk yield traits in dairy cattle. Moreover, bioinformatics analysis predicted that the SNPs rs720373055: T>C, rs715189731:A>G and rs720349928: G>A is located in the core promoter region and in TFBs, play key role in regulation of studied phenotypes.

Analysis of The Effect of Region, Province and Breed on Somatic Cell Count in Dairy Cattle in Turkey By Regression Tree Method

This study aimed to determine the effect of various environmental factors on the somatic cell count (SCC) in cow’s milk. The material of the study consisted of an SCC analysis result obtained from 207.614 raw milk samples collected from 65.288 head cattle had different breeds, ages, lactation number, and lactation length between May and December in 2019. They were raised on 6,305 dairy farms that are members of the Cattle Breeders Association (CBAT). In order to determine the effect of region, city, and cattle breed on SCC in raw milk of cattle, a regression tree was created using the Chi-square Automatic Interaction Detection (CHAID) algorithm, a Data Mining (DM) method. Accordingly, the mean SCC value of all enterprises was determined as 201.253 cells/mL. In this study, it was found that the region, city and breed groups with the highest average somatic cell counts were CAR, MSR, MR and SAR region group (285.430 cells/mL); C09, C45, C20, C64, C48, C43 city group (266.744 cells/mL); and HF, MC, and BS breed group (295.705 cells/mL). As a result of this study, the variables affecting SCC were determined as region, city, and breed respectively, in order of importance. Keywords: CHAID; Dairy cattle; Somatic cell count

Modelling Lactation Curve for Genetic Evaluation of Crossbred Cattle

The present study was conducted on first lactation 4415 monthly test-day milk yield records of 466 crossbred (CB) cattle sired by 89 bulls during 2000–2018 (19 years) maintained at Directorate of Livestock Farms, GADVASU, Ludhiana, Punjab, India. The crossbred cattle with lactation length of minimum 100 days were considered for the study. The aim was to develop the best lactation curve model and to compare the breeding values of sires based on actual and predicted first lactation 305-day milk yield (FL305DMY). The data were classified and coded according to different season and age at first calving groups for first lactation 305-day milk yield. Monthly test-day milk yields of first lactation were used to develop the best lactation curve model. The Polynomial Regression Function (PRF) model was the best model amongst all the models based on both R2 and RMSE values. The breeding values of 60 HF crossbred sires with two or more daughters were estimated from the actual and predicted FL305DMY using Polynomial Regression Function by applying two sire evaluation methods viz. least squares method (LSQ) and restricted maximum likelihood method (REML). The effectiveness of LSQ and REML methods of sire evaluation was compared on the basis of Spearman’s rank correlations, coefficients of determination (R2) and coefficients of variation (CV). LSQ was found most efficient and accurate method for sire evaluation using actual and predicted first lactation 305-day milk yield in HF crossbred cattle.

Management practices of dairy animals in Tarai region of Uttarakhand

The existing dairy farm housing, milking, feeding and calf management practices in Tarai region of Uttarakhand along with performance traits were studied. Total 30 households with 596 livestock were considered for this work. Agriculture is the mainstay in the locale with animal husbandry as subsidiary occupation. Dairy animals mainly comprise 76% crossbreds and 21% Murrah buffaloes. Farms with 43% concrete, 30% bricks on edge and 10% kuchha flooring were recorded. Only 37% herds had 24 hour access to drinking water, 43% farmers fed commercial concentrate preparations, Stripping was practiced by 70% at the end of milking, 93% herdsman bred their cows within 12-18 hour of estrus with 3-5 months service period, and 60% dairymen consulted a veterinarian for services. Least squares mean (LSM) and standard error for Age at first calving (AFC), Calving Interval (CI), Dry Period (DP), Number of service per conception (NS/C), Milk yield per day (MY/D) and Lactation length (LL) were 427.31±5.80 days, 706.74±6.23 days, 378.76±1.48 days, 95.17±2.06 days, 1.32±0.03, 8.98±0.11 litre/day/animal, 315.14±1.65 days, respectively in cattle and 708.06±6.05 days, 948.62±10.09 days, 384.82±2.65 days, 139.08±6.07 days, 1.31±0.03, 9.54±0.15 litre/day/animal and 311.80±2.7 days, respectively in buffaloes. Effect of location on MY/D, LL and CI; of parity on CI and DP; and of AFC on DP was significant in cattle. In buffaloes, CI was significantly affected by location; MY/D, DP and LL by parity; and CI and NS/C by AFC. The results revealed a requisite to focus on stress management, calf care and sick animal management to improve animal performance.

EL LARGO DE LACTACIÓN Y LOS INTERVALOS PARTO Y DESTETE PRIMER-SERVICIO AFECTAN EL SUBSECUENTE TAMAÑO DE CAMADA DE CERDAS EN UNA GRANJA COMERCIAL EN EL SURESTE DE MÉXICO

<p><strong>Background</strong>. Studies in temperate regions report the effect of lactation length (LL) and farrowing- service (IFS) and weaning-to-first service intervals (IWS) on the reproductive efficiency of sows in commercial farms. However, research about this topic under tropical conditions is scarce. <strong>Objective.</strong> To investigate the relationship of LL, IWS and IFS on subsequent number of piglets born alive (SPBA), and the effect of LL on number of parity per sow per year (NFY) and number of piglets born alive per sow per year (PBAY) in a commercial farm in the tropics of Mexico. <strong>Methodology</strong>. Data from 9663 litters were used. The statistical model for SPBA, NFY and PBAY included the fixed effects of farrowing year (2013, 2014), farrowing season (rainy, north and dry), farrowing number (1, 2, 3, 4, 5, 6), simple interaction of year by farrowing season, and the linear and quadratic effects of LL, IWS and IFS for SPBA, and the linear and quadratic effect of LL for NFY and PBAY. <strong>Results</strong>. The factors evaluated were significant for all variables of interest. Linear effect (P < 0.05) of LL, IWS and IFS was found only on SLNV. The predictive equation for SLNV was Y= 10.8551+0.02242*LLL+0.01515*IDS. The equation for SPBA with IFS was Y= 10.9939 + 0.01604*IFS. In addition, a negative linear and quadratic effect (P < 0.05) of LL on NFY, and a negative linear effect (P < 0.05) on SPBA were found. The predictive equation for NFY was Y= 2.7432-0.001689*LL-0.00032*LL<sup>2</sup> and for PBAY was Y= 32.2414-0.1444*LL. <strong>Implications.</strong> The effect of LL, IWS and IFS on sow productivity is fundamental for decision making and adapting management, techniques and technologies to production systems. <strong>Conclusion</strong>. Under the conditions of the present study, increasing LL and IWS increased sow SPBA. However, increasing LL reduced NFY and PBAY.</p>

Milk production of dairy cow at PT. Ultra Peternakan Bandung Selatan

This study aims to determine the effect of body condition score (BCS), lactation length, and dry period on milk production of dairy cows at PT. Ultra Peternakan Bandung Selatan (UPBS). The research was conducted at PT. UPBS, Pengalengan, West Java, the following method used is survey method, where the data of primary and secondary data using 130 lactating dairy cows 3. Complete milk production records as variable y and BCS, lactation length, and dry period as variable x. The effect of BCS, duration of lactation, and dry period were analyzed using multiple linear regression analysis. The results of this study discovered that each factor of BCS, lactation length and dry period duration a very significant effect (P<0,01) with a coefficient of determination (R2) of 76.2%, average milk production 7835±631,33 kg, BCS score 3,25 ±0,26; lactation length is 346±65,26 days, and dry period (R2) is 77±33,18 days. The conclusions of this study; to optimize milk production, the implementation of dairy cows maintenance needed on BCS, lactation length, and optimal dry period according to the recommendations.

The Scenario of Buffalo Production and Research in Bangladesh

Background: This study aimed to characterize the scenario of buffalo production in the northern part of Bangladesh and review the published scientific literature on buffalo from Bangladesh.&#x0D; Methods: The study was conducted from August to December 2022. A draft questionnaire was prepared and modified before the final one based on the study's objectives. Data were collected through personal interviews with individual respondents. In addition, the review article was collected on buffalo from Google, Google Scholar, Research Gate, Scopus, Bangladesh Journal-Online (BJO), and PubMed.&#x0D; Results: Data was collected from 1099 animals from the northern part of the Natore and Lalmonirhat districts of Bangladesh. Most of the farmers were illiterate, and the age was above 40 years. Regarding the purpose of buffalo production, 69.16% (n=83) of the farmers narrated that they are motivated to milk with calves selling. The average herd size was about 9 and consisted of indigenous and crossbred buffaloes. Most of the farmers kept their buffalo in the Bathan. The coat color was predominantly black, with brown hair. Farmers 94.16% (n=113) practice de-worming, and the frequency was thrice a year. Wallowing is performed at least once a day in the pond or river for the thermal regulation of the buffalo. Among the farmers, 67.50% (n=81) have no training in rearing buffalo. Farmers practice natural mating by their own or neighbor bull to serve the heated cow. Sometimes it’s free, or sometimes, with payment on an average of BDT 400-500 or 3.79-4.73 US dollars. In some areas, AI is being practiced in buffalo under different organizations (LAL Teer, BRAC), and the cost of AI was recorded as about BDT 600-700 or 5.68-6.63 US dollars per cow. The average daily milk yield was 3.0 liter, whereas the lactation length was recorded at 179.9±3.84 days. The major constraints were high feed price 91.66% (n=110), shortage of land 41.08% (n=51), and lack of suitable marketing facilities 50.82% (n=62). 100% of farmers stated that they need improved grass production technology and reduced feed and medicine price; 24.16% (n=29) need good quality semen. From 2004 to 2022, 51 studies were found related to buffalo, where the highest 27.45% (n=14) belonged to performance studies, and 54.90% (n=28) studies were carried out in the southern part of Bangladesh.&#x0D; Conclusion: It can be concluded that buffalo has great potential with different areas of improvement. Therefore, more research is needed from different perspectives on production, reproduction, nutrition, quality of milk/meat/products, health, and sustainability of buffalo farming in Bangladesh.

Survey of Herd Management on Conventional Dairy Farms in North Algeria

A survey was conducted to evaluate husbandry practices and herd health management in dairy farms in Mostaganem province, located in north Algeria. Data was collected through face-to-face interviews with 56 farmers, followed by a visit to the production environment of the dairy cows. The results showed that 64% of farmers feed their cows a basic ration of oat hay and straw, while 32% use corn silage. On average, 9.85 ±0.32 kg of concentrate was distributed per dairy cow. Most farms didn’t have efficient forage production, while only 21% of them produced all the necessary forage. The average milk production per cow on the surveyed farms was 18.19 ±0.45 L, with a lactation length of 293.5 ±1.65 days. The cows were milked using a portable milking machine in poor hygienic conditions. Estrus detection was performed occasionally by farmers, and natural breeding was the main method of insemination, occurring at a rate of 63%. The voluntary waiting period was on average 76.6 ±3.56 days, and the average calving interval was 14.35 ±0.2 months. The culling rate in dairy farms was 23% on average, with the most common reasons for culling being mastitis and age at a rate of 23% and 21% respectively. The main diseases reported by the farmers were mastitis (82%), followed by lameness (57%). All surveyed farmers vaccinated their herds against only rabies and foot-and-mouth disease. This survey can help to identify the challenges and potential opportunities for improving dairy farm productivity and welfare in the Mostaganem province. The agricultural and economic sectors should work with farmers towards improving dairy farming techniques and practices, using efficient feeding systems and enhanced technology of dairy herd management, providing training and education to farmers, and resolving herd health issues to increase the economic efficiency of the dairy industry.

Effect of parturition time and photoperiod on milk production, quality, and somatic cell count traits of pure and crossbred goats in a different production system.

This is the first study to compare the effects of parturition time and photoperiod on milk yield, quality, and somatic cell count (SCC) traits in pure and crossbred doe genotypes reared with supplementary feeding at various physiological stages in a mountain-pasture grazing system. Data were collected from Hair, Alpine × Hair F1 (AHF1), and Saanen × Hair F1 (SHF1) crossbred doe genotypes with an average live weight of 49.60±0.40 kg. Hair doe had significantly lower (P < 0.001) milk yields and lactation length, but higher (P < 0.001) fat, protein, and lactose contents and electrical conductivity (EC) than AHF1 and SHF1 crossbred doe genotypes. Does giving parturition in the hours of darkness had higher (P < 0.05) milk volume and lower (P < 0.05) SCC compared to does giving parturition in the hours of daylight. Daily milk yield was positively correlated with daylight (P < 0.05; r = 0.50 to 0.53), while milk fat, protein, and lactose contents were negatively correlated with daylight (P < 0.05 to P < 0.001; r = -0.51 to -0.82, respectively) in Hair, AHF1, and SHF1 crossbred doe genotypes. Lactation stages and daily milk yield levels significantly affected (P < 0.05) the SCC, pH, total solids, and freezing point of milk. It was concluded that the milk yield traits of goats can be rapidly improved by better modelling of physiological and environmental variations such as photoperiod, reproduction, and hormonal effects in sustainable production systems.

Synergies of feed, management trainings, and genetics on milk production of dairy cows in the tropics: The case of Ethiopian smallholder farmers

Efforts made so far to increase milk production of indigenous cattle by upgrading with exotic genotypes through crossbreeding under smallholder farmer conditions in Ethiopia have resulted in limited improvement. This study was conducted to determine if combining improved feed and management-related trainings with Holstein genetics will synergistically increase the milk production of dairy cows, and to examine the degree to which the increase or improvement is related to the level of exotic genetics involved. A total of 96 smallholder dairy farmers were purposively selected and allocated to one of three treatments reflecting differing degrees of capacity building support: (1) no training and no material support (Control); (2) training provided by another project (PAID) but without material support; (3) enhanced training plus material support (Feed-Mgt). Sixteen extension development agents and eight livestock experts were selected to provide training and weekly on-farm data collection, monitoring, technical support, and messaging reinforcement visits. Enhanced training addressed a broad range of topics related to feed and feeding, improved forage production, milk production and handling, construction and use of improved dairy housing, disease control, and dairy farm record keeping. Material support was in the form of formulated dairy concentrate feed and improved forage planting materials (seeds/seedlings). Data collection included variables describing animal performance, management practice adoption, and milk and butter quality. Tail hair samples for genetic profiling of breed makeup were also collected from all cows in the study. Results showed that there was a very significant effect of treatment (P &amp;lt; 0.001) on milk production, as well as treatment by week interaction (P = 0.034), with the effect of treatment markedly increasing over time (P = 0.032). That is, cows in Feed-Mgt group had up to 26.6% greater milk production compared to those in the Control group. Region and region by treatment interaction have no effects. Cows used in the experiment had varying proportions of Holstein-Friesian genome that ranged between 0 and 100%, suggesting prevalence of indiscriminate crossbreeding. Cows with a high proportion of Holstein genetics in treatment 3 produced more milk as compared to those in control group. Besides, supplemental feed improved body condition, reduced number of services per conception and resulted in higher lactation length of cows on treatment 3 compared with those on treatments 1 and 2 (P &amp;lt; 0.001). Overall, our findings suggest that an integrated approach of improved feed, feeding practices, and management training for smallholder dairy that goes beyond the improvement of genetics will increase milk production, improve milk quality and body condition, and resulted in higher length of lactation.

Haplotype-based association study of production and reproduction traits in multigenerational Vrindavani population

Haplotype-based association analysis promises to reveal important information regarding the effect of genetic variants on economic traits of interest. The present study aimed to evaluate the haplotype structure of Vrindavani cattle and explore the association of haplotypes with (re)production traits of economic interest. Genotyping array data of medium density (Bovine50KSNP BeadChip) on 96 randomly selected Vrindavani cows was used in the present study. Genotypes were called in GenomeStudio program while quality control was undertaken in PLINK using standard thresholds. The phenotypic traits used in the present study included age at first calving, dry days, lactation length, peak yield, total lactation milk yield, inter-calving period and service period. The haplotype structure of Vrindavani population was assessed, using a sliding window of 20 SNP with a shift of 5 SNPs at a time, in terms of the size of haplotype blocks regarding their length (in Kb) and frequency in chromosome-wise fashion. Haplotype blocks were assessed for possible association with important production and reproduction traits across three lactation cycles in Vrindavani cattle population. The first ten principal components were included in the model for haplotype-based association analysis to correct for stratification effects of assessed individuals. Multiple haplotypes were found to be associated with age at first calving, total lactation milk yield, peak yield, dry days, inter-calving period and service period. Various candidate genes were found to overlap haplotypes that were significantly associated with age at first calving (CDH18, MARCHF11, MYO10, FBXL7), total lactation milk yield (TGF, PDE1A, and COL8A1), peak yield (PPARGC1A, RCAN1, KCNE1, SMIM34 and MRPS6), dry days (CPNE4, ACAD11 and MRAS), inter-calving period (ABCG5, ABCG8 and COX7A2L) and service period (FOXL2 and PIK3CB). The putative candidate genes overlapping the significantly associated haplotypes revealed important pathways affecting the production and reproduction performance of animals. The identified genes and pathways may serve as good candidate markers to select animals for improved production and reproduction performance in future generations.

Comparative analysis of various methods for estimating expected genetic gain of production and reproduction traits in Murrah buffaloes

The present study was conducted to assess the expected genetic gain for first lactation production and reproduction traits in Murrah buffaloes, in addition to optimization of progenies/sire. Data for period 1971–2020 were used from National Dairy Research Institute. Performance traits considered were 305 days milk yield (305DMY), average daily milk yield (ADMY), peak yield (PY), lactation length (LL), calving to first insemination interval (CFI), days open (DO), and calving interval (CI). Expected ΔG was estimated and compared by three different methods; method I involved heritability and selection differential; method II involved selection intensity, phenotypic standard deviation, and heritability; method III involved estimation of ΔG through four paths of inheritance. Initially, eleven progenies/sire were utilized for assessing expected ΔG by method III, and expected ΔG was found as 34.33, 0.12, 0.12 kg, 2.63, 1.51, 2.74, and 2.80 days/year for 305DMY, ADMY, PY, LL, CFI, DO, and CI, respectively. Additionally, there was a significant increase in expected ΔG on increasing progenies/sire from 6 to 11 while subsequent increase upto 16 had little effect on expected ΔG. These findings will be helpful in formulating breeding strategies worldwide in small buffalo herds to obtain sustainable ΔG in production and reproduction traits.

Influence of non-genetic factors on first lactation and lifetime performance traits in Nili-Ravi buffaloes

The objective of this research was to evaluate the effects of various non-genetic factors on first lactation and lifetime productivity in Nili-Ravi buffaloes, including season of birth, period of birth, age at first calving, season of first calving, period of first calving, and number of lactations completed. The livestock data on first lactation and lifetime performance traits relevant to 501 Nili-Ravi buffaloes were collected from the history sheet of the animal for a period from 1983 to 2017 (i.e., 35 years) and maintained at the Indian Council of Agricultural Research—Central Institute for Research on Buffaloes (ICAR-CIRB) sub-campus, in Nabha, Punjab, India. To evaluate the least-squares means (LSMs) and the effect of non-genetic factors on performance traits, a least-squares analysis model was applied. The overall LSM for age at first calving (AFC) was 45.03 ± 0.40 months and ranged from 34 to 54 months. The results indicated that the effect of AFC was highly significant (p ≤ 0.01) on first lactation total milk yield (FLTMY), first lactation standard milk yield (305 days or less) (FLSMY), first peak milk yield (FPY), and first lactation length (FLL) in the Nili-Ravi breed of buffaloes. FLTMY, FLSMY, and FPY were highest (2,250.08 ± 48.16 kg, 1,944.68 ± 31.20 kg, and 9.32 ± 0.16 kg/day, respectively) for animals with an AFC of 42–48 months. Furthermore, FLTMY, FLSMY, and FLL were highest (2,411.02 ± 68.68 kg, 2,008.81 ± 44.49 kg, and 357.43 ± 8.13 days, respectively) in animals that first calved in the autumn season. However, the lowest first dry period (FDP), first service period (FSP), and first calving interval (FCI) (110.63 ± 7.42 days, 125.48 ± 9.04 days, and 443.63 ± 9.00 days, respectively) were found for animals that first calved in the rainy season. The overall LSM for herd life (HL), productive life (PL), productive days (PDs), unproductive days (UDs), total lifetime milk yield (total LTMY), standard lifetime milk yield (standard LTMY), milk yield per day of productive life (MY/PL), milk yield per day of productive days (MY/PDs), and milk yield per day of herd life (MY/HL) were estimated as 3,779.84 ± 31.86 days, 2,078.55 ± 24.32 days, 1,552.74 ± 20.06 days, 525.81 ± 12.44 days, 10,229.71 ± 195.31 kg, 9,203.64 ± 173.52 kg, 4.86 ± 0.08 kg/day, 6.46 ± 0.08 kg/day, and 2.66 ± 0.04 kg/day, respectively. The effect of AFC on HL, PDs, UDs, total LTMY, and standard LTMY was highly significant (p ≤ 0.01). Furthermore, the effect of season of first calving on HL, PL, and PDs was significant (p ≤ 0.05). In addition, the effect of the period of first calving on HL, PDs, standard LTMY, and total LTMY was significant (p ≤ 0.05). In these contexts, it can be concluded that the buffaloes of the Nili-Ravi breed with an AFC of 42–48 months performed better than animals with a later AFC in terms of production, reproduction, and lifetime traits.

Milk Production and Reproductive Performance of Holstein Friesian Dairy Cattle in the Working Area of ​​South Bandung Pangalengan Animal Husbandry Cooperative (KPBS) Bandung Regency

Increasing the population and productivity of dairy cows is one of the way to boost national milk production capacity. This study was aimed to determine and investigate the performance of milk production and reproduction of Friesian Holstein (FH) dairy cows in the Working Area of KPBS Pangalengan, Bandung Regency. This research used FH dairy cows with a complete milk production and reproduction record. In total, there were 90 heads of cows in the Pangalengan District and 178 heads of cows in the Kertasari District. This study used the survey method to collect the data. A Multistage Random Sampling Method was used in this research. Sampling was carried out in two stages, the first stage was sampling from two sub-district locations in Pangalengan and Kertasari Districts. In the second stage, two villages were selected from each district: Pangalengan and Margamukti Villages in Pangalengan District, and Santosa and Tarumajaya Villages in Kertasari District. Farmers and their cows were chosen by simple random sampling. Data on milk production and reproduction records were obtained from farmers and their cows through direct observation and interviews related to the identity of the cattle they owned. The results showed that the average performance of the milk production characteristics of FH dairy cows was: an average milk production of 3779.2±497.48 liters/head/day, an average length of lactation of 307.8±31.30 days, and an average dry period of 72.14±21.43 days. The lactation period had a significant effect (P&amp;lt;0.05) on milk production. The peak of milk production was reached in the fourth lactation period. The mean of reproductive traits consisting of the first postpartum mating was 77±20.5 days, the average length of days open was 96±26.4 days, the average number of services per conception was 1.8±0.85 times, and the average calving interval was 381.05± 24.5 days. In conclusion, FH dairy cows raised in Pangalengan and Margamukti Villages, Pangalengan District, Santosa and Tarumajaya Village, Kertasari District, in the working area of Pangalengan KPBS during the Covid-19 pandemic indicated a fairly good performance of milk production and reproduction characteristics.

A Comparative Study of Productive and Reproductive Performance between Mpwapwa Breed Cattle and Their Crosses

Mpwapwa cattle, a Tanzanian composite dual-purpose breed which was established in 1960s is suitable for medium to low input production systems, but is faced with limited country-wide distribution. The aim of this study was to assess the productive and reproductive performances of Mpwapwa cattle breed and its crosses reared at Tanzania Livestock Research Institute (TALIRI). Retrospective data on age at first calving (AFC), calving interval (CI), pregnancy percentage (PP), lactation length (LL), average milk yield per day (AMYD) and total lactation milk yield (TLMY) obtained from 295 cows with the total of 885 lactations during five consecutive years (2015-2019) were analyzed. Overall mean of AFC, CI, PP, LL, AMYD and TLMY were 38.5±5.9 months, 19.92±5.64 months, 29.1%±14.4%, 237.72±71.20 days, 2.65±1.12 liters and 667.18±397.11 liters, respectively. The results of AFC, CI, LL and TLMY showed significance difference (p &lt; 0.05) between Mpwapwa breed cattle and its crosses except for PP which did not show significance difference (p &gt; 0.05). The results shows that reproductive and productive performance of Mpwapwa breed cattle and its crossbred cows was lower compared to the breeding goal of this breed. Therefore, it is recommended to investigate factors required to improve reproductive and productive performances to meet the intended objectives of establishing Mpwapwa Breed