Lactation Length Research Articles

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<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>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.

Bayesian approach for assessment of co-variances and genetic parameters of production and reproduction traits in Sahiwal cattle.

Precise as well as unbiased estimates of genetic parameters of economically important traits is important for framing breeding programmes meant for genetic progress of dairy animals. Present work was carried out to assess the co-variances along with genetic parameters of production and reproduction traits in Sahiwal cattle with Bayesian approach. Records of Sahiwal cattle kept at ICAR-National Dairy Research Institute, Karnal, Haryana for the period 1988-2016 were used. Heritability estimates ± posterior standard deviation for 305 days' milk yield (305DMY), lactation milk yield (LMY), lactation length (LL), peak yield (PY), days to attain peak yield (DPY), dry period (DP), gestation period (GP), calving to first insemination interval (CFI), days open (DO) and calving interval (CI) as obtained were 0.23 ± 0.03, 0.26 ± 0.03, 0.18 ± 0.03, 0.18 ± 0.03, 0.07 ± 0.02, 0.08 ± 0.02, 0.08 ± 0.02, 0.07 ± 0.02, 0.09 ± 0.02 and 0.02 ± 0.02, respectively and estimates of repeatability for the corresponding traits were 0.23 ± 0.03, 0.26 ± 0.03, 0.21 ± 0.03, 0.21 ± 0.03, 0.12 ± 0.02, 0.14 ± 0.03, 0.16 ± 0.03, 0.16 ± 0.03, 0.17 ± 0.03 and 0.17 ± 0.03. Moderate heritability values for 305DMY and LMY implies that sufficient additive genetic variability is available to obtain selection response. Repeatability estimates for 305DMY, LMY and PY were moderate, pointing towards the possibility of early appraisal of Sahiwal cattle for selection. Antagonistic genetic associations were observed between reproduction and production traits suggesting that reproduction traits need due attention while selecting high producing Sahiwal animals.

Evaluation of performance and estimation of genetic parameters for milk yield and reproductive traits in Awassi and Asaf sheep breeds and crosses in the Palestinian territory.

This study aimed to estimate genetic parameters, including heritability and repeatability, for milk yield and prolificacy in sheep. It included 3682 records from 1837 ewes across various breeds: Awassi, Assaf, and Awassi x Assaf crosses, two Awassi lines: Improved Awassi, AFEC Awassi. The study measured total milk yield (TMY), yield up to 120 days (TMY120), and yield up to 150 days (TMY150), alongside reproductive traits: litter size (LS), number of lambs born alive (NLBA), and lambing interval (LI). The analysis utilized a mixed model and the REML procedure to estimate genetic parameters. Results indicated that litter size (LS) had no significant impact on milk traits, whereas breed, location, ewe parity, and lambing season showed significant effects. Lactation length also significantly influenced TMY. For reproductive traits, treatment was significant for NLBA, with location associated with breed, parity, and season affecting all traits. Heritability estimates for TMY ranged from 0.00 in Awassi x Assaf crosses to 0.11 in Awassi, and for TMY120 and TMY150, from 0.00 in Awassi x Assaf crosses to 0.16 in Awassi. Estimates for LS and NLBA varied similarly. The heritability for LI was 0.03 in Awassi and zero in other breeds and crosses. The findings suggest that in the northern West Bank regions of Nablus and Jenin, Assaf or Awassi x Assaf breeds are preferable. The study underscores the importance of comprehensive performance and pedigree recording for effective sheep farm management.

Influence of Maternal Dietary Protein during Late Gestation on Performance of Black Bengal Does and Their Kids.

The present study aimed to elucidate the effect of different levels of dietary protein during late pregnancy on the performance of Black Bengal does and their kids. Twelve does were divided into three groups, with four in each, and three diets, i.e., high protein (18% CP), medium protein (14% CP), and low protein (10% CP) were supplied for 50 days, commencing from 100 days post-coitum to parturition. During the first 100 days of pregnancy, uniform rations with similar ingredients were provided to fulfill the nutrient requirements depending on the live weight of does. All three diets were isocaloric (10.0 MJ/kg DM). Data were subjected to one-way ANOVA, and the significance of the difference among means was determined by Duncan's Multiple Range Test (DMRT). The main effects of diet and sex, as well as their interaction, were analyzed by two-way ANOVA by using the GLM procedure. The relative expression values of qPCR were calculated by using the 2-ΔΔCt analysis method. Live weight gain was significantly (p < 0.05) higher in high-protein-fed dams than other groups during the experimental period. The milk yield of does was significantly (p < 0.05) higher in high-protein-fed goats than in the low-protein group. The lactation length of does was significantly (p < 0.05) higher in the high- and medium-protein-fed does than in the low-protein-fed does. The duration of post-partum anestrus of does was significantly (p < 0.05) higher in the low-protein-fed dams than in the high-protein group. The birth weight of kids tended to be higher in the high-protein group but did not differ significantly among the treatment groups. In male kids, weaning weight, final weight, live weight gain, and average daily gain were significantly (p < 0.05) higher than in female kids. Weaning weight was higher (p < 0.05) in kids of the high-protein-fed does than the low-protein group. Final weight and live weight gain were significantly (p < 0.05) higher in kids of the high-protein-fed does than in the low-protein-fed group. On the other hand, average daily gain was significantly (p < 0.05) higher in kids of the high- and medium-protein-fed does than the low-protein group. The average body length and wither height of kids at the 32nd week was significantly (p < 0.05) higher in kids of high-protein-fed does than those of the low-protein-fed group. The average heart girth of kids at the 32nd week was significantly (p < 0.05) higher in kids of high-protein-fed does than the medium- and low-protein groups. The survival rate of kids was higher in the medium- and high-protein-fed does than in low-protein group. Hot carcass weight and ether extract content of meat were significantly (p < 0.05) higher in the high-protein group than in the other groups. The dressing percentage was significantly (p < 0.05) higher in the kids of high-protein-fed does than low-protein-fed goats. The expression of the H-FABP gene was significantly (p < 0.05) higher in kids of high-protein-fed does than those of the medium- and low-protein groups. In conclusion, maternal dietary protein levels positively influences the production performance of Black Bengal does and their kids.

Genetic and Phenotypic Trends for Production and Reproduction Traits in Murrah Buffaloes.

The objective of the study was to estimate genetic and phenotypic trends for first lactation production and reproduction traits in Murrah buffaloes. The information of pedigree and targeted traits of 640 Murrah buffaloes was collected for the period from 1997 to 2020. The first lactation production traits included first lactation milk yield (FLMY), 305 days first lactation milk yield (305FLMY), first lactation length (FLL), first lactation peak yield (FPY) whereas reproduction traits included first service period (FSP), first calving interval (FCI) and first dry period (FDP). Genetic and phenotypic trends were estimated. Phenotypic trends for FLMY, 305FLMY, FLL and FPY exhibited as 36.96 ± 8.58 kg/year, 31.93 ± 8.34 kg/year, 1.47 ± 0.55 days/year and 0.12 ± 0.02 kg/year, respectively and respective genetic trends exhibited as 3.73 ± 1.67 kg/year, 1.94 ± 0.76 kg/year, -0.15 ± 0.07 days/year and 0.01 ± 0.01 kg/year, respectively. It was revealed that there were significant (p < 0.05) and positive phenotypic trends for all production traits while genetic trends were significant (p < 0.05) for FLMY and 305FLMY traits. The phenotypic trends of studied reproductive traits indicated that only FDP trait significantly (p < 0.01) decreased (1.87 days/year) over time. For FSP and FCI traits, nonsignificant (p > 0.05) genetic and phenotypic trends indicated no change over time. This study highlighted potential challenges in maintaining reproductive efficiency alongside productivity improvements in Murrah buffaloes.

Characterization of smallholder irob cattle production system: contributions to develop a breeding program.

An exploratory survey (i) to investigate livestock production system, reproductive and production performance of Irob cattle and (ii) to recognize constraints to cattle production was conducted in eastern Tigray zone, northern Ethiopia. Six tabias (the smallest administrative unit consisting of several villages) were chosen using purposive sampling method and households from each tabia were randomly selected. Mixed crop-livestock farming system dominates the study area. Overall herd size was 5.3 ± 2.7, with each herd comprising of 1.7 ± 1.2 cows, 1.4 ± 0.9 oxen, 0.5 ± 0.7 heifers, 0.5 ± 0.7 bulls and 1.2 ± 0.9 calves. Cattle are kept for draught power (index = 0.43), milk (index = 0.32), income (index = 0.15), manure (index = 0.06) and crop threshing (index = 0.04). Major feed resources in the study area were natural pasture, crop residue and cactus pear (Opuntia ficus-indica). Overall mean (± SD) for age at first services (AFS), age at first calving (AFC), calving interval (CI), days open (DO), daily milk yield (DMY) and lactation length (LL) was 28.3 ± 3.9 months, 37.4 ± 5.5 months, 15.5 ± 4.1 months, 6.5 ± 1.8 months, 1.7 ± 0.4L and 7.4 ± 2.0 months, respectively. There was no significant (p > 0.05) difference in performance traits between districts. Well-known cattle production constraints in order of significance were feed, disease and parasites, AI, water and veterinary service. In conclusion, the study shown importance of taking into account the production environment in developing breed improvement program and recommends fit management system.

Influence of additive and maternal effects on production and reproduction traits in Murrah buffaloes: Insights from Bayesian analysis.

The aim of this research was to assess genetic parameters for first lactation production and reproduction traits in Murrah buffaloes by employing additive and maternal effects. Data on pedigree and specific traits of 640 Murrah buffaloes were gathered from 1997 to 2020. These traits encompassed first lactation milk yield (FLMY), 305-day first lactation milk yield (305FLMY), first lactation length (FLL), first lactation peak yield (FPY), first service period (FSP), first calving interval (FCI) and first dry period (FDP). Genetic evaluations employed six univariate animal models, accounting for both direct and maternal effects, facilitated by THRGIBBS1F90 and POSTGIBBSF90 programs. Fixed factors included in the analysis were period of calving, season of calving and age at first calving. The Bayesian estimates for direct heritability, derived from the most suitable model, were as follows: FLMY: 0.28 ± 0.01, 305FLMY: 0.30 ± 0.01, FLL: 0.19 ± 0.01, FPY: 0.18 ± 0.01, FSP: 0.12 ± 0.01, FCI: 0.14 ± 0.01 and FDP: 0.12 ± 0.01. Maternal effects were found significant, ranging from 5% to 10%, in first lactation traits under Model 2 and Model 5. Additionally, positive and significant genetic and phenotypic correlations were observed among the studied traits. In conclusion, selection based on 305-day first lactation milk yield suggests potential for genetic enhancement in Murrah buffaloes, advocating its inclusion in breeding programmes to bolster early performance. Also, consideration of maternal influences is necessary for genetic progress of animals.

Genetic and Phenotypic Trends along with Genetic Parameters of Production Traits in Murrah Buffalo

Aim: This study investigates the genetic parameters and trends in production traits of Murrah buffaloes over a 24-year period (1996-2019) at a farm in Hisar, Haryana. Data on key production traits including 305 days milk yield (305DMY), peak yield (PY), lactation length (LL), dry period (DP), lactation milk yield (LMY), and wet average (WA) were collected from 614 Murrah buffaloes. Methodology: Utilizing a univariate animal model, the average estimated breeding values for the production traits were computed: 2148.05 kg for 305DMY, 10.74 kg/day for PY, 319.19 days for LL, 117.88 days for DP, 2288.80 kg for LMY, and 7.12 kg/day for WA. Results: The study revealed a minimum genetic correlation of -0.81 and a phenotypic correlation of -0.32 between LL and WA. Heritability estimates for 305DMY, PY, LL, DP, LMY, and WA ranged from 0.13 to 0.48, while repeatability estimates varied from 0.35 to 0.54. The genetic trends were positive for all production traits except LL and DP, while phenotypic trends had positive values for all traits except DP. Conclusion: From this study, it can be inferred that selecting based on peak yield as a benchmark would be more fit for achieving correlated improvements in other production traits.

Effect of SNPs on Litter Size in Swine.

Although sows do not directly enter the market, they play an important role in piglet breeding on farms. They consume large amounts of feed, resulting in a significant environmental burden. Pig farms can increase their income and reduce environmental pollution by increasing the litter size (LS) of swine. PCR-RFLP/SSCP and GWAS are common methods to evaluate single-nucleotide polymorphisms (SNPs) in candidate genes. We conducted a systematic meta-analysis of the effect of SNPs on pig LS. We collected and analysed data published over the past 30 years using traditional and network meta-analyses. Trial sequential analysis (TSA) was used to analyse population data. Gene set enrichment analysis and protein-protein interaction network analysis were used to analyse the GWAS dataset. The results showed that the candidate genes were positively correlated with LS, and defects in PCR-RFLP/SSCP affected the reliability of candidate gene results. However, the genotypes with high and low LSs did not have a significant advantage. Current breeding and management practices for sows should consider increasing the LS while reducing lactation length and minimizing the sows' non-pregnancy period as much as possible.

Least Squares, Simple Linear Regression, and Pearson Correlation Analysis between the Lactation Milk Yield of Norduz Ewes and Their Lambs’ Live Weight

This study aimed to determine the lactation milk yield of Norduz ewes and to determine the effects of milk yield on their lambs’ growth and development characteristics. Additionally, the correlations between the sheep’s milk yield, lambs’ live weight, and affecting factors were determined. The study was conducted at the Van University of Yüzüncü Yıl Agricultural Research Center. In the study, 61 Norduz ewes and 66 male and female lambs they bore were included. The sheep were milked at 30-day intervals until the 180th day. Similarly, the lambs were weighed at 30-day intervals from birth to 180th day. The means and standard errors of the milk yields were obtained on the 30, 60, 90, 120, 150th, and 180th days of milking. The live weight means and standard errors of the lambs on the 30th, 60th, 90th, 120th, 150th, and 180th days are given. According to the GLM analysis results, sex significantly influenced lactation length (p&amp;lt;0.05), and there was a difference in favor of female lambs. The impact of dam age was notably significant on live weight at days 60 and 90 (p&amp;lt;0.05). Additionally, birth type significantly affected live weight at day 30 and 60 (p&amp;lt;0.001), as well as at day 90 (p&amp;lt;0.01). Regarding the linear relationship between dam weight and live weight, a significant effect was observed at day 30 (p&amp;lt;0.001), day 60 (p&amp;lt;0.01), and day 90 (p&amp;lt;0.05). Notably, the linear effects of lamb birth weight on live weight remained significant across all control periods (p&amp;lt;0.001).

Effect of Enzyme Supplementation on Nutrient Utilization and Production Performance in Lactating Murrah Buffaloes

Background: Enzyme stimulates metabolic and digestive processes leading to increased feed intake and improved nutrient availability in animals. This study was conducted to investigate the effect of enzyme supplementation on nutrient utilization and production performance in lactating Murrah Buffaloes during winter season. Methods: Twenty four lactating Murrah buffaloes were selected for the study from Livestock Research Centre, Sardar Vallabhbhai Patel University of Agriculture and Technology, Modipuram, Meerut (UP). All the selected animals were randomly allocated into four treatment groups having six animals in each group on the basis of body weight, lactation length and milk yield. The daily nutrient requirements of lactating Murrah buffaloes in term of DM, DCP and TDN were provided as per the feeding standards of Indian Council of Agricultural Research, New Delhi (2013). Total Mixed Ration for buffaloes was prepared by mixing of roughage and concentrates in the ratio of 60:40 after grinding/chaffing. Roughage part was consisting of available winter season green fodder e.g. oat and wheat straw available at research centre. Feeding trial was planned into four treatment groups viz. T1 (Basal diet without enzyme supplementation), T2 (Basal diet with supplementation of Xylanase @ 800000 IU), T3 (Basal diet with supplementation of Cellulase @ 240000 IU) and T4 (Basal diet with supplementation of Xylanase @ 800000 IU and Cellulase @ 240000 IU). Result: From the present study, it was observed that the average milk yield (5.34 litre/day) was higher in T4 as compared to other treatment groups, but the difference was non-significant. The average milk fat percent was recorded as 7.52, 7.58. 7.60 and 7.65 in T1, T2, T3 and T4 treatment groups, respectively. Although the results of T4 group animals were comparatively higher in all major milk constituents the differences were found to be statistically non-significant. The average DM intake (kg/d, kg/100 kg BW and g/kg W0.75) and CP intake (g/d, g/100 kg BW) were almost similar in all treatment groups. The TDN intake (kg/d, kg/100 kg BW and g/kg W0.75) was significantly (P less than 0.05) higher in enzyme supplemented groups. The digestibility coefficient of CP, CF, NDF and ADF were higher (P less than 0.05) in buffaloes of T4 over control (T1) group. So, it was concluded from the above study that the milk production and milk composition could be improved with the combine use of Xylanase and Cellulase enzyme in murrah buffaloes due to improved CP and fibre digestibility.

Dairy Farmers’ Perception on Dairy Cattle Feeds and Feeding System: Brewery By-product Utilization Practice at Kombolcha Regiopolitan City, Ethiopia

A survey was conducted in three selected kebeles of Kombolcha Regiopolitan City in South Wollo Zone. The selected kebeles were in proximity to brewery factory, Ethiopia. A semi-structured questionnaire was used to collect perception data from purposively selected three kebeles and a total of 57 randomly selected dairy farmers. Data collected were analyzed with a statistical package for social sciences (Version 20) and Microsoft Excel (2010). Smallholder dairy farmers had average herd size of 10.7 and 0.08 hectare total dairy farm per household. Average daily milk yield and lactation length of dairy cows was 10.8 liter/day and 9.5 months, respectively. The majority of farmers (59.6%) reared dairy cows with 50-75% exotic blood. The most smallholder dairy farmers satisfied their feed demand from the market and had a trend of providing both dense and poor quality affordable feed ingredients. Smallholder dairy farmers gave priority to feed different kind of cattle in the order of lactating cows, calve, pregnant, heifers and dry cows and used (100%) wet brewery spent grain as a source of dairy feed. Though, there was a brewery by-product supply deficit for half of year. The majority smallholder dairy farmers delivered brewery by-product directly from the brewery factories and followed by wholesalers and retailers. The majority of smallholder dairy farmers (96.4%) stated that the brewery spent grain was fed and stored freshly using different conservation techniques, and the remaining stored in ensiled (1.8%) and dried (1.8%) forms. Smallholder dairy farmers had no brewery spent grain ensiling practice and feeding brewery yeast to dairy animals. Smallholder dairy farmers indicated that high price due to abnormal market chain and shortage of brewery spent grain supply were the major challenges to sustain dairy industry in the study area, and the majority (40.6%) claimed to get swift solutions at high cost and less accessible brewery by-product.

Effects of Parity on Service per Conception, Gestation Length, Milk Yield, Calving Interval, and Calf Birth Weight of Crossbred Dairy Cows

AbstractThe average lactation number for a stable herd dairy cow would be 3.4 and many dairy farmers do not keep dairy cows for extended lactation numbers beyond the 6th lactation number. Thus, there is a limited number of information focused on the later lactation number or parity (6-10) effect on lactation traits. Therefore, this study was conducted to evaluate the effect of lactation number on the number of services per conception, gestation length, lactation milk yield, lactation length, calving interval, and calve weight in crossbred Holstein Friesian cows. The record data at Haramaya University dairy farm was collected and compiled to assess the effects of lactation numbers. Retrospective data records of 1863, 1742, 1280, 1280, 1329, 1170, and 848 data of dairy cows were respectively used for evaluating the number of services per conception, gestation length, lactation length, lactation milk yield, calving interval, and calf birth weight. The study revealed that lactation number significantly affected the total lactation milk yield, lactation length, calving interval, and calf birth weight but it did not affect the number of services per conception and gestation length. Based on this study result, crossbred Holstein Friesian cows could be productive until the 8th lactation number without a significant decrease in the lactation milk yield. Therefore; lactation number should be used as an important trait in the performance of dairy cattle. Further study should be conducted to evaluate the effect of lactation number on other lactation traits such as dry period, days open, and milk composition.Keywords: Birth weight; Calving interval; Gestation; Lactation; Milk yield; Parity

Computation of Heritability for Production and Reproduction Traits in Frieswal Cattle under Field Progeny Testing

Aims: To study the genetic parameter (heritability) for production and reproduction traits in Frieswal cattle under field progeny testing programme. Place and Duration of Study: G B Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India, between March, 2023 and March, 2024. Methodology: The present study was conducted on 1163 Frieswal cattle comprised of five different sets maintained at six field units over a period from 2013-2021. The traits considered were age at sexual maturity (ASM), age at first calving (AFC), gestation period (GP), test day peak yield (TDPY), 305 days milk yield (305D-MY), fat percentage (FP), lactation length (LL), calving interval (CI), service period (SP), number of services per conception (NSPC), dry period (DP). The data were analyzed for the estimation of heritability by the software WOMBAT. Results: The heritability estimates of the traits namely; ASM, AFC, GP, TDPY, 305D-MY, FP, LL, CI, SP, NSPC and DP were 0.469±0.082, 0.467±0.082, 0.259±0.067, 0.248±0.059, 0.354±0.013, 0.413±0.069, 0.389±0.071, 0.394±0.071, 0.452±0.072, 0.072±0.046 and 0.08±0.06, respectively. Conclusion: Therefore, the heritability estimates were found to be low to high magnitude for different reproduction and production traits and further it has been concluded that, this study will aid breeders in selecting high-performing animals for future generations, taking into account the genetic factors that influence milk production and reproductive traits during early lactation.

Unknown parent groups and truncated pedigree in single-step genomic evaluations of Murrah buffaloes

Missing pedigree may produce bias in genomic evaluations. Thus, strategies to deal with this problem have been proposed as using unknown parent groups (UPG) or truncated pedigrees. The aim of this study was to investigate the impact of modeling missing pedigree under ssGBLUP evaluations for productive and reproductive traits in dairy buffalos using different approaches: 1) traditional BLUP without UPG (BLUP), 2) traditional BLUP including UPG (BLUP/UPG), 3) ssGBLUP without UPG (ssGBLUP), 4) ssGBLUP including UPG in the A and A22 matrices (ssGBLUP/A_UPG), 5) ssGBLUP including UPG in all elements of the H matrix (ssGBLUP/H_UPG), 6) BLUP with pedigree truncation for the last 3 generations (BLUP/truncated), and 7) ssGBLUP with pedigree truncation for the last 3 generations (ssGBLUP/ truncated). UPGs were not used in the scenarios with truncated pedigree. A total of 3,717, 4,126 and 3,823 records of the first lactation for accumulated 305 d milk yield (MY), age at first calving (AFC) and lactation length (LL), respectively were used. Accuracies ranged from 0.27 for LL (BLUP) to 0.46 for MY (BLUP), bias ranged from -0.62 for MY (ssGBLUP) to 0.0002 for AFC (BLUP/truncated), and dispersion ranged from 0.88 for MY (BLUP/ A_UPG) to 1.13 for LL (BLUP). Genetic trend showed genetic gains for all traits across 20 years of selection and the impact of including either genomic information, UPG or pedigree truncation under GEBV accuracies ranged among the evaluated traits. Overall, methods using UPGs, truncation pedigree and genomic information exhibited potential to improve GEBV accuracies, bias and dispersion for all traits compared with other methods. Truncated scenarios promoted high genetic gains. In small populations with few genotyped animals, combining truncated pedigree or UPG with genomic information is a feasible approach to deal with missing pedigrees.

Characterization of Removal Reasons for Nurse Sows and the Associated Removal Due to Their Extended Lactation Length in Hyperprolific Farrow-Wean Herds.

This study aimed to characterize and quantify reasons for the removal of nurse sows and identify the removal associated with their extended lactation length (ELL). A total of 100,756 removed nurse sows within a period of 2016-2022 from 53 sow herds in the Midwest USA were analyzed. Reproductive failure was the most common removal reason (χ2 = 8748.421, p < 0.001) affecting P1, P2, and P3 nurse sows. Failure to conceive and absence of estrus were the main causes of reproductive failure (χ2 = 352.480, p < 0.001) affecting P1 and P2 nurse sows and P1 and P5 nurse sows, respectively. When P2 and P6 nurse sows had an ELL of 0-7 d, they faced a high chance (χ2 = 13.312, p = 0.021) of removal due to conception failure and failure to return to heat, respectively. When P2 and P5 nurse sows had an ELL of 8-14 d, they were highly vulnerable (χ2 = 59.847, p < 0.001) to removal due to failure to conceive and showing heat, respectively. Finally, when ELL was at 15-21 days, P4 and P5 nurse sows were more likely (χ2 = 41.751, p < 0.001) to be removed due to failure to express heat, whereas at the same time, P2 and P3 nurse sows experienced the same removal threat due to failing to conceive. These results could help producers manage nurse sow systems.

Farm-level risk factors associated with increased milk β-hydroxybutyrate and hyperketolactia prevalence on farms with automated milking systems

The objectives of this study were to determine the farm-level hyperketolactia (HKL) prevalence, as diagnosed from milk β-hydroxybutyrate (BHB) concentration, on dairy farms milking with an automatic milking system (AMS) and to describe the farm-level housing, management, and nutritional risk factors associated with increased farm-average milk BHB and the within-herd HKL prevalence in the first 45 DIM. Canadian AMS farms (n = 162; eastern Canada n = 8, Quebec n = 23, Ontario n = 75, western Canada n = 55) were visited once between April to September 2019 to record housing and herd management practices. The first test milk data for each cow under 45 DIM were collected, along with the final test of the previous lactations for all multiparous cows, from April 1, 2019 to September 30, 2020. The first test milk BHB was then used to classify each individual cow as having HKL (milk BHB ≥ 0.15 mmol/L) at the time of testing. Milk fat and protein content, milk BHB, and HKL prevalence were summarized by farm and lactation group (all, primiparous, and multiparous). During this same time period, formulated diets for dry and lactating cows, including ingredients and nutrient composition, and AMS milking data were collected. Data from the AMS were used to determine milking behaviors and milk production of each herd during the first 45 DIM. Multivariable regression models were used to associate herd-level housing, feeding management practices, and formulated nutrient composition with first test milk BHB concentrations and within-herd HKL levels separately for primiparous and multiparous cows. The within-herd HKL prevalence for all cows was 21.8%, with primiparous cows having a lower mean prevalence (12.2 ± 9.2%) than multiparous cows (26.6 ± 11.3%). Milk BHB concentration (0.095 ± 0.018 mmol/L) and HKL prevalence for primiparous cows were positively associated with formulated prepartum DMI and forage content of the dry cow diet while being negatively associated with formulated postpartum DMI, the major ingredient in the concentrate supplemented through the AMS, and the PMR-to-AMS concentrate ratio. However, multiparous cows' milk BHB concentration (0.12 ± 0.023 mmol/L) and HKL prevalence were positively associated with the length of the previous lactation, milk BHB at dry off, prepartum diet nonfiber carbohydrate content, and the major forage fed on farm, while tending to be negatively associated with feed bunk space during lactation. This is the first study to determine the farm-level risk factors associated with herd-level prevalence of HKL in AMS dairy herds, thus helping optimize management and guide diet formulation to promote the reduction of HKL prevalence.

288 Effects of increasing water concentrations of oregano essential oil supplementation for lactating sows

Abstract The use of essential oils as a supplement for sows has gained attention in recent years to potentially improve sow and litter performance. Sows (n = 182; avg. lactation length = 19.8 d) were blocked by parity, genetics, estimated farrowing date, and randomly allotted to one of four treatments when entering the farrowing barn. Treatments included: control, 0 mL, (CON, n = 46), 31 mL (L-OEO, n = 45), 47 mL (M-OEO, n = 46), or 63 mL (H-OEO, n = 45) of oregano oil (OEO; Ecodiar Liquid, Nutrinae, Palo Alto, CA) per liter of dosing water with medicators set at 1:128 dilution. Sows were fed a corn-soybean meal-DDGS based lactation diet that met or exceeded NRC (2012) requirements. Sow body weight (BW) was recorded upon entry, 2 d post-farrowing, and weaning. Sow backfat depth (BF) and loin muscle depth (LD) ultrasound measurements, body condition score (BCS), and Knauer sow caliper measurements were collected upon entry and weaning. Sow average daily feed intake (ADFI) was recorded daily 1-wk post-farrowing, then weekly until weaning. Sow water intake was recorded daily (DWI). Individual piglet BW were recorded d 1, d 7, and weaning. Data were analyzed using Proc Mixed procedure in SAS 9.4 with treatment and rep as fixed effects, parity class (P1, P2/P3, P4+) as a covariate, and individual sow as a random effect. Lactation length and number of piglets weaned were used as covariates for weaning data. Linear, quadratic, and cubic contrasts were analyzed among treatments. Litter scouring and medication rates were analyzed using chi-square analysis in the Proc Freq procedure in SAS 9.4. Differences were considered significant at P ≤ 0.05 and trend at 0.05 &amp;lt; P ≤ 0.10. Week 3 lactation sow ADFI increased for L-OEO and H-OEO treatments but decreased for M-OEO compared with CON sows (CON: 7.29 kg/d, L-OEO: 7.60 kg/d, M-OEO: 7.03 kg/d, H-OEO: 7.55 kg/d; cubic; P = 0.0427). No differences were observed among treatments in overall lactation ADFI, DWI, changes in BF, LD, BCS, and piglet and litter growth performance. Sow BW change tended to decline and then increased as OEO increased in the water (CON: -8.79 kg, L-OEO: -6.36 kg, M-OEO: -8.03 kg, H-OEO: -10.52 kg; quadratic, P = 0.0640). There was a cubic tendency for OEO supplementation to reduce loss of caliper measurement (CON: -1.91, L-OEO: -0.98, M-OEO: -1.68, H-OEO: -1.00; P = 0.0598). Percentage of piglets treated with medications for various health issues decreased in the H-OEO supplemented group compared with the L-OEO and M-OEO supplemented groups, with CON group being intermediate and not different (CON: 7.01%, L-OEO: 9.35%, M-OEO: 9.91%, H-OEO: 4.15%; P = 0.0322). Overall, there were no significant impacts of OEO supplementation on sow and litter performance in this study. Future research is needed to determine the effectiveness of OEO in health-challenged sows and litters and the long-term effects of OEO on piglets post-weaning.

Lifetime milk production of Holstein cattle in the humid tropics compared to Holstein-Gyr and Holstein-Brahman crosses.

Crossbred cattle are commonly used for milk production in the tropics, combining the potential benefits of pure breeds with the heterosis effects of the offspring. However, no comprehensive assessment of lifetime productivity for crossbred versus purebred cattle in low-altitude tropical environments has been carried out. The present study compares the lifetime productivity of purebred Holstein (HO, n = 17,269), Gyr (GY4, n = 435), and Brahman (BR4, n = 622) with crossbreds Gyr × Holstein (GY × HO, n = 5521) and Brahman×Holstein (BR × HO, n = 5429) cows from dairy farms located in low and medium altitude tropical regions in Costa Rica. The production traits of interest were age at first calving (AFC), days open (DO), milk production per lactation (TMP), lactation length (LLEN), age at culling (ACUL), and number of lactations (NLAC). Estimates of heterosis were also calculated. The AFC for GY × HO crosses (33-34 months) was not significantly different (p > .05) from HO (33.8 months). For BR × HO crosses, a significant (p < .05) decrease in AFC (BR3HO1 35.6 months, BR2HO2 34.5 months, and BR1H03 33.3 months) was observed as the fraction of HO breed increased. Estimates of heterosis for AFC were favourable for both crosses, of a magnitude close to 3%. The DO for F1 crosses (GY2HO2 94 days; BR2HO2 96 days) was significantly (p < .05) lower than HO (123 days). Estimates of heterosis for DO were also favourable and above 15% for both crosses. The TMP and LLEN were higher for HO (TMP = 5003 kg; LLEN = 324 days) compared with GY × HO (TMP = 4428 to 4773 kg; LLEN = 298 to 312 days) and BR × HO (TMP = 3950 to 4761 kg; LLEN = 273 to 313 days) crosses. Heterosis for TMP was favourable but low for both crosses, with a magnitude below 3.0%. The NLAC for HO (4.6 lactations) was significantly (p < .05) lower than F1 (GY2HO2, 5.8 lactations; BR2HO2, 5.4 lactations). Heterosis for NLAC was above 6.0% for both crosses. Overall, estimates of lifetime income over feed costs per cow on average were USD 2637 (30.3%) and USD 734 (8.4%) higher in F1 GY × HO and BR × HO, respectively, compared to HO. In conclusion, crossbred animals, specifically those with Gyr and Brahman genetics, extend the productive lifespan, increasing economic returns.

A Systematic Review on Buffalo Breeds, Lactation Performance, and Buffalo Milk Production Characteristics in Sri Lanka

Purpose: The current study aimed to systematically review the publications originating from Sri Lanka on buffalo milk to identify potential dairy buffalo breeds and their lactation performances, milk composition, physicochemical properties, and products originating from buffalo milk.Research Method: Articles published over the last 6 decades were found through Scopus and Google Scholar databases using keywords. Original Research articles which are relevant and published in English were only selected. The six-step selection process in line with the Preferred Reporting Items for Systematic Reviews and Meta-analysis Approach (PRISMA) was adopted.Findings: The majority of the publications focused on product development aspects rather than buffalo milk production aspects. Pure breeds of the locals, Murrah, Surti, and Nili-Ravi, and their crossbreeds are frequently cited in the literature. The daily average milk yields of Murrah, Local, Surti, and Nili-Ravi pure breeds were 4.7±2.3, 3.1±1.3, 3.0±1.19, and 1.2 L, respectively. Daily milk yields of the crossbreeds ranged from 1.1 – 5.0 L. Average lactation lengths were largely dependent on the breed in which Murrah recorded the highest (341±100 days). The average lactation length of the local breed was exceptionally shorter (156±27 days) than that of the exotic breeds (&gt;235 days). The calving interval of the Murrah and Local buffaloes was the same (636 d). Pure breeds of Surti and Nili-Ravi recorded calving intervals of 489 and 411 d, respectively. Whereas, it ranged from 417-477 d among crossbreeds. Studies focused on milk compositions and physicochemical properties were extremely rare. Curd and cheese were the most focused products originating from buffalo milk.Value: This study summarises the buffalo milk production aspects in Sri Lanka and identifies research gaps in the area. Current literature reflects a satisfactory level of information relevant to the buffaloes reared in the Dry-Zone. This study recommends more research in milk composition analysis and lactation performance of the breeds and buffalo production in the Low-Country Wet Zone and Up-Country regions.