Search

Researches results of cows of the Ukrainian Red-and-White lifetime productivity dairy breed on traits of duration of economic use within the limits of an estimation of crossbred genotypes and genealogical for-mations are resulted. Reliable influence of the conditional share of Holstein breed heredity on the economic use duration and lifetime milk productivity of cows has been established. For the longest time in the herd, crossbred cows with Holstein bloodline of 25.0 % and crossbreeds with heredity of the parent breed up to 50.0 % were used. At the final stage of crossing in animals with blood ratio of 62.5-87.5 %, a noticeable re-duction in the duration of economic use was observed. Animals with Holstein bloodlines of 75.0 and 87.5% were inferior to groups of crossbred cows with heredity of 25.0 and 50.0% with reliable difference of 590 and 633 (P

The retrospective analysis involved 562 Holstein cows, 545 Ukrainian Black-and-White dairy cows and 100 Ukrainian Red-and-White dairy cows in Breeding Station Terezyne, Kyiv region. The influence of age at first calving and first lactation milk yield on the duration and efficiency of the productive lifespan of cows was studied. The results showed that with the increase of age at first calving from less than 22 to more than 34 months there was a steady tendency to reduction in the longevity and lifetime productivity of cows. There was found a statistically significant (P

The results of researches of domestic and foreign authors were summarized in the aspect of studying the problematic issues concerning the evaluation of dairy cows on the traits of duration economic use and lifetime productivity. The researchers reported that productive longevity traits of cows largely depended on hereditary (conditional bloodliness by the improving breed when crossing, intralinear and interlinear selection, linear breeding, the degree of inbreeding, the strength of influence breeding value of ancestors) and paratypical (age at the first calving, correlative variability between linear traits and longevity) factors. In most cases, an increase the share of heredity due to absorption crossing led to reduction in the duration of productive use and lifetime productivity of cows. When studying population genetic parameters, the authors of many studies confirmed the low level of heritability of longevity traits, which did not contribute to effective selection based on the duration of productive use and lifetime productivity. Analysis of the results of these studies confirmed that linear traits of the conformation type of dairy animals can be used as early indirect predictors of longevity. This conclusion was based on the high heritability of linear traits and existence of positive correlations between them and duration of productive life.

Simple Summary: Selecting replacement beef females is often based on individual producers and their own individual needs. Selection criteria typically vary from producer to producer but generally include productivity of the mother, ability to rebreed and wean a heavy calf. Increased longevity of the dam may be an indicator of potential productivity of their female offspring. Greater longevity of females with beef herds allows producers to be more selective when choosing replacement females; although, this may increase generation intervals. Using comprehensive cow-calf production data can help improve overall selection criteria associated with cow-calf productivity such as reproductive ability, weaning weights of offspring and ability to remain in the herd. Comprehensive cow-calf production data was utilized to evaluate the impact of dam age on lifetime productivity of Angus replacement beef females. Cows used in this study were commercial Angus replacement females born between 2006 and 2020, ranging in age from 1 to 14-yr of age (n = 3568). To determine the impact of dam age on lifetime productivity, cows were classified by age groups, specifically 2-, 3-, 4-, 5-, 6/7-, and 8-yrs old and older. The 8-yr and older group consisted of females that were up to 14-yr of age. Cow BW at breeding exhibited a cow age × dam age interaction (p < 0.01). Cows at 5-yrs of age from 2-yr old dams weighed less at breeding than cows at 5-yrs of age from 3-, 4-, 5- and 8-years and older dams, with cows at 5-yr of age from 6/7-yr old dams being intermediate. The probability of remaining in the herd at the age of 5 was significant for dam age (p = 0.05) averaging 69.41%, but after further delineation, no significant impacts of dam age were observed. Productivity as a measure of total pounds of calf weaned through 5-yrs displayed a dam age effect (p = 0.01) with cows from 8-yrs or older dams weaning more total pounds of calf, than cows from 3-yr-old dams. In summary, the impact of dam age on lifetime productivity indicates that dam age can impact future productivity of their offspring. [ABSTRACT FROM AUTHOR]

Background: Lead exposure reduces the cognitive development and future economic prospects of children. While previous studies in high-income settings have explored productivity losses associated with lead exposure, limited research has focused on low and middle-income countries like Mexico., Objectives: This study aims to provide a comprehensive assessment of the economic implications of lead exposure on Mexican children using, for the first time, nationally representative Blood Lead Levels (BLLs) measurements in children aged 1-4, specifically focusing on the costs of forgone lifetime income due to cognitive losses., Methods: BLLs of children aged 1-4 were extracted from the 2018-2019 National Health and Nutrition Survey (ENSANUT). Estimations of cognitive losses were derived from a log-linear relationship between BLLs and IQ loss. Lost lifetime economic productivity per child was calculated, assuming a 2% reduction in lifetime potential productivity for each IQ point lost due to lead exposure, based on previous literature (Attina and Trasande, 2013; Larsen and Sánchez-Triana, 2023). Productivity data were obtained from representative sources for Mexico., Results: The estimated economic loss amounted to US $33.02 billion, equivalent to 2.76% of Mexico's Gross Domestic Product (GDP) in 2019 (calculated for a 1-year cohort). On a national scale, the long-term loss of cognition for children 1-4 years old is 4.14 IQ points per child due to lead exposure, with significant variability across States (range: 3.26 to 5.26). Lead-poisoned children (≥5 μg/dL) suffered an average loss of 6.42 IQ points (range: 0 to 6.97). In terms of economic impact, some States like Chiapas experienced losses of 7.08% of its GDP, while others had losses as low as 0.67%. Intriguingly, states with lower Human Development Index (HDIs) exhibited relatively higher economic losses despite lower average blood lead levels., Discussion: The heterogeneous impact of lead exposure across Mexican states underscores the necessity for tailored regional policies. These findings emphasize the urgency for targeted interventions and informed policy measures to mitigate the socioeconomic consequences of lead exposure on Mexican children., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Martha M. Tellez-Rojo reports financial support was provided by Pure Earth Blacksmith Institute. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The assessment of the operational stability of biocatalysts by conventional direct determination of the total turnover number (TTN), a useful indicator of lifetime biocatalyst productivity, via continuous isothermal experiments tends to be time‐consuming, material‐intensive, and prone to disturbances, especially in case of rather stable catalysts. In the present work, we present and validate two alternative methods for estimating the TTN of a biocatalyst for any desired operating temperature. The first method is a mechanistic approach, built upon mathematical derivation of enzyme deactivation models derived from first principles, in which TTN can be calculated from two straightforward isothermal biochemical batch measurements. The second method relies on a few non‐isothermal, continuous‐mode experiments in conjunction with mathematical modeling to determine the intrinsic deactivation parameters of the biocatalyst. We verify both methods on the test case of TEM‐1 β‐lactamase‐catalyzed penicillin G (Pen G) hydrolysis. Both alternative methods provide estimates of TTN which are typically within a factor of two to five or less of the values measured directly via lengthy, costly, and error‐prone conventional isothermal aging tests. Therefore, both the mechanistic approach and the non‐isothermal continuous approach are extremely valuable tools to enable calculation of catalyst cost contribution in continuous processing and to eliminate underperforming candidates in search of the most stable biocatalyst. [ABSTRACT FROM AUTHOR]

To determine the optimal voluntary waiting period to first service after calving for maximizing the lifetime productivity of cows in a dairy herd, we simulated the changes in lifetime productivity due to increasing the number of days from calving to first service. We also assessed the effects of changes in the maximum number of ser- vices within a lactation, maximum number of calvings, and calf sale prices on lifetime productivity. We evaluated lifetime productivity as lifetime average productivity, that is, the sum of daily revenues from milk and calf sales from first calving to culling. The lifetime productivity at ≤65 days to first service was low because of the low concep- tion rate during early lactation. In addition, lifetime productivity at ≥185 days to first service decreased as the number of days to first service increased. The number of days to first service for maximum lifetime productivity decreased as the maximum number of calvings increased. Furthermore, the decrease in lifetime productivity associated with decreasing the maximum number of services within a lactation from five to four was greater than that when the maximum number of calvings was decreased from six to five. [ABSTRACT FROM AUTHOR]

The retrospective analysis involved 562 Holstein cows, 545 Ukrainian Black-and-White dairy cows and 100 Ukrainian Red-and-White dairy cows in Breeding Station Terezyne, Kyiv region. The influence of age at first calving and first lactation milk yield on the duration and efficiency of the productive lifespan of cows was studied. The results showed that with the increase of age at first calving from less than 22 to more than 34 months there was a steady tendency to reduction in the longevity and lifetime productivity of cows. There was found a statistically significant (P <0.001) inverse correlation between the age at first calving and indicators of duration and efficiency of productive lifespan (r = –0.177…–0.459). The age at first calving determines 3.0–21.2% of the phenotypic variability of the considered indicators of duration and efficiency of the productive lifespan of cows (P <0.001). According to the set of features, the most rational is the planning of age at first calving before 26 months, i.e. heifers need to be served before 15 months of age. With the first lactation milk yield increases and the duration and efficiency of the productive lifespan of cows increase curvilinearly. Higher longevity is typical for cows with an average 305-d milk yield in the first lactation of 6 001–8 000 kg, and higher lifetime productivity – with the highest milk yield in the first lactation (over 9 000 kg). There was found a relatively low positive correlation between 305-d milk yield in the first lactation and the parity and lifespan (r = 0.087…0.164, P <0.001) and a moderately significant relationship – with lifetime productivity and lifetime daily milk yield (r = 0.327…0.504, P <0.001). The milk yield of primiparous cows has a relatively low impact on the variability of lifespan, productive lifetime and total lactation length (ηx² = 3.6–5.6%, P <0.001) and a higher impact on the indicators of lifetime milk productivity and milk productivity per one day of life, productive lifetime and lactation (ηx² = 12.5–35.6%, P <0.001). The productive lifespan of cows with first lactation milk yield over 6 000 kg can be considered quite effective. [ABSTRACT FROM AUTHOR]

An abbreviated history of genetic evaluation in Merinos demonstrates the remarkable changes that have occurred over the past 50 years. The amount of information available from an increasing number of studs adopting detailed measurement and recording is enormous and much effort has been directed at encouraging selection practices in studs on the basis of this information. In the past we have relied on genetic gains made in the ram breeding sector to be transferred on average to ram buyers, after a lag, for the benefit of the industry. But ram buyers can markedly influence their productivity by being active participants in genetic evaluation rather than relying on gains trickling down on average from ram breeders. Strategies for commercial producers involving choice of ram breeder(s), effective use of breeding values for ram purchases, and on-farm selection and management in the commercial flock are canvassed. [ABSTRACT FROM AUTHOR]

Comprehensive cow-calf production data was utilized to evaluate the impact of dam age on lifetime productivity of Angus replacement beef females. Cows used in this study were commercial Angus replacement females born between 2006 and 2020, ranging in age from 1 to 14-yr of age (n = 3568). To determine the impact of dam age on lifetime productivity, cows were classified by age groups, specifically 2-, 3-, 4-, 5-, 6/7-, and 8-yrs old and older. The 8-yr and older group consisted of females that were up to 14-yr of age. Cow BW at breeding exhibited a cow age × dam age interaction (p < 0.01). Cows at 5-yrs of age from 2-yr old dams weighed less at breeding than cows at 5-yrs of age from 3-, 4-, 5- and 8-years and older dams, with cows at 5-yr of age from 6/7-yr old dams being intermediate. The probability of remaining in the herd at the age of 5 was significant for dam age (p = 0.05) averaging 69.41%, but after further delineation, no significant impacts of dam age were observed. Productivity as a measure of total pounds of calf weaned through 5-yrs displayed a dam age effect (p = 0.01) with cows from 8-yrs or older dams weaning more total pounds of calf, than cows from 3-yr-old dams. In summary, the impact of dam age on lifetime productivity indicates that dam age can impact future productivity of their offspring.

The influence of the genotype for the Holstein breed on the longevity and life-long productivity of black-and-white cows was studied, and the intensity and reasons for the retirement of animals from the herd were analyzed. For this purpose, in the conditions of the breeding farm of the CJSC "Konstantinovo" of the Penza region, two groups were formed from the number of retired animals: group I with a blood content of the Holstein breed of less than 75% and group II with a blood content of more than 75%. As a result of the studies, it was found that the lifetime productivity of cows in group I was 24908 kg, which is 3816 kg higher than that of cows in the second group (P>0.95). The indicator of the period of economic use of cows was also higher in animals with a blood content of less than 75% for the Holstein breed - 4.58 units versus 3.66 in cows with a blood content of more than 75% (P> 0.99). According to the analysis of the reasons for cow retirement, depending on bloodiness, it was revealed that with blood content in the Holstein breed of less than 75%, the highest dropout rate is low productivity and udder diseases; if the blood in the Holstein breed is more than 75%, the largest dropout rate is leg diseases and other reasons. [ABSTRACT FROM AUTHOR]

A total of 1338 high-yielding cows with five lactations from a large well-managed commercial dairy operation in a hot environment of northern Mexico were used to evaluate milk yield and reproductive performance of cows undergoing unplanned extended lactations (EL; > 450 days). The null hypothesis that cumulative milk yield during five consecutive lactations is the same in cows not having unplanned EL and cows with several EL was tested. All EL resulted from cows failing to become pregnant with ≥ 4 services. Cows were allocated to 1 of 6 groups according to the number of EL (EL0 for cows with no EL to EL5 for cows with 5 EL). Cumulative milk yield was highest (P < 0.01) for EL5 cows (95,499 kg) and lowest for EL0 cows (56,236 kg). Likewise, cumulative days in milk were greatest (P < 0.01) in EL5 (2968 days) and lowest in EL0 (1857 days) cows. Mean milk yield per lactation increased linearly with the increase in the number of extended lactations with a maximum of 19,099 kg of milk/lactation for EL5 cows. Mean daily milk yield/productive life was lowest (P < 0.01) for EL0 (30.2 kg) and highest for EL5 (32.1 kg). The percentage of days in milk relative to days from birth to the end of the fifth lactation was highest for EL5 (78.1%) and lowest for EL0 (59.6%), with EL2 to EL4 cows intermediate. Length of calving interval was longest (P < 0.01) for EL5 (24.7 months) and shortest for EL0 (15.5 months) cows. It was concluded that it is worthwhile maintaining high-yielding cows incapable to conceive before 230 days in milk because they did conceive again and produced considerable amounts of milk during their productive life, which substantially prolonged their permanence time in the herd. [ABSTRACT FROM AUTHOR]

Evaluation of lifetime productivity of individual animals in response to various interventions allows assessment of long-term investment opportunities for farmers. In order to gain a better understanding of promising feed interventions for improvement of small ruminant production in Southwestern Nigeria, a dynamic modelling approach was used to explore the effect of different feeding strategies on the lifetime productivity of West African Dwarf (WAD) goats. Modifications were made to the current version of Livestock Simulator developed for cattle production to simulate goat production systems particularly for WAD goats. Effects of changes in input parameters (quality of feed and potential adult weight) confirmed the sensitivity of the modelled weight development and reproductive performance. The values of simulated model outputs corresponded well with observed values for most of the variables, except for the pre-weaning mortality rate in the cut-and-carry system where a wide discrepancy between simulated (2.1%) and observed (23%) data was found. The scenario analysis showed that simulated goats in the free grazing system attained sexual maturity and kidded much later than those in the grazing with supplementation and the cut-and-carry systems. The simulated results suggested that goats require supplementation with protein and energy sources, in order to promote lifetime productivity, early sexual maturity and higher birth weight. In terms of economic returns based on feed cost alone, the moderately intense system produced the most profit. We therefore conclude that grazing with adequate supplementation using farm-generated feed resources offers an opportunity for improving smallholder goat production systems in West Africa.

The Chokla sheep, renowned as the finest carpet wool producer of India, plays an important role in supporting the rural economy of the arid and semi-arid regions of its native state of Rajasthan. This study was carried out to assess the lifetime reproductive efficiency of Chokla ewes by analyzing the records of 1,001 ewes bearing 3,541 lambs over a period of 22 years (1994–2016) to assess five traits, namely total lambs born (TLB; 3.38±0.11 lambs), total lambs weaned (TLW; 2.97±0.11 lambs), cumulative lamb weights at birth (TLBW; 9.59±0.37 kg), weaning (TLWW; 39.59±1.68 kg) and 12 months of age (TLAW; 50.15±2.51 kg) produced by an ewe in her lifetime. Period of birth of ewe had a significant effect on all the traits whereas season of birth, inbreeding coefficient and birth weight of ewe had no influence. REML procedures were employed to estimate the genetic parameters through an animal model. Analysis revealed low heritability estimates for the lifetime reproductive traits (TLB; 0.06±0.04, TLW; 0.05±0.04, TLBW; 0.09±0.05, TLWW; 0.05±0.04 and TLAW; 0.02±0.04), suggesting greater role of environmental and managemental factors. Positive correlation among cumulative lamb weights (0.51–0.92) suggested selection for birth weights would result in higher weights at subsequent life stages of lambs. The low heritability estimates and high CV% for all the traits suggest the suitability of a management focussed approach for improvement of lifetime reproductive performance of ewes.

Copyright of Canadian Journal of Animal Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Animal Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Breeding and lactation efficiencies (BE and LE), parity-wise production profile, productive herd life and lifetime milk production (LTMP) of Gir cows (N=309), based on 1363 calvings during 1991 to 2010 at Cattle Breeding Farm, JAU, Junagadh were studied. Age at first calving (AFC) and calving interval (CI) of Gir cows were 1527.76±14.17 and 481.22±4.86 days, respectively. CI ranged from 386 to 505 days among different lactations. When AFC and CI were taken into account together, BE of the cows as per Tomar (BE-T) was estimated to be 86.91±0.49 %. About 17 % of Gir cows in the herd calved for the first time at <42 months of age (Av. 37.04 month) and 38 % of the cows had less than 14 months of CI. Lactation period (LP) of Gir cows varied significantly (P<0.05) from 230 days to 335 days showing an increasing trend with increase in no. of parity. Overall LP of Gir cows was 281.02±4.56 days, LE being 61.07±1.10%. Total lactation milk yield (TLMY) and standard lactation milk yield (SLMY) of Gir cows averaged 2006.29±48.77 and 1819.73±45.44 lit, respectively. Milk yield increased significantly (P<0.05), with increase in no. of parity, reaching peak TLMY (2425 lit) and SLMY (2303 lit) in 5th lactation. TLMY was 2134 to 2362 lit, and SLMY 1950 to 2110 lit in 6th to 8th lactation. Productive herd life averaged 3107.87±81.40 days (8.51 years). Mean number of calvings during lifetime was 4.25±0.15. A total of 19- 25 % of the total cows performed in the herd for more than 12 years, (average being 14.6 years) and for > 6 lactations. Gir cows produced 9988.71±649.08 lit LTMP. LTMP of Gir cows was significantly associated with both, the BE and LE (r =0.23 to 0.25). MSLMY showed significant (P<0.05) correlation (r=0.31 to 0.37) with BE-W and LE. Association of AFC was significant with BE-T (r=0.26). The 1st and 2nd CI showed a correlation (r= 0.57 to 0.59, P<0.01) of high magnitude with BE-W. The findings revealed that Gir cows in the herd are worth- retaining in the herd till 8th lactation with satisfactory breeding efficiency of about 87 % for economically viable sustainable dairy farming. [ABSTRACT FROM AUTHOR]

Evaluation of lifetime productivity of individual animals in response to various interventions allows assessment of long-term investment opportunities for farmers. In order to gain a better understanding of promising feed interventions for improvement of small ruminant production in Southwestern Nigeria, a dynamic modelling approach was used to explore the effect of different feeding strategies on the lifetime productivity of West African Dwarf (WAD) goats. Modifications were made to the current version of Livestock Simulator developed for cattle production to simulate goat production systems particularly for WAD goats. Effects of changes in input parameters (quality of feed and potential adult weight) confirmed the sensitivity of the modelled weight development and reproductive performance. The values of simulated model outputs corresponded well with observed values for most of the variables, except for the pre-weaning mortality rate in the cut-and-carry system where a wide discrepancy between simulated (2.1%) and observed (23%) data was found. The scenario analysis showed that simulated goats in the free grazing system attained sexual maturity and kidded much later than those in the grazing with supplementation and the cut-and-carry systems. The simulated results suggested that goats require supplementation with protein and energy sources, in order to promote lifetime productivity, early sexual maturity and higher birth weight. In terms of economic returns based on feed cost alone, the moderately intense system produced the most profit. We therefore conclude that grazing with adequate supplementation using farm-generated feed resources offers an opportunity for improving smallholder goat production systems in West Africa. [ABSTRACT FROM PUBLISHER]

Nutritional and environmental factors have been shown to cause epigenetic changes that influence characteristics of the offspring throughout life. In livestock, small differences in nutrition during gestation may alter lifetime production efficiency of offspring. Therefore, the potential for fetal programing should be considered when determining supplemental feeding strategies during gestation. For example, female offspring born to cows grazing dormant winter pasture supplemented with 1.1 kg/d of alfalfa hay during the last third of gestation were 10 kg heavier and had greater BCS at 5 yr of age than those from dams supplemented with 1.8 kg/d of alfalfa hay. These differences were beneficial for maintaining reproductive performance in offspring managed with fewer harvested feed inputs. Evaluation of female offspring from cows wintered on either low-quality or high-quality pasture for 30 to 45 d during the fifth to sixth month of gestation indicated a trend for longer duration of productivity in daughters from cows wintered on improved pasture. In recent studies comparing offspring from cows with or without protein supplementation while grazing dormant winter range during late gestation, heifers from proteinsupplemented dams had greater BW at weaning. This BW increase persisted throughout pregnancy and to subsequent calving, and pregnancy rates were greater in heifers from protein-supplemented dams. Heifers from protein-supplemented dams had lower G:F compared with heifers from unsupplemented dams. Therefore, in utero exposure to nutritionally limited environments (nonsupplemented dams) may promote greater feed efficiency in the heifer offspring later in life. Nutrition during postweaning development may also affect lifetime productivity. Heifers developed on low-quality native range with RUP supplementation had greater retention beyond 3 yr of age than cohorts developed in a feedlot with higher quality feed and greater ADG. Collectively, these examples show nutritional management strategies used during gestation and development may influence lifetime productivity. [ABSTRACT FROM AUTHOR]

The Yaroslavl region is a highly developed agricultural region of the Russian Federation. The level of milk production and the duration of the economic use of animals are the basics of success of leading dairy cattle breeding. These are indicators of biological and economical. Create of highly productive herds and increasing the span of the economic use of animals and lifetime productivity are the necessary goals of the intensification of dairy farming of the region. Therefore, the aim of our research was to determine the influence of milk yield during the first lactation on the controlled productivity signs and duration of the economic use of Yaroslavl breed of cows and its hybrids with Holstein. For statistical data have used the procedure generalized linear models (GLM) while in determining the strength of the influencing factor MATLAB 2000. Likewise, the assessment of phenotypic variability was performed using the multivariate analysis of variance. Our study has revealed that occur dependence between controlled signs and the factor milk yield during the first lactation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Many opportunities exist to reduce enteric methane (CH4) and other greenhouse gas (GHG) emissions per unit of product from ruminant livestock. Research over the past century in genetics, animal health, microbiology, nutrition, and physiology has led to improvements in dairy production where intensively managed farms have GHG emissions as low as 1 kg of CO2 equivalents (CO2e)/kg of energy-corrected milk (ECM), compared with >7 kg of CO2e/kg of ECM in extensive systems. The objectives of this review are to evaluate options that have been demonstrated to mitigate enteric CH4 emissions per unit of ECM (CH4/ECM) from dairy cattle on a quantitative basis and in a sustained manner and to integrate approaches in genetics, feeding and nutrition, physiology, and health to emphasize why herd productivity, not individual animal productivity, is important to environmental sustainability. A nutrition model based on carbohydrate digestion was used to evaluate the effect of feeding and nutrition strategies on CH4/ECM, and a meta-analysis was conducted to quantify the effects of lipid supplementation on CH4/ECM. A second model combining herd structure dynamics and production level was used to estimate the effect of genetic and management strategies that increase milk yield and reduce culling on CH4/ECM. Some of these approaches discussed require further research, but many could be implemented now. Past efforts in CH4 mitigation have largely focused on identifying and evaluating CH4 mitigation approaches based on nutrition, feeding, and modifications of rumen function. Nutrition and feeding approaches may be able to reduce CH4/ECM by 2.5 to 15%, whereas rumen modifiers have had very little success in terms of sustained CH4 reductions without compromising milk production. More significant reductions of 15 to 30% CH4/ECM can be achieved by combinations of genetic and management approaches, including improvements in heat abatement, disease and fertility management, performance-enhancing technologies, and facility design to increase feed efficiency and life-time productivity of individual animals and herds. Many of the approaches discussed are only partially additive, and all approaches to reducing enteric CH4 emissions should consider the economic impacts on farm profitability and the relationships between enteric CH4 and other GHG. [ABSTRACT FROM AUTHOR]

This study evaluated female lifetime productivity in a swine integration system of Brazil that combines segregated gilt development units called fourth sites (4S) and sow farms (SF). Records of 5,013 culled females from 3 4S and 10 SF were evaluated. The most frequent culling reasons were locomotor problems, in 4S, and litter performance, in SF. Days in herd at culling were 71.8 ± 0.8 in 4S. In SF, parity at culling was 4.4 ± 0.1; the lowest number of pigs born during lifetime (33.5 ± 1.1) was for females culled due to reproductive failures and the lowest number of pigs born per year of lifetime (22.8 ± 0.3) was for sows culled due to litter performance ( P < 0.05). [ABSTRACT FROM AUTHOR]

The objective of this study was to obtain heritability estimates for longevity (length of life, length of productive life, number of litters) and lifetime productivity traits (lifetime pig production, lifetime pig efficiency, lifetime litter efficiency) and genetic correlation between them and litter size at first farrowing, growth ( ADG), backfat thickness ( BF), loin depth, lean meat percentage ( LMP), phenotypic selection index ( PSI), and exterior in 19423 Polish Landrace (L) and 16049 Polish Large White ( LW) sows. Heritabilities for longevity and lifetime productivity traits were 0.10-0.13 for L sows and 0.09-0.11 for LW sows depending on the trait definition. The genetic correlations among these traits were all high and positive, ranging from 0.76 to 0.99. Antagonistic genetic correlations (−0.21 to −0.26) were found between longevity traits and PSI and LMP in LW sows, while in L sows the respective parameters were lower and not significant for length of productive life. The number of live-born piglets in the first litter was positively correlated with lifetime pig production and lifetime pig efficiency in both breeds. The genetic correlations of longevity and lifetime pig production with ADG, BF, loin depth and exterior were small, and in most cases, not significant. [ABSTRACT FROM AUTHOR]

To determine the optimal voluntary waiting period to first service after calving for maximizing the lifetime productivity of cows in a dairy herd, we simulated the changes in lifetime productivity due to increasing the number of days from calving to first service. We also assessed the effects of changes in the maximum number of services within a lactation, maximum number of calvings, and calf sale prices on lifetime productivity. We evaluated lifetime productivity as lifetime average productivity, that is, the sum of daily revenues from milk and calf sales from first calving to culling. The lifetime productivity at ≤65 days to first service was low because of the low conception rate during early lactation. In addition, lifetime productivity at ≥185 days to first service decreased as the number of days to first service increased. The number of days to first service for maximum lifetime productivity decreased as the maximum number of calvings increased. Furthermore, the decrease in lifetime productivity associated with decreasing the maximum number of services within a lactation from five to four was greater than that when the maximum number of calvings was decreased from six to five., (© 2022 Japanese Society of Animal Science.)

Presents abstracts of studies on swine species. "Gilt Selection For Improved Lifetime Productivity," by J.L. Patterson, G.R. Foxcroft, M.J. Pettitt and E. Beltranena; "Efficient Sows Are Good Mothers," by R. Bergsma; "Comparison of Different Measures of Carcass Composition and Lean Growth in Swine," by D.W. Newcom, K.J. Stalder and G.F. Jones.

Presents abstracts of studies on swine species. "Gilt Selection For Improved Lifetime Productivity," by J.L. Patterson, G.R. Foxcroft, M.J. Pettitt and E. Beltranena; "Efficient Sows Are Good Mothers," by R. Bergsma; "Comparison of Different Measures of Carcass Composition and Lean Growth in Swine," by D.W. Newcom, K.J. Stalder and G.F. Jones.

Presents abstracts of studies on swine species. "Gilt Selection For Improved Lifetime Productivity," by J.L. Patterson, G.R. Foxcroft, M.J. Pettitt and E. Beltranena; "Efficient Sows Are Good Mothers," by R. Bergsma; "Comparison of Different Measures of Carcass Composition and Lean Growth in Swine," by D.W. Newcom, K.J. Stalder and G.F. Jones.

Objective: To quantify the economic effects of a child conceived by in vitro fertilization (IVF) in terms of net tax revenue from the state's perspective in Greece., Methods: Based on previous international experience, a mathematical model was developed to assess the lifetime productivity of a single individual and his/her lifetime transactions with governmental agencies. The model distinguished among three periods in the economic life cycle of an individual: (1) early life, when the government primarily contributes resources through child tax credits, health care, and educational expenses; (2) employment, when individuals begin returning resources through taxes; and (3) retirement, when the government expends additional resources on pensions and health care. The cost of a live birth with IVF was based on the modification of a previously published model developed by the authors. All outcomes were discounted at a 3% discount rate. The data inputs - namely, the economic or demographic variables - were derived from the National Statistical Secretariat of Greece and other relevant sources. To deal with uncertainty, bias-corrected uncertainty intervals (UIs) were calculated based on 5000 Monte Carlo simulations. In addition, to examine the robustness of our results, other one-way sensitivity analyses were also employed., Results: The cost of IVF per birth was estimated at €17,015 (95% UI: €13,932-€20,200). The average projected income generated by an individual throughout his/her productive life was €258,070 (95% UI: €185,376-€339,831). In addition, his/her life tax contribution was estimated at €133,947 (95% UI: €100,126-€177,375), while the discounted governmental expenses for elderly and underage individuals were €67,624 (95% UI: €55,211-€83,930). Hence, the net present value of IVF was €60,435 (95% UI: €33,651-€94,330), representing a 182% net return on investment. Results remained constant under various assumptions for the main model parameters., Conclusion: State-funded IVF may represent good value for money in the Greek setting, since it has positive tax benefits for the government, notwithstanding its beneficial psychological effect on infertile couples.