Lifetime Milk Production Research Articles

Relationships between age at first calving; herd management criteria; and lifetime milk, fat, and protein production in Holstein cattle

ABSTRACT Data from 69,145 Holstein cows that calved in 2005 were evaluated to determine the influence of age at first calving (AFC) on first lactation and lifetime production in commercial dairy herds. A DHI database was divided into 4 herd management criteria (HMC). The 4 HMC were 1) 3X milking and rolling herd average (RHA) = 12,750 kg (3X-H), 2) 3X milking and RHA = 11,250 kg (3X-M), 3) 2X milking and RHA = 11,250 kg (2X-M), and 4) 2X milking and RHA = 9,250 kg (2X-L). For all HMC, a universal loss in first-lactation milk, fat, and protein yield was observed when AFC was

Association between age at first calving, year and season of first calving and milk production in Holstein cows

The effects of first calving (FC) in Holstein heifers on their first lactation, second lactation and lifetime milk production were examined from an initial database of 459 743 animals that first calved between 1 January 1990 and 31 July 2010 in Wallonia, Belgium. The FC age class (18 to 22, 22 to 26, 26 to 30, 30 to 34, 34 to 38 and 38 to 42 months), the FC season and FC year class (1990 to 1994, 1995 to 1999, 2000 to 2004 and 2005 to 2010) were considered when analysing the first and second lactation data. Lifetime data were similarly analysed, but did not include animals that calved after 2005 because many of them were still lactating. Only 24% of animals had their FC before 26 months of age. Animals that first calved between 22 and 26 months of age had more lactations and productive days during their life. They also had higher first and second lactation milk production and lifetime milk production. Summer or autumn FC improved first lactation, second lactation and lifetime milk production, as well as production per day of lactation, compared with winter or spring FC. Compared with animals that calved for the first time in 1990 to 1994, animals with a FC in 2000 to 2004 had a longer calving interval (0.5 months), fewer lactations per animal (−0.6) and fewer days in their lifetime lactation (a reduction of 144 days). As a result, the animals’ lifetime production did not increase between 1990 to 1994 and 2000 to 2004, although milk production per day of lactation (22.85v. 20.49 l/day) and per day of life (11.49v. 10.78 l/day) improved. Milk fat content was lower in 2000 to 2004 than in 1990 to 1994, but protein content remained relatively constant, probably because of the cows’ higher production level and increased dietary concentrate supplementation.

Prediction of lifetime milk production in synthetic crossbred cattle strain Vrindavani of North India

Ten-year data records on growth (birth weight-BWt), five initially reproductive traits (age at first calving-AFC, first dry period-FSP, first dry period-FDP, first calving interval-FCI and first lactation length-FLL) along with the part lactation records of 100, 170 and 240days of first lactation (my100_1, my170_1 and my240_1) and second lactation (my100_2, my170_2 and my240_2) and their respective total milk yields (total lactation milk yield of first lactation- TLMY1 and total lactation milk yield of second lactation-TLMY2) were used to predict LTMY5 (lifetime milk yield as total milk yield up to 5 lactations) and LTMY4 (lifetime milk yield as total milk yield up to 4 lactations). It was observed that first calving interval (FCI) happens to be important predictor (out of initially expressed growth – birth weight(BWt), reproductive traits- AFC, FSP, FDP, FCI, FLL and first lactation milk traits- my100_1, my170_1, my240_1 and TLMY1) for lifetime prediction (both LTMY4 and LTMY5). Prediction of LTMY4 and LTMY5 with respect to initial growth (birth weight), reproductive traits (AFC, FSP, FDP, FCI, FLL) and first 2 lactations (my100_1, my170_1 my240_1, TLMY1, my100_2, my170_2 my240_2 and TLMY2) indicated the contribution of my240_2 followed by TLMY1 and my170_2. They jointly explained 40.32% variation in estimated value of LTMY4. However, prediction of LTMY5, with respect to these predictors showed my240_2 together with FLL jointly explained 26.71% variation in estimated value.

Influence of age at first lambing on reproductive and productive performance of Lacaune dairy sheep under an intensive management system

The present study investigated the effect of age at first lambing (AFL) on the performance of Lacaune sheep under intensive management conditions. Records from 3088 maiden sheep from one farm, for the period 2005-2010, were classified into four experimental groups: group E (early) ewes with AFL ⩽390 d; group M (middle) with AFL of 391-450 d; group L (late) with AFL of 451-510 d; and group A (aged) with AFL ⩾511 d. The higher the number of lactations, the lower were the yield/lactation and yield/Day in Milk. Ewes from group M up to 450 days old lambed 0.2 times more often and had 0.25 more lactations than the ewes from group L; in addition, the former group lambed 0.5 times more often and had 0.49 more lactations than ewes from group A. Group A had the lowest yield per lifetime; the yield followed the sequence: group E (1032 l) >group M (1051 l) >group L (989 l) > group A (859 l) (P<0.0001). Yield/lactation was affected by AFL during the first three lactations (P<0.05). Group E produced significantly less milk in the first lactation than ewes from groups M, L and A. AFL correlated negatively with the number of lactations in life (r= -0.26; P<0.0001) and with total milk yield (r= -209; P<0.0001). The productive performance between the ewes that reached puberty early (n=404) or late (n=2684) in life were different (P<0.0001) with the early sheep having a lower total milk yield (591 v. 1073 l, P<0.0001). In conclusion, the current study indicates that the optimal AFL for the Lacaune breed under an intensive dairy system is between 390 and 450 d. Ewes with AFL earlier than 390 d or later than 450 d are likely to have a shorter productive life and a lower lifetime milk production.

A prospective study of calf factors affecting first-lactation and lifetime milk production and age of cows when removed from the herd

This prospective study was designed to investigate possible carryover effects of calf management practices and how events occurring during the first 16 wk of life affect first-lactation and lifetime milk production as well as age when animals are removed from production. This is the final of 3 stages in a longitudinal study that encompassed 10 yr of data collection. First, management and nutritional data were collected in the first 16 wk of life. The second part of this study evaluated conditions of animals at the time of first calving as affected by calf management, nutrition, and health. Both of these studies have been previously reported. This third portion covers the same calf effects on lactation performance and age at culling. Observations for the current study were collected from on-farm and Dairy Herd Improvement records. The multiple imputation technique was used in this analysis to avoid bias due to missing data. This study concluded that delivery score, weaning dry matter intake, days of illness before 4 mo, days treated before 4 mo, and body weight at first calving all had significant effects on first-lactation production of Holsteins. Delivery score and grain intake at a young age affected lifetime production. Age at culling was only affected by early grain intake in this study.

Artificial Neural Network versus Multiple Regression Analysis for Prediction of Lifetime Milk Production in Sahiwal Cattle

Gandhi, R.S., Raja, T.V., Ruhil, A.P. and Kumar, A. 2010. Artificial neural network versus multiple regression analysis for prediction of lifetime milk production in Sahiwal cattle. J. Appl. Anim. Res., 38: 233–237. First lactation records (1493) of Sahiwal cows comprising of age at first calving, first lactation 305-d or less milk yield, first lactation length, first service period and first dry period were analyzed to predict the lifetime milk production using multiple regression analysis (MRA) and artificial neural network (ANN). The data was divided into three sets i.e. cows retained in the herd up to first three parities (set I), 4th to 6th parities (set II) and more than 6th parities (set III). The accuracy of prediction of lifetime milk production in MRA was lower than the accuracy of ANN in all the test data sets. Also, the root mean square errors of prediction were lower from ANN in comparison to MRA. Higher estimates of accuracy of prediction of lifetime milk yield from ANN in comparison to MRA in both the data sets revealed that this methodology can be used as an alternate approach to predict lifetime milk production.

Rearing conditions and lifetime milk revenues in Swedish dairy cows

Associations between replacement heifer rearing conditions and lifetime milk revenues were studied throughout the productive life of Swedish dairy cows. Data were collected from 2127 cows, mainly Swedish Reds and Swedish Holsteins, representing all female animals born during 1998 in 110 herds and followed until May 2006. Lifetime net milk revenues were calculated for each cow based on the length of productive life, lifetime milk production, a fixed milk price of 0.3 €/kg ECM, and estimated costs for heifer rearing and cow feed. Median observed productive lifetime to culling, death, selling off or terminated recording was 26.9mo. Mean lifetime production was 9209kg ECM/cow-yr, calculated from monthly test-day yields. Rearing costs (median 631 €) were estimated using a template developed for Swedish advisory services, including costs related to purchase, feeding, labour, building investment, building maintenance and breeding. Net milk revenues had a median of 1169 €/cow-yr during productive life and were heavily skewed. Diarrhea and respiratory disease before 7mo of age had occurred in 11 and 11% of the cows, respectively, the majority cases being mild. The mean prepubertal growth rate was 670g/day. Cow net revenue values were transformed to achieve normality and analysed by a linear mixed model including fixed effects of breed, calf housing system from 3 to 7mo of age, body condition score at 1st breeding, year of 1st calving, age at 1st calving, cow housing system, mean milk cell count, the interaction between calf housing and breed, the interaction between cow housing and breed, and the random effect of herd. The model predicted net revenues to decrease with age at 1st calving and with body condition score at breeding over 4. Our results show that replacement rearing factors influence net milk revenues of a dairy operation and suggest that current recommendations to breed dairy heifers for calving at 24mo are economically justified.

Influence of parity at time of detection of serologic antibodies to Mycobacterium avium subspecies paratuberculosis on reduction in daily and lifetime milk production in Holstein cows1

Mycobacterium avium ssp. paratuberculosis (MAP) is the causative agent of bovine paratuberculosis, also known as Johne's disease. Two production variables (daily and lifetime milk) were compared in this longitudinal study of cows classified based upon serum ELISA results for MAP. The sample included adult Holstein cows that had completed their productive life (n = 2,808 animals) since testing began and that had been raised by and were located on 2 commercial dairies in Texas. These animals were tested at the conclusion of each of their lactations using a commercial ELISA. The serological response was interpreted based on the calculated sample-to-positive value, a quantifiable measure of antibodies, and categorized on both a dichotomous scale [positive (≥0.25) vs. negative] and into 5 classes (negative: 0 to 0.09, suspect: 0.10 to 0.24, low positive: 0.25 to 0.39, positive: 0.40 to 0.99, or strong positive: ≥1.00). All models developed were adjusted for herd, birth (year) cohort, and parity at first MAP test. Based on adjusted comparisons using the dichotomous scale: 1) cows detected as positive during their first parity produced less (P < 0.0001) milk per day of life since first parturition (-1.64 kg/d) and during their lifetime in the herd (-8,704 kg); 2) cows testing positive for the first time during second parity did not produce less per day of life (P > 0.05); however, cows did produce less (P = 0.024) milk overall during their lifetime in the herd, but only when tested for the first time during their second lactation (-4,058 kg); 3) cows testing positive for the first time during third parity did not differ (P > 0.05); and 4) cows testing positive for the first time during their fourth or later parity produced more milk during their lifetime, but only when tested for the first time at third or greater lactation (e.g., 10,602 kg for fourth parity; P = 0.005) compared with their always-negative herd mates tested for the first time in their first lactation. In the adjusted model developed to evaluate milk production losses throughout the lifetime of the animal, when categorizing animals into 5 MAP classes at their first test, suspect animals numerically have reduced production (-1,419 kg; P = 0.162), whereas significant losses occurred in the low positive class (-4,397 kg; P = 0.034) and highly significant losses in the positive (-7,724 kg; P < 0.0001) and strong positive classes (-10,972 kg; P < 0.0001) compared with herd mates testing negative.

Genetic Improvement of Total Milk Yield and Total Lactation Persistency of the First Three Lactations in Dairy Cattle

The objective of this study was to compare 6 selection criteria in terms of 3-parity total milk yield and 9 selection criteria in terms of total net merit (H) comprising 3-parity total milk yield and total lactation persistency. The 6 selection criteria compared were as follows: first-parity milk estimated breeding value (EBV; M1), first 2-parity milk EBV (M2), first 3-parity milk EBV (M3), first-parity eigen index (EI1), first 2-parity eigen index (EI2), and first 3-parity eigen index (EI3). The 9 selection criteria compared in terms of H were M1, M2, M3, EI1, EI2, EI3, and first-parity, first 2-parity, and first 3-parity selection indices (I1, I2, and I3, respectively). In terms of total milk yield, selection on M3 or EI3 achieved the greatest genetic response, whereas selection on EI1 produced the largest genetic progress per day. In terms of total net merit, selection on I3 brought the largest response, whereas selection EI1 yielded the greatest genetic progress per day. A multiple-lactation random regression test-day model simultaneously yields the EBV of the 3 lactations for all animals included in the analysis even though the younger animals do not have the opportunity to complete the first 3 lactations. It is important to use the first 3 lactation EBV for selection decision rather than only the first lactation EBV in spite of the fact that the first-parity selection criteria achieved a faster genetic progress per day than the 3-parity selection criteria. Under a multiple-lactation random regression animal model analysis, the use of the first 3 lactation EBV for selection decision does not prolong the generation interval as compared with the use of only the first lactation EBV. Thus, it is justified to compare genetic response on a lifetime basis rather than on a per-day basis. The results suggest the use of M3 or EI3 for genetic improvement of total milk yield and the use of I3 for genetic improvement of total net merit H. Although this study deals with selection for 3-parity milk production, the same principle applies to selection for lifetime milk production.

Relationships between age at first calving and first lactation milk yield, and lifetime productivity and longevity in dairy cows

Lifetime records of 442 Holstein cows on one farm in North Queensland, Australia, were analysed to evaluate the effects of age at first calving (afc) and first lactation milk yield...

Genetic and Phenotypic Evaluation of Milk and Fat Production Traits and Their Interrelationship in (Zebu×European) Crossbred Cattle Using Parent Group Mixed Model

Data pertained to 335 crossbred cows comprising of 1/2 Friesian (F) + 1/2 Hariana (H), 1/2 F + 1/4 Jersey (J) + 1/4 H, 1/2 F + 1/4 Brown Swiss (BS) + 1/4 H, 1/2 F + 1/4 Red Dane (R) + 1/4 H, FR (I) and FRH (I) genetic groups extending over a period of 21 years (1970-1990) maintained at Animal Farm of CCS HAU, Hisar. The averages for first lactation milk yield was 2,486.24±80.26 kg and peak yield of first three lactation were 11.35±0.72 kg, 13.97±0.60 kg and 16.02±0.42 kg, respectively. The lifetime milk production was observed as 11,305.16±1,004.52 kg in crossbred cattle. The average first lactation fat yield was observed as 102.06±0.01 kg and peak fat yield of first three lactation were 0.458±0.01, 0.490±0.01 and 0.500±0.02 kg, respectively. The lifetime fat production was estimated as 502.31±45.90 kg. LTMP and LTFP had reasonably good additive genetic variance which could be exploited either through mass selection/combined with family or pedigree selection. FLMY, peak yields and LTMP had significant positive phenotypic correlation with FLFY and LTFP and the correlation at the genetic level were also higher and positive for these traits. Finally, peak week milk yield of first lactation (PMY1) was the earliest available trait having desirable and significant correlation at phenotypic and positive at genetic level with FLFY, PFY1 and PFY2, PFY3 and LTFP and selection for this trait will help in early evaluation of sires and dams and will increase genetic advancement per unit of time. (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 9 : 1242-1246)

Relationships of Sire Predicted Transmitting Ability for Somatic Cell Score with Measures of Daughter Performance

The relationship between sire predicted transmitting ability (PTA) for somatic cell score (SCS) and occurrence of mastitis in daughters was characterized with 304 Holsteins first freshening since 1991 in the Virginia Tech dairy herd. No direct sire selection for PTA SCS was practiced in the herd. Linear regressions of first lactation average SCS (1.3), number of cases of mastitis (0.80), days clinical (7.0), and number of treatments for mastitis (2.0) on PTA SCS were significant. Linear regression coefficients for second and third lactations were generally positive, but like quadratic and cubic coefficients in this study, were not significant. Relationship of sire PTA SCS and measures of lifetime (84 mo opportunity) performance were determined for 2,494,195 Holsteins born between 1979 and 1987. Linear coefficients from regression on PTA SCS for number of lactations (−0.31), days of productive life (−87.0), total days in milk (−72.2), lifetime milk (−1609.1), fat (−80.7), and protein (−48.2) production, relative net income adjusted for opportunity cost for fluid markets (+13.47), first lactation average SCS (+1.00), and first lactation mature equivalent milk (+429.9) were different from zero. Partial regressions holding PTA milk or PTA protein constant were substantially larger than linear coefficients. When PTA productive life was held constant, the relationship between PTA SCS and measures of herd life and lifetime yield became positive, and relative net income adjusted for opportunity cost variables became moderately positive. One of the major expenses associated with higher susceptibility (higher PTA SCS) may be shorter herd life.

Mammary involution in dairy animals.

Lifetime milk production is maximized when dairy cows are pregnant during approximately 70% of each lactation. Between lactations, a nonlactating period is necessary for optimal milk production in the succeeding lactation. With cessation of milking, alveolar structure is largely maintained and little or no loss of cells occurs. However, increased apoptosis and cell proliferation, relative to that in lactating glands during the same stage of gestation, suggest that a nonlactating period serves to promote cell turnover prior to the next lactation. Even in the absence of pregnancy, mammary involution in dairy animals occurs at a slower rate than in rodents; alveolar structure is maintained for several weeks and lactation can be reinitiated after four weeks or more of involution. Although apoptosis appears to be initiated within a similar time frame to that in rodents, the maximum proportion of apoptotic epithelial cells appears to be lower than in rodents, and apoptosis may be accompanied by an initial increase in cell proliferation. The ability to manipulate apoptosis and cell proliferation during the nonlactating period and during lactation is expected to provide enormous benefits to the dairy industry.

Epidemiology of Enzootic Pneumonia in Minnesota Dairy Calves

Enzootic calf pneumonia (ECP) is one clinical manifestation of the bovine respiratory disease complex. Enzootic calf pneumonia results from a complex interaction between environmental factors, host factors, and infectious agents. The financial losses that result from ECP occur due to death loss, treatment cost, and decreased lifetime milk production. Calves that have experienced ECP have been shown to be at increased risk of culling once in the milking herd when compared to herdmates of the same age(1). Experimental studies involving the infectious agents themselves have been performed(2-9), as well as retrospective(10-16) and cohort studies(17-22). None of the current epidemiologic research has specifically targeted ECP, either through assessment of ventilation or laboratory sampling to validate morbidity or mortality.

Net Present Value and Economic Merit of Sexed Semen and Splitting Units of Semen for Australian Holsteins

Net present value of an artificial insemination sire was expected profit per semen unit due to genetic improvement for daughter lifetime milk production. Net present values were calculated for top 40 milk evaluation Australian Holstein sires from 4 studs by varying one of conception or survival rates, feed cost, herd production, herd genetic merit, age at first calving or discount rate, holding remaining parameters at population average. Sire transmitting values for mature equivalent milk ranged 62 to 549L and semen price $3.50 to $20. Average of cow transmitting values for mature equivalent milk was −97L. By region, milk was priced $.13 or $.23/L. Selection policy was top 5 sires for net present value with equal semen purchases.As probability of female embryo increased from 50 to 100% at no additional semen cost, average net present value per unit of 5 highest ranked sires increased from $3.41 to $13.43 and from $20.58 to $48.76 for $.13 and $.23/L milk. This represents a scale effect with identical sires selected for $.23/L milk. However, average semen price of selected sires increased from $4.50 to $7.60 for $.13/L milk due to sire reranking.Assuming halved semen price and a .1 decrease in conception rate affecting both net present value and semen requirement, dairy farmers could afford to pay at least an additional $2.19 per whole unit of semen for milk priced $.13/L and $3.50 per whole unit for $.23/L milk if that unit were to be split.

Use of Dairy Herd Improvement Variables to Predict Lifetime Profitability ,

This study was to determine if relative profitability of cows could be predicted accurately from variables available through Dairy Herd Improvement. Lifetime income was calculated from sales of milk and fat, calves produced, and salvage value; lifetime expenses were initial value of the animal, feed, mastitis treatment, breeding, and fixed costs. Methods to estimate total profit and profit per day were relative net income function, calculated from lifetime milk and fat production, age at first calving, number of freshenings, and days of herd life; and best fit regression models with one to four variables. The best fit regression models with one to four variables for predicting total profit from relative net income function variables had squared multiple correlations .76, .94, .95, and .96 compared to .95 for relative net income. The best fit regression models of one to three variables for predicting profit per day yielded .69, .83, and .86 compared to .85 for relative net income per day. The relative net income function was successful for accounting for most differences among cows for profit but was less successful for predicting profit per day. The relative net income function appears to be useful for estimating lifetime profitability for establishing the relative importance of traits measured early in the animal's lifetime.

Genetic and phenotypic parameters of some measures of lifetime production and their relationship with milk yield in the first three lactations in Tharparkar cows

SUMMARYThe genetic parameters of lifetime production traits and their relationship with milk yield in first, second and third lactations were estimated from information on 753 Tharparkar cows. The heritability estimates for milk yield in first, second and third lactations were 0·22 ± 0·10, 0·33 ± 0·14 and 0·49 ± 0·17 and for number of lactations completed, lifetime milk production, number of days in milk and herd life 0·58 ± 0·23, 0·51 ± 0·22, 0·54 ± 0·22 and 0·34 ± 0·20 respectively. The genetic and phenotypic correlations among the four lifetime production traits were in the range of 0·83–1·0 and 0·84–0·85 respectively. The phenotypic correlations of milk yield in first, second and third lactations with lifetime production traits were significant and ranged between 0·15 and 0·56. The corresponding genetic correlations ranged between 0·26 and 0·83. For the first three lactations, the genetic correlations of lifetime traits with the third lactation were high and that between lifetime milk yield and yield in third lactation the highest (0·83 ± 0·17). The direct and correlated responses from single trait selection were also estimated.

Relationships between lifetime milk production, productive life, level of production and a lifetime profit function in cows

Relationships between lifetime milk production, productive life, level of production and a lifetime profit function in cows

Relationships between lifetime milk production, productive life, level of production and a lifetime profit function in cows

Relationships between lifetime milk production, productive life, level of production and a lifetime profit function in cows

Lactational characteristics of imported British Friesian cattle in Western Nigeria

SummaryDuring the period 1962–73, the majority of the 92 lactations of imported British Friesian animals were initiated during the dry season (October–March). The following average values were obtained: lifetime number of lactations, 4·5; lifetime milk production, 9392 kg; age at producing first live calf, 39·6 months; milk yield of nine lactations, 2159 kg; lactation length, 336·5 days; daily milk yield, 6·3 kg; 305-day milk yield, 2012 kg; dry period, 173 days.Milk production was highest in the fourth lactation when the animals averaged 7 years old. Differences in milk yield among lactations were small. Peak daily milk yield was greatest in the third lactation and was reached within the first 21 days of each of the first four lactations. A second but lower peak with the highest milk production persistencies at a later stage of lactation apparently depended on feed availability. The 305-day milk yield was reasonably predicted from the 100- and 200-day yields.Lactations subsequent to abortions and stillbirths were slightly longer, gave less milk (P&gt; 0·05) and were followed by longer dry periods than those initiated by normal births.