Effects of parity order on performance, metabolic, and hormonal parameters of grazing beef cows during pre-calving and lactation periods

Effects of transport age (14 versus 28 days of age) on blood total cholesterol, insulin, and insulin-like growth factor-1 concentrations of veal calves

The main aim of the current study was to find biomarkers of health in calves transported at different ages. The selected blood parameters were total cholesterol, insulin, and IGF-1, and the longitudinal study investigated whether or not these concentrations were different between calves that were transported from the dairy farm to the veal farm at 14 or 28 d of age. Relationships between these blood variables and health characteristics of veal calves were investigated. In a 34-wk study period, a total of 683 calves originating from 13 Dutch dairy farms were transported at an age of 14 or 28 d to 8 Dutch veal farms. Calves were blood sampled the first week after birth (mean and SD: 4.4 ± 2.1 d), 1 d before transport (mean and SD: 25.8 ± 7.3 d), and in wk 2 post-transport (mean and SD: 36.7 ± 12.2 d). In these samples, insulin, IGF-1, and total cholesterol were determined and analyzed with a linear mixed model (LMM). Individual medical treatments were recorded from birth until the day of transport at the dairy farm, and from the moment of arrival at the veal farm until slaughter, and analyzed as a binary response variable (calf treated or not) with a generalized LMM. Fecal (calf with or without loose or liquid manure) and navel (calves with or without swollen and inflamed navel) scores measured during a single visit in wk 2 post-transport were also analyzed as binary response variables, whereas carcass weights at slaughter age were analyzed with a LMM. Cholesterol, insulin, and IGF-1 were included as covariates in the previous models to test their relationships with the likelihood of calves being medically treated, fecal and navel scores, and carcass weights. One day before transport 28-d-old calves had higher blood cholesterol (Δ = 0.40 mmol/L) and IGF-1 (Δ = 53.6 ng/mL) concentrations, and evidence of higher insulin (Δ = 12.2 µU/mL) compared with 14-d-old calves. In wk 2 post-transport, 28-d-old calves had higher blood IGF-1 (Δ = 21.1 ng/mL), with evidence of higher insulin (Δ = 12.2 µU/mL) concentrations compared with 14-d-old calves. Cholesterol concentration measured 1 d before transport and in wk 2 post-transport had a positive relationship with carcass weight at slaughter (regression coefficients [β] = 4.8 and 7.7 kg/mmol per liter, respectively). Blood cholesterol concentration in wk 2 post-transport was negatively associated with the fecal score measured at the same sampling moment (β = -0.55/mmol/L), with the likelihood of a calf of being treated with antibiotics (β = -0.36/mmol/L) and other medicines (β = -0.45/mmol/L) at the veal farm. Blood IGF-1 concentration in wk 2 post-transport was negatively associated with the likelihood of a calf of being treated with antibiotics and other medicines (both β = -0.01/ng/mL) at the veal farm, and with fecal score recorded in wk 2 post-transport (β = -0.004/ng/mL). When looking at the blood indicators, it appeared that calves transported at 28 d of age were more developed compared with 14-d-old calves, thus transport at an older age might be more beneficial for the animals. It can be concluded that both blood cholesterol and IGF-1 concentrations seemed to be valuable biomarkers of health and energy availability in veal calves.

Performance and metabolic evaluation in primiparous beef cows under grazing at different breeding ages

We aimed to evaluate the metabolic and performance differences in primiparous Nellore cows, which became pregnant at 14 or 24-mo old. Thirty-eight cows with 202 ± 5 days of gestation were divided into two treatments according to breeding age: 14 or 24-mo. Cows were evaluated for body weight (BW), body condition score (BCS), carcass characteristics, milk yield, calves's performance, and blood characteristics. The animals were managed in eight paddocks under continuous grazing and evaluated from 90 d before parturition until 240 d after calving. We observed an interaction between breeding age and time (P < 0.01) for cow BW. Both breeding age categories experienced BW loss during parturition, with a concurrent decrease in BCS. However, following their first calving, the BW of 24-mo cows remained stable (P > 0.05), whereas 14-mo cows exhibited a gradual recovery in BW after parturition (P < 0.05). Milk yield was greater in 24-mo animals (P < 0.01), but decreased with increasing milking days (p < 0.05) for both groups. The weight gain calves from the heifers bred at 24-mo was greater (P < 0.01), which reflected in greater BW at weaning. The beta-hydroxybutyrate (β-OHB) concentration was greater before calving and a marked decrease after parturition (P < 0.05). The 24-mo cows had greater blood β-OHB (P < 0.01) at prepartum and 30 days after calving. Blood progesterone was greater in 24-mo cows (P > 0.05). Primiparous beef cows that conceive at either 14 or 24-months of age exhibit distinct nutritional requirements and metabolic profiles. Notably, cows that conceive at 24-months of age have the advantage of weaning heavier calves and displaying a more consistent reproductive cycle following their first calving than cows that conceive at 14-months.

Influence of proportion of Brahman genetics on productivity of Brahman-Angus cows at weaning

This study evaluated the association between the proportion of Brahman genetics and productivity of Brahman-Angus cows at weaning using a 31-yr dataset containing 6,312 cows and 5,405 pregnancies. Cows were contemporaneously reared and enrolled in yearly breeding seasons under subtropical conditions of North-Central Florida. They were evenly distributed in six-breed groups (G) according to the proportion of Brahman genetics: G0% to 19%, G21% to 34%, G38% (Brangus), G41% to 59%, G63% to 78%, and G81% to 100%. The proportion of cows calving (84.9%) did not differ across the six-breed groups. However, cows in the G81% to 100% weaned fewer calves (90.8%) than cows in the G0% to 19% and G21% to 34% (95.7%, each). The weaning rate of cows in the G38% (94.3%), G41% to 59% (94.2%), and G63% to 78% (93.0%) was intermediate between these three breed groups. The preweaning calf mortality was greater for cows in the G81% to 100% (9.2%) than cows in the G0% to 19% and G21% to 34% (4.3%, each), but intermediate for cows in the G38% (5.7%), G41% to 59% (5.8%), and G63% to 78% (7.0%). Cows in the G81% to 100% also weaned lighter calves (220.6 kg) than cows in the G0% to 19% (245.2 kg), G21% to 34% (250.2 kg), G38% (247.9 kg), G41% to 59% (252.5 kg), and G63% to 78% (245.2 kg). Cows in the G0% to 19% weaned lighter calves than cows with 21% to 78% of Brahman genetics. The 205-d adjusted weaning weight evidenced the less productive results of cows in G0% to 19% and G81% to 100% compared with other genetic groups, as they calved at the fastest and slowest rate, respectively. Thus, the 205-d adjusted weaning weight eliminated this bias. Additionally, younger cows weaned lighter calves; and male calves were heavier at weaning than female calves. Both parity order of cow and calf sex altered the magnitude of the described association between breed group of cows and calf weaning weights. Overall, after adjusting for weaning rate and age of calves at weaning, the number of kilograms produced per cow submitted to reproduction was less for cows in the G0% to 19% (191.1 kg) and G81% to 100 (181.8 kg) compared with cows in the G21% to 34 (197.0 kg), G38 (195.9 kg), G41% to 59 (199.7), and G63% to 78 (196.2). Cows in the G81% to 100% were the least productive. Thus, a proportion of Brahman genetics between 21% and 78% ensured superior productivity of Brahman-Angus cows subjected to subtropical conditions.

The curse of the firstborn: Effects of dam primiparity on developmental programming in ruminant offspring

The first parity, or first pregnancy, of ruminant females has negative effects on offspring during fetal, perinatal, and pre-weaning periods which ultimately lead to diminished pre-weaning productivity. Offspring born to primiparous ruminant females can have decreased fetal and pre-weaning growth, resulting in lower body weights at birth and weaning in cattle, sheep, and goats. Moreover, mortality is greater during both neonatal and pre-weaning periods. Insults during these critical developmental windows likely also have long-term consequences on first-parity offspring through developmental programming, but less research has been done to investigate effects in the post-weaning period. Many potential physiological, metabolic, and behavioral mechanisms exist for the outcomes of dam primiparity. Although competition for nutrient partitioning between maternal and fetal growth or lactation is often cited as a major contributor, we hypothesize that the most important mechanism causing most first-parity outcomes is the relative physiological inexperience of reproductive tissues such as the uterus and mammary gland during the first pregnancy and lactation, or a "first use theory" of tissues. More research is necessary to explore these areas, as well as if primiparous dams respond differently to stressors than multiparous dams, and if stress during the first parity affects subsequent parities.

Does Parity Influence the Magnitude of the Stress Response of Nellore Cows at Weaning?

Most studies investigate the impact of stress at weaning on calves; however, little is known about the responses of cows, and whether they would differ according to parity. This study aims to investigate whether parity would influence the weaning stress response in beef cows. Thirty pregnant Nellore cows with their respective calves were randomly allocated to five paddocks and two females from each parity group were placed in the paddocks. There was an interaction (p < 0.05) between parity and evaluation days regarding cortisol, where on d + 7, the higher concentration was observed for multiparous cows. There was an interaction (p < 0.05) between parity and evaluation day for red blood cells (RBC), hematocrit (HCT), and hemoglobin (HB), whereby higher RBC counts on d + 4 were observed for multiparous cows. For HCT and HB, on all post-weaning collection days, higher values were observed for multiparous cows. The day of evaluation had an (p < 0.05) effect on all recorded behaviors, except for rumination (p > 0.05). Nellore cows, regardless of parity, underwent behavioral and physiological changes on abrupt weaning. Physiological parameters indicated that the magnitude of stress was greater in multiparous cows.

Metabolic Profiling in Ruminant Diagnostics

A herd-based approach and interpretative perspective is necessary in using metabolic profile testing in contrast to individual animal disease diagnostics. Metabolic profile testing requires formulating a question to be answered, followed by the appropriate selection of animals for testing. A range of blood analytes and nutrients can be determined with newer biomarkers being developed. Sample collection and handling and herd-based reference criteria adjusted to time relative to parturition are critical for interpretation. The objective of this article is to review the concepts and practical applications of metabolic profile testing in ruminants.

Impact of age at first calving on performance traits in Irish beef herds

Reducing age at first calving (AFC) has been a challenge in beef herds. There is anecdotal evidence that herd owners choose to calve heifers older because of the perceived consequences of calving heifers at 24 mo of age compared to 36 mo on performance traits in beef herds. The objective of this study was to estimate the association of calving heifers at younger ages on subsequent performance traits, calving interval, longevity, cow weight, dystocia, and progeny weaning weight for parities 1 to 5. Available to the study after data edits were 219,818 calving interval records, 219,818 longevity records, 118,504 cow live-weight records, 230,998 dystocia records, and 230,998 weaning weight records. Linear mixed models were used to quantify performance of each trait in AFC groups for each parity. As parity increased, there was a favorable reduction in calving interval and dystocia (P < 0.001), while the likelihood of cows surviving reduced (P < 0.001). Both cow live weight and progeny weaning weight increased as parity increased. Age at first calving only had a significant association with dystocia within parity 1 (P < 0.001), where older heifers at first calving subsequently had lower risk of calving. Calving interval for parity 1 cows was observed to be longer by 6 d in cows that calved for the first time at 33 to 36 mo compared to cows calved for the first time at 22 to 24 mo (P < 0.001). No statistical difference was observed for longevity between cows with an AFC of 22 to 24 mo compared to cows with an AFC of 33 to 36 mo (P > 0.05). Cows that calved at a younger age did wean lighter calves for their first three lactations (P < 0.01) but had no association with weaning weight for parity 4 and 5 cows (P > 0.05). Cows with a lower AFC were lighter for parity 1 to 4 (P < 0.001); at parity 5, AFC had no association with cow live weight (P > 0.05). The performance of mature cows for calving interval, longevity, calving difficulty, cow live weight, and weaning weight was not impacted by AFC. In conclusion, calving cows for the first time at younger ages do pose risks and associated performance loss but this risk and loss should be minimized by good management.

Effects of Parity and Stage of Lactation on Trend and Variability of Metabolic Markers in Dairy Cows

Simple Summary

The rise in milk yield per cow, herd size, and the percentage of primiparous cows in dairy herds increasingly requires optimized health management in order to ensure the health of the cows. The transition period (three weeks before to three weeks after calving) has a key role in health problems, because dairy cows undergo tremendous metabolic changes. Metabolic monitoring provides an in-depth insight into how the cows cope with these challenges. A remarkable variability in the metabolic parameters reflects the adaptation of dairy cows during the transition from pregnancy to lactation. In addition, primiparous cows undergo physical adaptations because of growth, first gestation, the maturation of the mammary glands, the onset of lactation, and fighting for social dominance. Previous studies have rarely considered these specific demands due to the influences of parity and the lactation stage. Thus, the objective of our study was to describe the variation in metabolic parameters due to parity and the stage of lactation based on a huge number of primiparous and multiparous cows, observed at all stages of lactation, in a retrospective analysis of laboratory data. The remarkable impact of both parity and lactation was elucidated for most parameters. This should be taken into account for a correct interpretation of the laboratory diagnostics in the framework of metabolic monitoring.

Abstract

Metabolic monitoring is a tool that is helpful with the increasing requirements regarding feeding and health management in dairy herds. This study aimed at describing the trend and variability of different biochemical parameters in blood and urine in relation to the stages of lactation and parity, in a retrospective analysis of laboratory data from clinically healthy German Holstein cows. The results were derived from metabolic monitoring in Thuringia (Germany), during 2009–2019. A total of 361,584 measured values, of 13 different metabolic variables, were assigned to parity (primiparous and multiparous) and stage of lactation (10 classes from −30 to 300 days in milk). The Kruskal–Wallis test was applied for the evaluation of differences regarding parity or the stage of lactation. Non-esterified fatty acids, beta hydroxybutyrate, and the activity of aspartate aminotransferase in serum were clearly affected by parity and lactation. Serum concentrations of cholesterol, bilirubin, and phosphorus, as well as the serum activity of glutamate dehydrogenase, were affected by the stage of lactation, while parity impacted urea concentration. The serum activity of creatine kinase, serum concentrations of calcium, and urine concentrations of net acid base excretion, potassium, and sodium were not affected by parity or lactation. In conclusion, specific reference limits, with respect to parity and the stage of lactation, are necessary.

Evaluation of Non-linear Models to Predict Potential Milk Yield of Beef Cows According to Parity Order Under Grazing

This study aimed to evaluate the effect of parity order on milk yield (MY) and composition over time of grazing beef cows and to evaluate non-linear models to describe the lactation curve. Thirty-six pregnant Nellore cows (12 nulliparous, 2 years; 12 primiparous, 3 years; and 12 multiparous, 4-6 years) were included in the study. With calving day assigned as day 0, milking was performed using a milking machine to estimate MY on days 7, 14, 21, 42, 63, 91, 119, 154, and 203. Dummy variable analyses were applied to estimate its effects on MY, composition (kg and percentage), afternoon/morning, and afternoon/total proportions. Since multiparous cows had higher MY than nulliparous and primiparous cows, two different groups were used for lactation curve analysis: Mult (multiparous) and Null/Prim (nulliparous and primiparous). The MY estimated by the last edition of BR-Corte (Nutrient Requirements of Zebu and Crossbred Cattle) equation was compared with the observed values from this study. Five nonlinear models proposed by Wood (WD), Jenkins & Ferrell (JF), Wilmink (WK), Henriques (HR) and Cobby & Le Du (CL) were evaluated. Models were validated using an independent dataset of multiparous and primiparous cows. The estimates for parameters a, b, and c of the CL equation were compared between groups, and the BR-Corte equation used the model identity methodology. Nulliparous and primiparous cows displayed similar MY (P > 0.05); however, multiparous cows had an average MY that is 0.70 kg/day greater than that of nulliparous and primiparous cows (P < 0.05). Milk protein and total solids were higher for multiparous cows (P < 0.05). Effect of days in milking was found for milk fat, protein, and total solids (P < 0.05). The yield of all milk components was higher for multiparous cows than for nulliparous and primiparous cows. The afternoon/morning and afternoon/total proportions of milk production were not affected by parities and days in milking (P > 0.05), with an average of 0.76 and 0.42, respectively. The BR-Corte equation did not correctly estimate the MY (P < 0.05). The equations of WD, WK, and CL had the best estimate of MY for both Mult and Null/Prim datasets. The equations had a very similar Akaike's information criterion with correction and mean square error of prediction.