INVITED REVIEW: Nutritional and management factors that influence colostrum production and composition in dairy cows

Colostrum is a rich source of nutritional and non-nutritional components and is recognized as essential to transfer passive immunity to newborn calves. Because of the individual and seasonal variability in colostrum yield and composition, maintaining an adequate supply of high-quality colostrum year-round remains a challenge for commercial dairy producers. In this narrative review, we described the individual, seasonal, and herd-level variability of colostrum production and summarized the association between individual animal factors such as parity, sex of the calf, calf birth weight, as well as indicators of the cow's metabolic status and the yield and composition of colostrum. Further, we reviewed the current knowledge on the influence of prepartum nutrition and management strategies on colostrum production. Research on the metabolizable energy and protein supplied in the prepartum diet as well as into the inclusion and source of vitamins, minerals, and feed additives suggests prepartum nutrition influences the yield, quality, and composition of colostrum. Furthermore, the prepartum environment and dry period length remain influential factors in the production of colostrum. However, additional research is needed to understand the mechanisms by which prepartum nutrition and management affects colostrum production. Lastly, time to colostrum harvest and oxytocin administration as well as the current knowledge on the effect of heat-treatment and colostrum storage strategies on colostral components were discussed. To conclude, we identify critical gaps in knowledge for future focus of investigation in colostrum research.

Effects of altering prepartum and postpartum dietary cation-anion difference on calcium concentrations and blood metabolites of Holstein dairy cows

We determined effects of pre- and postpartum dietary cation-anion difference (DCAD) on urine pH, serum calcium and hormone concentrations, and milk production with 48 multiparous Holstein cows (average body weight = 706 ± 7.3 kg). Treatments were 3 prepartum DCAD concentrations (0, -100, or -180 mEq/kg dry matter [DM]) and 2 postpartum DCAD concentrations (+250 or +350 mEq/kg DM) starting 29 days before parturition through 90 days in milk. Prepartum urine pH was lower (p < 0.05) for -180 than for -100 or 0 DCAD, and postpartum urine pH was higher (p < 0.05) for +350 than for +250 DCAD. Prepartum serum total and ionized calcium and hydroxyproline were greater (p < 0.05) for -180 than for -100 and 0 DCAD, whereas parathyroid hormone was greater (p < 0.05) for 0 than for -100 and -180 DCAD. After calving, negative prepartum DCAD increased (p < 0.05) serum total and ionized calcium, but effects varied by sampling day. Pre- and postpartum DCAD did not affect milk yield or milk fat, but milk protein percent and total solids were increased (p < 0.05) by negative prepartum DCAD. Feeding an acidogenic diet prepartum improved postpartum calcium status without major effects on milk yield and composition.

Associations between the metabolic status of the cow and colostrum quality as determined by Brix refractometry

Supplying newborn calves with immunoglobins is critical for their health and a daily challenge in the dairy industry. Among various factors determining colostrum quality, the prepartum metabolic status of the cow might be of particular importance. The objective of this observational cross-sectional study was to evaluate relationships between cow-level variables and the colostrum quality as determined by Brix refractometry. A total of 873 cows of varying breed and parity from 124 German dairy herds were included in the study, and blood and urine samples were taken 3 to 1 wk before the expected calving date. Effectively, samples were collected on average 8.2 d (geometric mean) before calving, ranging from 2 to 45 d. The final variable set included body condition score, lameness score, breed, parity, vaccination of the cow, the activity of glutamate dehydrogenase and aspartate aminotransferase, the urine concentration of creatinine, net acid-base excretion, the serum concentration of cholesterol and calcium, and the difference in albumin and total protein concentration. Generalized linear mixed effects regression models with hierarchically structured random effects (cow within herd) using the maximum likelihood method were fitted to the data to identify associations between the Brix value as an outcome and cow-level variables as predictors. Cows entering second parity had lower Brix values compared with cows entering third or greater parity, and prepartum vaccination of cows led to higher Brix values compared with nonvaccinated cows. Cows with a moderate to high lameness score had lower Brix values than cows with low-grade lameness. An increase of glutamate dehydrogenase serum activity and serum calcium concentration were associated with lower Brix values, whereas an increase in the difference of total protein and albumin serum concentration led to higher Brix values. In conclusion, the metabolic health of the cow affects colostrum quality and may cause failure of passive immunoglobulin transfer as well as impaired calf health.

Effects of maternal level of dietary cation-anion difference fed to prepartum nulliparous cows on offspring acid-base balance, metabolism, and growth

The objectives were to determine the effects of dietary cation-anion difference (DCAD) fed to pregnant cows during the last 22 d of gestation on offspring acid-base balance, metabolism, growth, and health preweaning. A total of 132 nulliparous Holstein cows were enrolled at 250 (248 to 253) d of gestation in a randomized block design. Cows were blocked by genomic merit of energy-corrected milk yield and assigned randomly to diets varying in DCAD: +200 (P200, n = 43), -50 (N50, n = 45), or -150 (N150, n = 44) mEq/kg of dry matter (DM). Newborn calves (15 males and 28 females in P200, 22 males and 23 females in N50, and 18 males and 26 females in N150) were followed for the first 7 or 56 d of age if males or females, respectively. Measures of acid-base balance and concentrations of minerals in blood were measured in all calves on d 0 before colostrum feeding, and on d 1, 3, and 7. Each calf was fed 3.78 L of colostrum from the respective treatment, and apparent efficiency of IgG absorption was determined. All calves were weighed at birth, and females were weighed again at 21, 42, and 56 d of age. Concentrations in serum of total calcium (tCa), total magnesium (tMg), and total phosphorus (tP) were measured up to 56 d of age; intakes of milk and starter grain DM were measured daily from 21 to 56 d of age; and incidence of disease was recorded for the first 56 d of age in females. Treatment did not affect acid-base balance measured in all calves. Calves were born with metabolic and respiratory acidosis, which reversed by 1 d of age. In the first 24 h after birth, blood pH increased from 7.215 to 7.421 and bicarbonate from 26.2 to 31.7 mM, whereas partial pressure of CO₂ decreased from 64.1 to 48.7 mm of Hg in all treatments. Maternal DCAD did not affect colostrum IgG content fed to calves (P200 = 95.0 vs. N50 = 91.0 vs. N150 = 97.1 ± 4.1 g/L) or apparent efficiency of IgG absorption (P200 = 33.1 vs. N50 = 33.1 vs. N150 = 34.2 ± 1.9%). Males were born heavier than females, but maternal DCAD did not affect birth weight of all calves (P200 = 37.7 vs. N50 = 37.3 vs. N150 = 37.8 ± 0.7 kg) or daily weight gain in females in the first 56 d of life (P200 = 0.80 vs. N50 = 0.81 vs. N150 = 0.77 ± 0.03 kg/d). Treatment did not affect intake of milk (P200 = 1.11 vs. N50 = 1.04 vs. N150 = 1.19 ± 0.06 kg/d) or starter grain DM (P200 = 0.27 vs. N50 = 0.27 vs. N150 = 0.21 ± 0.06 kg/d), or measures of feed efficiency. Treatment did not affect concentrations of minerals in serum, morbidity, or age at morbidity. Manipulating the DCAD of pregnant nulliparous dams during late gestation did not affect offspring performance in the first 2 mo of age.

Impact of a Ration Negative in Dietary Cation-Anion Difference and Varying Calcium Supply Fed before Calving on Colostrum Quality of the Dams and Health Status and Growth Performance of the Calves

Simple Summary

We fed diets with low and high levels of calcium or a negative dietary cation–anion difference (DCAD) to dairy cows before calving and compared their colostrum quality and the health and growth performance of their calves. There were no differences in birth weight and colostrum quantity and composition among groups. However, calves born to cows fed a diet with a negative DCAD had lower body weight and higher prevalence for diarrhea before weaning. The level of Ca in the diet of the dams before calving had no impact on the body weight, feed intake, and health of the calves.

Abstract

This study investigated the effect of diets negative in dietary cation–anion difference (DCAD) or restricted in Ca fed prepartum to dairy cows for three weeks on colostrum yield and composition, and the health and growth performance of their calves. Thirty-six pregnant non-lactating Holstein-Friesian cows were randomly assigned to three isoenergetic diets: (1) low Ca: 0.24% Ca, DCAD: +86 mEq/kg; (2) high Ca: 1.23% Ca, DCAD: +95 mEq/kg; and (3) low DCAD: 1.28% Ca, DCAD: −115 mEq/kg (all dry matter (DM) basis). While colostrum quality was not affected, low Ca supply prepartum tended to increase the colostrum yield compared to high Ca (low Ca = 8.81 vs. high Ca = 5.39 kg). However, calves from cows fed low DCAD showed higher serum concentrations of K, lower body weight (BW), starter feed intake and average daily weight gain before weaning compared to low Ca and high Ca calves (53.12 vs. 57.68 and 57.32 kg) but BW was similar postweaning (d 70). In addition, calves from dams fed low DCAD were more likely to develop diarrhea and had increased number of days with abnormal fecal scores. Consequently, calves from low DCAD dams had to be treated more frequently.

Negative dietary cation-anion difference and amount of calcium in prepartum diets: Effects on milk production, blood calcium, and health

Acidogenic prepartum diets with negative dietary cation-anion difference (DCAD) induce compensated metabolic acidosis, which stimulates calcium (Ca) mobilization before calving and decreases clinical and subclinical hypocalcemia postpartum. This strategy is often combined with limiting dietary Ca concentrations, which historically has been used to mobilize Ca prepartum to prepare cows for lactation. Supplemental dietary Ca in combination with a negative DCAD formulation that does not reverse the effect of compensated metabolic acidosis may be beneficial. Our objective was to determine the effects of prepartum dietary strategies on dry matter intake (DMI), milk production, peripartal Ca status, and health during the transition period in multiparous Holstein cows (n = 81). Treatments during the last 28 d before calving were: (1) positive DCAD diet, +6 mEq/100 g of DM, target urine pH >7.5, low dietary Ca (0.40% DM; CON); (2) negative DCAD diet, -24 mEq/100 g of DM, target urine pH 5.5 to 6.0, low dietary Ca (0.40% DM; ND); or (3) negative DCAD diet, -24 mEq/100 g of DM, target urine pH 5.5 to 6.0, , high dietary Ca (2.0% DM; NDCA). Preplanned treatment contrasts were: (1) CON versus (ND and NDCA), and (2) ND versus NDCA. Individual DMI were recorded daily. Cows were milked 3 times daily, with individual DMI and milk yield summarized by week. Whole blood sampled at calving and 24 h, 48 h, and 4 d after calving was analyzed for ionized Ca concentration, and serum was analyzed for total Ca. Prepartum urine pH for cows fed ND or NDCA averaged 5.7, whereas cows fed CON remained >7.5. During the 3 wk before calving, cows fed CON had greater DMI than cows fed ND or NDCA, with NDCA greater than ND. Postpartum DMI (% of body weight) tended to be less for cows fed CON than for those fed ND or NDCA prepartum. Thresholds for subclinical hypocalcemia were ionized Ca <1.0 mM at 24 h, and total Ca ≤2.125 mM at 48 h after calving. On average, blood Ca for cows fed CON indicated subclinical hypocalcemia, whereas blood Ca for cows fed ND or NDCA was greater than subclinical hypocalcemia thresholds for both ionized Ca and total Ca. No milk production differences were detected. Cows fed CON had an elevated adverse health score (calculated by assigning numerical values to recorded health events) and tended to have an elevated somatic cell count during the fresh period compared with cows fed ND or NDCA. Overall, an acidogenic diet prepartum without or with high Ca improved postpartum Ca status and health. Supplementation of additional Ca to the acidogenic diet had little effect.

Symposium review: Late-gestation maternal factors affecting the health and development of dairy calves

Efficient production of heifers is fundamental to the productivity and sustainability of dairy farms. However, high preweaning morbidity and mortality rates are frequently reported worldwide, imposing substantial welfare and economic implications. A major contributing factor to disease susceptibility in the neonatal stage is the inability of calves to mount an effective immune response. Appreciation is now greater that exposure in utero to several stresses (nutritional, social, metabolic, and so on) during the last stages of pregnancy have downstream carryover effects in calves' health, growth, and development. Suboptimal intrauterine conditions during critical periods of development lead to changes in tissue structure and function that may have long-term consequences on the offspring's physiology and disease susceptibility. Indeed, preweaning metabolic function and growth are associated with future milk production. Thus, late-gestation carryover effects span into the lactating stage of the heifers. Nevertheless, researchers have been studying how to minimize these effects. This review will discuss the effects of maternal stress during late gestation on the offspring's growth, productivity, metabolism, and health. In addition, strategies focusing on maternal interventions that improve neonatal health will be discussed. A better understanding of the intrauterine conditions affecting calf health and growth may facilitate the design of management practices that could improve neonatal development and future cow productivity.