Associations between putative risk factors and poor colostrum yield in Holstein Friesian cattle

When dairy cows produce little or no colostrum, calves are likely to suffer from failure of passive transfer (FPT). Volume of colostrum produced by the dam may be affected by: nutrition; environmental conditions; time from calving to milking; parity; dry period length; calving difficulty; calf weight; calf sex; calf viability; cow BCS / body weight; milk production in previous lactation and dam health. While risk factors for poor IgG concentration in colostrum have been extensively studied, there is little published literature on low colostrum yields and associated risk factors. The aim of this observational study was to identify risk factors for poor colostrum yield in dairy cows and to quantify the effect of variation in those variables that the farmer can directly control (length of dry period, and close-up transition period nutrition) using inverse probability modelling. 439 animals from a single Scottish dairy farm were used as a convenience sample. First milking colostrum yield was measured by farmers using a graduated bucket. For each animal, risk factor data and meteorological data from the nearest weather were obtained. Decreased colostrum yield was associated with increasing daily temperature range, while increasing UV index, lactation number and number of days dry increased colostrum yield. Marginal effect models revealed that for each additional day of dry period, colostrum yield increased. Higher UV indices the month before calving were positively associated with colostrum yield, particularly in primiparous cows, and higher temperatures in the months before calving were positively associated with colostrum yield in all cows.

Relative prolactin-to-progesterone concentrations around farrowing influence colostrum yield in primiparous sows

In swine, colostrum production is induced by the drop of progesterone (P4) concentrations which leads to the prepartum peak of prolactin (PRL). PRL regulates mammary cell turnover and stimulates lacteal nutrient synthesis. P4 inhibits PRL secretion and downregulates the PRL receptor in the mammary gland. The aim of the present study was to determine if the relative prepartum concentrations of P4 and PRL (PRL/P4 ratio) influence sow colostrum production. The performance of 29 Landrace × Large White primiparous sows was analyzed. Colostrum yield was estimated during 24 h starting at the onset of parturition (T0) using litter weight gains. Colostrum was collected at T0 and 24 h later (T24). Repeated jugular blood samples were collected during the peripartum period, that is, from -72 to +24 h related to farrowing and were assayed for P4 and PRL. Sows were retrospectively categorized in 2 groups according to their PRL/P4 ratio 24 h before farrowing being either <2 (low PRL/P4, n = 16) or >3 (high PRL/P4, n = 13). During the peripartum period, the circulating concentrations of P4 were lower (P < 0.05) and those of PRL tended to be greater (P < 0.10) in high PRL/P4 compared with low PRL/P4 sows. Colostrum yield was greater in high PRL/P4 compared with low PRL/P4 sows (4.11 vs 3.48 kg [root mean square error = 0.69], P < 0.05). Colostrum composition (dry matter, energy, protein, lipid, and lactose contents) and IgG and IgA concentrations did not differ between the 2 groups of sows (P > 0.10). The Na/K ratio in colostrum 24 h after the onset of farrowing was lower in high PRL/P4 compared with low PRL/P4 sows (P < 0.05). Piglet mortality between birth and T24 averaged 10.0% in low PRL/P4 litters and 7.0% in high PRL/P4 litters (P = 0.29). In conclusion, a greater PRL/P4 ratio 24 h prepartum, characterized by lower P4 concentrations and a trend for greater PRL concentrations peripartum, led to increased colostrum yield in primiparous sows.