Association between gestation length and lactation performance, lactation curve, calf birth weight and dystocia in Holstein dairy cows in Iran

Abstract

In this study, 252,798 lactations on 108,077 cows in 433 herds were used to determine the association between gestation length (GL) and lactation performance, lactation curve, calf birth weight and dystocia in Holstein dairy cows in Iran. The GL averaged 278.1 ± 5.41 d, was categorized as short (SGL; at 1 SD below the population mean), average (AGL; the population mean ± 1 SD), or long (LGL; at least 1 SD above the population mean). Factors including parity, calf gender and calving season were associated with the GL. Primiparous cows with SGL had less lactation performance than those with longer GL; however, there was no difference between those with AGL and LGL. Multiparous cows with longer GL always had more partial and 305-d lactation performance. Primiparous cows with SGL produced less milk at the beginning of lactation and at the peak than those with AGL or LGL; inverse trends were found for lactation persistency, upward and downward slopes of the lactation curve. Within multiparous, a direct relationship was found between GL and the peak yield, where cows with longer GL always produced more milk at the peak. Multiparous cows with SGL produced less milk at the beginning of lactation, reached their peaks later, had higher lactation persistency and showed a lower upward slope of lactation curve than those with AGL orLGL. There was a direct relationship between GL and calf birth weight, where cows with longer GL had calves with more weight at the birth. Within primiparous, cows with SGL had the lowest and those with LGL had the highest rate of dystocia. However, multiparous cows with AGL had a lower rate of dystocia than those with SGL or LGL. Although there was a direct relationship between GL and lactation performance, intermediate GL seems optimal when considering dystocia.

The effect of extended lactation on parameters of Wood’s model of lactation curve in dairy Simmental cows

“…The differences reported in other studies may be explained by different breeds and farming conditions. Different values of peak yield and day of peak was described by many authors [1,2,5,7,14]. 37 % of the total milk yield) was produced in the period between 306 and 547 days.…”

“…Czech dairy Simmental cattle belongs to the family of dual-purpose breeds of the phylogenetic group of "Simmental type breed" as well as other breeds derived from Simmental cattle such as Fleckvieh, Montbé liarde and Pezzata Rossa. The description of lactation curve is still current in livestock research and was analysed by many authors [1,2,3].…”

Calf-Sex Influence in Bovine Milk Production

“…Recently, Atashi and Asaadi [77], using 252,798 lactations on 108,077 Holstein dairy cows in Iran showed that multiparous cows with longer gestations performed better in lactation than primiparous cows. This study also showed that multiparous cows with short gestation length had a lower yield at the beginning of lactation and higher raising and declining slopes of the lactation curve compared with cows presenting longer or average length of pregnancy.…”

“…It is also known that there is a higher frequency of dystocia in male calves' birth [60,74,79]. Dystocia significantly reduces the whole lactation milk yield [40,50,54,69,[75][76][77], besides increasing veterinary treatment costs [76], and reducing cow fertility. After dystocia there is a higher incidence of metritis [77], ketosis [80,81], both associated with a decrease in milk production.…”

“…Dystocia significantly reduces the whole lactation milk yield [40,50,54,69,[75][76][77], besides increasing veterinary treatment costs [76], and reducing cow fertility. After dystocia there is a higher incidence of metritis [77], ketosis [80,81], both associated with a decrease in milk production. Also, an easy calving presumably leads to a higher milk production because it is associated with reduced stress and pain during calving, consequently leading to a lower energy imbalance that can cause more metabolic disorders [41].…”