Effect of Calf Gender on Milk Yield and Fatty Acid Content in Holstein Dairy Cows

Abstract

The scale of sexed semen use to avoid the birth of unwanted bull calves in the UK dairy industry depends on several economic factors. It has been suggested in other studies that calf gender may affect milk yield in Holsteins- something that would affect the economics of sexed semen use. The present study used a large milk recording data set to evaluate the effect of calf gender (both calf born and calf in utero) on both milk yield and saturated fat content. Linear regression was used to model data for first lactation and second lactation separately. Results showed that giving birth to a heifer calf conferred a 1% milk yield advantage in first lactation heifers, whilst giving birth to a bull calf conferred a 0.5% advantage in second lactation. Heifer calves were also associated with a 0.66kg reduction in saturated fatty acid content of milk in first lactation, but there was no significant difference between the genders in second lactation. No relationship was found between calf gender and milk mono- or polyunsaturated fatty acid content. The observed effects of calf gender on both yield and saturated fatty acid content was considered minor when compared to nutritional and genetic influences.

Bias of Calf Sex on Milk Yield and Fat Yield in Holstein Crossbreed Cows

“…Additionally, in several other studies [ 11 , 26 , 30 , 31 ], mothers of female offspring also had higher milk yield, but these differences compared to the male sex differed depending on lactation order or cattle breed. Studies conducted by some of the researchers [ 10 ] also indicate slightly higher milk production in mother cows that calved female calves during four consecutive lactations.…”

“…The above authors suggest that the sex of the calf in utero affects the endocrine control of mammogenesis. It is generally accepted that prolactin and placental lactogens play an important role in mammogenesis and lactogenesis [ 22 , 23 , 24 , 25 , 26 ]. Prolactin, growth hormone, and placental lactogens form a group of structurally linked hormones, which probably evolved from a peptide that belonged to a common ancestor.…”

Calf-Sex Influence in Bovine Milk Production

“…Moreover, the sex of the fetus gestated on the first parity has persistent consequences for milk synthesis on the subsequent parity. Contrastingly, Gillespie et al [57] did not detect a significant effect of the sex of the calf being gestated on the mother milk production. Dallago et al [55].…”

“…According to the same study, the milk composition was similar whether the gestation produced a gestation of a son or daughter; the fat concentration was 3.61% after gestation of a daughter and 3.62% after gestation of a son; protein concentrations were the same (3.17%) [1]. Gillespie et al [57] also showed that, in the UK, calving a heifer was associated with a 1% milk yield advantage in first lactation heifers, but calving a bull calf conferred a 0.5% advantage in second lactation. Heifer calves were also associated with a 0.66 kg reduction in saturated fatty acid content of milk in first lactation, even though there was no significant difference between genders in the second lactation.…”

“…The use of sorted semen in dairy industry screws the gender ratios into the female sex, seeking the production of future genetically superior replacement animals. Under the sex-biased milk production framework, and according to some studies [1,41,57], it would be expected to observe an increase in milk yield in cows that calved a female in their first and eventually in the second parity. This effect would overcome any negative effects exerted by the calving of a larger male fetus (increasing the stress over nutrients partitioning between the fetus and the mother during pregnancy, and increasing the risk for dystocia) and variations in pregnancy length.…”