Biomaterial Database

Effects of month of kidding, parity number, and litter size on milk yield of commercial dairy goats in Australia. 2020

F Zamuner, and K DiGiacomo, and A W N Cameron, and B J Leury

Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria 3010, Australia. Electronic address: fzamuner@student.unimelb.edu.au.

The aim of this observational study was to identify the influence of key nongenetic factors such as month of kidding, parity, and litter size on milk yield and composition of Australian dairy goats throughout lactation. The study was conducted over 4 consecutive kidding seasons from June 2016 to March 2017. Data from 940 lactations of Saanen goats from a commercial herd were used to observe the effects of month of kidding, parity number, and litter size on total milk yield (L/goat) in early lactation (kidding to 90 d in milk; DIM), mid lactation (91-180 DIM), and late lactation (181-270 DIM), cumulative milk yield (from kidding to 270 DIM; CMY), average lactation length, proportion (%) of does reaching their target lactation length (270 DIM), somatic cell count (SCC), and percentages of milk fat and protein in early lactation. The mean herd responses throughout the entire study were as follows: CMY = 519 L/goat; lactation length = 233 d, with 70% of does reaching 270 DIM; milk fat = 4.2%; milk protein = 2.9%; and SCC = 6.2 × 105 cells/mL. Average milk production peaked in February and was lowest in June (2.4 vs. 1.8 L/goat per day, respectively). Milk yield was affected by month of kidding, parity number, and litter size in all phases of lactation. November kidders had the greatest CMY, and March kidders had the lowest CMY. March kidders had the shortest lactation length and the lowest proportion of does reaching 270 DIM. June kidders had the longest lactation length, whereas September kidders had the highest proportion of does reaching 270 DIM. Maximum milk yield was attained in third parity. Goats in fourth or greater parity had the shortest lactation length, the lowest proportion of does reaching 270 DIM, and the highest SCC. Goats delivering single kids had lower CMY, lower SCC, and higher percentages of fat and protein than does delivering multiple kids. Our findings indicate that milk yield was primarily influenced by month of kidding, and the effects of month of kidding on milk yield were accentuated during mid lactation. However, the effects of month of kidding on milk yield varied significantly among parities.

UI	MeSH Term	Description	Entries
D007774	Lactation	The processes of milk secretion by the maternal MAMMARY GLANDS after PARTURITION. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including ESTRADIOL; PROGESTERONE; PROLACTIN; and OXYTOCIN.	Lactation, Prolonged,Milk Secretion,Lactations, Prolonged,Milk Secretions,Prolonged Lactation,Prolonged Lactations
D008098	Litter Size	The number of offspring produced at one birth by a viviparous animal.	Litter Sizes,Size, Litter,Sizes, Litter
D008892	Milk	The off-white liquid secreted by the mammary glands of humans and other mammals. It contains proteins, sugar, lipids, vitamins, and minerals.	Cow Milk,Cow's Milk,Milk, Cow,Milk, Cow's
D010298	Parity	The number of offspring a female has borne. It is contrasted with GRAVIDITY, which refers to the number of pregnancies, regardless of outcome.	Multiparity,Nulliparity,Primiparity,Parity Progression Ratio,Parity Progression Ratios,Ratio, Parity Progression,Ratios, Parity Progression
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D005260	Female		Females
D006041	Goats	Any of numerous agile, hollow-horned RUMINANTS of the genus Capra, in the family Bovidae, closely related to the SHEEP.	Capra,Capras,Goat
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001315	Australia	The smallest continent and an independent country, comprising six states and two territories. Its capital is Canberra.	Canton and Enderbury Islands,Christmas Island,Christmas Island (Australia)