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

Abstract

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 × 10 5 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 deliv-ering 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.

Determination of the reproductive characteristics of Saanen goats using estrus synchronization and the growth performances of kids

“…The data of reproductive characteristics of Saanen goats were presented in Table 1. In the present study, litter size was similar to the results of other studies using Saanen goat breeds of Australian origin in Turkey (9,20). This value is higher than the data of other studies (4,6,8,12,14,16,17,19) conducted with goats that were stated to be Saanen goats but which origin is unknown.…”

Caracterización de la curva de lactancia y rendimiento en cabras Saanen de un tambo de la provincia de Buenos Aires, Argentina

“…Estos promedios están muy por encima de nuestros resultados para la raza Saanen en Buenos Aires, como lo demuestra la Tabla 2. Los mismos se asemejan a los encontrados por Irano et al (2012) para las razas Alpina y Saanen del sudeste de Brasil con 511,7 kg y 2,4 kg de producción media diaria (ajustado a 211 días de lactancia) y por Zamuner et al (2020) en Australia, que fue 519 ± 7,3 kg para la producción total de leche ajustada 270 días de lactancia. En nuestro trabajo se Steffen et al / FAVE Cs.…”

“…En relación al número de lactancia, la producción de leche aumenta hasta la tercera y cuarta para luego disminuir en las sucesivas lactancias. Este resultado se corrobora con la mayoría de los trabajos encontrados en la literatura sobre cabras lecheras (Soares Filho et al, 2001;Olivier et al, 2005;Mioč et al, 2008;Torres-Vázquez et al, 2010;Bolacali y Küçük, 2012;Irano et al, 2012;Lôbo et al, 2017;Zamuner et al, 2020), en coincidencia con lo observado en nuestro trabajo. En disidencia con Garcés et al (2004), trabajando con cabras Saanen, observaron que las cabras multíparas obtuvieron igual producción lechera que las primíparas.…”

“…En disidencia con Garcés et al (2004), trabajando con cabras Saanen, observaron que las cabras multíparas obtuvieron igual producción lechera que las primíparas. Lôbo et al (2017), Zamuner et al (2020), identificaron una productividad significativamente mayor en los partos múltiples, probablemente la presencia de una directa y estrecha correlación entre la producción de leche y la masa placentaria expresada en gramos, atribuyendo dicho efecto a una correlación positiva entre la cantidad de lactógenos placentarios y el número de fetos (Haydn et al, 1979).…”

“…Además, puede ayudar a identificar animales enfermos antes de que aparezcan signos clínicos, como aquellos animales con producción disminuida de leche por mastitis subclínica (Gipson y Grossman, 1989;Takma et al, 2009). Varios autores concluyeron que la forma de la curva de lactancia se ve afectada por diversos factores, tales como: componente racial o genotipo, la dieta, las condiciones climáticas, el período de lactancia, el año y la época de parto, número y el tipo de parto (Gipson y Grossman, 1989;Gipson y Grossman, 1990;Paz et al, 2007;Salvador y Martínez, 2007;Mioč et al, 2008;Frau et al, 2010;Torres-Vázquez et al, 2010;Irano et al, 2012;Bolacali y Küçük, 2012;Rojo-Rubio et al, 2016;Lôbo et al, 2017;Zamuner et al, 2020).…”