Growth and pre-weaning mortality of Katahdin lamb crosses

Abstract

SummaryBackground: Katahdin breed sheep is highly disseminated in Mexico. This breed and its crosses have recently gained attention among sheep producers. However, research with crosses between Katahdin and other meat breeds is limited. Objective: to evaluate the genetic and non-genetic factors affecting growth and mortality rate of crossbred lambs from Katahdin ewes fecundated with breeds specialized for meat production. Methods: crossbred lambs (n = 152) from Katahdin ewes sired with Hampshire (KH; n = 43), Texel (KT; n = 53) or Charolais (KCH; n = 56) were evaluated under intensive management conditions. The effects of genotype and non-genetic factors on birth weight, weaning weight, pre-weaning daily weight gain, and mortality rate were determined. Results: breed differences were not detected for birth weight (4 ± 1.1, 4.3 ± 0.9 and 4 ± 1.1 Kg for KCH, KH, KT, respectively), nor for the 60-d weaning weight (20.2 ± 4.3, 20.9 ± 4.3, 18.2 ± 4.2 Kg for KCH, KH, KT, respectively). Weight of lambs did not differ significantly between sexes, but it decreased (p<0.05) with increased litter size (weaning weight at 60 days for single, twins and triplets was 24.5 ± 2.6, 19.2 ± 3.5, and 14.3 ± 3.8 Kg, respectively). Pre-weaning mortality of KH lambs was 13.3% and it was significantly lower than that of the other genotypes (24.5 and 39.3% for KT and KCH, respectively). Conclusion: inclusion of Charolais, Hampshire or Texel rams in Katahdin flocks results in similar lamb weaning weight, but Hampshire-sired progeny excels regarding pre-weaning survival.

Pre-weaning growth performance and carcass traits of Awassi and Chios-Awassi lambs

“…These results agree with Abdullah & Tabbaa (2011), who found that weaning weight for F 1 Chios-Awassi lambs did not differ from purebred Awassi lambs. However, Mellado et al (2016) reported that crossbred Dorper-Turcana lambs were heavier at weaning than the purebred Turcana lambs. Birth weight is related directly to the genetics and nutrition of the pregnant ewe.…”

Evaluating the relationship between fecal egg count, FAMACHA score, and weight in dewormed and non-dewormed Katahdin rams during a parasite challenge

“…Lambs were raised and observed in 100 flocks across the United States with different management systems that may have introduced greater weight variations than the present forage-based system. Several other studies varying in breed and environment confirm this general trend in body weight in young animals, but vary in magnitude ( Carrillo and Segura, 1993 ; Akpa et al, 2006 ; Stafford et al, 2007 ; Mellado, 2016 ). Some studies propose that birth type primarily influences birth weight and becomes less important as animals age ( Jucá et al, 2016; Pesántez-Pacheco et al, 2019 ).…”

Crecimiento de corderos de pelo en el altiplano semiárido de Zacatecas durante el invierno

“…Al respecto, Bores-Quintero et al (2002) observaron que durante la etapa postdestete la GDP de los machos superó (P<0.05) en 27 % a la GDP de hembras, mientras que De Vargas Junior et al (2014), Schanbacher et al (1980 y Ghafouri-Kesbi y Notter (2016) concluyen que las diferencias en el peso y desarrollo entre los corderos y corderas reflejan la diferencia en el entorno endocrino y requerimientos de nutrientes entre los sexos. Las crías nacidos en parto simple presentaron una mayor tasa de crecimiento pre-destete con respecto a aquellos de parto múltiple, lo cual coincide con lo reportado previamente por Garduño et al (2002), Mellado, et al (2016) y Simeonov et al, (2014. Sin embargo, los corderos de parto múltiple compensaron el menor crecimiento previo al destete y obtuvieron una mayor GDP post-destete para terminar con un peso ajustado a 145 d similar al de los corderos nacidos en parto sencillo.…”