Reproductive response to suckling manipulation in Spanish goats.
One hundred and fifty-six Spanish does were used to evaluate the effect of suckling manipulation on postpartum breeding. Does were divided into four herds dependent upon their kidding dates (range from October to January) and location. All kids were nursed ad libitum for approximately 30 days following birth. Groups were then subdivided, and does with kids were randomly allotted to one of the following treatment groups: 1) continuous suckling (CS), 2) once-daily suckling (ODS) or 3) early weaning (EW). Nonlactating does (NL) which lost a kid or aborted were also evaluated for rebreeding performance. At least one fertile male equipped with a marking harness was placed with each treatment group for estrus detection. After 30 days, ODS kids were returned to their dams. The proportion of does exhibiting estrus within 60 days postpartum was greater for ODS and EW does compared to CS does (P<0.05 and P<0.001, respectively). Postpartum interval to first estrus was shorter (P<0.05) for ODS does than for CS does (41.7 and 48.0 days, respectively). The percentage of does conceiving within 60 days postpartum was 25.0, 44.7, 74.4 and 70.7% for CS, ODS, EW and NL does, respectively. The interval from parturition to conception was shorter (P<0.05) for ODS does (43.6 days) than for CS does (50.4 days). Overall kid production was 1.87 kids/doe/year. These results indicate that reducing the suckling stimulus in Spanish does during the breeding season may result in an earlier return to estrus with a greater percentage of does rebreeding within 60 days postpartum.
Lawson
J L
JL
Department of Animal Science Texas A&M University College Station, Texas 77843 USA; Texas A&M University Agricultural Research Center San Angelo, Texas 76901 USA.
Forrest
D W
DW
Shelton
M
M