| Abstrakt: |
The objectives of this study were to examine the effects of gender and breed type on performance, feed efficiency, and feeding behavior traits in growing goats. The trial was conducted with 36 intact male (n = 16) and female (n = 20) goats of 4 breed types;12 purebred Spanish, 12 F1 Spanish x Boer (dam-sire), 8 F1 Boer x Spanish, and 4 purebred Boer. Goats with initial BW of 30.9 ± 6.0 kg and 38.8 ± 7.4 kg for females and males, respectively, were fed a concentrate diet in pens equipped with electronic feed bunks (GrowSafe System). Individual dry matter intake (DMI) and feeding behavior traits were collected daily for 44 d and BW measured weekly. Residual feed intake (RFI) was calculated as the residual from the regression of DMI on ADG and mid-test BW0.75. Feeding behavior traits evaluated were frequency and duration of bunk visit (BV) events, head-down (HD) duration, BV eating rate (BVER), and day-to-day variation of these traits, defined as the root mean squared error (RMSE) from linear regression of each trait on the day of trial. A mixed model (JMP) with fixed effects of gender, breed type, and gender x breed type interaction with pen as a random effect was used. Gender x breed type interactions were not significant for any traits. Male goats had heavier (P <0.01) initial and final BW, but similar ADG during the trial. Male goats consumed more (P <0.05) DMI, but had similar F:G and RFI compared with female goats. Gender did not affect feeding behavior traits, but male goats had greater BVER and more (P <0.05) day-to-day variation in DMI than female goats. Purebred Boer goats had heavier (P <0.05) initial and final BW and greater ADG than purebred Spanish and both F1 crosses. However, DMI and RFI were not affected by breed type. G:F was greater (P <0.05) in Boer and Boer x Spanish goats (0.183, 0.153) than Spanish goats (0.115), with Spanish x Boer (0.132) goats being intermediate. Breed type did not affect feeding behavior traits in this trial. Minimal effects of gender and breed type on feed efficiency were detected in growing goats in this trial. Further research is warranted to examine effects of breed type on life-cycle feed efficiency including growing goats and female goats during pregnancy and lactation. |
