Effects Of Ovariectomy On Growth And Meat Quality Of The Doe Kids

The blood growth axis hormones, biochemical indicators, immunity levels and musclequality indicators of the ovariectomized doe kids were detemined in this study in order toexplore the effects of ovariectomy on growth, healthy and meat quality to the doe kids. Theresults were as follows:1.40similar body weight(20.30±3.64kg)F1hybrid doe kids of Boer Goats♂×Guanzhongdairy goats♀at the same age of5-month-old were randomly divided into treatment and controlgroup under the conditions of stall-feeding throughout the whole test, which included pre-test(15d) and formal test (50d). The doe kids of the treatment group were ovariectomized at thebeginning of the test, but the control group were not done. The two group doe kids were weighedand their venous blood were collected in the morning at days1,10,20,30,40and50after test.The serum were separated from blood samples to determine the growth hormone (GH) levels,serum somatostatin (SS) levels, and serum insulin-like growth factor (IGF) levels. The resultsshowed that the average daily gain of the treatment group was128g, which was13g higher thanthe control group(p＜0.05). The total weight gain of the treatment group was6.41kg at day50,which was0.67kg higher than the control group (p＜0.05). The serum GH levels of the treatmentgroup had been an upward trend from the twentieth day, and the level was significant higher thanthe control group(p＜0.05), and the levels was11.55ug/L at50th day, which was2.21ug/L higherthan the control group. The serum SS levels of the treatment group was28.99ng/L at10th day,and it was significant lower than the control group(p＜0.05), and it had been a low level sincethen. But the control group had maintained a stable level. There was no difference for serum IGFlevels between the two groups during the test. It showed that the serum GH secretion could bepromoted and the serum SS secretion could inhibited by ovariectomy, there was the effect that thegrowth rate of the doe kids was been promoted.2. The serum urea nitrogen, glucose, creatinine, triglycerides and cholesterol of the twogroups doe kids were determined. The results showed that the serum urea nitrogen levels ofboth groups increased at day10(p＜0.05). Two groups triglycerides levels were bothincreased slightly at day20, but there was no significant difference(p＞0.05).The glucose, creatinine and cholesterol all did not change, and there were no significant differencesbetween the two groups. This showed that the ovariectomy was ineffective on these indicatorsof the doe kids.3. The serum IgG levels and the serum SOD activity of the two groups were determined. Theresults showed that the serum IgG levels of two groups had been maintained stability duringduring the whole test, and it also showed that there was no difference between the two groups.The serum SOD activity at the day0～10was relatively low, but it rose to a higher level at thetwentieth day and the level had been kept until the last day, and there was no significantdifferences between groups. Thus, the health status and immunity of the doe kids were notaffected by ovariectomy.4. Each five doe kids from the two groups were selected randomly to slaughter at the endof the test. The production performances of meat were determined. The results showed thatthe carcass weight of the treatment group was12.85±0.64kg, which was1.62kg higher thanthe control group(p＜0.05). The net meat weight of the treatment group was10.36±0.58kg,which was1.37kg higher than the control group(p＜0.05). The dressing percentage of thetreatment group was45.62%,but the control group was42.41%, and there were significantdifferences between them(p＜0.05). The lean percentage of the treatment group was36.42%,but the control group was34.81%, and there were significant differences between them(p＜0.05). The average of the eye muscle area of the treatment group was9.32cm~2, which was0.27cm~2higher than the control group. There was no significant difference on meat color, pHvalue, water holding capacity, cooking loss, crude protein and crude ash between the twogroups. But the crude fat of the treatment group was6.71%,which was3.34%higher than thecontrol group. The muscle shear force value of the treatment group was61.38kg/cm~2,whichwas significant lower than the control group(74.16kg/cm~2)(P<0.05). These results indicatedthat the carcass weight, dressing percentage, lean percentage, eye muscle area and meattenderness of the doe kids could been improved significantly by ovariectomy.