牛舍環境調節
（七）熱緊迫影響泌乳量之程度
吾人已知熱緊迫會影響泌乳量，
溫濕度指標（ THI
）值增加，不舒適程度增加，泌乳量減少。Berry
等（ 1964 ）提出的經驗公式允許由 THI
值與正常天候下（ 0 ∼ 21
℃）之泌乳量計算溫度大於21 ℃時，
由於熱緊迫所損失之泌乳量，此公式為美國農業工程師學會收編入其定期出版的標準手冊（
ASAE Standards，1988
）中。以下說明此經驗公式：
MPD = 1.08 - 1.736 NL + 0.02474 (NL) (THI)
其中，MPD:
每日每頭牛之泌乳減少量，公斤／(日頭）
NL :
正常溫濕度狀況下每日每頭牛之泌乳量，公斤／(日頭）
THI: 溫濕度指標，請參考表13a與13b
表 14a，14b 與 14c 分別為 NL 等於 20 公斤／(日頭）、25公斤／(日頭）與
30 公斤／(日頭）時，在溫度超過 21
℃的情況下的 THI 值與 MPD
值。由表中可知，THI
值高時對產乳量高者之影響遠大於產量較少者。
表14a. NL等於20公斤／(日頭）時之THI 與 MPD 值（方，1995）
| 乾球溫度℃ |
相對濕度，% | 平均 |
| 40 | 50 | 60 | 70 | 80 | 90 | 100 |
|---|
| MPD/THI | MPD/THI | MPD/THI | MPD/THI | MPD/THI | MPD/THI | MPD/THI | MPD |
|---|
| 22 | 0.0/66.0 | 0.0/67.2 | 0.1/68.2 | 0.5/69.1 | 0.9/69.8 | 1.2/70.5 | 1.6/71.1 | 0.6 |
|---|
| 24 | 0.3/68.6 | 0.9/69.9 | 1.4/70.9 | 1.9/71.8 | 2.3/72.5 | 2.6/73.2 | 2.9/73.8 | 1.8 |
|---|
| 26 | 1.6/71.3 | 2.3/72.5 | 2.8/73.6 | 3.2/74.5 | 3.6/75.2 | 3.9/75.9 | 4.2/76.6 | 3.1 |
|---|
| 28 | 2.9/73.9 | 3.6/75.2 | 4.1/76.3 | 4.5/77.2 | 4.9/77.9 | 5.3/78.6 | 5.6/79.3 | 4.4 |
|---|
| 30 | 4.2/76.6 | 4.9/77.9 | 5.4/79.0 | 5.9/79.9 | 86.3/0.6 | 6.6/81.3 | 6.9/82.0 | 5.7 |
|---|
| 32 | 5.6/79.2 | 6.2/80.5 | 6.8/81.6 | 7.2/82.6 | 7.6/83.4 | 8.0/84.1 | 8.3/84.7 | 7.1 |
|---|
| 34 | 6.9/81.9 | 7.5/83.2 | 8.1/84.3 | 8.5/85.3 | 8.9/86.1 | 9.3/86.8 | 9.6/87.4 | 8.4 |
|---|
| 36 | 8.2/84.5 | 8.8/85.9 | 9.4/87.0 | 9.9/87.9 | 10.3/88.8 | 10.6/89.5 | 11.0/90.2 | 9.7 |
|---|
| 38 | 9.5/87.2 | 10.2/88.5 | 10.7/89.7 | 11.2/90.6 | 11.6/91.5 | 12.0/92.2 | 12.3/92.9 | 11.1 |
|---|
| 40 | 10.8/89.8 | 11.5/91.2 | 12.1/92.4 | 12.5/93.3 | 13.0/94.2 | 13.3/94.9 | 13.7/95.6 | 12.4 |
|---|
表14b. NL等於25公斤／(日頭）時之THI 與 MPD 值（方，1995）
| 乾球溫度℃ |
相對濕度，% | 平均 |
| 40 | 50 | 60 | 70 | 80 | 90 | 100 |
|---|
| MPD/THI | MPD/THI | MPD/THI | MPD/THI | MPD/THI | MPD/THI | MPD/THI | MPD |
|---|
| 22 | 0.0/66.0 | 0.0/67.2 | 0.0/68.2 | 0.4/69.1 | 0.9/69.8 | 1.3/70.5 | 1.7/71.1 | 0.6 |
|---|
| 24 | 0.1/68.6 | 0.9/69.9 | 1.5/70.9 | 2.1/71.8 | 2.5/72.5 | 3.0/73.2 | 3.4/73.8 | 1.9 |
|---|
| 26 | 1.8/71.3 | 2.5/72.5 | 3.2/73.6 | 3.7/74.5 | 4.2/75.2 | 4.6/75.9 | 5.0/76.6 | 3.6 |
|---|
| 28 | 3.4/73.9 | 4.2/75.2 | 4.9/76.3 | 5.4/77.2 | 5.9/77.9 | 6.3/78.6 | 6.7/79.3 | 5.3 |
|---|
| 30 | 5.0/76.6 | 5.8/77.9 | 6.5/79.0 | 7.1/79.9 | 7.6/80.6 | 8.0/81.3 | 8.4/82.0 | 6.9 |
|---|
| 32 | 6.7/79.2 | 7.5/80.5 | 8.2/81.6 | 8.7/82.6 | 9.2/83.4 | 9.7/84.1 | 10.1/84.7 | 8.6 |
|---|
| 34 | 8.3/81.9 | 9.1/83.2 | 9.8/84.3 | 10.4/85.3 | 10.9/86.1 | 11.3/86.8 | 11.8/87.4 | 10.2 |
|---|
| 36 | 9.9/84.5 | 10.8/85.9 | 11.5/87.0 | 12.1/87.9 | 12.6/88.8 | 13.0/89.5 | 13.4/90.2 | 11.9 |
|---|
| 38 | 11.6/87.2 | 12.4/88.5 | 13.1/89.7 | 13.7/90.6 | 14.2/91.5 | 14.7/92.2 | 15.1/92.9 | 13.6 |
|---|
| 40 | 13.2/89.8 | 14.1/91.2 | 14.8/92.4 | 15.4/93.3 | 15.9/94.2 | 16.4/94.9 | 16.8/95.6 | 15.2 |
|---|
表14c. NL等於30公斤／(日頭）時之THI 與 MPD 值（方，1995）
| 乾球溫度℃ |
相對濕度，% | 平均 |
| 40 | 50 | 60 | 70 | 80 | 90 | 100 |
|---|
| MPD/THI | MPD/THI | MPD/THI | MPD/THI | MPD/THI | MPD/THI | MPD/THI | MPD |
|---|
| 22 | 0.0/66.0 | 0.0/67.2 | 0.0/68.2 | 0.3/69.1 | 0.8/69.8 | 1.3/70.5 | 1.8/71.1 | 0.6 |
|---|
| 24 | 0.0/68.6 | 0.9/69.9 | 1.6/70.9 | 2.3/71.8 | 2.8/72.5 | 3.3/73.2 | 3.8/73.8 | 2.1 |
|---|
| 26 | 1.9/71.3 | 2.8/72.5 | 3.6/73.6 | 4.3/74.5 | 4.8/75.2 | 5.3/75.9 | 5.8/76.6 | 4.1 |
|---|
| 28 | 3.9/73.9 | 4.8/75.2 | 5.6/76.3 | 6.3/77.2 | 6.9/77.9 | 7.4/78.6 | 7.8/79.3 | 6.1 |
|---|
| 30 | 5.8/76.6 | 6.8/77.9 | 7.6/79.0 | 8.3/79.9 | 8.9/80.6 | 9.4/81.3 | 9.9/82.0 | 8.1 |
|---|
| 32 | 7.8/79.2 | 8.8/80.5 | 9.6/81.6 | 10.3/82.6 | 10.9/83.4 | 11.4/84.1 | 11.9/84.7 | 10.1 |
|---|
| 34 | 9.8/81.9 | 10.8/83.2 | 11.6/84.3 | 12.3/85.3 | 12.9/86.1 | 13.4/86.8 | 13.9/87.4 | 12.1 |
|---|
| 36 | 11.7/84.5 | 12.7/85.9 | 13.6/87.0 | 14.3/87.9 | 14.9/88.8 | 15.4/89.5 | 15.9/90.2 | 14.1 |
|---|
| 38 | 13.7/87.2 | 14.7/88.5 | 15.6/89.7 | 16.3/90.6 | 16.9/91.5 | 17.4/92.2 | 17.9/92.9 | 13.6 |
|---|
| 40 | 15.6/89.8 | 16.7/91.2 | 17.5/92.4 | 18.3/93.3 | 18.9/94.2 | 19.4/94.9 | 20.0/95.6 | 18.1 |
|---|
 
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