Determination of the nutrient digestibility of herbage consumed by grazing animals

doi:10.11686/cyxb2021089

Abstract

Abstract:

Nutrient digestibility of herbage consumed by grazing livestock is one of the key indicators for grassland management， and is a function of both the biomass and nutritional quality of forage， and the health and production status of livestock. Nutrient digestibility of forage consumed by grazing livestock can be determined by direct or indirect methods. The direct methods include， among others， the total feces collection method， the indigestible marker method and near infrared spectroscopy （NIRS）. The indirect methods include in vivo or in vitro fermentation digestibility determinations， the forage quality prediction method and the climate prediction method. The total fecal collection method is a comparatively accurate method， provided that the feed dry matter intake and feces dry weight are accurately determined. However， it is time-consuming and laborious， and has a great impact on the grazing behavior. Moreover， it is difficult to reflect the spatial heterogeneity of forage supply in the pasture. The indigestible marker method estimates the nutrient digestibility according to the proportion of indigestible matter recovered and causes little disturbance to the grazing behavior of livestock. However， it is not easy to analyze for the indigestible marker， and the method is not suitable for wild grazing animals. The NIRS method has high efficiency， low labor intensity， low cost， and does not have any effects on livestock， so it can estimate the nutrient digestibility of forage consumed by grazing livestock on a large scale. However， NIRS requires a lot of directly measured calibration data to improve the prediction accuracy. The climate estimation method is fast， and therefore time-saving but is also less accurate. Climate estimation is therefore suitable for large spatial and temporal scales. The nutrient digestibility of forage consumed by grazing livestock is closely related to biological factors， environmental factors and social factors such as livestock class， grassland type， grazing methods employed， temperature and precipitation. Combined with remote sensing， unmanned aerial vehicle methods and artificial intelligence， the nutrient digestibility of forage consumed by grazing livestock can be accurately and quickly measured， providing support for grassland ecological restoration and livestock health and management.

Key words: grassland, forage quality, total fecal collection method, indicator method, climate, NIRS, nutrient digestibility

You-shun JIN, Fu-jiang HOU. Determination of the nutrient digestibility of herbage consumed by grazing animals[J]. Acta Prataculturae Sinica, 2022, 31(5): 200-212.

Figures/Tables 12

Fig.1 Method for determination of nutrient digestibility of grazing livestock

Table 1 Nutrient digestibility of grazed animals measured by total fecal collection method

类型 Type	地点 Site	AMP （mm）	AMT （℃）	家畜品种 Breeds	性别 Gender	DMD （%）	CPD （%）	NDF/ADF （%）	参考文献References
TSS	阿根廷Argentina （36°46′ S； 64°16′ W）	900	20.0	Pampinta羊Pampinta sheep	公Male	40.90 （OMD）	-	-	［12］
TCG	临泽县Linze County （39°24′ N； 100°6′ E）	89	8.3	西门塔尔牛Simmental	公Male	76.70	72.90	60.90 （NDF）	［13］
TCG	临泽县Linze County （39°24′ N； 100°6′ E）	89	8.3	湖羊×小尾寒羊Hu sheep×Small-tailed Han sheep	公Male	60.70	63.30	59.70/57.10	［14］
TCG	临泽县Linze County （39°24′ N； 100°6′ E）	89	8.3	西门塔尔牛Simmental	公Male	58.70	49.50	39.60 （NDF）	［15］
TCG	临泽县Linze County （39°24′ N； 100°6′ E）	89	8.3	湖羊×小尾寒羊Hu sheep×Small-tailed Han sheep	公Male	56.48	-	51.23/53.80	［16］
FAM	青海省Qinghai Province （29°46′ N； 94°44′ E）	350~550	0~1.4	藏羊×半细毛羊Tibetan sheep×Semifine-wool sheep	羯羊 Wether	53.07	-	-	［17］
EBF	意大利Italy （36°28′ N； 6°38′ E）	500~1000	2.0~26.0	马Horse	阉马 Gelding	42.10	54.80	43.40 （NDF）	［4］
SBF	巴西Brazil	1300	200.0	马Horse	-	51.19	69.73	72.35/68.91	［18］
TTS	锡林郭勒XilinGol （41°35′ N； 111°9′ E）	300	1.5	萨福克肉羊×蒙古羊Suffolk sheep×Mongolian sheep	-	69.99	-	-	［19］

Table 2 Estimation of nutrient digestibility of animals by alkane method

类型 Type	地点 Site	AMP （mm）	AMT （℃）	家畜品种 Breeds	性别 Gender	DMD （%）	CPD （%）	NDF/ADF （%）	链烷烃 Alkane	参考文献 References
EBF	美国America （37°11′ N； 80°35′ W）	921	15.3	赫里福德牛 Hereford cattle	-	65.30	-	-	C29	［26］
WTTS	英国England （43°38′ S； 172°27′ E）	500~700	14.0	马鹿Red deer	-	67.70	-	69.90 （ADF）	C32-C36	［27］
FAM	西藏Tibet （30°27′ N； 83°4′ E）	380	-3.3~-0.9	绒山羊 Cashmere goat	母Female	49.03	50.36	45.68/ 33.48	C32	［28］
EBF	圣保罗Sao Paulo （34°51′ N； 138°30′ E）	1000	15.0~28.0	内洛尔肉牛 Nellol beef cattle	阉牛Bullock	62.55	-	-	C35	［29］
TSS	墨西哥Mexico （19°24′ N； 99°9′ W）	800~1000	10.0~26.0	驴Donkey	-	45.90	-	-	C31-C33	［30］
TSS	拉潘帕Rapanpa （36°46′ S； 64°16′ W）	800~1000	10.0~26.0	Pampinta羊 Pampinta sheep	公Male	56.80 （OMD）	-	-	C31-C32	［12］
-	-	1000	17.0	荷斯坦奶牛 Holstein cow	母Female	56.70	-	-	C31	［31］
TTS	锡林郭勒XilinGol （42°25′ N； 116°2′ E）	359	1.6	蒙古羊 Mongolian sheep	母Female	71.40	-	-	C25-C35	［32］
EBF	里兹维尔Ritzville （36°24′ N； 79°43′ W）	125	16.5	安格斯肉牛 Angus beef cattle	母Female	51.70	-	-	-	［33］

Table 3 Determination of nutrient digestibility of animals by AIA method

类型 Type	地点 Site	AMP （mm）	AMT （℃）	品种 Breeds	性别 Gender	DMD （%）	CPD （%）	NDF/ADF （%）	参考文献 References
SBS	阿尔及利亚Algeria （36°42′ N； 3°15′ E）	455	17.5	羊Sheep	母Female	64.0	66.00	47.00 （ADF）	［37］
EBF	意大利Italy （36°27′ N； 6°38′ E）	750	2.0~26.0	马Horse	-	45.5	56.10	45.00 （NDF）	［4］
EBF	宾夕法尼亚州Pennsylvania （42°52′ N； 74°43′ W）	1067	-6.0~20.0	荷斯坦奶牛 Holstein cow	母Female	67.1	65.60	54.50/50.00	［35］
TRF	巴西巴伊亚Bahia， Brazil （8°6′ S； 37°5′ W）	1900	24.5	波尔山羊 Boer goat	-	67.0	-	-	［38］
SBS	法国 France （48°11′ N； 1°71′ W）	630	10.5	荷斯坦奶牛 Holstein cow	母Female	66.7	-	-	［39］
EBF	意大利Italy （36°27′ N； 6°38′ E）	750	2.0~26.0	马Horse	公Male	59.7	-	-	［40］
EBF	意大利Italy （36°28′ N； 6°38′ E）	500~1000	2.0~26.0	马Horse	公Male	60.5	-	-	［40］
FAM	东北平原Northeast plain （43°48′ N； 129°10′ E）	500~600	1.0~4.0	西门塔尔牛 Simmental	阉牛Bullock	43.0	52.19	44.32/36.65	［41］
-	-	1000	17.0	荷斯坦牛 Holstein cow	母Female	58.4	-	-	［31］

Table 4 Determination of nutrient digestibility of animals by exogenous indicator method

类型 Type	地点 Site	AMP （mm）	AMT （℃）	家畜品种 Breeds	性别 Gender	DMD （%）	指示剂 Indicator	参考文献 References
EBF	巴西Brazil （23°32′ S； 46°37′ W）	1000	15.0~28.0	荷斯坦奶牛Holstein cow	母Female	68.8	Cr₂O₃	［20］
EBF	巴西Brazil （23°32′ S； 46°37′ W）	1000	15.0~28.0	荷斯坦奶牛Holstein cow	母Female	71.8	TiO₂	［20］
TTS	内蒙古Inner Mongolia （43°39′ N； 116°43′ E）	296	1.4	蒙古羊Mongolian sheep	母Female	56.3	TiO₂	［42］
SBS	法国雷恩市Rennes， France （48°11′ N； 1°71′ W）	630	10.0	荷斯坦奶牛Holstein cow	母Female	72.6	Cr₂O₃	［43］
TSS	墨西哥Mexico （19°24′ N； 99°9′ W）	800~1000	10.0~26.0	Pelibuey羊Pelibuey sheep	-	83.0	Cr₂O₃	［21］
TSS	墨西哥Mexico （19°24′ N； 99°9′ W）	800~1000	10.0~26.0	Pelibuey羊Pelibuey sheep	-	81.0	TiO₂	［21］
SSF	澳大利亚棉花山Cotton hill， Australia （27°28′ S； 153°2′ E）	1153	20.5	美利奴×多塞特Merino×Dorset	公Male	68.2	Cr-EDTA	［44］
EBF	西班牙萨拉戈萨Zaragoza， Spain （43°21′ N； -6°53′ W）	300~800	10.0~25.0	荷斯坦×弗里赛Holstein×Frisai	公Male	72.0	Cr₂O₃	［45］

Table 5 Determination of nutrient digestibility of animals by NIRS method

类型 Type	地点 Site	AMP （mm）	AMT （℃）	家畜品种 Breeds	性别 Gender	OMD （%）	参考文献 References
TDB	塞内加尔Senegal （15°58′ N； 15°10′ W）	300.0	29.0	Toronke绵羊Toronke sheep	-	59.0	［46］
TDB	塞内加尔Senegal （15°58′ N； 15°10′ W）	300.0	29.0	瘤牛Zebu	-	65.0	［46］
EBF	让布卢Gembloux （53°32′ N； 4°40′ E）	600.0	7.2~25.0	荷斯坦奶牛Holstein cow	母Female	69.8	［47］
TXF	加勒比Caribbean （16°17′ N； 61°31′ W）	1116.0	25.0	Martinik羊Martinik sheep	母Female	64.4	［48］
TXF	加勒比Caribbean （16°17′ N； 61°31′ W）	1116.0	15.3	克里奥尔牛Creole cow	-	64.0	［49］
WFG	法国农科院试验农场Institut Nationale de la Recherche Agronomigue （43°55′ N； 3°5′ E）	775.1	10.5	Romane羊Romane sheep	母Female	59.5 （DMD）	［50］
TSS	卡梅尔山脊Carmel ridge （32°32′ N； 34°52′ E）	600.0	-	大马士革山羊Damascene goat	-	56.4 （DMD）	［51］
TSS	卡梅尔山脊Carmel ridge （32°32′ N； 34°52′ E）	600.0	-	大马士革山羊Damascene goat	-	59.0	［51］

Table 6 Determination of nutrient digestibility of animals by in vitro gas production method

类型 Type	地点 Site	AMP （mm）	AMT （℃）	家畜品种 Breeds	性别 Gender	DMD （%）	CPD （%）	NDF/ADF （%）	参考文献References
TSS	拉潘帕Rapanpa （36°46′ S； 64°16′ W）	900.0	10.0~26.0	Pampinta羊 Pampinta sheep	公Male	40.10	-	-	［12］
TCG	爱尔兰Ireland （53°23′ N； 8°6′ W）	750.0~1000.0	15.5	羊Sheep	阉羊 Wether	75.50	-	-	［52］
TCG	爱尔兰Ireland （53°23′ N； 8°6′ W）	750.0~1000.0	15.5	牛Cow	-	74.70	-	-	［52］
TRF	巴伊亚Bahia （8°6′ S； 37°5′ W）	1950.0	24.5	波尔山羊 Boer goat	-	59.90 （OMD）	-	-	［38］
TCG	爱尔兰Ireland （52°9′ N； 8°15′ W）	1000.0~1200.0	14.5	羊Sheep	公Male	76.50	-	76.90/63.30	［3］
-	-	89.0	8.3	湖羊×小尾寒羊Hu sheep×Small-tailed Han sheep	公Male	79.40	-	-	［53］
FAM	西藏Tibet （29°46′ N； 94°44′ E）	361.6	0.6~3.8	高山美利奴 Alpine Merino	公Male	62.94	84.95	60.70/64.08	［54］
-	-	450.0	17.5	牛Cow	公Male	66.30	-	-	［55］
-	-	450.0	17.5	牛Cow	公Male	49.40	-	-	［55］

Table 7 Prediction of nutrient digestibility of animals by forage quality

家畜种类Breeds	预测方程Prediction equation	R²	参考文献References
杂交公羊Crossbred rams	$D M D = 89 . 604 1.903 - 0.658 N D F 0.045$	0.956	［56］
特塞尔绵羊Texel sheep	$O M D = - 0.0004 N D F + 0.8589$	0.144	［57］
藏羊Tibetan sheep	$C P D = - 125 . 331 (21.259) C P 2 + 24 . 251 3.383 C P 2 - 0 . 399 0.117$	0.660	［58］
甘肃高山细毛羊 Gansu alpine fine-wool sheep	$D M D = 3 . 244 0.229 C P - 0 . 541 0.072 N D F + 0 . 611 0.677 A D F + 92 . 117 7.424$	0.701	［59］
马Horse	$O M D = 67.78 + 0.07088 C P - 0.000045 N D F 2 - 0.0121180 A D L$	0.878	［60］
奶牛Cow	$O M D = 0 . 281 0.173 + 8 . 186 1.281 N - 144 . 5 25.8 N 2 + 2 . 173 0.688 N D F - 2 . 559 0.682 N D F 2$	0.640	［61］
绵羊Sheep	$O M D = 0.432 + 0.0079 F N$	0.380	［62］

Table 7 Prediction of nutrient digestibility of animals by forage quality

家畜种类Breeds	预测方程Prediction equation	R²	参考文献References
杂交公羊Crossbred rams	$D M D = 89 . 604 1.903 - 0.658 N D F 0.045$	0.956	［56］
特塞尔绵羊Texel sheep	$O M D = - 0.0004 N D F + 0.8589$	0.144	［57］
藏羊Tibetan sheep	$C P D = - 125 . 331 (21.259) C P 2 + 24 . 251 3.383 C P 2 - 0 . 399 0.117$	0.660	［58］
甘肃高山细毛羊 Gansu alpine fine-wool sheep	$D M D = 3 . 244 0.229 C P - 0 . 541 0.072 N D F + 0 . 611 0.677 A D F + 92 . 117 7.424$	0.701	［59］
马Horse	$O M D = 67.78 + 0.07088 C P - 0.000045 N D F 2 - 0.0121180 A D L$	0.878	［60］
奶牛Cow	$O M D = 0 . 281 0.173 + 8 . 186 1.281 N - 144 . 5 25.8 N 2 + 2 . 173 0.688 N D F - 2 . 559 0.682 N D F 2$	0.640	［61］
绵羊Sheep	$O M D = 0.432 + 0.0079 F N$	0.380	［62］

Fig.2 Relationship between AMP， AMT， AMT/AMP and dry matter digestibility of different animals

Fig.3 Outline of the stages in research on determination of nutrient digestibility of grazing animals

Table 8 Comparison of the methods for determination of nutrient digestibility in grazing animals

测定方法 Determination method	适用性Applicability		准确性Accuracy		成本Cost		尺度Scale		特殊性Particularity
测定方法 Determination method	放牧 Grazing	舍饲 Feeding	放牧 Grazing	舍饲 Feeding	放牧 Grazing	舍饲 Feeding	放牧 Grazing	舍饲 Feeding	放牧 Grazing	舍饲 Feeding
全收粪法Total fecal collection method	++	+++	+++	+++	+++	++	+	++	影响放牧行为Affecting grazing behavior	-
烷烃法Alkane method	+++	+++	++	+++	+	+	+++	++	饲喂烷烃胶囊Feeding alkane capsules	饲喂烷烃胶囊Feeding alkane capsules
酸不溶灰分法AIA method	++	+++	+	++	++	+	++	+	嗜土行为Pedophilic behavior	-
外源指示剂法Exogenous indicator method	+	++	++	+++	++	+	++	++	饲喂外源指示剂Feeding exogenous indicator	饲喂外源指示剂Feeding exogenous indicator
近红外光谱技术NIRS method	++	+++	++	+++	+	+	+++	+++	代表性采食牧草Representative forage samples	-
体外产气法In vitro gas production method	++	+++	++	++	++	+	+	+++	代表性采食牧草Representative forage samples	-
牧草品质预测法 Forage quality prediction method	++	+++	+	++	+	+	+++	+++	代表性采食牧草Representative forage samples	-
气候预测法Climate prediction method	+++	+	+	+	+	++	+++	+	-	-

Fig.4 Big data prediction model for nutrient digestibility of grazing animals

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