海兰褐蛋鸡产蛋高峰至后期蛋壳品质的变化特征

doi:10.3864/j.issn.0578-1752.2021.17.017

摘要/Abstract

摘要：

【目的】通过观察海兰褐蛋鸡产蛋高峰至后期（31—80周龄）鸡蛋表观指标、物理属性和力学特性的变化规律,探究产蛋后期蛋壳品质下降的关键时期及蛋壳结构与组成的变化,为产蛋后期蛋壳品质的调控提供参考和依据。【方法】以84只30周龄健康的海兰褐蛋鸡为研究对象,随机分为7个重复,每重复12只鸡。试验期饲喂玉米-豆粕型基础日粮,自由采食、饮水,饲养50周。分别于31、36、41、46、50、55、60、65、70、75和80周龄时,每重复每天采集3枚鸡蛋,连续采集3d。所有鸡蛋样品均检测表观指标、物理属性和力学特性。选择31、41、50、60、70和80周龄组蛋壳,使用扫描电子显微镜观察蛋壳横截面和内表面的超微结构、X-射线衍射分析仪检测蛋壳晶体结构,灼烧法检测蛋壳有机物含量,考马斯亮蓝法检测蛋壳总蛋白含量,电感耦合等离子体发射光谱法检测蛋壳钙和磷含量。【结果】（1）31—80周龄蛋重、长径和蛋壳面积线性增加（P<0.01）;蛋壳重、蛋壳比例、蛋壳厚度和蛋壳指数随蛋鸡周龄先增加后降低（P<0.05）;50周龄后蛋壳强度和蛋壳韧性较31周龄显著降低,65—80周龄各周龄均显著低于之前各采样时间点（P<0.05）。（2）蛋壳品质主成分载荷分析中,在第一主成分（PC1）中,蛋壳强度、蛋壳比例、蛋壳韧性和蛋壳指数的载荷值高,而第二主成分（PC2）中,蛋壳重、蛋壳厚度和蛋壳面积的载荷值高;根据产蛋期蛋壳物理属性和力学特性变化,可划分为31—50和55—80周龄2个阶段,后者还可划分为55—60周龄和65—80周龄2个阶段。（3）70和80周龄蛋壳乳突厚度和比例显著低于31—60周龄各组（P<0.05）;乳突密度显著低于31周龄组蛋壳（P<0.05）。（4）随蛋鸡周龄增加,蛋壳晶体大小无显著变化（P>0.05）。（5）蛋壳有机物和总蛋白含量、单位蛋壳面积含量和每枚蛋壳含量均无显著变化;每枚蛋壳钙含量无显著变化（P>0.05）;70和80周龄单位蛋壳面积钙含量显著降低（P<0.05）;60、70和80周龄蛋壳磷百分含量显著低于之前各周龄组（P<0.05）,而每枚蛋壳磷含量和单位蛋壳面积磷含量显著低于31周龄组（P<0.05）。（6）蛋壳力学特性与钙化层厚度、有效层厚度、乳突密度、有效层比例、单位蛋壳面积钙含量、磷百分含量、每枚蛋壳磷含量和单位蛋壳面积磷含量均显著正相关（P<0.05）,与乳突比例显著负相关（P<0.05）。【结论】根据蛋壳物理属性和力学特性变化,海兰褐蛋鸡产蛋期可划分为31—50周龄和55—80周龄2个阶段,65周龄后蛋壳力学特性下降尤为明显;超微结构层厚度和比例的变化可能导致了产蛋期蛋壳力学特性的下降;60—80周龄蛋壳力学特性降低可能与蛋壳磷含量下降有关,乳突层结构异常和蛋壳面积增大导致的单位蛋壳面积钙含量下降加剧了70—80周龄蛋壳力学特性的下降。

关键词: 产蛋期, 蛋壳品质, 力学特性, 超微结构, 化学组成

Abstract:

【Objective】 In this study, the changes of egg physical and eggshell quality properties from peak to late phase of production (31 to 80-wk-old) of Hy-Line Brown layers were observed to investigate the critical period when eggshell quality deteriorated and the changes of eggshell structure and components, so as to provide reference for improving the eggshell quality of the late phase of production. 【Method】 A total of 84 healthy 30-wk-old Hy-Line Brown layers were randomly divided into 7 replicates with 12 birds each. All hens had free access to corn-soybean meal basal diet and water for 50 weeks. Three eggs per replicate were collected every day for 3 consecutive days at the hen age: 31, 36, 41, 46, 50, 55, 60, 65, 70, 75 and 80-wk-old, and then eggshell physical and mechanical properties were tested. Eggshell from the hens aged: 31, 41, 50, 60, 70 and 80-wk-old was tested the following items, eggshell ultrastructure of cross section and inner surface by scanning electron microscope, the crystal structure by X-ray diffraction analyzer, organic content by burning method, total eggshell protein content by Coomassie brilliant blue method, and eggshell calcium and phosphorus content by inductively coupled plasma atomic emission spectrometry. 【Result】 (1) Egg weight, egg length and eggshell area of 31 to 80-wk-old were increased linearly (P<0.01). Eggshell weight, eggshell percentage, eggshell thickness and eggshell index were increased and then decreased with hen age increasing (P<0.05). After 50-wk-old, eggshell strength and eggshell fracture toughness were decreased significantly (P <0.05), and reached the lowest value from 65 to 80-wk-old (P<0.05). (2) Based on the principal component loading analysis of eggshell quality, in PC1, the load values of eggshell strength, eggshell percentage, eggshell fracture toughness and eggshell index were higher, while in PC2, the loading values of eggshell weight, eggshell thickness and eggshell area were higher. According to properties of eggshell quality, the laying cycle was divided into 2 stages of 31 to 50-wk-old and 55 to 80-wk-old, and the later could further be divided into 55 to 60-wk-old and 65 to 80-wk-old. (3) For eggshell ultrastructure, mammillary thickness and rate of 70 and 80-wk-old were significantly lower than those of 31 to 60-wk-old (P<0.05), and mammillary knob density was significantly lower than that of 31-wk-old (P<0.05). (4) There were no significant changes in the contents of organic matter and total protein, per unit area and per eggshell and no significant change in calcium content per eggshell (P>0.05), but the calcium content per unit area of 70 and 80-wk-old were decreased significantly (P<0.05). The phosphorus content of 60, 70 and 80-wk-old was significantly lower than others (P<0.05), while the phosphorus content per eggshell and per unit area were significantly lower than those of 31-wk-old (P<0.05). (6) The eggshell mechanical properties was significantly positively correlated with the thickness of calcified layer and effective layer, mammillary knob density, effective layer rate, calcium content per unit area and the content of phosphorus, per eggshell and per unit area (P<0.05), was significantly negatively correlated with mammillary layer rate (P<0.05). 【Conclusion】 According to eggshell physical and mechanical properties, the laying cycle of Hy-Line Brown layers could be divided into 2 stages: 31 to 50-wk-old and 55 to 80-wk-old. The eggshell mechanical properties were decreased significantly after 65-wk-old, as the changes of eggshell ultrastructure layer thickness and rate might contribute to the decrease of eggshell mechanical properties in the laying cycle. The decrease of eggshell phosphorus content might be one of the reasons for the decrease of eggshell mechanical properties from 60 to 80-wk-old. From 70 to 80-wk-old, eggshell ultrastructural variation and the decrease of eggshell calcium content per unit area might aggravate the decrease of eggshell mechanical properties

Key words: laying period, eggshell quality, mechanical properties, eggshell ultrastructure, chemical composition

马玲玲,冯嘉,王晶,齐广海,马友彪,武书庚,张海军,邱凯. 海兰褐蛋鸡产蛋高峰至后期蛋壳品质的变化特征[J]. 中国农业科学, 2021, 54(17): 3766-3779.

MA LingLing,FENG Jia,WANG Jing,QI GuangHai,MA YouBiao,WU ShuGeng,ZHANG HaiJun,QIU Kai. The Changes of Eggshell Quality in the Laying Cycle of Hy-Line Brown Layers[J]. Scientia Agricultura Sinica, 2021, 54(17): 3766-3779.

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https://www.chinaagrisci.com/CN/Y2021/V54/I17/3766

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表7

蛋壳力学特性、结构和化学组成的相关性分析"

	ES	FT	MW	ET	MT	CT	ER	MR	MD	Ca	CaP	CaD	P	PP	PD	OM	OMP	OMD	TP	TPP	TPD	GS
ES	1.00
FT	0.91**	1.00
MW	0.24	0.07	1.00
ET	0.70**	0.65**	0.34	1.00
MT	-0.44	-0.43	-0.02	-0.71**	1.00
CT	0.66**	0.60*	0.50*	0.89**	-0.32	1.00
ER	0.61*	0.59*	0.12	0.91**	-0.93**	0.62*	1.00
MR	-0.63*	-0.60*	-0.14	-0.92**	0.92**	-0.65**	-1.00**	1.00
MD	0.64**	0.65**	0.19	0.48	-0.45	0.35	0.53*	-0.52*	1.00
Ca	0.05	0.09	-0.09	0.56*	-0.77**	0.26	0.72**	-0.71**	0.04	1.00
CaP	0.42	0.51*	0.04	0.38	-0.01	0.52*	0.18	-0.20	-0.24	0.01	1.00
CaD	0.57*	0.67**	0.09	0.55*	-0.23	0.61*	0.39	-0.41	-0.02	0.14	0.96**	1.00
P	0.71**	0.81**	0.43	0.55*	-0.12	0.67**	0.35	-0.37	0.69**	-0.11	0.36	0.49*	1.00
PP	0.64**	0.72**	0.47	0.48*	0.01	0.65**	0.25	-0.27	0.62*	-0.25	0.34	0.45	0.96**	1.00
PD	0.75**	0.85**	0.35	0.57*	-0.06	0.73**	0.33	-0.34	0.52*	-0.15	0.55*	0.62*	0.93**	0.91**	1.00
OM	0.28	0.24	0.40	0.32	-0.07	0.36	0.23	-0.24	0.65**	-0.03	-0.36	-0.23	0.57*	0.66**	0.40	1.00
OMP	0.22	0.18	0.51*	0.18	0.18	0.35	0.00	-0.02	0.49*	-0.30	-0.20	-0.12	0.58*	0.74**	0.45*	0.93**	1.00
OMD	0.27	0.24	0.52*	0.23	0.12	0.38	0.07	-0.08	0.53*	-0.26	-0.17	-0.07	0.61*	0.77**	0.49	0.93**	1.00**	1.00
TP	0.01	0.08	-0.36	-0.04	-0.42	-0.37	0.27	-0.25	0.37	0.05	-0.38	-0.26	-0.11	-0.06	-0.20	0.23	0.10	0.11	1.00
TPP	0.02	0.08	-0.14	-0.10	-0.18	-0.28	0.09	-0.08	0.37	-0.24	-0.29	-0.20	0.04	0.19	-0.04	0.39	0.40	0.41	0.91**	1.00
TPD	0.09	0.15	-0.11	-0.03	-0.25	-0.22	0.17	-0.15	0.43	-0.20	-0.26	-0.14	0.11	0.24	0.01	0.41	0.41	0.43	0.91**	1.00**	1.00
GS	0.36	0.37	-0.37	0.03	-0.20	-0.07	0.13	-0.12	0.29	0.01	0.09	0.15	0.06	-0.15	0.04	-0.44	-0.55*	-0.52*	-0.09	-0.29	-0.26	1.00

表7

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[44]	BAIN M M. Eggshell strength: A relationship between the mechanism of failure and the ultrastructural organization of the mammillary layer. British Poultry Science, 1992, 33(2): 303-319. doi: 10.1080/00071669208417469

项目 Items	蛋鸡周龄 Hen age (wk)											P
项目 Items	31	36	41	46	50	55	60	65	70	75	80	P
蛋重 Egg weight (g)	61.01f±0.62	61.18ef±0.41	61.80de±0.89	62.19d±0.84	62.91c±0.72	63.13c±0.62	63.23bc±0.38	63.46abc±0.73	63.53abc±0.77	63.92ab±0.93	64.18a±0.35	< 0.001
短径 Width (cm)	4.37ab±0.02	4.34abc±0.02	4.36ab±0.05	4.34bc±0.02	4.37ab±0.04	4.37a±0.02	4.35abc±0.03	4.36abc±0.02	4.35abc±0.03	4.33c±0.02	4.37ab±0.02	0.004
长径 Length (cm)	5.65f±0.04	5.63f±0.06	5.71e±0.04	5.74de±0.06	5.77cd±0.05	5.79bcd±0.04	5.78cd±0.04	5.81bcd±0.05	5.80bc±0.05	5.84b±0.04	5.91a±0.05	< 0.001
蛋形指数 Egg shape index	1.29e±0.01	1.30de±0.01	1.31cd±0.02	1.32b±0.02	1.32bc±0.01	1.32bc±0.01	1.33b±0.01	1.33b±0.01	1.33b±0.02	1.35a±0.01	1.37a±0.01	< 0.001
蛋壳面积 Eggshell surface area (cm²)	72.53f±0.54	72.66ef±0.32	73.12de±0.71	73.46d±0.54	74.02c±0.53	74.20c±0.53	74.28bc±0.30	74.46abc±0.57	74.51abc±0.61	74.82ab±0.79	75.02a±0.28	< 0.001

项目 Items	蛋鸡周龄 Hen age (wk)											P
项目 Items	31	36	41	46	50	55	60	65	70	75	80	P
蛋壳重 Eggshell weight (g)	5.91cd±0.25	5.99bcd±0.25	6.36a±0.24	6.34a±0.27	6.19abc±0.22	6.14abcd±0.37	6.27ab±0.14	5.89d±0.28	5.87d±0.14	6.07abcd±0.36	6.14abcd±0.20	< 0.001
蛋壳比例 Eggshell percentage (%)	9.79bc±0.34	9.91bc±0.36	10.31a±0.28	10.19ab±0.40	9.84bc±0.35	9.72c±0.19	9.92bc±0.22	9.28d±0.37	9.27d±0.30	9.56cd±0.40	9.56cd±0.33	< 0.001
蛋壳指数 Eggshell index (mg·mm^-2)	8.15bc±0.34	8.24bc±0.32	8.74a±0.25	8.63a±0.36	8.36ab±0.30	8.09bc±0.49	8.44ab±0.19	7.91c±0.34	7.89c±0.23	8.15bc±0.43	8.18bc±0.28	< 0.001
蛋壳厚度 Eggshell thickness (×10^-2mm)	45.39cde±0.83	45.61cde±0.93	44.89e±0.47	46.81a±0.68	46.56ab±0.21	45.45cde±0.75	45.87bcd±0.61	45.13de±0.93	43.86f±0.67	46.05abc±0.55	45.21de±0.85	< 0.001
蛋壳强度 Eggshell strength (N)	48.60a±2.79	46.68ab±2.46	46.19abc±1.47	47.60ab±2.60	45.18bcd±3.21	42.71d±2.80	43.55cd±2.35	36.01ef±3.74	38.55e±2.86	38.24ef±2.19	35.28f±2.26	< 0.001
蛋壳韧性 Eggshell fracture toughness (N/mm^3/2)	390.65a±18.79	382.44ab±15.37	386.93ab±16.07	378.48ab±17.83	367.91b±11.93	326.70cd±11.87	336.69c±25.35	290.33f±21.47	315.68de±20.61	300.06ef±16.70	280.97f±10.27	< 0.001

项目 Items	主成分 Principal components
项目 Items	PC1	PC2
X-exp²	64%	23%
参数 Parameters
蛋壳强度 Eggshell strength	-0.428	0.262
蛋壳重 Eggshell weight	-0.326	-0.519
蛋壳厚度 Eggshell thickness	-0.187	-0.440
蛋壳面积 Eggshell surface area	0.343	-0.512
蛋壳比例 Eggshell percentage	-0.454	-0.134
蛋壳韧性 Fracture toughness	-0.419	0.335
蛋壳指数 Eggshell index	-0.420	-0.276

项目 Items	蛋鸡周龄 Hen age (wk)						P
项目 Items	31	41	50	60	70	80	P
钙化层厚度 Calcified thickness (μm)	357.05±15.78	345.99±13.83	363.50±9.71	356.41±24.60	345.80±13.31	342.91±23.87	0.300
乳突厚度 Mammillary thickness (μm)	90.01c±5.80	106.56b±6.14	114.35b±9.37	114.18b±8.03	125.98a±6.24	130.41a±8.43	<0.001
有效层厚度 Effective thickness (μm)	268.14a±12.91	243.06b±9.77	246.91b±10.18	243.50b±17.63	220.22c±10.25	212.04c±26.74	<0.001
乳突宽度 Mammillary knob width (μm)	70.18±4.27	71.24±6.24	72.27±6.15	72.01±4.10	73.66±7.16	70.93±5.79	0.926
乳突比例 Mammillary layer rate (%)	24.87c±1.67	30.80b±1.46	31.32b±1.78	32.12b±0.85	36.31a±1.35	37.85a±2.08	<0.001
有效层比例 Effective layer rate (%)	75.13a±1.67	69.20b±1.46	68.68b±1.78	68.13b±0.88	63.69c±1.35	62.15c±2.08	<0.001
乳突密度 Mammillary knob density (1 mm²)	286.66a±11.75	268.97ab±17.45	270.96ab±27.20	271.40ab±11.46	256.07b±8.44	230.93c±11.90	0.001

项目 Items	蛋鸡周龄 Hen age (wk)						P
项目 Items	31	41	50	60	70	80	P
有机物百分含量Organic matter (%)	3.54±0.16	3.56±0.42	3.71±0.08	3.48±0.20	3.47±0.13	3.33±0.34	0.482
每枚鸡蛋蛋壳有机物含量 Organic matter per eggshell (mg)	209.33±12.62	226.19±30.90	235.47±7.65	217.06±11.57	214.26±24.24	204.06±21.34	0.266
单位蛋壳面积有机物含量 Organic matter per unit area (mg·cm^-2)	2.88±0.17	3.09±0.42	3.19±0.08	2.92±0.16	2.88±0.32	2.72±0.28	0.163
总蛋白百分含量Total protein (%)	1.33±0.26	1.27±0.13	1.32±0.11	1.32±0.22	1.30±0.12	1.50±0.17	0.292
每枚鸡蛋蛋壳总蛋白含量 Total protein per eggshell (mg)	77.59±14.88	79.90±8.38	81.90±7.37	82.20±14.43	76.01±7.62	92.22±10.08	0.196
单位蛋壳面积总蛋白含量 Total protein per unit area (mg·cm^-2)	1.07±0.20	1.09±0.11	1.11±0.10	1.11±0.19	1.02±0.11	1.23±0.14	0.301
Ca (%)	37.29a±0.73	34.11b±0.54	33.57b±1.52	35.02b±0.35	34.87b±1.11	34.85b±1.09	0.001
每枚鸡蛋蛋壳钙含量 Calcium content per eggshell (mg)	2176.08±78.59	2158.57±74.75	2108.28±88.13	2148.98±50.53	2069.85±52.24	2100.90±64.76	0.305
单位蛋壳面积钙含量 Calcium content per unit area (mg·cm^-2)	29.93a±1.11	29.53ab±1.17	28.54ab±1.10	28.99ab±0.77	27.79b±0.69	27.76b±0.69	0.033
P (%)	0.13a±0.01	0.14a±0.01	0.13a±0.01	0.11b±0.01	0.10b±0.00	0.11b±0.01	< 0.001
每枚鸡蛋蛋壳磷含量 Phosphorus content per eggshell (mg)	7.66b±0.38	8.89a±0.55	8.18ab±0.73	6.75c±0.78	6.01c±0.22	6.46c±0.58	< 0.001
单位蛋壳面积磷含量 Phosphorus content per unit area (mg·cm^-2)	0.11b±0.01	0.12a±0.00	0.11b±0.01	0.09c±0.01	0.08c±0.00	0.09c±0.01	< 0.001