Impact of Parity Order on Nutritional Values of Camel Milk in Modern System

Ayman Balla Mustafa1, Abdalla Elgenaidi1, Aldukali Alkeskas1, Asim Faraz2,*, Ahmed Eisa Elhag3, Mohanad Bashari4 and Bernard Faye5 1Therapeutic Nutrition Department, Faculty of Nursing and Health Sciences, Misurata University, Misurata, Libya 2Department of Livestock and Poultry Production, Bahauddin Zakariya University, Multan, Pakistan 3Faculty of Veterinary Sciences, University of Gadarif, Gadarif, Sudan 4A’Sharqiah University, Department of Food Science and Human Nutrition, Ibra, Sultanate of Oman 5CIRAD-ES, Campus international de Baillarguet TAC/dir B, 34398 Montpellier, France Article Information Received 27 May 2020 Revised 11 July 2020 Accepted 27 August 2020 Available online 02 December 2020

C amel produces milk in arid and semi-arid region where other animals fail to produce (Faraz et al., 2019a). Camel milk is an essential food for pastoral community and it may be the only milk available in places where other milking animals cannot be reared (Faraz et al., 2019b). In pastoral conditions, milk is always consumed either fresh or in varying degrees of sourness (Abdelrahman et al., 2011). A lot of information is still to be generated about camel milk as a source of food. Camel milk is a component of fat, protein, lactose, minerals, and vitamins and miscellaneous constituents dispersed in water (Iqbal et al., 2001;Faraz et al., 2019c).
The parity order, season and physiological state play important role in variation in constituents of camel milk (Konuspayeva et al., 2009). Camel milk composition was found to be less stable than bovine milk. Wide variations had been detected in camel milk constituents, which may be attributed to some factors such as analytical procedures, geographical location, feed formulation, environmental variables and breed in addition to others factors such as lactation stage, camel age and number of calving (Khaskheli et al., 2005). In Saudi Arabia, no significant effect of parity, gestation length or calf birth weight was recorded on milk constituents (Abdelgadir et al., 2013). Camel milk was found to contain 86.94% moisture, 3.67% protein, 5.78% lactose, 0.66% ash and 5.76% fat during 1 st month, 6.59% during 3 rd month and 6.08% during 6 th month (Sohail, 1983). Sawaya et al. (1984) reported 11.7% total solids, 3.0% protein, 3.6% fat and 0.13% acidity in camel milk. Substantial variation in camel milk was therefore observed in fat (2.1 to 4.7%), protein (2.20 and 2.59%) and lactose (4.59 and 5.33%) contents. Fat content of dromedary camel milk ranged between 1.2 and 6.4%. A strong positive correlation was reported O n l i n e

F i r s t A r t i c l e
between fat and protein contents by Haddadin et al. (2008) and Konuspayeva et al. (2009). This study was aimed to elucidate the impact of parity order, lactation period, postpartum and age on nutritional value and camel milk composition under modern system.

Materials and methods
The study was carried out at Alzakiat Camel Farm, in Ezba area close to Bahri City, Khartoum from June to December 2013. Two clinically healthy groups, each of eight lactating she-camels at 2 nd week postpartum, 6-17 years, average mean body weight 477.13±32.291 kg were chosen from the mixed herd of camels. All selected camels belonged to Arabi Kenana breed from Alzakiat Farm. Group of early lactation (GY) included she-camels in first and second parity, whereas group of mid lactation (GD) included she-camels in third, fourth and fifth parity. All experimental animals were herded in closed pen and provided ration feed, which consisted of concentrates in addition to roughages feed. Water source was available daily ad libitum.
Milk samples were collected in sterile glass bottles (40 ml) by manual milking four times a day (7:00 am, 12:00 noon, 5:30 pm and 11:00 pm). The collection of samples was started in second week postpartum and continued biweekly interval up to 4 th month postpartum. These samples were delivered to dairy laboratories in University of Khartoum within 24 h for laboratory analysis. During experiments, one case each of mastitis and internal parasites were observed. Therefore, the dams in this case were discarded from experiment.
Major fat, protein, lactose, solid non-fat (SNF) and density percentages were determined biweekly for 16 weeks postpartum by automatic milk analyzer device (lactoscan Model-90, Europe).
All data were subjected to General Linear Model using Statistix8 version-2 software program; variations of means regarding treatments and weeks were calculated. Least significant differences (LSD) test used for means separations (Free Software Foundation, Boston, MA 02110, USA). Table I shows the effect of parity order on milk constituents and nutritional values, and fat content (%) of milk produced by young camel group versus old camel group camel under intensive farming system. There is no difference in fat content among two groups, but the fat content continue to increase regularly from week 2 to 8 postpartum. It ranged between 3.46±0.85 and 6.34±0.85% in GY compared to that of GD which ranged between 3.46±0.70 and 3.92±0.70%. The results also indicated that there was no significant (P˃0.05) effect of parity and age on lactose content. The lactose level in milk fluctuated during the first 8 weeks, but thereafter it increased stably.

O n l i n e F i r s t A r t i c l e
Different letters in same column and row indicates significant difference (P˂0.05). GY, young group (early lactation); GD, old group (late lactation).
The protein content had lower values in the beginning of lactation in both groups but later increased significantly (P˂0.05) throughout the lactation stage with higher value at week 14 (3.77±0.11%). The content of SNF likewise increased significantly (P˂0.05) with advancement in lactation stage during four months postpartum. There was no difference in milk density during the first eight weeks after calving but it decreased during week 10 and 12 and later increased till the end of experiments.
The results of this study revealed that milk of young camel is slightly richer in fat content compared to that of old camel. These findings are similar to those who stated that parity seemed to have no effect on milk fat content (Bakheit et al., 2008;Aljumaah et al., 2012;. In contrast, the effect of parity on fat content of camel milk was significant as reported by Zeleke (2007) and milk yield was also reported to be affected significantly by parity (Raziq et al., 2010).
High value of milk lactose content during four months postpartum was recorded. These findings are close to previous studies, who mentioned that high lactose content were recorded during first lactation. This is justified by general herders who think that camel milk is sweeter in first lactation (Zeleke, 2007;Aljumaah et al., 2012;Wafa and El-Zubeir, 2014;Elagba et al., 2016). The results of current study showed no significant difference of milk lactose, fat and density content between two groups during experiment period. These findings are in agreement with those who show insignificant differences of fat, lactose, SNF and density contents of milk camel after calving (Bakheit et al., 2008;Wafa and El-Zubeir, 2014). The variation in protein content recorded in current study is close to studies reported in Sudan and Ethiopia (Zeleke, 2007;Mustafa et al., 2014). There are many limitations of working with camels since the owners look for trade benefits rather than scientific researches. Moreover, camels are expensive in modern farm.

Conclusion
Wide variations of camel milk constituents and nutritional values have been detected in current study. These variations might be attributed to difference in parities, lactation stage postpartum, calving number, ecological and physiological variables and reproductive age of she-camel. The study findings elucidated that the camel milk production in modern system can be provided with better nutritional values with adequate amount of nutrients in desert and semi desert regions. Therefore, management practices, parity order and camel breed should be considered. In addition to, physiological adaptation to certain types of commercial feed, feed additives and milking times. However, significant intervention to improve and maintain the milk nutritional value is recommended.