Physiological and Performance Parameters of Changthangi Sheep in Response to Cold and Nutritional Stress

Asma Altaf Malik (  asmamallik92@gmail.com ) Sher-E-Kashmir University of Agricultural Sciences and Technology Faculty of Veterinary Sciences and Animal Husbandry https://orcid.org/0000-0003-3036-9063 Hilal Musadiq Khan Sher-E-Kashmir University of Agricultural Sciences and Technology Faculty of Veterinary Sciences and Animal Husbandry Anees Ahmad Shah Sher-E-Kashmir University of Agricultural Sciences and Technology Faculty of Veterinary Sciences and Animal Husbandry Gowher Gull Sheikh Sher-E-Kashmir University of Agricultural Sciences and Technology Faculty of Veterinary Sciences and Animal Husbandry Zahoor Ahmad Pampori Sher-E-Kashmir University of Agricultural Sciences and Technology Faculty of Veterinary Sciences and Animal Husbandry Niha Ayman Sher-E-Kashmir University of Agricultural Sciences and Technology Faculty of Veterinary Sciences and Animal Husbandry


Introduction
Sheep farming forms an integral component for socio-economic upliftment of resource poor farmers in Jammu and Kashmir region of India. Many sheep breeds exist in this temperate region which provide for nutritional and livelihood security of more than 20% of the population which depend on this sector as a fulltime enterprise or as a subsidiary occupation. Tribals of this region undertake transhumance production system or semi-migratory production system of sheep rearing for securing their nutritional and economic demands. Winter in this part of the world is severe where temperature dips below minus and there is shortage of feeds and fodders during this period. This period coincides with the late gestation of the ewes wherein nutrition demand is more but the resource poor farmers rely on poor or meagre nutritional resources which adversely affects the performance of sheep and results in less economic gains. Many sheep breeds were introduced in this region for breed improvement programmes which resulted in better economic returns to the stakeholders. As a prelude to that Changthangi sheep breed known for its hardiness and thriving ability under harsh climatic conditions was introduced in temperate Himalayan Region of Kashmir valley for performance evaluation and breed improvement programme.
Changthangi sheep is a breed of Changthang region, a cold arid region of Ladakh, reared by local Changpa tribe. This sheep and Changthangi goats are the sole source of income for the tribals who rear these animals under trans-humance production system. Marked differences exist in geo-climatic conditions of these two regions in terms of climate and availability of nutrion. Distinguishable wool follicles, staple length and other wool characteristics (Malik et al., 2021) of this breed makes it breed of choice for R & D and reviving the sick woolen sector of this region and hence the socio-economic status of the stakeholders. No work has been conducted so for in temperate region of Kashmir valley (nontraditional belt) necessitated its evaluation for productive and reproductive performance under different housing and feeding interventions during winter months.

Material And Methods
The experiment was conducted at Mountain Research Centre for Sheep and Goat (MRCSG), Shuhama, Sher-e-Kashmir University of Agricultural Sciences and Technology, Kashmir during the year 2019 for the winter months of January to March.The animals were reared under intensive system of housing during the experimental period.
Thirty three pregnant Changthangi ewes were selected for the experimental trial and divided into three groups of 11each on the basis of body weight, age and parity. Ewes of G 1 and G 2 were kept inside the closed shed all the time whereas the ewes of G 3 were kept in an open area which was chain-link fenced from four sides and was provided with a roof shelter to protect from direct rain or snow. G 1 and G 3 were fed 400g concentrate and 600g fodder per head per day as per ICAR feeding standard. Ewes of G 2 were given concentrate @ 500g and fodder @ 1000g per head per day. Concentrate was provided in the form of commercial pelleted feed (89% DM, 20% CP, and 72% TDN) which was offered daily at 4:00 pm on the group basis. The trial was conducted for a period of 90 days. The following parameters were recorded during the experimental period. Where "v" is the wind velocity (m/sec) and "Ta" is air temperature (°C) and wind velocity was calculated using anemometer (Make: Nielsen-Kellerman).

Physiological parameters:
Rectal temperature (°C), Pulse rate (beats/min) and Respiratory rate (breaths/min) were recorded on weekly basis in the morning. Rectal temperature (°C) was recorded with a clinical thermometer by keeping the thermometer in contact of rectal mucosa for about 2 min. Respiration rate per minute of each animal was recorded by visual observations of inward and outward abdominal movement. Pulse rate per minute was recorded with the help of stethoscope.

Performance parameters
i. Body weight of dam Body weight of the experimental animals was recorded every 15 days upto 90 days of the study period using an electronic weighing balance and expressed in kilograms. The animals were weighed in the morning before feeding and watering so as to avoid any possible variation.
ii. Birth weight of lambs: The birth weight of lambs was recorded immediately after birth using electronic weighing balance.
iii. Weight gain: Body weight of the lambs was recorded after every 30 days in subsequent months till weaning (90 days).
All the recordings were taken in the morning using electronic weighing balance.

iv. Mortality and Morbidity
Any mortality or morbidity, if observed during the study period was duly recorded.

Economics:
Keeping all other factors constant, the economics of additional concentrate/fodder fed during the trial period was worked out on the basis of current market rates of the feed and the market value of the additional weight achieved by the experimental ewes/lambs. The cost of extra concentrate fed to the ewes during the experimental period was equated against the additional weight gain achieved by dams and their lambs at the end of the experiment period.
Statistical Analysis: Data generated was subjected to statistical analysis by the General Linear Model procedure of Statistical Package for the Social Sciences, Base 20.0 (SPSS Software products, Marketing Department, SPSS Inc. Chicago, USA).

Results And Discussion
The average environmental parameters recorded during the experimental trial are provided in Table 1. The results have been presented in Table 2 and  Animals try to cope up with the environmental stresses by physiological adjustments. For implications following physiological parameters were recorded on weekly basis during the entire trial period.
Pulse rate: The changes in pulse rate in experimental ewes during the trial period have been presented in Decrease in pulse rate in animals kept outside could be attributed to physiological response of ewes to conserve energy. increase in BMR thereby leading to an increase in the respiratory rate. Increase in respiration rate may be reaction of homoeothermic animals to cold stress by enhancing the thermoregulatory mechanism to avoid undesirable increase in rectal temperature as has been reported earlier (Maurya et al., 2013). The changes in rectal temperature (°F) in experimental ewes during the trial period have been presented in Table 4.6 (c). In general it was found that G 3 had higher values followed by G 1 and G 2 . The rectal temperature (ºF) varied throughout the study period but overall higher values were observed for the group kept outside or exposed to cold. Results similar to present ndings have been reported earlier by Maurya et al. (2013) and Doubek et al. (2003) in Malpura and Merino and Romney sheep wherein they reported that animals in open house had higher rectal temperature than those provided protection against the cold weather. Ekpe and Christopherson, (2000) concluded that both cold exposure lowered rectal temperature which is in contrast with present ndings wherein animals housed outside with no supplementation had higher rectal temperature. Increase in rectal temperature might be as a result of activation of the thyrotropic axis together with shivering thermogenesis (Doubek et al., 2003). The hypothalamic-pituitary-thyroid (HPT) axis plays an essential role in the maintenance of metabolic homeostasis in response to alterations in metabolism and external environment. From the present study it can be concluded that Changthangi sheep are well adapted to climatic extremes and maintain homeostasis even under cold conditions. Managemental interventions re ect in the overall performance of the animals. Since different managemental interventions were adopted in the present study, a regular assessment of performance parameters was made in order to evaluate their effects which are discussed under following headings.

Effect of managemental interventions on fortnightly dam weight
Results obtained have been presented in Table 4. Overall, higher body weight (Kg) was obtained in G 2 followed by G 1 (2012) reported that supplementation of extra concentrate in ewes during peri-partum period results in improvement in growth performance of their lambs in terms of body weight which is in agreement with the present ndings. Higher birth weight could be attributed to higher plan of nutrition in the dams resulting in enhanced foetal growth during prenatal period while better weaning weight could be because of higher milk production in supplemented ewes. Results obtained have been presented in Table 5 (b). ADG was found to be signi cantly (P<0.05) higher in G 2 (160g/day) than G 3 (110g/day) during the rst month. Overall signi cantly (P<0.05) higher average daily gain was attained in G 2 (90g/day) followed by G 1 (80g/day) and G 3 (70g/day) at the end of three months. Results similar to present ndings have been reported earlier (Chaturvedi et al., 2003 andShah et al., 2012). Due to faster growing rates, ADG was higher during the rst month as compared to the following two months. Also, higher average daily gain ( rst month) in G 2 could be due to higher plan of nutrition in the dams resulting in better foetal growth during prenatal period whereas as better ADG during third month could be attributed to better pastures which in turn lead to higher milk production. Results obtained have been presented in Table 5 (c). In the experimental groups all dams gave birth to apparently healthy lambs without any assistance. No case of stillbirth or dystocia was recorded. One mortality each in G 1 and G 3 was recorded during the rst month wherein cause of the death was hypothermia. There was no mortality in G 2 wherein the animals were kept in closed shed and given extra supplementation. The results obtained have been presented in Table 6. Present study revealed that the supplementation of ewes which were kept inside the sheds during the trial period resulted in enhanced performance which was also re ected in the performance of their lambs. A net gain of Rs. 3672.15 was achieved in the group reared in a closed shed and supplemented with extra concentrate while a loss of Rs. 593 occurred in the group reared in open housing system with no supplementation. It can be concluded that the Changthangi ewes should be supplemented with better nutrition during prepartum period for better economic returns.  Wind Chill Index of animal houses