|تاریخ چاپ: 1399/05/18|
|اثر سن از شیرگیری بره بر عملکرد تولیدی و اقتصادی میش و بره بلوچی|
|نویسنده(گان):||مجید جعفری، رضا ولی زاده *، عباسعلی ناصریان|
|این آزمایش به منظور تعیین بهترین سن از شیرگیری بره برای افزایش بازده تولیدی و اقتصادی می شها و بره های بلوچی انجام شد. تعداد 30 راس 47 کیلوگرم و 30 راس بره آنها ( 15 راس نر و 15 راس ماده ) با میانگین وزن ± 0/ میش بلوچی تک قلوزا و شکم دوم زایش با میانگین وزن 5 8 و 12 هفتگی بعد ، 4/5 کیلوگرم به طور تصادفی به 3 گروه 10 راسی شامل 5 راس بره نر و 5 راس بره ماده تقسیم شدند. بره ها در سه سن 4 ± 0/05 از زایش به روش ناگهانی از شیر گرفته و می شها نیز خشک شدند. میزان افزایش وزن روزانه، وزن، ماده خشک مصرفی روزانه، فراسنجه های خونی بره ها در هفته دوازدهم بعد زایش، وزن و ماده خشک مصرفی روزانه میش ها در زمان از شیرگیری و نسبت اقتصادی سود به هزینه در هر تیمار با در قالب طرح کاملا تصادفی بررسی شد. بر اساس نتایج به دست آمده، زود از شیرگیری بره ها در سن 4 هفتگی SAS نرم افزار GLM استفاده از رویه موجب بهبود معن یدار در افزایش وزن روزانه، وزن، مقدار ماده خشک مصرفی روزانه در می شها و بره ها و کاهش مصرف شیر توسط بر ه ها شد . سطح سرم خون بره های از شیرگرفته شده در 4 هفتگی در مقایسه با دو گروه دیگر بالاتر بود. نسبت اقتصادی سود به هزینه IGF- و هورمون 1 ALP آنزیم نیز نشان داد از شیرگیری در 4 هفتگی می تواند موجب افزایش معنی دار سود دامدار در مقایسه با دو روش دیگر شود.|
|کلیدواژگان:||افزایش وزن روزانه، سن از شیرگیری، فراسنجه های خونی، نسبت سود به هزینه|
|نوع مقاله:||مقاله پژوهشی/اصیل|
|انتشار در:||فصلنامه پژوهشهای علوم دامی ایران، سال دهم شماره 4 (زمستان 1397)|
|نسخه الکترونیکی:||متن این مقاله در سایت مگیران قابل مطالعه است.|
|Effects of Weaning Age on Production and Economic Performance of Baluchi Ewe and Lamb|
|Author(s):||Majid Jafari، Reza Valizadeh *، Abbas Ali Naserian|
IntroductionEarly-weaning of lambs could led to improve the efficiency and profitability of Baluchi ewes and lambs in Iranian sheep husbandry. Early weaning of lambs can stimulate growth of gastrointestinal tract, minimize weaning stress and guarantee post-weaning health. However, results on weaning age of lambs vary widely because of the effects of available feeds, feeding management and genotype. Iranian rural and nomadic herders are usually weaning their lambs when the pastures are in good condition. Reducing the duration of suckling lamb can be associated with optimal results, including sales of surplus milk of ewes and helping the herder household’s economy and entering the early weaned lambs into the feedlot systems and breed the ewes in a well-controlled condition. The aim of this study was to determine the appropriate weaning age of Baluchi lambs to achieve the better production and economic performances as well as the higher ewe's reproductive efficiency.
Materials and MethodsThirty monoparous Baluchi ewes in their second lambing with an average body weight of 47± 0.5 (Kg) and their lambs (15 males and 15 females with an average birth weight of 4.5 ± 0.05 Kg) were allocated to the experimental groups randomly. The lambs were left with their mothers for 3 days, in order to consume adequate colostrum and then were divided into 3 groups according to their gender (5 males and 5 females in each group) and kept in individual boxes. The experimental ewes were also kept separately in individual boxes. These lambs were allowed to be with their mothers twice a day for 2 hours. Lambs had free access to water and TMR ration including 10% Alfalfa leaves and 90% concentrate. Ewes also had free access to water and a TMR ration containing 65% alfalfa hay and 35% concentrate. The respective lambs were weaned at ages of 4, 8 and 12 weeks, abruptly and fed with the above noted TMR ration. The birth weight of each lamb and the weight of ewes were recorded at birth and until the end of the test weekly, each of the ewes and lambs were weighed individually before morning feeding. During the experiment, every two weeks, samples were taken from forage, consumed concentrate and existing residues, and their dry matter and nutrient content were determined. The average daily weight gain, weight fluctuations, dry matter intake, milk consumption and blood parameters at age of 12 weeks in lambs, weight fluctuations, dry matter intake at weaning time in ewes and benefit to cost ratio were measured. Data were analyzed with Proc GLM of SAS (9.1) software in completely randomized design.
Results and DiscussionBased on the results, early weaning of lambs at age of 4 weeks led to a significant (P<0.05) improvement in average daily weight gain, body weight, dry matter intake, reduction in milk consumption at the end of week 12 by lambs, and improvement in body weight and dry matter intake at the weaning time by ewes. Also, the daily milk consumption of lambs showed that the production of milk decreased gradually from the ninth week after lambing. ALP enzyme levels and IGF-1 hormone in serum of lambs weaned at age of 4 weeks were higher in comparison with the other 2 groups. In this experiment, the average cost of feed for lambs weaned at age of 4 weeks was significantly higher than the other two groups, and in the ewes, this ratio was in contrast. On the other hand, the average cost of milk consumed by lambs in the three groups was completely reverse the feeds and the differences between groups were significant. The cost of labor was also significant in the groups due to the variability of the number of days. Average weight loss of ewes from lambing to weaning their lambs at age of 4 weeks was significantly lower than the other two groups. The average benefit from lamb weight gain in the group weaned at age of 4 weeks was significantly higher than the other two groups. Also, the benefit from ewe weight gain from the weaning to mating (2 weeks after weaning) was significantly higher in the ewes weaned their lambs at age of 4 weeks than in the other two groups. The benefit to cost indicator showed weaning of lambs at age of 4 weeks could be a suitable and economical management practice in rural and nomadic situation in sheep industry.
ConclusionThe obtained results revealed that early weaning of lambs (at age of 4 weeks) may be regarded as a method of lambs and ewes' management in Iranian sheep husbandry. Preparing ewes for the next pregnancy and reducing the lambing interval are the noticeable results. The offered feeds can be used efficiently, and ewe's readiness for the next pregnancy increased by lowering metabolic stress. Furthermore, according to the benefit to cost ratio indicator, better economical outcome could be resulted.
|Keywords:||Age of weaning، Benefit to cost ratio، Blood parameters، Body weight، Early-weaning|
|Article Type:||Research/Original Article|
|Published:||Iranian Journal of Animal Science Reaserch, Volume:10 Issue: 4, 2019|
|Full text:||PDF is available on the website.|