| Livestock Research for Rural Development 29 (7) 2017 | Guide for preparation of papers | LRRD Newsletter | Citation of this paper |
The study was conducted to investigate the effects of non-genetic factors on pre weaning growth, survivability, and litter size of Boer x Central Highland goats semi-intensively managed at on station. A total of 585 records from Boer cross goat were collected from 2009 to 2014 and analyzed. The overall mean±standard error for birth weight, one month, two month, three month weight and pre weaning growth rate of kids were 2.6±0.02 kg, 5.75±0.07 kg, 8.06±0.11kg, 9.63 kg and 77.4±1.6 g/day respectively. Pre weaning live weight and growth rate of kids were influenced by non genetic factors such as birth type, sex of kid, kid birth weight, season, year and age of dam.; but were not affected by genetic factors such as dam genotype and kid blood level.
The overall survivability indices of Boer x Central Highland goats were 88.8±1.3%, 84.1±1.5%, 75.8±1.7%, 65.9±1.9%, and 62.7±2.0% up to one month, two month, three month (weaning age), six month and yearling age, respectively. Survival of kids was negatively correlated with litter size. Kids born from Central Highland goat had higher survival rate than those of kids born from 50% Boer x Central Highland goats. Survivability of kids with 50% blood level was better for kids with 75% blood level (86.6±1.6 vs. 77.8±3.7%) up to two month and (78.0±1.9 vs 70.4±4.1%) up to weaning age; but there was no difference for post weaning survivability. Survivability of kids increased linearly with birth weight. Kids born in the dry season had higher survival rate up to one month and two months than kids born in short and main rain seasons. However, post weaning survivability of kids born in main and short rain seasons was higher than for kids born in the dry season. The lowest survival rate was observed in 2011 and 2014. Maximum pre weaning and post weaning survival rate was observed for kids from 3 and 4 year old goats and minimum survival rate for kids from 2 year old goats. Pre weaning survival rate of kids increased with dam age up to 4 years and slightly decreased for kids from 5 year does. Sex had no effect on survivability of kids. Overall mean litter size of was 1.75±0.02 for Central Highland goats and 1.62±0.03 for Boer x Central Highland goats. Litter size of Central Highland goat was influenced by year of kidding. However, sex and season had no effect on litter size of both local and crossbred dams. Increasing litter size decreased kid survivability.
Key words: cross-breeding, litter size, mortality
Ethiopia has the largest livestock population among African countries and has different agro-ecological zones ranging from semi-arid to arid environments which are suitable for goat production. There are approximately 570 breeds and types of goats in the world of which 89 are found in Africa (Gala 2005).The present estimated population of goats in Ethiopia is estimated to be about 29.70 million. Out of these total goats, 71.57 percent are females and about 28.43 percent are males (CSA 2016). Goats play important roles in communities by improving the livelihood of resource-challenged farmers by creating alternative employment opportunities, enhancing family income by sale of live animals, skin, manure etc. Apart from contributing to human nutrition in form of meat and milk, they also act as an income buffer to the risks associated with erratic climatic changes (Rumosa et al 2009).
Despite huge number and genetically diverse, Ethiopian indigenous goats are genetically less productive as compared to temperate breeds (Mohammed et al 2012). Annual meat production is estimated 8–10 kg per sheep and goats slaughtered (Ameha 2008). Therefore, increasing the current level of productivity is essential to provide meat to the ever-increasing human population, to increase export earnings and household income thereby improving the living standard of smallholders (Markos 2006).
The Boer goat is a famous meat purpose breed for its rapid growth, excellent meat quality and high fertility (Malan 2000). Thus, the use of Boer bucks as terminal sires should yield crossbred kids that grow faster and produce a more uniform and well-muscled carcass (Cameron et al 2001). In Ethiopia, Boer goat has been used in crossing with the indigenous goat breeds to improve their productivity. Central Highland goat is one of the indigenous Ethiopian breed that are crossed with Boer goat in order to improve productivity with the objective of distributing F1 crossbred male Central Highland x Boer goat for farmers produced from the research center station. The skins from Central Highland goats are well known as the best quality skin 'Bati Genuine' of brown/fawn colored goats in the Bati area of Wollo which was used as an important export product (Farm-Africa 1996).
Genetically and environmental factors are dramatically affect the goat production. Among these factors, pre weaning mortality of young kids is the essential problem for the breeders. Mortality is documented as the main factor adversely affecting goat production in the tropics. Kid losses, as high as 50%, have been recorded in Ethiopia with the highest losses occurring before weaning (Dereje et al 2015).
Birth weight, litter size and pre-weaning survivability are important traits that can affect the profitability of the goat enterprise. In some livestock species, these traits are affected by a number of environmental factors (Hagan et al 2014). Non-genetic factors are largely expected to contribute to kid and/ or lamb mortality (Vostry and Milerski 2013) and affect production potential (Gbangboche et al 2006). Moreover, Rapid growth during the early period can minimize the cost of rearing and thus provide more profit to the farmers. The birth weight and early growth rate of animals are determined not only by genetic potential but also by maternal and environmental factors (Mandal et al 2006). Therefore, Knowledge of the non-genetic factors on production traits allows a more accurate assessment of breeding values. However, information is lacking in this regard, and no study has yet been conducted to identify factors affecting survival rate and pre weaning growth of this crossbred goats. Hence, this study was conducted to determine influences of non-genetic factors on survivability, pre weaning growth and litter size of Boer x Central Highland goats in North Eastern Ethiopia.
The study was conducted at Sirinka Agricultural Research Center sheep and goat breeding, evaluation and distribution site which is found in Eastern Amhara Rigional State of Ethiopia. The site is located 508 km away from Addis Ababa and 372 km from Bahirdar capital city of the Region at an altitude of 1850 m.a.s.l and at 110°451’ 0011" N and 390°361’ 3611" E.The rainfall pattern is bimodal, with two-rainfall season, ‘belg’ (Feb./Mar.- April) and ‘meher’(July-Sept.). During the study period the mean annual rainfall amount was on average about 1064 mm. The area has a moderate warm temperature zone with mean daily temperature range of 20.18 °C.
|
Table 1. Mean monthly rainfall distribution, temperature and
humidity data for 6 |
|||
|
Months |
Rainfall |
Temperature |
Humidity |
|
January |
25.68 |
17.27 |
72.07 |
|
February |
14.95 |
18.80 |
61.43 |
|
March |
57.76 |
19.87 |
61.71 |
|
April |
98.67 |
21.28 |
60.59 |
|
May |
88.42 |
21.86 |
57.77 |
|
June |
86.88 |
23.71 |
47.01 |
|
July |
204.64 |
22.65 |
58.37 |
|
August |
326.20 |
20.99 |
69.81 |
|
September |
55.41 |
21.15 |
67.14 |
|
October |
31.84 |
19.66 |
63.93 |
|
November |
46.66 |
17.81 |
65.31 |
|
December |
47.90 |
17.06 |
66.09 |
|
Mean |
90.42 |
20.18 |
62.60 |
Central Highland goat and their cross with Boer goats were the study subjects. The animals were managed intensively and semi-intensively. Newly born kids were kept together for 3-5 days with their mother then after kids were isolated and suckled three times per day at morning, mid-day and evening until weaning (3 months) age. Kids had access to concentrate feed in addition to their dam’s milk until weaning. After weaning male kids kept intensively within individual pen and fed by using chopped grass hay as basal feed and supplemented concentrate mix (Noug cake and wheat bran) 200 g/d/kid until they were distributed to farmers. However, female kids were kept separately from their does and allowed to graze on natural pasture for 6:00 hours per day from 9:00-11:00 in the morning and from 14:00-16:00 in the afternoon and housed in semi opened concrete barns at night. In addition to grazing/browsing pregnant does at late gestation, and lactating doe’s at early lactation were supplemented with concentrate mixture of 400 g/d/animal and cultivated forages However, the supplementation of the flock is not regular. All animals had access to water freely.
Goats kidding throughout the year following natural controlled breeding program. Does were mated in single sire groups of at least 30 does for one buck. At mating does were herded with their respective sire groups during the day time and depart for the night time. The birth weight was taken within 24 hours and the animal identified by using ear tagging. During summer period, most of the time all flocks was fed indoor to prevent tick infestation. Goats were vaccinated against sheep and goat pox, Anthrax, and pestides petites ruminitis (PPR). They were treated regularly for internal and external parasites. All animals were dipped and sprayed for ticks, mites and other ecto parasites with Diazinon 60% and Amitrazine (12.5%) and regularly drenched for internal parasites with Albendazole for treatment and for prophylaxis measure.
A total of 585 birth weights, 1 month weight, 2 month weight, 3month weight, birth type, litter size and survivability records on Boer x Central Highland goats were collected from 2009 to 2014. Birth weight was defined as the weight of a kid within 24 hours of birth. Birth type was the number of kids born per doe per parturition. Survivability was defined as the percentage of kids alive at the time of 1 month, 2 month and 3 month, 6 month and yearling age. Kids were weighed monthly on suspended weight balance of 200 g precision after they forced to fast overnight in order to avoid effect of gut fill. Dam age was recorded only for crossbred does born at on station, but not determined for local goats as they bought from local market. Still births and abortion cases were not included in survival analysis. Season of birth were categorized as dry (October-February), short rain (March- June) and main rain (July- September).
Preliminary data analysis like homogeneity test, normality test and screening of outliers were employed before conducting the main data analysis by using Gen Stat 18 Edition statistical software. Survival rate was studied from birth to one month, birth to two month, birth to weaning, birth to six month and birth to yearling age. Kid’s records were coded 1 for survival to 1 month, to 2 month, to 3 month, to 6 month and to yearling age and 0 for dead kids before 1 month, 2 month, 3 month, 6 month and yearling age. Finally data were analyzed using the Generalized Linear Model procedure of the Statistical Analysis System (SAS 2002) and differences between means of a trait for different factors were tested using Duncan Multiple Range Test.
The statistical model for pre weaning weight and survivability was as follows:
Yijklmnop = µ + Li + Sj + Xk + Dl + Tm+ Bn+ Go+ Wp + eijklmnop
Where:
Yijklmnop= pre weaning weight and pre-weaning survivability
µ = overall mean
Li = fixed effect of the ith birth type (3 levels: single, twin, and triple)
Sj = fixed effect of the jth season of birth (3 levels: main rain, short rain, and dry)
Xk = fixed effect of the kth sex of kid (2 levels: male and female)
Dl = fixed effect of the lth age of doe (5 levels: 1,2,3,4 and 5)
Tm = fixed effect of the mth year of birth (6 levels: 2009-2014)
Bn= fixed effect of the nth blood level (2 levels:50% and 75%)
Go = fixed effect of the othdam genotype (2 levels: local and cross)
Wp= fixed effect of the pth birth weight (4 levels)
eijklmnop= random error term associated with each observation
For prolificacy/litter size, the model used was as follows:
Yijkl = µ + Si + Dj + Tk +B l + eijkl
Where:
Yijkl = litter size (3 levels)
µ = overall mean
Si = fixed effect of the ith season of birth (3 levels)
Dj = fixed effect of the jth age of doe (5 levels)
Tk = fixed effect of the kth year of kidding (6 levels)
Bl= fixed effect of the breed (2 levels)
eijkl = random error term associated with each observation.
For all traits the effect of dam age was analyzed separately for crossbred goats as the definite age of Central Highland goats was not known.
Pre weaning body weight and growth rate are summarized in (Table 2). Birth weight of Boer x Central Highland goat kids (2.6±0.02 kg) in this study relatively higher than the result 2.01±0.03 kg reported by Deribe and Taye (2013) for central Highland goats, 2.42±0.05 kg for Borena and 2.19±0.08 kg for Short-eared Somali goats reported by Hulunim (2014) and lower than the result reported by Berhane and Eik (2006) 3 to 3.5 kg for Begait and Abergelle goats under improved management condition. Results of the present study for weaning weight (9.63±0.15 kg) were lower than the value of 12.8 kg (pure Boer), 10.8 kg (Boer x Baladi) goat kids reported by (Salama et al 2015) under semi intensive management and higher than the result observed by Mahlet (2008) for Arsi Bale goat (9.2kg) under station management. The result reported by Belay et al (2014) was 2.9 kg at birth weight and 15.3 kg at weaning weight for Boer x Abergele goats weaned at 4 month age were higher than the current result for CHG x Boer goats 2.69 kg at birth weight and 9.63 kg at weaning weight. This might be due to breed type and management variation for kids and does during critical physiological stages. Andualem et al (2016) reported that there was a positive relationship (r = 0.82) between weaning weight of kids and average daily milk yield of their respective mothers. Supplementary feed increased milk yield and thereby enhancing growth performance of kids. Hence growth rate of kids was influenced by the milk yield produced by their respective does.
Effect of birth type
Kids born as single were higher in pre weaning body weight and growth rate than twins and triplets. Similarly, Belay and Mengistie (2013), and Alula et al (2013) also reported that kids born as singles were heavier than twins and triplets. This difference is probably due to the intrauterine environment where a higher availability of nutrients to the single kid, lack of competition as well as more space may facilitate growth. The uterine space and available nutrient shared by more than one kid may be responsible for the reduced birth weight with increasing litter size. It was also crucial to improve the feeding and management especially for higher number of litter (twins and triplets) in maintaining the body weight during mating and pregnancy in order to increase birth weight and daily gain and also attain good weaning weights.
Effect of sex
Male kids were heavier than females at birth and at weaning. These results agree with previous studies in other breeds by several authors Sodiq (2012) on Ettawah grade goat and Zhang et al (2009) on Boer goat. It has been attributed that the growth superiority of male kids to higher birth weight and presence of androgens, which play a role in growth (Nkungu et al 1995; Kiango 1989). Differences in sexual chromosomes, probably in the position of genes related to growth, physiological characteristics, difference in endocrinal system (type and measure of hormone secretion especially sexual hormones) lead to difference in animal growth. In relation to endocrinal system, estrogen hormone has a limited effect on the growth of long bones in females. That could be one of the reason in which females have smaller body and lighter weight against males (Baneh and Hafezian 2009).
Effect of dam genotype and kid blood level
Even though, the difference was non-significant birth weight, weaning weight and pre weaning average daily gain of kids from Central Highland dam were slightly higher than kids from Boer x Central Highland dam. And also kids with 50% blood level had slightly higher birth weight, weaning weight and pre weaning average daily gain than kids with 75% blood level. It is expected that when the blood level increases the growth performance also increases. However, it is only true when there is improved management. During this study both blood levels were managed equally; this might be the reason for lack of variation between blood levels.
Effect of birth weight
Weaning weight and average daily gain of kids were increases in line with birth weight of kids (Table 2).This result agrees with Mioc et al (2011) reported for Croatian multicolored goat kids.
Effect of season
The mean birth weight of kids born in the short rainy season (2.67±0.03 kg) was heavier than those born in the dry (2.57±0.03kg) and main rain (2.43±0.06 kg) seasons. The effect of season may be explained partly by the climatic conditions and feed availability during mating and pregnancy of dam. Season of birth plays an important role in growth performance indirectly through its influence on the dam's nutrition and hence amount of milk available to the unweaned kids. However, there was no significant difference observed between seasons for weaning weight and pre average daily gain of kids.
Effect of year
The poor performance of kids was observed in year 2009, 2011 and 2014.Variation in the weather, nutrition and farm management from year to year might be responsible for the variation of kids weight and growth. This difference might be due to younger dams in 2009, high diarrhea case in 2014, and a critical feed shortage at the farm in 2011 which might have caused nutritional stress during late gestation period that might have resulted in loss of dams’ body weight, induced retardation of fetal growth and reduced birth weight.
Effect of dam age
Birth weight, weaning weight and pre weaning average daily gain of kids increases as dam age increases. This observation could be linked to the explanations given by Bemji et al (2006) that live-weight of does increased significantly with parity which reflected on the birth weights of their kids. This should also have effect on their early growth rate. These findings are in agree with several reports by Sodiq (2012), Jimenez-Badillo et al (2009), and Hermiz et al (2009). This fact is probably due to the development of the physiological processes with increase in parity of the dam (Sodiq 2012).
|
Table 2. Mean ± standard error of birth weight, 1 month, 2 month, 3 month weight and pre weaning average daily gain of Boer x Central Highland kids. |
||||||||||
|
Source of |
Birth weight |
1 month weight |
2 month weight |
3 month weight |
(Birth-3month) ADG |
|||||
|
N |
Mean± SE |
N |
Mean ±SE |
N |
Mean ±SE |
N |
Mean ±SE |
N |
Mean ±SE |
|
|
Over all |
585 |
2.6±0.02 |
515 |
5.75±0.07 |
492 |
8.06±0.11 |
443 |
9.63±0.15 |
441 |
77.4±1.6 |
|
Cv% |
585 |
9.3 |
515 |
21.3 |
492 |
24.5 |
443 |
26.6 |
441 |
36.6 |
|
Birth type |
P <.0001 |
P <.0001 |
P< .0001 |
P <.0001 |
P< .0001 |
|||||
|
Single |
184 |
2.9±0.04a |
165 |
6.98±0.14a |
162 |
9.68±0.22a |
149 |
11.5±0.29a |
149 |
95.6±3.1a |
|
Twine |
389 |
2.46±0.02b |
341 |
5.17±0.07b |
321 |
7.3±0.1b |
288 |
8.7±0.14b |
286 |
68.1±1.5b |
|
Triple |
12 |
2.18±0.14c |
9 |
4.6±0.47b |
9 |
5.7±0.53c |
6 |
8.3±0.78b |
6 |
65.5±9.5b |
|
Sex |
P =0.0004 |
P =0.005 |
P =0.011 |
p =0.011 |
P =0.03 |
|||||
|
Male |
271 |
2.69±0.03a |
238 |
5.97±0.12a |
227 |
8.36±0.18a |
200 |
10.0±0.24a |
198 |
81.2±2.5a |
|
Female |
314 |
2.52±0.02b |
277 |
5.56±0.09b |
265 |
7.8±0.14b |
243 |
9.28±0.18b |
243 |
74.2±1.9b |
|
Dam genotype |
P = 0.67 |
P = 0.76 |
P= 0.19 |
P= 0.23 |
P= 0.23 |
|||||
|
Cross |
211 |
2.56±0.04 |
178 |
5.77±0.14 |
168 |
8.32±0.2 |
146 |
9.4±0.26 |
146 |
75.1±2.6 |
|
Local |
374 |
2.62±0.02 |
337 |
5.74±0.09 |
324 |
7.92±0.13 |
297 |
9.74±0.18 |
295 |
78.5±1.9 |
|
P = 0.30 |
P =0.06 |
P =0.22 |
P =0.14 |
P =0.13 |
||||||
|
50% |
455 |
2.58±0.02 |
403 |
5.7±0.08 |
394 |
7.9±0.12 |
355 |
9.6±0.16 |
355 |
77.2±1.8 |
|
75% |
126 |
2.7±0.05 |
110 |
5.19±0.17 |
98 |
8.46±0.26 |
88 |
9.74±0.34 |
88 |
78.0±3.6 |
|
P <.0001 |
P< .0001 |
P <.0001 |
P< .0001 |
P< .0001 |
||||||
|
<1.5kg |
12 |
1.3±0.04d |
11 |
3.1±0.19d |
8 |
4.2±0.29d |
4 |
5.6±0.56d |
4 |
47.5±7.1c |
|
1.5-2.49kg |
242 |
2.12±0.01c |
203 |
4.7±0.08c |
187 |
6.8±0.13c |
169 |
8.2±0.19c |
168 |
67.3±2.16bc |
|
2.5-3.49kg |
298 |
2.9±0.01b |
270 |
6.3±0.09b |
268 |
8.7±0.14b |
243 |
10.2±0.18b |
242 |
80.8±2.05b |
|
≥3.5kg |
33 |
3.8±0.04a |
31 |
8.3±0.31a |
29 |
11.5±0.52a |
27 |
14.1±0.77a |
27 |
114±8.5a |
|
Season |
P =0.002 |
P =0.045 |
P =0.14 |
P= 0.43 |
P =0.22 |
|||||
|
Main rain |
76 |
2.43±0.06c |
64 |
5.33±0.23b |
61 |
7.85±0.36 |
59 |
10.13±0.5 |
59 |
84.5±5.24 |
|
Short rain |
282 |
2.67±0.03a |
240 |
5.71±0.1a |
225 |
8.07±0.15 |
207 |
9.61±0.2 |
207 |
76.0±2.1 |
|
Dry |
227 |
2.57±0.03b |
211 |
5.92±0.12a |
206 |
8.18±0.18 |
177 |
9.48±0.24 |
175 |
76.54±2.5 |
|
Year |
P =0.04 |
P <.0001 |
P <.0001 |
P< .0001 |
P< .0001 |
|||||
|
2009 |
102 |
2.45±0.04c |
92 |
5.05±0.13c |
90 |
7.02±0.22c |
85 |
8.92±0.30dc |
85 |
71.3±3.28b |
|
2010 |
129 |
2.79±0.04a |
120 |
6.14±0.15b |
112 |
8.4±0.23b |
105 |
10.6±0.31b |
105 |
86.0±3.3a |
|
2011 |
92 |
2.48±0.05c |
81 |
5.31±0.13c |
75 |
7.25±0.23c |
63 |
8.06±0.27d |
62 |
61.3±2.74c |
|
2012 |
83 |
2.85±0.06a |
70 |
6.6±0.23a |
65 |
9.5±0.34a |
62 |
11.5±0.5a |
62 |
95.1±5.38a |
|
2013 |
115 |
2.65±0.05b |
104 |
5.91±0.17b |
101 |
8.26±0.24b |
86 |
9.36±0.29c |
85 |
74.3±2.97b |
|
2014 |
64 |
2.16±0.07d |
48 |
5.28±0.26c |
49 |
8.12±0.4b |
42 |
8.8±0.47dc |
42 |
71.8±4.8b |
|
P =0.005 |
P =0.002 |
P =0.004 |
P <.0001 |
P =0.0002 |
||||||
|
1 year |
11 |
2.4±0.16ab |
10 |
5.0±0.47bc |
10 |
7.15±1.0bc |
9 |
7.6±1.14b |
9 |
64.0±9.5b |
|
2 year |
44 |
2.4±0.07ab |
36 |
4.87±0.25c |
29 |
6.95±0.35c |
21 |
7.8±0.43b |
21 |
59.0±4.5b |
|
3 year |
57 |
2.73±0.09a |
50 |
6.29±0.34a |
44 |
9.4±0.45a |
43 |
11.5±0.64a |
43 |
96.5±6.6a |
|
4 year |
70 |
2.7±0.06ab |
64 |
6.17±0.21ab |
62 |
8.45±0.3abc |
54 |
9.23±0.38b |
54 |
73.0±3.7b |
|
5 year |
37 |
2.37±0.07b |
26 |
6.07±0.38ab |
31 |
8.75±0.57ab |
27 |
9.4±0.69b |
27 |
76.4±7.01b |
|
Means within a column and factor bearing different superscripts are significantly different at p<0.05; N=number of sample size and SE: Standard error 1year includes 12 month to 18 months. |
||||||||||
Pre weaning and post weaning survival rate of Boer x Central Highland goats is summarized in (Table 3). This study indicates that pre weaning mortality rate was about 24.2% which is lower than 25-31% pre weaning mortality rate of Arsi Bale goat under station management condition (Hailu et al 2006; Mahlet 2008). And higher than result of Zeleke (2007) pre-weaning mortality rate recorded for Somali goats under station management at Hwassa and Haramaya Universities is about 12 %.
The increasing of litter size was negatively influence the survival rate of kids. Similarly, Adenaike and Bemji (2011) reported that high litter size negatively affect kids survival. The lower survivability observed with increased litter size can be attributed to reduced birth weight of kids (Snyman 2010) as litter size increases reducing their chances of survival. Single born kids also had higher survivability up to six month and up to yearling age than triple kids although not significantly different from twine born kids (Table 3). These might be due to higher birth weight of single born kids. That means kids with heavy weight have better survival rate than those light kids. Survival rates tended to increase with the increase in birth weight (Debele et al 2011).
Sex of kids had not influence on pre weaning and post weaning kid survival rates. These results in agreement with Browning and Leite-dBrowning (2014) for Boer, Kiko, and Spanish meat goat breeds semi intensively managed on humid subtropical pasture. Similar result was observed by Hagan et al (2014) for West African Dwarf goats, Al-Najjar et al (2010), Deribe et al (2014) and Al-Najjar et al (2010) for Shami goats.
Kids born from Central Highland goats had higher survival rate up to weaning, up to six month and up to yearling than those of kids born from 50% Boer x Central highland goats, but not different up to one month. Similar result was obtained by Perez et al (1998) for Alpine, Granadina, Nubian, Saanen and Toggenburg goat breeds.
Survivability of kids with 50% blood level were higher than kids with 75% blood level up to two month and up to weaning age. But, no difference was observed for survivability up to one month, six month and yearling age. This might be due to poor management: as blood level increases they need better management for survival. However, in this study both blood levels were treated equally.
Pre weaning and post weaning survival rate was affected by birth weight of kids (Table 3). Survival rates tended to increase with the increase in birth weight. Finding of this study agree with the result obtained by Debele et al (2011), Singh et al (1990), and Singh (1991). Birth weight of kids was positively correlated with other growth traits. The correlation coefficients between birth weights and each 1 month, 2 month and 3 month weight were 0.65, 0.53 and 0.47 respectively.
Kids born in dry season were significantly higher survival rate up to one month and two month than kids born in short and main rain seasons. Similarly, Debele et al (2011) reported that higher percent 16.4% (n=88) kids were died in wet season followed by dry 4.5% (n=24) season of the year for Arsi-Bale goats. These might be due to cold stress of short and main rainy season, variation of feed availability and diseases incidences. However, post weaning survivability of kids born in main and short rain seasons was higher than for kids born in the dry season,;but no difference was observed between kids born in main rain and short rain. Such fluctuation in survivability might be attributed to variation in climatic conditions and heavy incidences of some specific disease(s) in a particular season. According to Debele et al (2011) most of goats affected by internal parasite during wet and early dry season and growing kids are more susceptible for internal parasite than adult goats.
The lowest survival rate was observed in 2011 and 2014. This might be due to lower birth weight of kids in 2011 and 2014. However, no systematic trend in relation to year of kidding was observed for survival rate up to one month, two month, three month (weaning), six month and yearling. But defined significant differences among the years might be effects of diseases prevalence, feed availability, climatic conditions, and managerial systems This finding in agreement with the result of Al-Najjar et al (2010) for Shami goats and Hagan et al (2014) for West African dwarf goats.
Maximum pre weaning and post weaning survival rate was observed for kids from 3 and 4 year goats and minimum survival rate for kids from 2 year does. Pre weaning survival rate of kids increases with dam age up to 4 year and slightly decreases for kids from 5 year age of does. This probably due to milk producing ability and body condition of does; young does may not produce enough amount of milk to nurse their kids and lower birth weight of kids from very aged does. Similarly, Chowdhury et al (2002) for Black Bengal goat, and Al-Najjar et al (2010) for Shami goats reported that pre weaning survivability was found to be increases linearly with increasing parity or dam age.
|
Table 3. Means ± standard error (SE) of pre-weaning survivability (%) as influenced by different non genetic and genetic factors |
||||||
|
Source of |
Pre weaning survival rate |
Post weaning survival rate |
||||
|
Up to 1month |
Up to 2month |
Up to 3month |
Up to 6 month |
Up to year |
||
|
N |
Survival % |
Survival % |
Survival % |
Survival % |
Survival % |
|
|
Cv % |
585 |
33.2 |
41.0 |
54.1 |
65.7 |
70.1 |
|
Over all |
585 |
88.8±1.3 |
84.1±1.5 |
75.8±1.7 |
65.9±1.9 |
62.7±2.0 |
|
Birth type |
P =0.02 |
P =0.26 |
P =0.013 |
P= 0.025 |
P= 0.042 |
|
|
Single |
184 |
91.8±2.0a |
88.0±2.4 |
81.9±2.8a |
72.2±3.3a |
68.4±3.4a |
|
Twine |
389 |
87.9±1.6ab |
82.5±1.9 |
73.8±2.2a |
63.7±2.4a |
60.6±2.4ab |
|
Triple |
12 |
75.0±13.0b |
75.0±13.0 |
50.0±15.1b |
41.6±14.8b |
41.6±14.8b |
|
Sex |
P =0.83 |
P =0.47 |
P =0.12 |
P =0.11 |
P =0.06 |
|
|
Male |
270 |
88.9±1.9 |
83.7±2.2 |
73.7±2.6 |
63.4±2.9 |
59.4±2.9 |
|
Female |
314 |
88.8±1.7 |
84.3±2.0 |
77.7±2.3 |
68.1±2.6 |
65.6±2.6 |
|
Dam genotype |
P =0.47 |
P =0.04 |
P =0.027 |
P<. 0001 |
P<. 0001 |
|
|
Cross |
211 |
87.2±2.3 |
79.1±2.8b |
69.5±3.1b |
54.5±3.4b |
52.1±3.4b |
|
Local |
374 |
89.8±1.5 |
86.8±1.7a |
79.4±2.1a |
72.4±2.3a |
68.7±2.4a |
|
Blood level |
P =0.36 |
P <.0001 |
P =0.001 |
P =0.62 |
P =0.72 |
|
|
50% |
455 |
90.1±1.4 |
86.6±1.6a |
78.0±1.9a |
67.0±2.2 |
64.2±2.2 |
|
75% |
126 |
87.3±2.9 |
77.8±3.7b |
70.4±4.1b |
64.2±4.2 |
62.8±4.2 |
|
Birth weight |
P =0.21 |
P =0.005 |
P =0.012 |
P= 0.003 |
P= 0.007 |
|
|
<1.5kg |
12 |
91.6±8.3 |
53.8±14.8b |
41.6±14.8b |
8.3±8.3c |
8.3±8.3c |
|
1.5-2.49kg |
242 |
83.5±2.4 |
77.6±2.7a |
69.8±2.9a |
57.8±3.1b |
54.1±3.2b |
|
2.5-3.49kg |
298 |
92.6±1.5 |
89.9±1.9a |
81.4±2.2a |
73.1±2.5ab |
70.1±2.6ab |
|
≥3.5kg |
33 |
94.0±4.2 |
87.8±5.7a |
81.8±6.8a |
81.8±6.8a |
78.7±7.2a |
|
Season |
P <.0001 |
P <.0001 |
P =0.15 |
P= 0.008 |
P =0.006 |
|
|
Main rain |
76 |
84.2±4.2b |
80.2±4.6b |
77.6±4.8 |
72.3±5.1a |
68.4±5.3a |
|
Short rain |
281 |
85.1±2.1b |
79.7±2.4b |
73.6±2.6 |
67.7±2.7ab |
65.2±2.8a |
|
Dry |
227 |
95.1±1.4a |
90.7±1.9a |
77.9±2.7 |
61.6±3.2b |
57.7±3.2b |
|
Year |
P =0.001 |
P =0.013 |
P= 0.009 |
P <.0001 |
P<. 0001 |
|
|
2009 |
102 |
90.1±2.9a |
88.2±3.2a |
83.3±3.7a |
79.4±4.0a |
76.4±4.2a |
|
2010 |
129 |
93.0±2.2a |
87.6±2.9a |
81.4±3.4a |
75.9±3.7a |
72.0±3.9a |
|
2011 |
93 |
86.0±3.6ab |
80.6±4.1ab |
67.7±4.8b |
47.3±5.2b |
41.9±5.1b |
|
2012 |
82 |
85.3±3.9ab |
79.2±4.5ab |
75.6±4.7ab |
75.6±4.7a |
75.6±4.7a |
|
2013 |
115 |
93.0±2.3a |
87.8±3.0a |
74.5±4.1ab |
69.5±4.3a |
67.8±4.3a |
|
2014 |
64 |
79.6±5.0b |
75.0±5.4b |
67.1±5.9b |
32.8±5.9c |
26.5±5.5c |
|
Dam age |
P = 0.47 |
P =0.046 |
P =0.001 |
P =0.0001 |
P<.0001 |
|
|
1year |
13 |
84.6±1.0 |
76.9±12.1ab |
69.2±13.3ab |
53.8±14.3ab |
53.8±14.3ab |
|
2 year |
46 |
73.9±6.5 |
63.0±7.1b |
47.7±7.6b |
28.2±6.7c |
28.2±6.7c |
|
3 year |
57 |
89.4±4.1 |
77.1±5.6ab |
76.7±5.6a |
68.4±6.2a |
66.6±6.2a |
|
4 year |
71 |
90.1±3.5 |
87.3±3.9a |
77.1±5.0a |
53.8±14.3a |
66.2±5.6a |
|
5 year |
37 |
86.4±5.6 |
81.0±6.5ab |
72.9±7.4a |
37.8±8.0bc |
32.4±7.8bc |
|
Means within a column and factor bearing different superscripts are significantly different at p<0.05; N=number of sample size and SE: Standard error and 1year includes 12 month to 18 months. |
||||||
Litter size of Central Highland and their crosses with Boer goat presented in (Table 4). Overall mean litter size of was 1.75±0.02 for Central Highland goat and 1.62±0.03 for Central Highland x Boer goat. The findings of this study were higher than many reports for indigenous goats; 1.08 for Abelgele goat kept under on station condition reported by Belay et al (2014), 1.64 for Arsi-Bale goat kept under station condition reported by Dadi et al (2008), and 1.24 for Adilo goat reported by Getahun (2008).
Year of kidding had a significant (p<0.01) influence on litter size of Central Highland goat, but not on their cross with Boer goat (Table 4). These findings on Central Highland goat are agreed with result of Hagan et al (2014) worked on West African dwarf goat. Central Highland does kidded in 2013 (2.05±0.12) and 2014 (2.06±0.15) had significantly higher litter size than those of other years. Central Highland x Boer does kid in 2013 and 2014 had non- significantly higher litter size than those kidded in other years. The differences in litter size from year to year probably due to dam age and variation in feed availability.
Season of birth had no effect on litter size of both breeds. However, goats which kidded in short rainy season non-significantly higher litter size than those kidded in dry and main rainy season (Table 4).The seasonality in feed availability and quality is an important constraint to biological productivity of small ruminants in the tropics (Berhane and Eik 2006; Ben Salem and Smith 2008). Low litter size in the main rainy season might be due to does mating season which was in the dry season where there is nutritional stress resulting in decreased ovulation rate (Hagan et al 2014).
Sex of kids did not significantly affect litter size of does. Similarly, Dadi et al (2008) reported similar result for Arsi-Bale goats. Litter size showed general trend of gradual increases as dam age increases. The probability of getting multiple kids increased with increased dam age up to 4 year of age and slightly decreased at 5 year of age. These findings are agreed with result of Hagan et al (2014) worked on West African dwarf goat, and Dadi et al (2008) worked on Arsi- Bale goats. This may be attributed to the improvement in the reproduction efficiency of goats as they mature (Levasseur and Thibault 1980).
|
Table 4. Mean ± standard error of litter size of Central Highland goats and their cross with Boer |
||||
|
Source of |
CHG |
CHG x Boer |
||
|
N |
Mean ±SE |
N |
Mean ±SE |
|
|
Cv% |
377 |
27.6 |
29.8 |
|
|
Over all mean |
377 |
1.75±0.02 |
1.62±0.03 |
|
|
Year |
p =0.003 |
p =0.37 |
||
|
2009 |
101 |
1.70±0.04b |
- |
- |
|
2010 |
128 |
1.77±0.04b |
- |
- |
|
2011 |
68 |
1.67±0.05b |
27 |
1.59±0.09 |
|
2012 |
46 |
1.74±0.06b |
37 |
1.46±0.08 |
|
2013 |
19 |
2.05±0.12a |
99 |
1.67±0.04 |
|
2014 |
15 |
2.06±0.15a |
49 |
1.67±0.06 |
|
Season |
p=0.06 |
p= 0.91 |
||
|
Main rain |
57 |
1.66±0.06 |
19 |
1.52±0.11 |
|
Short rain |
210 |
1.81±0.03 |
72 |
1.65±0.05 |
|
Dry |
110 |
1.71±0.05 |
121 |
1.61±0.04 |
|
Sex |
p =0.22 |
p =0.32 |
||
|
Male |
172 |
1.77±0.03 |
99 |
1.58±0.04 |
|
Female |
202 |
1.74±0.03 |
114 |
1.65±0.04 |
|
Dam age(year) |
- |
- |
P =0.67 |
|
|
1 |
13 |
1.46±0.14 |
||
|
2 |
45 |
1.64±0.07 |
||
|
3 |
49 |
1.53±0.07 |
||
|
4 |
71 |
1.69±0.05 |
||
|
5 |
34 |
1.67±0.08 |
||
|
Means within a column and factor bearing different superscripts are significantly different at p<0.05; N=number of sample size; SE: Standard error; CHG=Central highland goat and 1year includes 12month to 18 months. |
||||
We thank all the livestock research directorate staff of the Sirinka Agricultural Research Center for the effort making the data available for analysis and change the livelihood of the farmers at house hold level. This work was come true by the financial support of USAID and Amhara Regional Agricultural Research Institute. We also thank gratefully Technical Assistants Mekonnen Shibesh and Ali Hasen for their great effort in monitoring and collecting the data as required.
Adenaike A S and Bemji M N 2011 Effects of environmental factors on birth weights and weaning weights of West African dwarf goats under intensive and extensive management systems. Advances in Agricultural Biotechnology 1: 9-14.
Al-Najjar K, Salhab S, Al-Merestani R, Kasem R, Al-Azzawi W, Dawa M, Omed H and Saatci M 2010 Environmental Factors Affecting Kid Mortality in Shami Goats. KafkasUniv Vet FakDerg, 16: 431-435.
Alula Petros, Kassaye Aragaw and Berhanu Shilima 2013 Pre-weaning kid mortality in AdamituluJedokombolcha District, Mid Rift Valley, Ethiopia . Journal of Veterinary Medicine and Animal Health 6:1-6
Ameha Sebsibe 2008 Sheep and Goat Meat Characteristics and Quality. In: AlemuYami and R.C. Merkel (eds.) .Sheep and Goat Production Handbook for Ethiopia. Ethiopian Sheep and Goat Productivity Improvement Program (ESGPIP), Addis Ababa, Ethiopia.345P
Andualem D, Negesse T and Tolera A 2016 Milk yield and composition of grazing arsi-bale does Supplemented with dried stinging nettle (urticasimensis) leaf meal and growth rate of their suckling kids. Advances in Biological Research 10 (3): 191-199.
Baneh H and Hafezian S H 2009 Effects of environmental factors on growth traits in Ghezel sheep. Afr. J. Biotechnol. 8:2903-2907.
Barding R P, Mohite P M, Patil G R and Dhoble R L 2000 Effect of season on kidding birth weight and pre-weaning mortality in Osmanabadi goats. 7thinternational Conference on Goats, 1521 May, France, 2000.
Belay S, Gebru G, Godifey G, Brhane M, Zenebe M, Hagos H and Teame T 2014: Reproductive performance of Abergelle goats and growth rate of their crosses with Boer goats. Livestock Research for Rural Development. Volume 26, Article #5. http://www.lrrd.org/lrrd26/1/bela26005.htm
Bemji M N, Osinowo O A, Ozoje M O, Adebambo O A and Aina A B J 2006 Live weight changes during lactation and its relationship with milk off take and yield in West African Dwarf and Red Sokoto goats intensively managed within the humid zone of Nigeria. Nig. J. Anim. Prod. 2006; 33 (1): 145-150
Ben Salem H and Smith T 2008 Feeding strategies to increase small ruminant production in dry environments. Small Rumin. Res. 77:174-194.
Berhane G and Eik L O 2006 Effect of vetch (Vicia sativa) hay supplementation to Begait and Abergelle goats in northern Ethiopia II. Reproduction and growth rate. Small Ruminant Research, 64, 233-240.
Browning R and Leite-Browning M L 2014 Birth to weaning kid traits from a complete diallel of Boer, Kiko, and Spanish meat goat breeds semi-intensively managed on humid subtropical pasture. J. Anim. Sci. 2011. 89:2696–2707.
Cameron M R , Luo J, Sahlu T, Hart S P , Coleman S W and Goetsch A L 2001 Growth and slaughter traits of Boer x Spanish, Boer x Angora, and Spanish goats consuming a concentrate-based diet. Journal of Animal Science79: 1423–1430.
Central Statistical Agency; Federal Democratic Republic of Ethiopia 2016 Agricultural Sample Survey,Report on Livestock and Livestock Characteristics ; statistical bulletin583CSA: Addis Ababa, Ethiopia, volume 2,pp. 12–25.
Chanie D, Mekuriaw Z and Taye M 2014: Evaluation of pre-weaning growth performances and survival rate of Western Highland goats under traditional management system in Amhara Region, Ethiopia. Livestock Research for Rural Development. Volume 26, Article #145. http://www.lrrd.org/lrrd26/8/chan26145.htm
Chowdhury S A, Bhuiyan M S A and Faruk S 2002 Rearing Black Bengal goat under semi-intensive management. 1. Physiological and reproductive performances. Asian-Australasian Journal of Animal Sciences 15: 477–484.
Dadi H, Duguma G, Shelima B, Fayera T, Tadesse M, Woldu T and Tucho T A 2008: Non-genetic factors influencing post-weaning growth and reproductive performances of Arsi-Bale goats. Livestock Research for Rural Development. Volume 20, Article #114. http://www.lrrd.org/lrrd20/7/dadi20114.htm
Debele G, Duguma M and Hundessa F 2011 Effect of Different Factors on Mortality Rate ofArsi- Bale Kids in Mid Rift Valley of Ethiopia. Global Veterinaria, 6 (1): 56-60, 2011.
Dereje T, Mengistu U, Getachew A and Yoseph M 2015: A review of productive and reproductive characteristics of indigenous goats in Ethiopia. Livestock Research for Rural Development. Volume 27, Article #34. http://www.lrrd.org/lrrd27/2/dere27034.html
Deribe B and Taye M 2013 Evaluation of growth performance of Abergele goats under traditional management systems in sekota district, Ethiopia. Pak. J. Biol. Sci., 16: 692-696.
Deribe G, Abebe G and Tegegne A 2014 Non-genetic factors influencing reproductive traits and pre weaning mortality of lambs and kids under smallholder management, southern Ethiopia . Journal of Animal & Plant Sciences, 24(2): 2014, Page: 413-417.
Farm-Africa 1996 Goat Types of Ethiopia and Eritrea. Physical Description and Management Systems. Published Jointly by FARM-Africa, London, UK, and ILRI (International Livestock Research Institute), Nairobi, Kenya. 76p.
Gala S 2005 Biodiversity in goats. Small Rumin. Res.60, 75–81.
Gbangboche A B, Adamou-Ndiaye M, Youssao A K I , Farnir F , Detilleux J , Abiola F A and Leroy P L 2006 Non-genetic factors affecting the reproduction performance, lamb growth and productivity indices of Djallonke sheep. Small Ruminant Res., 64:133–142.
Getahun L 2008 “Productive and Economic Performance of Small Ruminants in Town Production Systems of the Highlands of Ethiopia”, Doctorial Thesis, Hohenheim University, CuvllierVerlag, Gottingen, Germany.
Grum Gebreyesus 2010 Community based participatory characterization of the short-eared Somali goat population around Dire Dawa. An MSc thesis.
Hagan B A, Nyameasem J K, Asafu-Adjaye A and Duncan J L 2014: Effects of non-genetic factors on the birth weight, litter size and pre-weaning survivability of West African Dwarf goats in the Accra Plains. Livestock Research for Rural Development. Volume 26, Article #13. http://www.lrrd.org/lrrd26/1/haga26013.htm
Hailu Dadi, Meiso Guru, Nigatu Alemayehu, Fufa Dawo and Gamada Duguma 2006 The effect of environmental factors on pre-weaning survival rate of Borena and Arsi-Bale kids. Small Ruminant Res., 66, 291-294.
Hermiz H N, Alkass J F , Hobi A A and Asofi M K 2009 Genetic and phenotypic parameters of body weights in Iraqi local goat and their crosses with Damascus. J. Duhok Univ. 12: 189-194.
Hulunim Gatew 2014 On-Farm Phenotypic Characterization and Performance Evaluation of Bati, Borena and Short-Eared Somali Goat Populations of Ethiopia. An M.Sc. thesis, Haramaya University, Ethiopia: 140p. https://cgspace.cgiar.org/bitstream/handle/10568/53933/Theses_HulunimGatew.pdf?sequence=1
Jimenez-Badillo M R, Rodrigues S, Sanudo C and Teixeira A 2009 Non-genetic factors affecting live weight and daily Non-genetic factors affecting live weight and daily gain weight in SerranaTransmontano kids. Small Rumin. Res. 84: 125-128. DOI:10.1016/j.smallrumres.2009.06.00.
Kiango S M 1989 Some features influencing performance of dairy goats at MagaduFarm.B.Sc. Agriculture Special Project, Sokoine University of Agriculture, Morogoro, Tanzania.1989:55.
Levasseur M and Thibault C 1980 Reproduction life cycles, in Hafez, E.S.E. (Ed.), Reproduction in Farm Animals. Philadelphia, PA, pp. 130-149.
Mahlet S 2008 Reproduction in Arsi-Bale female goats and growth performances of Toggenburg x Arsi-Bale crosses. An MSc Thesis, Hawassa University, Ethiopia.
Malan S W 2000 The improved Boer goat. Small Ruminant Research 36: 165 – 170.
Mandal A, Neser F, Rout P and Notter D 2006 Estimation of direct and maternal (co)variance components for pre-weaning growth traits in Muzaffarnagari sheep. Livest. Sci. 99:79–89.
Markos Tibbo 2006 Productivity and Health of Indigenous Sheep Breeds and Crossbreds in the Central Ethiopian Highlands, Doctoral Dissertation, Swedish University of Agriculture, Uppsala.
Mioč B, Sušić V, Z Antunović, Prpić Z, Vnučec I and Kasap A 2011 Study on birth weight and pre-weaning growth of Croatian multicolored goat kids. VeterinarskiArchiv. 81: 339-347.
Mohammed B, Aynalem H, Hailu D and Tesfaye A T 2012: Estimates of genetic and phenotypic parameters for milk traits in Arsi-Bale goat in Ethiopia. Livestock Research for Rural Development. Volume 24, Article #98. http://www.lrrd.org/lrrd24/6/bedh24098.htm
Ndamukong K J N 2008 Effects of management system on mortality of small ruminants in Bamenda, Cameroon (http:// www.fao.org/Wairdocs/ILRI/x5464B/x5464b0o.html), 2006. Accessed: 17, 11, 2008.
Nkungu D R, Kifaro G C and Mtenga L A 1995 Performance of dairy goats, in Mgeta, Morogoro, Tanzania.S rnet Newsletter.1995; 28: 3-8.
Perez-Razo M A, Sánchez F and Meza H C 1998 Factors affecting kid survival in five goat breeds. Can. J. Anim. Sci. 78:407–411.
Salama R, Mohamed M I, Abd-Allah S, L-Kady R I E , Kadry A I and Mabrouk M M 2015 Improving the Productive Performance of Local Baladi Goats throughout Crossbreeding with South African Boer.Adv. Environ. Biol., 9(27), 224-231, 2015.
Rumosa-Gwaze F G, Chimonyo M and Dzama K 2009 Communal goat production in Southern Africa:A review. Trop. Anim. Health Prod.41, 1157–1168.
SAS 2002 JMP-5 Statistical Software, Version 5.Cary, NC, USA.
Singh D K 1991 Pre weaning survival in Black Bengal kids and half breeds with Beetal and Jamnapari goats. Indian J. Anim. Sci. 61: 888–890.
Singh D K., Mishra H R. and Singh C S P 1990 Genetic and non genetic factors affecting pre-weaning survival in kids. Anim. Prod. 51: 559–564.
Snyman M A 2010 Factors affecting pre-weaning kid mortality in South African Angora goats. South African Journal of Animal Science 40: 54-64.
Sodiq A 2012 Non genetic factors affecting pre-weaning weight and growth rate of ettawah grade goats. Media Peternakan, April 2012, pp. 21-27.
Solomon A, Gemeda D, Ulfina G , Berhanu S and Fikru T 2005 Small ruminant production system in East Wollega and West Shoa zones. Research Report, Oromia Agricultural Research Institute, Bako Agricultural Research Center, Bako, Ethiopia. pp 31.
Vostry L and Milerski M 2013 Genetic and non genetic effects influencing lamb survivability in the Czech Republic. Small Ruminant Res.,113: 47– 54.
Zahraddeen D, Butswat I S R and Mbap S T 2008 Evaluation of some factors influencing growth performance of local goats in Nigeria. African journal of food agriculture nutrition and development, volume 8 no. 4 December 2008.
Zeleke Mekuriaw 2007 Environmental influences on pre-weaning growth performances and mortality rates of extensively managed Somali goats in Eastern Ethiopia. Livestock Research for Rural Development. Volume 19, Article #186.http://www.lrrd.org/lrrd19/12/zele19186.htm
Zhang, C Y, Zhang Y, Xu D Q, Xiang Li, Jie Su and Yang L G 2009 Genetic and phenotypic parameter estimates for growth traits in Boer goat. Livest. Sci. 124: 66-71. Sci. 124: 66-71. DOI:10.1016/0301-6226(94)90173-2.
Received 13 May 2017; Accepted 6 June 2017; Published 2 July 2017