Horro Lambs Research Articles

The Effects of Maize and Napier Grass Ensiled with Dolichos Lablab on Feed Intake Growth Performance and Carcass Traits of Horro Lambs

The Effects of Maize and Napier Grass Ensiled with Dolichos Lablab on Feed Intake Growth Performance and Carcass Traits of Horro Lambs

Cajanus cajan and Lablab purpureus leaf meal-potential supplements over conventional protein sources for yearling Horro sheep fed a basal diet of fodder oat (Avena sativa) hay

A 90-day feeding trial with 25 yearling Horro lambs (22.6 ± 1.8 kg) was conducted from November 2022 to January 2023. The trial was designed to see how supplementing forage varieties of Cajanus cajan (Degagsa and Belabas) and Lablab purpureus (Beresa-55 and Gebis-17) affected the growth performance, feed intake and digestibility of Horro lambs fed a basal diet of fodder oat hay compared to conventional protein supplements. Five experimental sheep per treatment were arranged in a Randomized Complete Blocked Design to receive dietary treatments formulated on an iso-nitrogenous basis which was targeted to provide crude protein (CP) of 64.37 g/h/day. Data were taken on weight gain, feed conversion ratio, feed intake and refusal, and in-vivo digestibility features. All lambs were fed ad-libitum fodder oat hay containing 91.5 % Dry matter, 7.8 % ash, 6.4 % crude protein, 60 % neutral detergent fiber, 42.8 % acid detergent fiber, 13.4 % acid detergent lignin and 65 % in-vitro organic matter digestibility. The dietary treatments were fodder oat hay plus 280.8 g Gebis-17 variety (T1), 274.4 g Beresa-55 variety (T2), 320.9 g Belabas variety (T3), 329.3 g Degagsa variety (T4) and 300 g concentrate mixture (T5). The total dry matter intake (DMI) was higher in T3 and T4 than in the other treatment groups. Except for CP, nutritional consumption differed significantly across treatments. T3 and T4 had higher fiber intakes than the other treatments, while T2 had higher ash intakes and T5 had higher metabolizable energy intakes. Even though there was no significant variation in final body weight, lambs in T5 and T1 showed the greatest weight change and average daily gain. Although the diet in T5 induced the lamb performance in a manner comparable to that of the other dietary supplements, its inaccessibility and high cost would limit the use of such supplements by smallholder farmers. Thus, depending on their availability, either Lablab purpurues or Cajanus cajan varieties could be employed as feed supplements in the lambs` diet.

English

This study was conducted to evaluate and determine the carcass pH and color of Horro rams under different management practices at Ambo University. A total of 24 Horro rams were randomly assigned to the following three treatments: T1 (Day 1 rest before slaughter), T2 (Rhodes hay ad libitum) and T3 (Rhodes hay ad libitum + 400 g concentrate per head/day). Carcass pH was determined at 15 min, 24, 48, and 72 h post slaughter using pH Meter. Data were analyzed using the General linear model procedures of Statistical Analysis System Software 9.2 (SAS, 2009). The ultimate carcass pH of concentrate supplemented Horro rams (pH24 = 5.67) was lower (P < 0.001) than rams fed on Rhodes hay ad libitum and animals slaughtered immediately after day 1 rest of transportation to experimental site (5.88, and 5.87, respectively). The majority of sensory panelists (> 62%) reported that carcass color was bright red for supplemented Horro rams and red color for those fed on Rhodes hay ad libitum and slaughtered immediately after one day rest of transportation. Carcass darkness/discoloration was not observed up to four days post slaughter from values of carcass pH, color estimation of this experiment and from comparisons of carcass pH measures with values in the literatures. Concentrate supplementation had significant and positive influence on carcasses pH and color of Horro rams. This study disproved the dispute or claim about the problem of early darkening of carcasses of highland animals. Thus, management practices like optimum feeding along sufficient rest after transportation would improve the carcass pH and color.   Key words: Carcass, pH, color, concentrate, Horro lambs.

Feed Intake, Digestibility and Growth Performance of Horro Lambs Fed Natural Pasture Hay Supplemented Graded Level of <i>Vernonia amygdalina</i> Leaves and Sorghum Grain Mixture

Article Information This study was undertaken with the objectives of evaluating the effect of dried and ground Vernonia (V. amygdalina) leaves and ground sorghum (S. bicolor) grain mixture supplementation on feed intake, digestibility, body weight change, feed conversion efficiency of Horro lambs fed a basal diet of natural pasture hay. The feeding and digestibility trials were conducted using twenty male lambs of similar yearling age and average body weight of 15.4 ±0.58kg. The lambs were blocked into five blocks of four animals each based on their initial body weight and randomly allocated to four dietary treatments from each block giving five animals per treatment. Treatment 1 was fed on grass hay alone, while treatments 2, 3, and 4 received graded levels (150, 300 and 450g, respectively) of a mixture of dried and ground Vernonia leaves and ground sorghum grain mixture as supplements to the grass hay basal diet. Supplementation with dried Vernonia leaves and sorghum grain mixture improved feed intake, nutrient digestibility and body weight gain of the lambs as compared to the unsupplemented animals. The body weight gain of the lambs was lowest in T1 (7.6g/day), intermediate in T2 (40 g/day) and highest in T3 (81.3 g/day) and T4 (93.8 g/day) (P < 0.01). It was concluded that supplementation of vernonia leaves and sorghum grain mixture improved feed intake and digestibility of the diet and body weight gain of the lambs. In general increased performance was observed with increasing level of supplementation. However, cost-benefit analysis is required to determine the optimum level of supplementation, particularly as the level of supplementation exceeds 300 g. Article History: Received : 29-03-2013 Revised : 25-06-2013 Accepted : 27-06-2013

Digestion, Intake and Live Weight Changes of Horro Lambs Fed Vetch (Lathyrus sativus) Haulm Basal Diet Supplemented with Sole Wheat Bran, Acacia albida Leaf Meal or Their Mixture

2 Abstract: Twenty five yearling male Horro lambs with initial body weights (IBW) of 23.14±2.45 kg (mean±SD) were used to determine effect of supplementation of wheat bran (WB), Acacia albida leaf meal (AA) or their mixture on nutrient digestibility, feed intake and growth performance of yearling Horro lambs fed a basal diet of vetch (Lathyrus sativus) haulm (VH). Animals were blocked into 5 based on IBW and were randomly assigned to treatments. Treatments were ad libitum feeding of VH either without supplement (T1) or with daily supplement of 300 g DM of sole WB (T2), sole AA (T5), or mixture of the two at 2:1 (T3) or 1:2 (T4) ratios of WB:AA. The study had 7 days digestibility and 84 days feeding trial. The VH, WB and AA had crude protein (CP) contents of 6.5, 16.0 and 19.5%, respectively. Supplementation did not impact (P > 0.05) dry matter (DM), neutral detergent fiber and acid detergent fiber digestibility but significant increased (P 0.05). Positive and significant (r=0.82, P < 0.05) correlation was observed between ADG and CP digestibility. This relationship might have caused growth performance differences among treatments.

Estimates of (co)variance function for growth to yearling in Horro sheep of Ethiopia using random regression model

Abstract. Random regression analyses of weight data from birth to 396 days were done using 22 141 weight records of 1 951 Horro lambs. Six different models formed from three different orthogonal polynomial regressions (legendre scale)orders (quadratic, cubic, quartic) of fit for both additive genetic and animals’ permanent environmental effects, with assumption of either homogeneous or heterogeneous residual variance, were compared. Fixed effects of year and type of birth, sex and age of dam were fitted along with a fourth order polynomial. Both likelihood ratio test (LRT) and Akaike's Information Criterion (AIC) were used for model comparison. Model fit improved with increased order of polynomial and assumption of heterogeneity of residual variance. Components for additive genetic and permanent environmental (co)variance increased from 0.03 and 0.09 at birth to 23.8 and 37.6 at 396 days of age, respectively. The first three eigenvalues of the coefficient matrix of the additive genetic covariance accounted for about 98 % of the sum of all the eigenvalues. Heritability estimates have shown a declining and increasing trend at different parts of the trajectory, the lowest estimate being 0.14 for weight at birth while the highest being 0.36 for weight at about 390 days of age. Higher heritability estimates in previous uni- and bi-variate models and in the current study and also strong correlation with weight at early age makes weight at one year of age the most important trait to consider in improving productivity in Horro sheep.

Effects of non-genetic factors on responses to gastro-intestinal nematode infections in Ethiopian sheep

The effects of non-genetic factors on responses to gastrointestinal nematode infections were examined in artificially infected indigenous Horro and Menz lambs in the central highlands of Ethiopia. The experiment involved lambs of two sexes, infection and monitoring regimens (3 levels), dam parity (4 levels) and birth types (2 levels). A total of 152 weaner lambs (103 Menz and 49 Horro) were used. Endoparasite challenge involved three infection periods (primary, secondary and tertiary) each separated by an anthelmintic treatment. Data were collected on faecal egg counts (FEC), packed cell volume (PCV), worm count, and weight gain. Female lambs were found to harbor lower numbers of T. colubriformis counts and had lower (p < 0.01) FEC in tertiary infection compared to males. Younger animals were more susceptible to the nematode infections than older animals as measured by all the parameters studied (p < 0.01). Twins had higher FEC in both secondary and tertiary infections compared to singles. Lambs born to dams of first parity had higher PCV and lower FEC values during the tertiary infection compared to other parities. These results would be used as basic information in designing a more rational control strategy and should also help to advise on better management care for less resistant sheep.

Reproductive performance and mortality rate in Menz and Horro sheep following controlled breeding in Ethiopia

The reproductive and lamb mortality data ( n = 4890) of Horro and Menz ewes following controlled breeding in Ethiopia were analyzed. Sheep were treated with flugestone acetate (FGA) intravaginal sponges during the wet and dry seasons to compare the reproductive performance of the two indigenous Ethiopian highland sheep breeds. There was a significant ( P < 0.001) difference in the fertility rate (conception rate) (79% versus 70%), weaning rate (92% versus 78%) and lamb mortality rate (13% versus 27%) for the Menz and Horro breeds, respectively. The difference in lambing rate (lambs born/ewes mated) for the Menz and Horro ewes was also significant ( P < 0.01) (81% versus 76%), respectively. There was no significant difference in fecundity between the two breeds. It is concluded that the Menz ewes have more acceptable reproductive performance than Horro ewes following controlled breeding. Additionally, Menz lambs have recorded a higher survival rate than the Horro lambs under the same environmental conditions.

Effects of dietary protein supplementation and infection with gastrointestinal nematode parasites on some nutritional and metabolic parameters in Ethiopian Menz and Horro sheep

The effect of subclinical artificial nematode parasite infection on dry matter intake (DMI), apparent digestibility (AD), efficiency of feed utilisation (EFU), plasma protein (PPC) and albumin concentrations (AC) was examined in lambs of the Horro and Menz breeds. The factorial experimental design involved two breeds, two infection treatments (infected vs. noninfected) and three nutrition treatments [hay plus wheat bran (basal diet), hay plus molasses urea block (MUB), hay plus cotton seed cake (CSC)]. Diets were formulated to be isocaloric but with varying protein and/or nitrogen sources. At the start of the study, 152 lambs (103 Menz and 49 Horro) were assigned to the 12 treatment combinations each in a separate pen, with an average of about 13 animals per pen. Challenge with endoparasites involved three infection periods each separated by an anthelmintic treatment. The first two infections were with Haemonchus contortus while the third infection was with a mixed infection of H. contortus, Longistrongylus elongata and Trichostrongylus colubriformis. Infected lambs had lower total DMI, EFU (not significant in third infection), AD (significant only in third infection) and total PPC and AC than noninfected lambs. Horro lambs had higher DMI and EFU but lower AD than Menz lambs. PPC was significantly higher in lambs supplemented with CSC compared to those on the basal diet or supplemented with MUB in the primary and secondary infections; but during the tertiary infection, no significant differences were found. AC was significantly greater in CSC-supplemented lambs than those on the basal diet or supplemented with MUB. It was concluded that subclinical nematode infection had an adverse effect on feed intake, efficiency of feed utilisation and apparent digestibility. Infection was also found to cause hypoproteinaemia and hypoalbuminaemia. Protein supplementation would help mitigate the effects of infection on total plasma protein and albumin concentrations, especially in the low-input systems typified by the Ethiopian highlands.

Growth and carcass composition of tropical fat-tailed Menz and Horro sheep breeds

AbstractThe pattern of growth and carcass composition of indigenous Ethiopian fat-tailed Menz and Horro lambs were assessed through serial slaughter and carcass dissection of 147 lambs at five different growth phases. The GLM procedure of Statistical Analysis Systems Institute and allometric growth equations were used to assess the effects of various factors and differential growth of carcass components, respectively. Results showed that the growth and carcass composition of Menz and Horro lambs was significantly (P &lt; 0.05 to P &lt; 0.001) affected by the genotype, growth phase and season of birth of lambs. The effects of growth phase clearly showed that slower growth of the body and of carcass components was observed during the third phase (i.e. after weaning). Although there was an effect on fat to lean ratios (P &lt; 0.05), growth phase had no significant effect on dressing out proportion, and lean to bone ratios. A significant influence of genotype (P &lt; 0.001) and sex (P &lt; 0.05) on lean to bone ratios indicated that the Horro sheep and ram lambs had a much more developed and heavier skeleton than the Menz sheep and ewe lambs. Higher pre-slaughter, hot carcass, lean and bone and fat weights of May/June born lambs revealed significant advantages of wet season lambing for fast growth and improved carcass composition. The log/log regression of weights of dissectible carcass components on hot carcass and empty body weight showed that the differential growth of bone was declining and that of lean was isometric relative to the growth of empty body weight. For carcass fat, the allometric growth coefficients (b) of 1.5 and 1.8 for Menz and Horro sheep, respectively indicated that fat is a late maturing body component. Moreover the growth of carcass fat relative to empty body weight in the Menz and Horro sheep is slower than that reported for tropical sheep breeds.

Patterns of growth and partitioning of fat depots in tropical fat-tailed Menz and Horro sheep breeds

A total of 147 Menz and Horro lambs of both sexes were serially slaughtered and dissected at five different stages of growth to define the pattern of growth and partitioning of fat among body depots in indigenous Ethiopian Menz and Horro sheep breeds. The GLM procedure of SAS and allometric growth equation were used to assess the effects of various factors on the growth of body depots and to estimate its growth relative to total carcass fat (TCF) and empty body weight (EBW), respectively. Results obtained showed that the growth of carcass fat (CF), non-carcass fat (NCF) and tail fat (TF) is significantly affected by the genotype ( P<0.001) and stages of growth ( P<0.001) of lambs. Except for CF, the growth of both NCF and TF were also significantly affected ( P<0.001 and P<0.05) by the sex and the season in which the lambs were born. Of the two breeds, the Menz sheep deposited more fat into the carcass and less into the non-carcass depots as compared to the Horro sheep and ewe lambs in both breeds deposited more fat intra-abdominally than the ram lambs. The highest allometric growth coefficient was obtained for TF (1.2–2.1 relatively to TCF and EBW) and the lowest for NCF (0.8–1.3 relative to TCF and EBW) indicating that the former is a late developing while the later is an early maturing depot in the tropical fat-tailed Menz and Horro sheep breeds.

Effects of breed and dietary protein supplementation on the responses to gastrointestinal nematode infections in Ethiopian sheep

The effects of breed and dietary protein supplementation on the development of resistance and resilience to gastrointestinal nematode parasites (endoparasites) were examined in artificially infected Horro and Menz lambs from 4 to 12 months of age. The factorial design involved two breeds, two infection treatments (infected vs non-infected) and three dietary protein treatments (hay and wheat bran (basal diet), hay plus molasses urea block (MUB), hay plus cotton seed cake (CSC)). At the start of the study, 152 weaner lambs (103 Menz and 49 Horro) were assigned to the 12 treatment combinations each in a separate pen. Endoparasite challenge involved three infection periods (primary, secondary and tertiary) each separated by an anthelmintic treatment. The first two infections were with Haemonchus contortus, while the third infection was a mixed infection of H. contortus, Longistrongylus elongata and Trichostrongylus colubriformis. During the entire study, infected lambs gained significantly less weight and had a lower blood packed cell volume (PCV) than the non-infected lambs. Protein supplementation of lambs with CSC resulted in lower faecal egg counts (FEC) and higher PCV and growth rates than lambs fed the basal diet. In the first two infection periods there was no significant effect of infections in lambs supplemented with MUB, probably due to low intake of MUB. In the tertiary infection period MUB was fed ad libitum which resulted in MUB-supplemented lambs having significantly higher PCV than lambs on the basal diet, with CSC-supplemented lambs intermediate. During the primary infection, naive Horro lambs had a significantly lower FEC than Menz lambs, but there was no significant breed difference for PCV. In the secondary infection period there was no significant breed difference for FEC or PCV in infected lambs. However, during the tertiary infection, while there was no significant breed difference for FEC, the Menz had a significantly higher PCV than Horro irrespective of infection status. At the end of the tertiary infection, the Menz lambs ( n=26) had significantly lower adult worm burdens for H. contortus and L. elongata than Horro lambs ( n=18), but there was no significant difference between the breeds for T. colubriformis worm burdens. Both the worm count and PCV data suggest that Menz lambs acquire the ability to resist and tolerate endoparasite infections better than the Horro lambs.

Effect of breed and season on production and response to infections with gastro-intestinal nematode parasites in sheep in the highlands of Ethiopia

The effects of breed (Menz and Horro), season (wet and dry), and the breed by season interaction on production and response to naturally acquired gastro-intestinal (GI) nematode parasite infections (predominantly Longistrongylus elongata and Trichostrongylus spp. and a small proportion of Haemonchus contortus) of lambs in the highlands of Ethiopia were investigated. A total of 2395 Menz and 1966 Horro lambs, born from five lambings in the wet season and five lambings in the dry season, were recorded in the study from birth to 12 months of age. These were the progeny of 43 Menz and 41 Horro rams. Horro lambs were significantly ( P<0.001) heavier than Menz lambs from birth to 12 months of age and in young lambs this was particularly marked in the wet season. Young Menz lambs born in the wet season had a significantly lower ( P<0.001) logarithm-transformed faecal egg count (LFEC) than Horro lambs at 2 and 3 months of age. The Menz lambs had a significantly higher ( P>0.001) packed cell volume (PCV) than the Horro lambs at 3 and 12 months of age, possibly indicating a better adaptation of the Menz to a high altitude environment. The Menz lambs had significantly ( P<0.001) lower cumulative mortality (37%) to 12 months of age than the Horro (68%), principally due to better adaptation of the Menz to the study environment and not due to resistance to GI nematode parasites. Heritabilities for and genetic correlations among live weight (LWT), PCV and LFEC were estimated. Overall results showed that, in this environment, the Menz are more productive than the Horro.

Between and within breed variation in lamb survival and the risk factors associated with major causes of mortality in indigenous Horro and Menz sheep in Ethiopia

Data collected on 3256 lambs born to Horro and Menz breed ewes single-sire mated to 71 rams at the International Livestock Research Institute (ILRI) Debre Berhan station between September 1992 and June 1996 were analysed for rates of survival and growth from birth to weaning. A significantly lower proportion of Menz lambs died before 1 year of age (28%) than the Horro lambs (59%). Least squares means for pre- and post-weaning mortality were 8.8 and 19.3%, respectively in Menz, and 25.3 and 34.2% for Horro sheep. Major causes of death were similar in Horro versus Menz lambs and were pneumonia (53 vs. 54%, respectively), digestive problems (14 vs. 12%), endoparasite infections (9 vs. 13%), starvation–mismothering–exposure (SME) complex (10 vs. 7%) and septicemia (3 vs. 2%). Relationships among causes of mortality with breed, birth weight (BWT), season of birth, parity, litter size and lamb health category (number of times a lamb was sick between birth and 1 year of age) were determined. The impact of these factors on mortality varied with lamb age. Lambs that were born with <2 kg BWT had a greater risk of dying from any cause except pneumonia. But, even though Horro lambs were heavier than Menz at birth (2.4 vs. 2.1 kg, respectively), twice as many died before 1 year of age. The cause of mortality was further influenced by season of birth, lamb sex and health category. In addition, sires were a significant source of variation for progeny survival at 6, 9 and 12 months of age, but not at the younger ages. The best and worst Horro ram sired progeny groups that had mortality rates up to 1 year of age of 22 vs. 80%, respectively. The same estimates in Menz rams were 11 and 48%, respectively. Reduced mortality rate would significantly increase lamb output. However, isolated efforts to solve this problem are likely to have limited impact. Instead, an integrated approach to minimise the impact of underlying factors is advocated. Farm (animal) management routines that could be introduced in the short or longer term are discussed.