Olaf Andreas Bakke

Body composition and nutritional requirements of protein and energy for body weight gain of lambs browsing in a tropical semiarid region

Este trabalho foi realizado com o objetivo de avaliar a composicao corporal em gordura, proteina e energia e as exigencias nutricionais para ganho de peso em cordeiros em sistema de pastejo na regiao semi-arida. Foram utilizados 32 cordeiros Santa Ines, castrados, com peso inicial de 15,8 kg ± 1,4 kg e idade variando entre 3 e 4 meses. Desses animais, oito cordeiros foram abatidos no inicio do experimento, como animais-referencia, para determinacao da composicao corporal inicial na metodologia do abate comparativo. Os 24 animais remanescentes foram utilizados em delineamento em blocos casualizados, com tres tratamentos e oito blocos. Cada um dos oito blocos experimentais foi composto inicialmente de tres cordeiros de 15 kg, aos quais foram aplicados os tratamentos (0,0, 1,0 e 1,5% do peso vivo do animal de suplementacao diaria com mistura concentrada composta de fuba de milho, farelo de soja e mistura mineral, ajustada para ganho de peso medio diario estimado em 200 g) aleatoriamente designados. Quando um dos animais de cada lote atingiu 30 kg de peso, os tres animais do lote foram abatidos. Os valores estimados de composicao corporal variaram de 171,59 a 145,84 g de proteina/kg de peso do corpo vazio (PCV); 0,53 a 319 g de gordura/kg de PCV; e 2,06 a 3,90 Mcal/kg de PCV para animais de 15 a 30 kg de PCV. As exigencias liquidas para ganho medio de 200 g/dia variaram de 25,99 a 22,09 g de proteina e de 0,311 a 0,591 Mcal de energia para animais de 15 a 30 kg de PV, respectivamente. Cordeiros Santa Ines em pastejo na regiao semi-arida necessitam de mais proteina e menos energia que cordeiros confinados em regioes temperadas ou confinados em areas tropicais como reportado na literatura.

Substitution of Pennisetum purpureum by Opuntia ficus-indica and Mimosa tenuiflora in the diet of lambs

Os objetivos deste estudo foram quantificar a digestibilidade aparente dos componentes da dieta e o desempenho de cordeiros alimentados com niveis crescentes de uma mistura balanceada (peso) de farelo de Opuntia ficus indicae e feno de Mimosa tenuiflora em substituicao a 0, 33 e 67% do feno Pennisetum purpureum, em uma dieta com 60% de volumoso e 40% de concentrado, formulada para um ganho de peso diario de 150 g/animal. O experimento foi conduzido na UFCG, Patos-PB, usando 18 cordeiros inteiros com (20,4±1,16) kg (peso medio±EP). O CD da MS, MO, PB, EE e dos carboidratos totais foram afetados pelos niveis da mistura (P 0,05). A inclusao da mistura afetou linear e positivamente o ganho de peso medio diario (120, 149 e 170g/animal, respectivamente para 0, 33 e 67% de substituicao do feno de P. purpureum), e o consumo de MS, MO, PB, carboidratos totais e nao fibrosos. A mistura balanceada do farelo de Opuntia ficus indica e do feno de Mimosa tenuiflora pode substituir ate 67% da fracao volumosa (P. purpureum) da dieta de cordeiros Santa Ines e melhorar o ganho de peso medio diario em 50g/animal.

Enxertia da faveleira (Cnidoscolus phyllacanthus) sem espinhos

The faveleira tree (Cnidoscolus phyllacanthus Pax et K. Hoffm.) is a forage producing xerophyte of the semiarid region of Northeast Brazil. Forage collection from faveleira plants is difficult due to its caustic thorns, however thornless mutants may be reproduced vegetatively. The present study was carried out in the Seedling Nursery of UFCG, in Patos-PB, to develop a protocol to produce thornless faveleira seedlings by full cleft-grafting using grafts in the dormant or active growth phase on rootstocks in the active growth phase. Dormant grafts were kept refrigerated (+5°C) (T1) or protected from the sun at room temperature (T2), for three days before grafting in December 2003, while active growth grafts were cut off from the tree in December 2003 (T3) or June 2004 (T4), just before grafting. There were 38, 26, 40 and 30 grafts for T1, T2, T3 and T4, respectively. Data collected in successful grafts consisted of rootstock and graft diameter and height, and percentage of successfully sprouted grafts. Rootstock and graft mean diameter (from 10.9 to 11.9mm and from 8.6 to 9.6mm, respectively) and height (from 7.7 to 12.6cm and from 23.7 to 29.8cm, respectively) were similar for all treatments. Grafting was successful in 45, 85, 15 and 33% of the cases for T1, T2, T3 and T4, respectively. Thus, the use of dormant 9mm-thick and 25cm-high grafts, kept protected from the sun at room temperature for three days before grafting, results in the highest rate of success in grafting of thornless faveleira.

Scrotum bipartite in sheep as a parameter indicative of adaptation to semi-arid climates: A thermographic and reproductive study

With the objective of assessing the influence of scrotum bipartition on scrotum-testiclar thermoregulation and semen quality in sheep native to a semiarid region, 14 adult crossbred rams were placed into groups, GI (7 with bipartition in the scrotum) and GII (7 without bipartition). Images were taken of the caudal scrotum surface using a Fluke (Ti25®) thermographic camera, for temperature analysis. Two semen collections were made, at an eight-day interval, by electroejaculation, to analyze macroscopic and microscopic parameters. It was observed that the surface temperatures of the proximal, medial and distal regions of the testicle and the epididymis tail did not present significant statistical difference (p > 0.05) between the groups. The GI showed a great ability to regulate the temperature in the tail region of the epididymis (p = 0.062), location of the bipartition, and the difference in temperature between the body surface and the epididymis tail was 0.54 °C much lower than the G2. Although no significant statistical difference (p > 0.05) was observed, the animals with bipartition presented higher means for body surface temperature, showing greater efficiency in heat dissipation and indicating that these animals used peripheral vasodilation on a larger scale to eliminate excess heat and thus had a lower energy expenditure. The semen parameters studied in both groups were within the desirable values for the species, with no differences between the groups (p > 0.05). Higher scrotum testiclar values were observed (scrotum circumference GI = 30.40 cm ± 0.53 and GII = 28.42 ± 1.13 cm, testicle length, right and left, respectively GI = 8.14 ± 0.90 cm, 8.00 ± 0.00 cm and GII = 7.28 ± 0.04 cm, 7.28 ± 0.48 cm) and bodyweight (GI = 44.57 ± 5.25 Kg and GII = 39.85 ± 1.57 Kg) in rams with scrotum bipartition (p > 0.05). It is concluded that scrotum bipartite in rams was shown to be an evolutionary indicator showing that animals with this characteristic dissipate heat more efficiently, have bigger scrotum-testicle biometrical parameters and heavier body weight. However, as the rams with scrotum bipartite presented division of less than 50% of the scrotum length, this degree did not influence the scrotum surface temperature and semen quality, as has been observed in goats with the same characteristic.

REGENERAÇÃO HERBÁCEA EM ÁREAS DEGRADADAS DE CAATINGA ENRIQUECIDAS COM ÁRVORES NATIVAS

Herb recovery was evaluated in degraded Caatinga sites protected from grazing and enriched with native trees, in Patos-PB state, Brazil . Treatments were randomized according to a block design with five treatments (no tree planting –T 0 – or tree planting of three tree species in pure –T 1 = Poincianella pyramidalis , T 2 = Mimosa tenuiflora and T 3 = Cnidoscolus quercifolius – or mixed balanced stands –T 4 ) and five replications of squared-144-m 2 plots with 36 seedlings developing in planting holes enriched with manure and chemical fertilizers, arranged in a 2 m x 2 m grid. Data were collected from September 2008 to October 2009. After this period, natural tree regeneration was still not observed, and tree canopy covered 15 to 49% of the soil and did not affect herb growth and species composition. Initial and final herb cover were 16% and 100%, respectively. The number of dicot herbs increased from five, mainly two Sida species, to 13 species, monocots were represented by one species only (Aristida sp .), and quantity of herb forage reached 3 ton/ha (2:1, dicot:monocot). Adjacent overgrazed plots kept the initial low level of herb cover and species composition. Animal deferment during one year allowed the increase in soil cover and plant diversity in degraded Caatinga sites into which planted tree seedlings established successfully. This management practice could be implemented to avoid further environmental degradation and recover degraded areas.