Influence of tropical upright pasture structural and chemical characteristics on lamb grazing time.

Tropical pasture canopy characteristics can alter lamb ingestive behavior. Our study evaluated the ingestive behavior of young lambs in different tropical pastures to identify which variables interfere in their grazing activity. Two years of study were carried out with 54 weaned lambs distributed in three different pasture canopies: 1) monoculture of an upright grass, guinea grass (Panicum maximum; GG); 2) monoculture of a shrubby legume pigeon pea (Cajanus cajan; PP) and 3) contiguous paddock with half GG and half PP (GP). The experiment was set out in a randomized complete block design (3 blocks). Lamb ingestive behavior was observed from sunrise to sunset with records every 5 minutes. To identify the main variables that affected lamb grazing activity, a multivariate analysis of the Decision Tree was performed. Our results showed that there was no difference in the ingestive behavior parameters of young lambs in different canopies (P > 0.05). There was interaction among the canopies and the experimental periods for the variables idleness time and biting rate (P ≤ 0.05). Lambs in all canopies showed more idleness time in the first evaluation period. Lambs in canopies containing grass (GG and GP) exhibited greater bites per minute throughout the experimental period. Lamb grazing time increased 40% as experimental period progressed and plants matured. The Decision Tree identified leaf:stem ratio as the variable that most influenced lamb grazing time in GG and GP canopies while in the PP, grazing time was directly related to canopy height. The behavior of young lambs on tropical pasture is variable as there is a change in the behavioral response to canopy characteristics over time. In addition, the grazing time of these animals can be estimated by means of variables related to canopy structural characteristics (leaf:stem ratio and height) together with chemical variables.

Desempenho produtivo e saúde de cordeiros lactentes consumindo sucedâneos lácteos com diferentes proporções de lactose / Growth performance and health of lactating lambs consuming milk replacers with different proportions of lactose

Objetivou-se avaliar o ganho de peso, consumo de alimentos e a saúde de cordeiros lactentes da raça Lacaune consumindo leite de ovelha ou sucedâneos lácteos com diferentes proporções de lactose (LAC). Foram utilizados 36 cordeiros machos lactentes, com aproximadamente seis dias de idade (4,98 ± 1,20 kg) e avaliados até o desmame (60 dias de idade). Estes foram divididos em 12 lotes, com três animais cada, e alojados em baias, correspondendo a quatro baias por tratamento. Os tratamentos experimentais foram: Leite de ovelha; Sucedâneo 36% LAC, sucedâneo lácteo contendo 36% de lactose e; sucedâneo 29% LAC, sucedâneo lácteo contendo 29% de lactose. Os cordeiros alimentados com sucedâneo 29% LAC apresentaram menores (p≤0,05) peso corporal final, ganho médio diário, consumo total de alimentos e pior conversão alimentar, em relação aos animais do tratamento Leite de ovelha. Os cordeiros que receberam Sucedâneo 36% LAC não diferiram (p>0,05) dos animais dos tratamentos Leite de ovelha e Sucedâneo 29% LAC para as variáveis acima citadas. Não houve efeito de tratamento (p>0,05) na taxa de mortalidade ou na ocorrência de diarreia. Assim, o Sucedâneo 36% LAC pode substituir o Leite de ovelhas sem prejuízos ao desempenho, consumo e saúde dos cordeiros, porém a utilização do sucedâneo 29% LAC, apesar de não ter afetado a saúde, pode reduzir o desempenho e o consumo de alimentos pelos cordeiros.(AU)

The objective was to evaluate growth performance, feed intake and health by suckling Lacaune lambs consuming ewe's milk or milk replacers with different lactose (LAC) ratios. Thirty-six male lambs with approximately six days of age (4,98 ± 1,20 kg) were used, and evaluated until weaning (60 days of age). These were divided in 12 cohorts, with three animals each, and housed in pens, corresponding to four pens per treatment. The experimental treatments were: Ewe's milk; Milk replacer 36% LAC, milk replacer containing 36% of lactose and; Milk replacer 29% LAC, milk replacer containing 29% of lactose. The lambs fed with Milk replacer 29% LAC showed lower (p≤0.05) final body weight, average daily gain, total feed intake and worse feed conversion, in relation to the animals treated with Ewes milk. The lambs that received Milk replacer 36% LAC did not differ (p>0.05) from the animals treated with Ewes milk and Milk replacer 29% LAC for the variables mentioned above. There was no treatment effect (p>0.05) on the mortality or diarrhea rate. Thus, Milk replacer 36% LAC can replace the Ewe's milk without impairing growth performance, intake and health of lambs, but the use of the Milk replacer 29% LAC, despite not having affected the health, can reduce the growth performance and feed intake in lambs.(AU)

Desempenho produtivo e saúde de cordeiros lactentes consumindo sucedâneos lácteos com diferentes proporções de lactose / Growth performance and health of lactating lambs consuming milk replacers with different proportions of lactose

Objetivou-se avaliar o ganho de peso, consumo de alimentos e a saúde de cordeiros lactentes da raça Lacaune consumindo leite de ovelha ou sucedâneos lácteos com diferentes proporções de lactose (LAC). Foram utilizados 36 cordeiros machos lactentes, com aproximadamente seis dias de idade (4,98 ± 1,20 kg) e avaliados até o desmame (60 dias de idade). Estes foram divididos em 12 lotes, com três animais cada, e alojados em baias, correspondendo a quatro baias por tratamento. Os tratamentos experimentais foram: Leite de ovelha; Sucedâneo 36% LAC, sucedâneo lácteo contendo 36% de lactose e; sucedâneo 29% LAC, sucedâneo lácteo contendo 29% de lactose. Os cordeiros alimentados com sucedâneo 29% LAC apresentaram menores (p≤0,05) peso corporal final, ganho médio diário, consumo total de alimentos e pior conversão alimentar, em relação aos animais do tratamento Leite de ovelha. Os cordeiros que receberam Sucedâneo 36% LAC não diferiram (p>0,05) dos animais dos tratamentos Leite de ovelha e Sucedâneo 29% LAC para as variáveis acima citadas. Não houve efeito de tratamento (p>0,05) na taxa de mortalidade ou na ocorrência de diarreia. Assim, o Sucedâneo 36% LAC pode substituir o Leite de ovelhas sem prejuízos ao desempenho, consumo e saúde dos cordeiros, porém a utilização do sucedâneo 29% LAC, apesar de não ter afetado a saúde, pode reduzir o desempenho e o consumo de alimentos pelos cordeiros.

The objective was to evaluate growth performance, feed intake and health by suckling Lacaune lambs consuming ewe's milk or milk replacers with different lactose (LAC) ratios. Thirty-six male lambs with approximately six days of age (4,98 ± 1,20 kg) were used, and evaluated until weaning (60 days of age). These were divided in 12 cohorts, with three animals each, and housed in pens, corresponding to four pens per treatment. The experimental treatments were: Ewe's milk; Milk replacer 36% LAC, milk replacer containing 36% of lactose and; Milk replacer 29% LAC, milk replacer containing 29% of lactose. The lambs fed with Milk replacer 29% LAC showed lower (p≤0.05) final body weight, average daily gain, total feed intake and worse feed conversion, in relation to the animals treated with Ewe’s milk. The lambs that received Milk replacer 36% LAC did not differ (p>0.05) from the animals treated with Ewe’s milk and Milk replacer 29% LAC for the variables mentioned above. There was no treatment effect (p>0.05) on the mortality or diarrhea rate. Thus, Milk replacer 36% LAC can replace the Ewe's milk without impairing growth performance, intake and health of lambs, but the use of the Milk replacer 29% LAC, despite not having affected the health, can reduce the growth performance and feed intake in lambs.