Management of stocking rate and supplementation with local resources are viable alternatives for the intensification of livestock production systems in the tropics. However, most studies have been directed to evaluate both aspects separately. The objective of this experiment was to evaluate the effect of the stocking rate and supplementation with Leucaena leucocephala, on the productivity of grazing Bos taurus x Bos indicus cows. Twenty cows in their first and second lactation were used in a completely random design with a factorial arrangement 2x2. The treatments were: LSNL: 2 AU/ha without Leucaena; LSWL: 2 AU/ha with Leucaena; HSNL: 3.5 AU/ha without Leucaena; HSWL: 3.5 AU/ha with Leucaena. The Leucaena was used by cutting and carrying, the intakes being 1.82 and 1.75 kg DM cow / d/, for LSWL and HSWL, respectively.
There were no significant differences in milk production among the low stocking treatments (LSNL, LSWL) nor between these and the high stocking treatment with Leucaena (HSWL). However, the saleable milk production and total milk production were lower in HSNL. The saleable milk production and total milk production were 54 and 35% higher, respectively, in HSWL than in HSNL. No significant differences were found for stocking rate and supplementation effects separately, but the interaction was significant. No significant differences were found in milk fat nor in body weight changes, however, supplemented cows tended to lose less body weight at both stocking rates.
Supplementation with Leucaena improved the productivity of cows grazing at high stocking rates but this was not true for the lowest stocking rate. Leucaena leucocephala is a resource that could help to intensify milk production systems in the tropics.
Facultad de Medicina Veterinaria y
Zootecnia. Universidad Michoacana de San Nicolás de Hidalgo (UMSNH) Morelia
*Instituto de Investigaciones Agropecuarias y Forestales. Universidad Michoacana de San Nicolás de Hidalgo (UMSNH) Morelia Michoacán, México.
Beef performance and production cost were analysed in a cattle fattening trial carried out in a commercial pig farm. Sixty eight Cebu X Brown Swiss cattle of 316 kg initial weight, were fed ad libitum with fresh pig faeces (30 % of diet DM), sugarcane molasses (35 % of diet DM) and two sources of fibre (35 % of diet DM): M: mature and dehydrated corn stover (Zea mays) without cobs (straw, corn by-products, corn stubble) and, S: mature and dehydrated sorghum stovers (Sorghum vulgare) without heads (straw, sorghum by-products, sorghum stubble). The animals were previously identified, drenched and implanted with Zeralanol and were allocated in six groups in a completely randomized design.
Daily liveweight gains were 0.945 and 0.922 kg,
dry matter voluntary intakes were 11.0 and 10.4 kg, and feed conversion 11.6
and 11.4 for treatments M and S, respectively. There were no significant
differences between treatments. Production cost per kg liveweight was 10.9 pesos and 11.2 pesos for
treatments M and S, respectively. These results suggest that both fiber sources
provide a similar buffer capacity during the digestive process with similar
characteristics regarding: chewing, ruminating and transit rate of feed
particles and liquids in the digestive tract.
Key words: Fattening, cattle, pig faeces, fibre sources, molasses
An experiment was conducted to determine the nutritive value of forage collected via oesophageal fistula with two cows that grazed two pastures: native grass (NP) and NP associated with Arachis pintoi CIAT 17434 (NP+Ap), both in the morning (between 7 and 8 AM) and in the afternoon (between 5 and 6 PM). Rumen degradation was expressed as y = a + b(1 - e-ct), where ‘y’, is the dry matter degraded at time ‘t’, ‘a’ is the highly soluble dry matter when t = 0 (%), ‘b’ is the insoluble but slowly degradable dry matter (%), ‘a+b’ is the extent of degradation (%), ‘c’ is the degradation rate of b (%/h) and ‘t’ is the rumen incubation time (h).
Neither cow nor time of grazing had a significant effect upon the immediately soluble fraction (‘a’) or the insoluble but rumen degradable fraction (‘b’). However, the effect of pasture was significant upon ‘c’, the degradation rate of ‘b’, being the values 4.07 %/h and 7.66 %/h for NP and NP+Ap, respectively. Crude protein content (CP) was not affected by cow or time of grazing, but the effect of pasture was highly significant. The cows in NP harvested material with 9.8% CP while those in the NP+Ap selected forage with 13.5% CP in dry matter. The relationship between CP and percent A. pintoi in extrusa was not significant due to a limited number of observations (n=7). The NP and NP+Ap pastures showed 9.12 g of CP/MJ of ME and 11.84 g of CP/MJ of ME, enough to support maintenance, pregnancy and 4 and >6 kg of milk/cow/day, respectively.
It was concluded that the NP+Ap pasture presented a higher nutritive quality than the NP pasture and, as a consequence, a higher milk production potential.
Daily activities and spatial location of three sows (Pietrán cross Landrace) and one boar (Duroc) were studied in an open air housing system in a commercial farm in the Department of Antioquia in Colombia. The study was for a period of 3 months with 264 hours of observations.
The most frequent activities were: lying (59%), eating (15%), rooting (11%) and grazing (8%). The areas frequented were the feed trough (39%), shelter (24%), drinker (7%) and others (30%). Between animal interactions took place 1.93 times per hour and were classified as agressive or friendly.Using these data to determine the hierarchical order of dominance within the group, it was found that the boar was always the dominant member and among the sows the older animals dominated the younger ones. The order of dominance did not change when new animals were introduced in the group in place of the existing ones.
Chopped rice straw was treated according to a 3 x 3 factorial arrangement, using quick lime (0, 3 and 6%, w/w) and urea (0, 2 and 4%, w/w). The treated straws (TS) were stored at a 50% moisture level for 3 weeks. The treatments were repeated three times, 2 months apart, within an ambient temperature range from 20 to 35oC. Effects of these treatments were evaluated based on straw chemical composition, in-vitro gas production, and in-sacco degradation.
It was found that treatment with urea increased nitrogen (N) content, and solubilised NDF and hemicellulose. Lime treatment did not affect N content, but appeared to be more powerful in delignification, reducing not only NDF and hemicellulose , but also ADF and ADL. In general, all the treatments increased in-vitro gas production and in-sacco degradability of rice straw. The effects were increased with increasing levels of lime and/or urea in spite of some negative interactions between the two chemicals. However, a level of 2% urea alone seemed to be too low for effective treatment and a level of 6% lime seemed to be too high for rumen cellulolysis.
The present studies indicate that 3% lime alone, 4% urea alone, and a combination of 3% lime with urea (2 or 4%) are promising for rice straw treatment.
Two trials were carried out to compare voluntary intake and digestibility of rice straw which was treated according to a 3 x 3 factorial design using unslaked lime (0, 3, and 6%, w/w) and urea (0, 2, and 4%, w/w). In Trial 1, 27 growing beef bulls were divided into 9 groups to be fed on the 9 types of straw. Voluntary intake was first measured, followed by digestibility determination when a restricted level of straw (47 g OM/kg W0.75/day) was fed. In Trial 2, three rumen-fistulated adult oxen were fed ad libitum (20% in excess) on the same 9 types of straw to determine intake and digestibility concurrently.
It was found that both lime and urea significantly increased straw intake, digestibility, and thus its energy availability. The intake and digestibility of 2% urea-treated straws and especially 4% urea-treated straws were higher than those of untreated straw. A level of 3% lime significantly increased straw intake and digestibility. Treatment with 6% lime continued to increase apparent digestibility, but depressed straw intake compared with 3% lime in Trial 1. In addition, rumen liquor analyses showed that rumen ammonia (NH3) and total volatile fatty acids (VFA) were decreased by the treatments.
The findings suggest that both lime and urea are effective in increasing straw intake and apparent digestibility.
Eight Mong Cai castrate male pigs of mean initial weight 12.3 kg were fed diets containing sugar palm (Borassus flabellifer) syrup and dry fish substituted or not with ensiled cassava leaves (0 and 50% of the daily ration in dry basis) according to a change over design. The silage was made from sun-dried, wilted, chopped leaves and petioles in a single batch of cassava foliage harvested after 8weeks of regrowth. The pH was 4.39, DM 41.2%, NDF 66.7%, N 2.87% and cyanide 120 mg/kg in dry basis. Mean environmental temperature was 34.5oC at midday (12:00) during the trial in May 2001.
The pattern of feed intake was characterized by a very fast intake of the syrup and a slow ingestion of solid materials. There were no silage refusals. Voluntary feed intake was 36.6 g DM/kg body weight per day. The animals were in a positive body weight balance when they were fed the ensiled cassava leaf -based diet and averaged 140 g body weight gain during the trial.
Nutrient digestibility of the silage as predicted by difference (n = 8) was DM 77.7%, organic matter 79.8%, NDF 82.5% and N 74.2%. There appeared to be a positive response in N retention due to incorporation of cassava leaf silage in the diet, either related to N intake (improvement of 10.6%) or to N digested (improvement of 19.2%; P<0.10). It appears that young Mong Cai pigs have a high capacity for digestion of cell wall materials, further supported by lower faecal pH values (P<0.05) and DM concentration (P<0.01) in the diet containing cassava leaf silage (6.74 and 29.3%) as compared to the basal diet (7.26 and 39.1%).
It is concluded that total N digestibility by pigs of ensiled cassava leaves can be high when the dietary protein supply is high and rich in sulphur amino acids.
The effects on the reproductive performance of Mong Cai sows of three crude protein (CP) concentrations in gilt, gestation and lactation diets were evaluated. Dietary treatments LP, MP and HP consisted of 10, 12 and 14% CP in gilt diets, 8, 10 and 12% CP in gestation diets and 12, 14 and 16% CP in lactation diets, respectively.
In the gilt rearing period the low (10%) CP diet resulted in significantly higher mean age and lower live weight at first oestrus compared to the medium and high CP diets, which were not significantly different from each other. In gestation the low (8%) CP diet gave significantly lower piglet and total litter live weights at birth than the medium and high CP treatments, although mean litter size was not affected by diet. The low (12%) CP lactation diet resulted in significantly lower mean piglet and total litter weaning weights, higher sow live weight losses to weaning and longer weaning to oestrus intervals. The differences for all parameters measured between the medium and high CP diets were small and non-significant during the gestation and lactation stages.
It is concluded that the optimum levels of crude protein for Mong Cai pigs are 12% in gilt rearing diets, 10% in gestation, and 14% in lactation diets.
The following study aimed to improve the utilization of available resources and develop a system for fattening local cattle in Cambodia. It is based on two principles: ruminants use their feed more efficiently when protozoa are absent from the rumen and cassava foliage has been found to be a source of by-pass protein for ruminants. Twelve growing local "Yellow" cattle of mean weight 114 kg (SE ±4.35) received a basal diet of ad libitum rice straw and a rumen supplement (13% urea; 3% diammonium phosphate) at 300g/head/day. The 4 treatments, arranged according to a 2×2 factorial design, were the basal diet alone (RS), or RS plus fresh cassava foliage at 3% of LW (fresh basis) (RSC), RS plus a single oil drench (cooking oil at 5ml/kg LW) (RSO), or RSC with oil drench (RSCO). Rumen samples were taken at the 7th, 14th, 28th, 56th and 84th day related to the day of the oil drench to determine pH, ammonia concentration and protozoa count. Daily feed intakes and fortnightly live weights were recorded for 4 months.
The oil drench reduced the protozoa population. However, there was a rapid re-infestation of the small protozoa (mainly Entodinia) to a level comparable to the control groups. Only a few large protozoa (mainly Polyplastron and Holotrichs) were observed, being present in significantly smaller numbers than in non-oil animals. The overall protozoal biomass in the oil groups throughout the 84 day trial was estimated to be at least 4 times lower than in the non-oil groups. Rumen ammonia concentrations were significantly lower in oil-drenched animals. Feed intake increased significantly in both oil and non-oil animals when cassava foliage was given but was not affected by the oil drench.
Growth rates were increased significantly by the oil drench and the cassava supplement. The mean values were 53, 124, 210 and 302 g/day (SEM ± 30) for RS, RSO, RSC and RSCO, respectively.